beta-carotene and Liver-Neoplasms

Previous evidence supports that vitamin A decreases the risk of several types of cancer. However, the association between vitamin A and liver cancer is inconclusive.. This systematic review and meta-analysis summarizes the existing literature, discussing the association between vitamin A intake, serum vitamin A, and liver cancer in adult populations.. A systematic literature review was performed by searching the EMBASE, PubMed, Scopus and International Pharmaceutical Abstract databases using terms related to vitamin A (e.g. retinol, α-carotene, β-carotene, and β-cryptoxanthin) and hepatic cancer without applying any time restriction. A meta-analysis was performed using random effect models.. The meta-analysis of five studies showed no association between serum retinol and liver cancer (pooled risk ratio = 1.90 (0.40-9.02); n = 5 studies, I. Current information on the association between vitamin A intake and liver cancer or serum vitamin A and liver cancer are limited. Most studies demonstrated no association between dietary vitamin A and the risk of liver cancer. However, the finding was based on a small number of studies with potential publication bias. Therefore, large observational studies should be conducted to confirm these associations.

Topics: beta Carotene; Beta-Cryptoxanthin; Carotenoids; Humans; Liver Neoplasms; Observational Studies as Topic; Randomized Controlled Trials as Topic; Risk Factors; Vitamin A

This paper (and an extensive supplementary report) considers how far cancer/risk factor associations based on epidemiology have been confirmed by evidence from 226 studies involving interventions other than smoking. Many are small, uncontrolled, of unrepresentative populations, concern cancer markers not cancer, and may involve combinations of agents. Many agents suspected of causing cancer are untested by intervention trials. For seven of 16 agents tested (fibre, folic acid, low-fat diet, riboflavin, zinc, vitamin Bs, and vitamin D), the evidence is clearly inadequate to confirm or deny the epidemiology, while the evidence relating to calcium only concerns biomarkers. For other agents, the evidence relating to cancer itself is weak. In studies where cancer is the endpoint, only three effects have been replicated: (a) selenium supplementation and decreased liver cancer incidence, (b) treatment by the retinoid etretinate and reduced bladder tumours in susceptible individuals, and (c) beta-carotene supplementation and increased lung cancer incidence. Studies involving pre-cancerous conditions as the endpoint, which have a number of practical advantages, more frequently report benefits of intervention. Thus, oral pre-cancerous lesions can certainly be reduced by beta-carotene, vitamin A, and other retinoids, and possibly by vitamin E. It also seems that retinoids can reduce pre-cancerous cervix, skin and lung lesions, that vitamin C and the NSAID sulindac can reduce colonic polyps, and that sunscreens can reduce solar keratoses. Our findings clearly show that the great majority of causal relationships suggested by epidemiology have not been validated by intervention trials. This may be partly due to lack of suitable studies of adequate size or duration, or to using single dietary compounds as agents that are by themselves not responsible for the epidemiologically-observed associations between diet and cancer. However, this lack of validation must cause concern in view of the markedly conflicting evidence on beta-carotene and lung cancer between epidemiological and intervention studies. More intervention studies are needed, but in their absence, caution in interpreting epidemiological findings is warranted.

Topics: beta Carotene; Clinical Trials as Topic; Dietary Fiber; Dietary Supplements; Epidemiologic Methods; Etretinate; Humans; Liver Neoplasms; Lung Neoplasms; Neoplasms; Reproducibility of Results; Selenium; Urinary Bladder Neoplasms

Retinol, the most biologically active form of vitamin A, might influence cancer-related biological pathways. However, results from observational studies of serum retinol and cancer risk have been mixed. We prospectively examined serum retinol and risk of overall and site-specific cancer in the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study (n = 29,104 men), conducted in 1985-1993, with follow-up through 2012. Serum retinol concentration was measured using reverse-phase high-performance liquid chromatography. Cox proportional hazards models estimated the association between baseline serum retinol quintile and overall and site-specific cancer risk in 10,789 cases. After multivariable adjustment, higher serum retinol was not associated with overall cancer risk (highest vs. lowest quintile: hazard ratio (HR) = 0.97, 95% confidence interval (CI): 0.91, 1.03; P for trend = 0.43). Higher retinol concentrations were, however, associated with increased risk of prostate cancer (highest vs. lowest quintile: HR = 1.28, 95% CI: 1.13, 1.45; P for trend < 0.0001) and lower risk of both liver and lung cancers (highest vs. lowest quintile: for liver, HR = 0.62, 95% CI: 0.42, 0.91; P for trend = 0.004; and for lung, HR = 0.80, 95% CI: 0.72, 0.88; P for trend < 0.0001). No associations with other cancers were observed. Understanding the mechanisms that underlie these associations might provide insight into the role of vitamin A in cancer etiology.

Topics: Aged; Alcohol Drinking; alpha-Tocopherol; beta Carotene; Body Weights and Measures; Cholesterol, HDL; Chromatography, High Pressure Liquid; Diet; Dietary Supplements; Double-Blind Method; Exercise; Finland; Humans; Liver Neoplasms; Lung Neoplasms; Male; Middle Aged; Neoplasms; Proportional Hazards Models; Prostatic Neoplasms; Residence Characteristics; Smoking; Socioeconomic Factors

Recent data suggest the possible benefits of α-tocopherol and β-carotene supplementation on liver cancer and chronic liver disease (CLD), but the long-term trial data are limited.. We evaluated the efficacy of supplemental 50 mg day(-1) α-tocopherol and 20 mg day(-1) β-carotene on incident liver cancer and CLD mortality in a randomised trial of 29,105 Finnish male smokers, who received supplementation for 5-8 years and were followed for 16 additional years for outcomes.. Supplemental α-tocopherol, β-carotene, or both, relative to placebo, did not reduce the risk of liver cancer or CLD, either overall, during the intervention or during the post-intervention period.. Long-term supplemental α-tocopherol or β-carotene had no effect on liver cancer or CLD mortality over 24 years of follow-up.

Topics: Aged; alpha-Tocopherol; beta Carotene; Chronic Disease; Humans; Incidence; Liver Diseases; Liver Neoplasms; Male; Middle Aged

Since the incidence of liver cancer is increasing in the world, it is valuable to develop an effective method for its prevention. Various phytochemicals have been shown to suppress liver carcinogenesis in experimental studies. Using these phytochemicals, a clinical trial was conducted. Combination of carotenoids and myo-inositol was found to prevent hepatocellular carcinoma development in patients with chronic viral hepatitis and cirrhosis.

Topics: alpha-Tocopherol; Animals; Anticarcinogenic Agents; beta Carotene; Carcinoma, Hepatocellular; Carotenoids; Cryptoxanthins; Dietary Supplements; Hepatitis, Viral, Human; Humans; Inositol; Kaplan-Meier Estimate; Liver Cirrhosis; Liver Neoplasms; Lycopene; Male; Mice; Mice, Inbred C3H; Tumor Burden; Xanthophylls

Vitamin A and its precursor (β-carotene) have been linked with cancer incidence and mortality. However, the relationship between vitamin A and the prognosis of hepatocellular-carcinoma (HCC) is still unknown. Therefore, we investigated whether dietary intakes of vitamin A, retinol, and β-carotene were associated with survival in patients with HCC who participated in the Guangdong Liver Cancer Cohort (GLCC) study. Patients aged 18-80 years with a diagnosis of incident Primary Liver Cancer (PLC) were enrolled within one month of diagnosis prior to cancer treatment at the Sun Yat-sen University Cancer Center. Dietary information one year before diagnosis of HCC was obtained using a 79-item, validated semiquantitative food frequency questionnaire (FFQ). We restricted the present analysis to 877 HCC patients enrolled in the GLCC between September, 2013 and April, 2017 who had completed FFQ. Cox proportional hazard regression models were used to estimate hazard ratios (HR) and 95% confidence intervals (CIs) for overall and HCC-specific survival. After a median follow-up of 797 days, 384 deaths were documented, 343 of which died from HCC. The multivariable-adjusted HRs (95% CI) of overall and HCC-specific survival for the highest versus the lowest quartile were 0.70 (0.53-0.94) and 0.68 (0.50-0.92) for vitamin A, and 0.72 (0.54-0.96) and 0.69 (0.51-0.94) for β-carotene, respectively. However, no significant association of dietary retinol intakes with survival outcomes was observed. Our observations suggest that higher prediagnostic dietary intakes of vitamin A and β-carotene were associated with improved overall and HCC-specific survival.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; beta Carotene; Carcinoma, Hepatocellular; China; Diet; Female; Humans; Liver Neoplasms; Male; Middle Aged; Proportional Hazards Models; Risk Factors; Surveys and Questionnaires; Survival Analysis; Vitamin A; Young Adult

Approximately 2.7 million Americans are chronically infected with hepatitis C virus (HCV). HCV patients with cirrhosis form the largest group of persons at high risk for hepatocellular carcinoma (HCC). Increased oxidative stress is regarded as a major mechanism of HCV-related liver disease progression. Deficiencies in retinoid and carotenoid antioxidants may represent a major modifiable risk factor for disease progression. This study aims to identify key predictors of serum antioxidant levels in patients with HCV, to examine the relationship between retinoid/carotenoid concentrations in serum and hepatic tissue, to quantify the association between systemic measures of oxidative stress and antioxidant status, and to examine the relationship between retinoids and stellate cell activation.. Patients undergoing liver biopsy (n = 69) provided fasting blood, fresh tissue, urine and completed a diet history questionnaire. Serum and questionnaire data from healthy volunteers (n = 11), normal liver tissue from public repositories and patients without liver disease (n = 11) were also collected. Urinary isoprostanes, serum and tissue retinoid concentrations were obtained by UHPLC-MS-MS. Immunohistochemistry for αSMA was performed on FFPE sections and subsequently quantified via digital image analysis. Associations between urinary isoprostanes, αSMA levels, and retinoids were assessed using Spearman correlation coefficients and non-parametric tests were utilized to test differences among disease severity groups.. There was a significant inverse association between serum retinol, lycopene, and RBP4 concentrations with fibrosis stage. Serum β-carotene and lycopene were strongly associated with their respective tissue concentrations. There was a weak downward trend of tissue retinyl palmitate with increasing fibrosis stage. Tissue retinyl palmitate was inversely and significantly correlated with hepatic αSMA expression, a marker for hepatic stellate cell activation (r = -0.31, P < 0.02). Urinary isoprostanes levels were inversely correlated with serum retinol, β-carotene, and RBP4.. A decrease in serum retinol, β-carotene, and RBP4 is associated with early stage HCV. Retinoid and carotenoid levels decline as disease progresses, and our data suggest that this decline occurs early in the disease process, even before fibrosis is apparent. Measures of oxidative stress are associated with fibrosis stage and concurrent antioxidant depletion. Vitamin A loss is accompanied by stellate cell activation in hepatic tissue.

Topics: Actins; Adult; beta Carotene; Biomarkers; Biopsy; Carcinoma, Hepatocellular; Carotenoids; Chromatography, High Pressure Liquid; Cross-Sectional Studies; Disease Progression; Diterpenes; Enzyme-Linked Immunosorbent Assay; Female; Hepatic Stellate Cells; Hepatitis C, Chronic; Humans; Immunohistochemistry; Isoprostanes; Lipid Peroxidation; Liver; Liver Cirrhosis; Liver Neoplasms; Lycopene; Male; Middle Aged; Oxidative Stress; Retinoids; Retinol-Binding Proteins, Plasma; Retinyl Esters; Risk; Severity of Illness Index; Tandem Mass Spectrometry; Vitamin A

Neuroblastoma is the most prevalent extracranial solid tumor in childhood and has poor clinical outcome due to its high potential for metastasis. Consequently, an understanding of the mechanisms that modulate cancer cell invasion, migration and metastasis is important for the development of more effective chemotherapeutic agents. While β-carotene is a vitamin A precursor that has been shown to exert antioxidant and anticancer effects, the anti-metastatic effects of β-carotene on neuroblastoma cells remain poorly understood. The aim of the present study was to investigate the anti-metastatic effects of β-carotene on highly malignant SK-N-BE(2)C neuroblastoma cells in vitro and in vivo. Treatment of SK-N-BE(2)C cells with β-carotene was found to attenuate the migratory and invasive capabilities of the cells. In addition, the enzymatic activity and expression of matrix metalloproteinase (MMP)-2 was suppressed following β-carotene treatment under both normoxia and hypoxia. To induce metastasis, immunodeficient nude mice were injected with SK-N-BE(2)C cells via the tail vein in vivo. The incidence of liver metastasis and mean tumor volume in mice that were administered β-carotene was decreased compared to controls. Furthermore, mRNA levels of MMPs, membrane-type (MT) 2 MMP and tissue inhibitors of metalloproteinases in liver tumor tissues were also lower following β-carotene treatment. Level of hypoxia-inducible factor-1α (HIF-1α) and its downstream targets, vascular endothelial growth factor and glucose transporter 1 (GLUT1), were lower both in vitro and in vivo following β-carotene treatment. In conclusion, the present study provides the first evidence that β-carotene may represent an effective chemotherapeutic agent by regulating the invasion and metastasis of neuroblastoma via HIF-1α.

Topics: Animals; Antineoplastic Agents, Phytogenic; beta Carotene; Cell Hypoxia; Cell Line, Tumor; Cell Movement; Dietary Supplements; Gene Expression Regulation, Neoplastic; Humans; Hypoxia-Inducible Factor 1, alpha Subunit; Liver Neoplasms; Male; Matrix Metalloproteinase 2; Mice, Nude; Neoplasm Invasiveness; Neoplasm Proteins; Neuroblastoma; Random Allocation; Specific Pathogen-Free Organisms; Tissue Inhibitor of Metalloproteinases; Tumor Burden; Xenograft Model Antitumor Assays

Helicobacter have been detected in human bile and hepatobiliary tissue. Despite evidence that Helicobacter species promote gallstone formation and hepatobiliary tumors in laboratory studies, it remains unclear whether Helicobacter species contribute to these cancers in humans. We used a multiplex panel to assess whether seropositivity to 15 Helicobacter pylori proteins was associated with subsequent incidence of hepatobiliary cancers in the Finnish Alpha-Tocopherol, Beta-Carotene Cancer Prevention (ATBC) Study. We included 64 biliary cancers, 122 liver cancers, and 224 age-matched controls which occurred over the course of 22 years. Helicobacter pylori seropositivity was defined as those positive to ≥ 4 antigens. Odds ratios (OR) and 95% confidence intervals were adjusted for major hepatobiliary cancer risk factors. Among the controls, 88% were seropositive to H. pylori at baseline. Among those who subsequently developed hepatobiliary cancer, the prevalence of seropositivity was higher: 100% for gallbladder cancer, 97% of extrahepatic bile duct cancer, 91% of ampula of Vater cancer, 96% of intrahepatic bile duct cancer, and 94% of hepatocellular carcinoma. Although the OR for gallbladder cancer could not be calculated, the OR for the other sites were 7.01 (95% confidence interval [CI]: 0.79-62.33), 2.21 (0.19-25.52), 10.67 (0.76-150.08), and 1.20 (0.42-3.45), respectively, with an OR of 5.47 (95% CI: 1.17-25.65) observed for the biliary tract cancers combined. ORs above 1 were observed for many of the investigated antigens, although most of these associations were not statistically significant.. Seropositivity to H. pylori proteins was associated with an increased risk of biliary tract cancers in ATBC. Further studies are needed to confirm our findings and to determine how H. pylori might influence the risk of biliary tract cancer.

Topics: alpha-Tocopherol; beta Carotene; Biliary Tract Neoplasms; Carcinoma, Hepatocellular; Case-Control Studies; Helicobacter Infections; Humans; Liver Neoplasms; Male; Middle Aged; Randomized Controlled Trials as Topic; Vitamins

The laver (Porphyra tenera), red seaweed, has been reported to have anticancer activity, but little is known about its molecular mechanisms of action. The objective of this study was to determine the effects of laver extract on cancer cell proliferation, invasion, and metastasis in SK-Hep1 cells using migration and invasion assays. We also investigated the relationship of MMP-2/-9 and TIMP-1/-2 expression at both the protein and gene level in SK-Hep1 human hepatoma carcinoma cells after laver extract treatment. Laver extract inhibited cancer cell growth in a dose-dependent manner. In an invasion assay conducted in Transwell chambers, laver extract showed 19.6 and 27.2% inhibition of cancer cell at 200 and 400 μg/mL, respectively, compared to the control. The mRNA levels of both MMP-2 and MMP-9 were down-regulated by laver extract treatment in a dose-dependent manner. Laver extract, at 400 μg/mL, was inhibited by MMP-2 and MMP-9 expressions by 70.1 and 77.0%, respectively. An inverse relationship in the mRNA contents of MMP-2/-9 and TIMP-1/-2 expressions in SK-Hep1 cells was found by laver extract treatment. Our results demonstrate antimetastatic properties of laver extract in inhibiting the adhesion, invasion, and migration of SK-Hep1 human hepatoma cancer cells.

Topics: Antineoplastic Agents; beta Carotene; Carcinoma, Hepatocellular; Cell Adhesion; Cell Line, Tumor; Cell Movement; Cell Proliferation; Chlorophyll; Flavonoids; Gene Expression Regulation, Neoplastic; Humans; Liver Neoplasms; Matrix Metalloproteinase 2; Matrix Metalloproteinase 9; Neoplasm Invasiveness; Phenol; Plant Extracts; Porphyra; Tissue Inhibitor of Metalloproteinase-1; Tissue Inhibitor of Metalloproteinase-2

Micronutrients may influence the development or progression of liver cancer and liver disease. We evaluated the association of serum α-tocopherol, β-carotene, and retinol with incident liver cancer and chronic liver disease (CLD) mortality in a prospective cohort of middle-aged Finnish male smokers.. Baseline and 3-year follow-up serum were available from 29,046 and 22,805 men, respectively. After 24 years of follow-up, 208 men were diagnosed with liver cancer and 237 died from CLD. Hazards ratios and 95% confidence intervals were calculated for highest vs lowest quartiles from multivariate proportional hazards models.. Higher β-carotene and retinol levels were associated with less liver cancer (β-carotene: 0.35, 0.22-0.55, P-trend <0.0001; retinol: 0.58, 0.39-0.85, P-trend=0.0009) and CLD mortality (β-carotene: 0.47, 0.30-0.75, P-trend=0.001; retinol: 0.55, 0.38-0.78, P-trend=0.0007). α-Tocopherol was associated with CLD mortality (0.63, 0.40-0.99, P-trend=0.06), but not with liver cancer (1.06, 0.64-1.74, P-trend=0.77). Participants with higher levels of β-carotene and retinol, but not α-tocopherol, at both baseline and year 3 had lower risk of each outcome than those with lower levels.. Our findings suggest that higher concentrations of β-carotene and retinol are associated with incident liver cancer and CLD. However, such data do not indicate that supplementation should be considered for these diseases.

Topics: Aged; alpha-Tocopherol; beta Carotene; Chronic Disease; Humans; Incidence; Liver Diseases; Liver Neoplasms; Male; Middle Aged; Vitamin A

The radioisotope iodine-131 [(131)I] can damage DNA. One way to prevent this is to increase the amount of antioxidants via dietary consumption. The goal of this study was to evaluate the radioprotective effect of fresh acerola pulp and synthetic beta-carotene in Rattus norvegicus hepatoma cells (HTC) in response to [(131)I] exposure in vitro. Cellular DNA damage was subsequently assessed using a cytokinesis block micronucleus assay. The mutagenic and cytotoxic activities of doses of [(131)I] (0.1, 0.5, 1, 5, and 10 µCi), acerola (0.025, 0.125, and 0.25 g acerola pulp/mL), and beta-carotene (0.2, 1, and 2 µM) were evaluated. Radioprotective tests were performed by simultaneous treatment with acerola (0.25 g/mL) plus [(131)I] (10 µCi) and beta-carotene (0.2 µM) plus [(131)I] (10 µCi). Acerola, beta-carotene, and low concentrations of [(131)I] did not induce micronucleus formation in HTC cells; in contrast, high concentrations of [(131)I] (10 µCi) were mutagenic and induced DNA damage. Moreover, neither acerola nor beta-carotene treatment was cytotoxic. However, acerola reduced the percentage of [(131)I]-induced damage, although beta-carotene did not show a similar effect. Thus, our results suggest that acerola diet supplementation may benefit patients who are exposed to [(131)I] during thyroid diagnostics and therapy.

Topics: Animals; Anthocyanins; Antioxidants; Ascorbic Acid; beta Carotene; Carcinoma, Hepatocellular; Carotenoids; Dietary Supplements; DNA; DNA Damage; Flavonoids; Iodine Radioisotopes; Liver Neoplasms; Malpighiaceae; Mutation; Plant Preparations; Radiation-Protective Agents; Rats; Rats, Wistar; Tumor Cells, Cultured

Oral administration of β-carotene (BC) was found to exert opposite effects on plasma levels of vascular endothelial growth factor (VEGF) in two animal models. One study in nude mice injected via tail vein with hepatocarcinoma SK-Hep-1 cells showed that BC decreases the plasma VEGF level, whereas the other study in nude mice injected subcutaneously with prostate tumor PC-3 cells showed that BC increases the plasma VEGF level. Herein we investigated whether BC (0.5-20 μM) possesses diverse effects on VEGF secretion in SK-Hep-1, PC-3 and melanoma B16F10 cells. We found that incubation of SK-Hep-1 cells with BC (1-20 μM) for 6 h significantly decreased VEGF secretion, whereas BC (1-10 μM) significantly increased the VEGF secretion in PC-3 cells. However, these effects disappeared at 12 h of incubation. Similar effects occurred in VEGF mRNA and protein expression after treatment of SK-Hep-1 and PC-3 cells with BC for 6 h. In contrast, BC (0.5-20 μM) did not affect mRNA and protein expression and secretion of VEGF in B16F10 cells. We also found that the proliferation of SK-Hep-1 and B16F10 cells was significantly inhibited by 20 μM BC at 6 and 12 h of incubation, whereas the proliferation of PC-3 cells was significantly inhibited by 20 μM BC at 12 h of incubation. In summary, the present study demonstrated the tumor-specific effect of BC on VEGF secretion in different cancer cell lines.

Topics: Animals; beta Carotene; Carcinoma, Hepatocellular; Cell Line, Tumor; Gene Expression Regulation, Neoplastic; Humans; Liver Neoplasms; Male; Mice; Prostatic Neoplasms; RNA, Messenger; Vascular Endothelial Growth Factor A

The aim of the present study was to investigate the anticancer and immunity activity of β-carotene in hepatocellular carcinoma (HCC) rats. Three days after transplantation, forty Wistar rats were randomly divided into four groups, each group consisting of 10 animals. These groups were control group (untreated), low-dose β-carotene-treated group (20 mg/kg), middle-dose group (40 mg/kg) and high-dose (60 mg/kg) group. β-Carotene-treated groups were fed with β-carotene (20, 40, 60 mg/kg b.w.) orally for 30 days. Control group was treated with the same volume of physiological saline. Another ten rats were served as the normal group. Results showed that 30 days of β-carotene treatment could significantly inhibit tumour growth, enhance blood NK, IL-2, TNF-α, WBC, TP, ALB and A/G levels, and decrease blood ALT, AST and ALP activities in HCC rats. Pathological analysis of liver tissue showed that β-carotene treatment may decrease damage of liver tissue in HCC rats. It can be concluded that β-carotene may improve the immunity function and inhibit tumour growth in HCC rats.

Topics: Animals; beta Carotene; Carcinoma, Hepatocellular; Cell Line, Tumor; Immunity; Liver Neoplasms; Mice; Neoplasms, Experimental; Rats; Rats, Wistar

Recent studies have demonstrated that vegetable rich diets have protective effects on the occurrence and prognosis of various cancers. In addition to dietary intakes, ascorbic acid and β-carotene are also taken as supplements. The aim of this study was to assess effects of ascorbic acid, β-carotene and their combinations on human hepatocellular carcinoma cell line HepG2. Ascorbic acid and β-carotene were applied to cells as plasma peak concentrations (70 and 8 μM, respectively) and their half concentrations (35 and 4 μM, respectively) for 24 and 48 h. Genotoxic and cytotoxic effects of ascorbic acid and β-carotene were evaluated by alkali single cell gel electrophoresis (SCGE), acridine orange/ethidium bromide staining patterns of cells (apoptosis and necrosis) and lipid peroxidation (thiobarbituric acid reactive substances, TBARS). Results of the SCGE demonstrated that both ascorbic acid and β-carotene caused DNA damage on HepG2 which were also concordant to increased apoptosis and necrosis of cells. Increased TBARS values also demonstrated increased lipid peroxidation in these cells. Results of the present study demonstrates that when dietary intakes of ascorbic acid and β-carotene and their relevant achievable plasma level concentrations were considered, both ascorbic acid and β-carotene induce genotoxic and cytotoxic damage on HepG2 together with increased oxidative damage in contrast to their protective effect on healthy cells. This may be correlated to oxidative status and balance of ROS in hepatocellular carcinoma cells.

Topics: Acridine Orange; Apoptosis; Ascorbic Acid; beta Carotene; Carcinoma, Hepatocellular; Cell Line, Tumor; Comet Assay; DNA Damage; Ethidium; Genome, Human; Hep G2 Cells; Humans; Lipid Peroxidation; Liver Neoplasms; Necrosis; Staining and Labeling; Thiobarbituric Acid Reactive Substances

The chemical investigation of the twigs of Morus mesozygia resulted in the isolation of three new prenylated 2-arylbenzofurans, named moracin KM, LM, and SC (1-3), nine known 2-arylbenzofurans (4-12), and two known flavonoids (13-14). The structures of the new compounds were established as [2'',3'':6,7]-(6-(S)-hydroxymethyl-6-methylpyrano)-2-(3,5-dihydroxyphenyl)benzofuran-5-ol (1), [2'',3'':6,7]-(4,7-dihydro-6-methyloxepine)-2-(3-hydroxy-5-methoxyphenyl)benzofuran-5-ol (2), and [2'',3'':6,7]-(6,6-dimethylpyrano)-2-(3,5-dihydroxyphenyl)benzofuran (3). One of the new compounds, moracin LM (2), displayed modest antioxidant activity, whereas known compounds 4, 13, and 14 showed significant hepatoprotective and antioxidant activities.

Topics: Animals; Antioxidants; Benzofurans; beta Carotene; Carcinoma, Hepatocellular; Cell Survival; Drug Evaluation, Preclinical; Flavonoids; Lipid Peroxidation; Liver Neoplasms; Magnetic Resonance Spectroscopy; Microsomes, Liver; Molecular Structure; Morus; Plant Extracts; Plants, Medicinal; Protective Agents; Rats; Spectrophotometry, Infrared

Although hepatitis C and B viruses and alcohol consumption are the major risk factors for hepatocellular carcinoma (HCC), dietary habits may also be relevant. A hospital-based case-control study was conducted in Italy in 1999-2002, including 185 HCC cases and 412 cancer-free controls. Dietary habits were assessed using a validated food-frequency questionnaire to compute nutrient intakes. Odds ratios (OR) and corresponding confidence intervals (CI) were calculated using the energy-adjusted residual models. Inverse association emerged for linoleic acid (OR=0.35 for highest versus lowest tertile; 95% CI: 0.18-0.69) and, possibly, beta-carotene (OR=0.48; 95% CI: 0.24-0.93). Among minerals, iron intake was associated with increased HCC risk (OR=3.00; 95% CI: 1.25-7.23), but the association was considerably reduced when iron from wine was excluded (OR=1.61; 95% CI: 0.78-3.30). In conclusion, a diet rich in linoleic acid containing foods (e.g. white meats and fish) and beta-carotene was inversely related to HCC risk.

Topics: Adult; Aged; Aged, 80 and over; Alcohol Drinking; beta Carotene; Carcinoma, Hepatocellular; Case-Control Studies; Diet; Diet Surveys; Female; Humans; Italy; Linoleic Acid; Liver Neoplasms; Male; Middle Aged; Risk Factors; Surveys and Questionnaires

Retinol and its derivatives (retinoids), which have antioxidant activity and promote cell differentiation, may protect against the development of hepatocellular carcinoma (HCC) by controlling hepatocellular differentiation and reducing inflammatory responses.. We examined prospectively the relationship between prediagnostic serum concentrations of retinol, alpha-carotene; beta-carotene; beta-cryptoxanthin; lutein; lycopene; zeaxanthin; alpha-, gamma-, and delta-tocopherols; and selenium and the risk of developing HCC among 213 patients with HCC and 1087 matched control subjects from a cohort of 18,244 men in Shanghai, China, who were monitored from 1986 through 2001. Odds ratios (ORs) and 95% confidence intervals (CIs) for men by quartile of serum concentrations of micronutrients were estimated by using logistic regression with adjustment for cigarette smoking status, alcohol intake, self-reported history of physician-diagnosed hepatitis or liver cirrhosis at recruitment, and seropositivity for hepatitis B surface antigen (HBsAg). All statistical tests were two-sided.. Men with high prediagnostic serum retinol levels had a lower risk of HCC than men in the lowest quartile (Q2 versus Q1, OR = 0.37, 95% CI = 0.22 to 0.61; Q3 versus Q1, OR = 0.30, 95% CI = 0.17 to 0.50; and Q4 versus Q1, OR = 0.13, 95% CI = 0.06 to 0.26; Ptrend < .001). A statistically significant interaction was observed between retinol and HBsAg seropositivity on HCC risk; HBsAg-positive men in the lowest tertile of retinol had a greater than 70-fold higher risk (OR = 72.7, 95% CI = 31.6 to 167.4) of HCC than HBsAg-negative men in the highest tertile of retinol (Pinteraction = .018). No independent effect of serum levels of alpha-carotene; beta-carotene; beta-cryptoxanthin; lutein; lycopene; zeaxanthin; alpha-, gamma-, and delta-tocopherols; or selenium on HCC risk were observed.. High prediagnostic serum level of retinol is associated with a decreased risk of HCC in this population.

Topics: beta Carotene; Carcinoma, Hepatocellular; Carotenoids; Case-Control Studies; China; Cryptoxanthins; Humans; Incidence; Liver Neoplasms; Logistic Models; Lutein; Lycopene; Male; Micronutrients; Middle Aged; Odds Ratio; Prospective Studies; Risk Assessment; Risk Factors; Selenium; Tocopherols; Vitamin A; Xanthophylls; Zeaxanthins

The carotenoid lycopene has been associated with decreased risks of several types of cancer, such as prostate cancer and hepatoma. Tumor metastasis is the most important cause of cancer death. Although lycopene was shown to inhibit metastasis, the mechanism underlying this action is not well understood. Here, we tested the possibility that lycopene may inhibit cancer cell metastasis by upregulating the expression of nm23-H1, a metastasis suppressor gene, in SK-Hep-1 cells, a highly invasive hepatoma cell line, and we determined migration and invasion activities and the expression of nm23-H1 protein and mRNA. We showed that lycopene inhibited SK-Hep-1 migration and invasion in a bell-shaped manner, with the highest effect at 5 micromol/L (91 and 63% inhibition for migration and invasion, respectively; P < 0.05). At the same test level (10 micromol/L), lycopene was much more effective than beta-carotene in reducing cell invasion (by approximately 870%). In contrast to the effects on migration and invasion, lycopene enhanced nm23-H1 expression at both the protein and mRNA levels; the effects were also bell shaped, and at 5 micromol/L, lycopene enhanced nm23-H1 protein and mRNA expressions by 220 +/- 33 and 153 +/- 22% (P < 0.01), respectively. These bell-shaped effects of lycopene may be related to autoxidation of lycopene at elevated concentrations (> or =10 micromol/L). Significant correlations existed between nm23-H1 protein expression and migration (r2= 0.78, P < 0.001) and between nm23-H1 protein expression and invasion (r2= 0.84, P < 0.001) in lycopene-treated SK-Hep-1 cells. We conclude that lycopene has significant antimigration and anti-invasion activity, and that this effect is associated with its induction of nm23-H1 expression.

Topics: alpha-Tocopherol; Anticarcinogenic Agents; Antioxidants; beta Carotene; Carcinoma, Hepatocellular; Carotenoids; Cell Line, Tumor; Cell Movement; Drug Combinations; Humans; Liver Neoplasms; Lycopene; Neoplasm Invasiveness; NM23 Nucleoside Diphosphate Kinases; Nucleoside-Diphosphate Kinase; Oxidation-Reduction; RNA, Messenger; Up-Regulation

To analyze the serum levels of retinoids and Leiden mutation in patients with esophageal, gastric, liver, pancreatic, and colorectal cancers.. The changes in serum levels of retinoids (vitamin A, alpha- and beta-carotene, alpha- and beta-cryptoxanthin, zeaxanthin, lutein) and Leiden mutation were measured by high liquid performance chromatography (HPLC) and polymerase chain reaction (PCR) in 107 patients (70 males/37 females) with esophageal (0/8), gastric (16/5), liver (8/7), pancreatic (6/4), and colorectal (30/21 including 9 patients suffering from in situ colon cancer) cancer. Fifty-seven healthy subjects (in matched groups) for controls of serum retinoids and 600 healthy blood donors for Leiden mutation were used.. The serum levels of vitamin A and zeaxanthin were decreased significantly in all groups of patients with gastrointestinal (GI) tumors except for vitamin A in patients with pancreatic cancer. No changes were obtained in the serum levels of alpha- and beta-carotene, alpha- and beta-cryptoxanthin, zeaxanthin, lutein in patients with GI cancer. The prevalence of Leiden mutation significantly increased in all groups of patients with GI cancer.. Retinoids (as environmental factors) are decreased significantly with increased prevalence of Leiden mutation (as a genetic factor) in patients before the clinical manifestation of histologically different (planocellular and hepatocellular carcinoma, and adenocarcinoma) GI cancer.

Topics: Adult; Aged; beta Carotene; Colorectal Neoplasms; Esophageal Neoplasms; Factor V; Female; Humans; Liver Neoplasms; Male; Middle Aged; Pancreatic Neoplasms; Point Mutation; Retinoids; Stomach Neoplasms; Vitamin A; Xanthophylls; Zeaxanthins

Chronic alcohol consumption is directly related to the induction of liver damage. The continuous use of ethanol induces the isoenzyme cytochrome P450CYP2E1, which promotes the formation of free radicals, resulting in lipid peroxidation. Among the main antioxidants are vitamin E, reduced glutathione (GSH), vitamin C, and beta-carotene. beta-Carotene has antioxidant activity per se, with a probable protective effect against different types of cancer. However, some studies have shown an increased number of cancer cells when beta-carotene is administered in the presence of chronic ethanol ingestion. On this basis, the objective of the present study was to assess the effect of beta-carotene supplementation on rats chronically treated with a hydroalcoholic solution by determining the levels of vitamin E, beta-carotene, GSH, and thiobarbituric acid reactive species (TBARS). Both the plasma and liver concentrations of beta-carotene were higher in the supplemented groups. Plasma vitamin E levels were decreased in the control group and liver vitamin E levels were significantly decreased (p < 0.05) in all groups compared to basal levels. GSH levels were increased over basal values in the group supplemented with beta-carotene for 14 days. TBARS values were increased as much as four-fold in the control group at 14 days, and declined again at 28 days, whereas they were increased in the supplemented group, with the increase remaining until the end of the experiment. The study indicates that beta-carotene had no beneficial effect as an antioxidant on rats submitted to chronic alcohol intake, and could be act as prooxidant when administered with ethanol.

Topics: Animals; Antioxidants; beta Carotene; Body Weight; Cytochrome P-450 CYP2E1; Drug Administration Schedule; Eating; Ethanol; Glutathione; Liver; Liver Neoplasms; Male; Rats; Rats, Wistar; Thiobarbituric Acid Reactive Substances; Time Factors; Vitamin E

We investigated the effects of astaxanthin on the antitumor effector activity of natural killer (NK) cells suppressed by stress in mice in order to define the immunological significance of astaxanthin (ASX) when combined with restraint stress treatment. When the mice were treated with restraint stress alone, the total number of spleen cells, and the level NK cell activity per spleen were reduced to a nadir on day 3. The stress also caused a significant increase in the lipid peroxidation of liver tissue. ASX (100 mg/kg/day, p.o., 4 days) improved the immunological dysfunction induced by restraint stress. On the other hand, metastatic nodules were observed in the livers of syngenic DBA/2 mice on day 12 after inoculation of P815 mastocytoma cells. Hepatic metastasis was promoted further by restraint stress when applied on day 3 before the inoculation of P815. Daily oral administration of ASX (1 mg/kg/day, p.o., 14 days) markedly attenuated the promotion of hepatic metastasis induced by restraint stress. These results suggested that astaxanthin improves antitumor immune responses by inhibiting of lipid peroxidation induced by stress.

Topics: Animals; Antineoplastic Agents, Phytogenic; Antioxidants; beta Carotene; Cells, Cultured; Female; Immunosuppressive Agents; Killer Cells, Natural; Lipid Peroxidation; Liver; Liver Neoplasms; Mast-Cell Sarcoma; Mice; Mice, Inbred C57BL; Mice, Inbred DBA; Neoplasm Metastasis; Neoplasm Transplantation; Restraint, Physical; Stress, Psychological; Thiobarbituric Acid Reactive Substances; Tissue Distribution; Tumor Cells, Cultured; Xanthophylls

The inhibitory effect of beta-carotene on the proliferation of hepatic cancer was studied. Cells from a hepatic cancer cell line SMMC-7721 were incubated in culture media with 20, 40 and 80 mumol/L beta-carotene for 12, 24 and 48 h respectively. MTT test, Trypan blue exclusion test and DNA gel electrophoresis were used. The results of MTT test revealed that beta-carotene (20-80 mumol/L) could inhibit the proliferation of SMMC-7721 cells in a dose-dependent manner. DNA gel electrophoresis showed that the apoptosis of hepatic cancer cells could be induced by beta-carotene (40 mumol/L). It is concluded that the proliferation of hepatic cancer cells inhibited by beta-carotene, probably through interfering DNA metabolism and inducing cell apoptosis.

Topics: Antineoplastic Agents, Phytogenic; Antioxidants; Apoptosis; beta Carotene; Cell Division; Humans; Liver Neoplasms; Tumor Cells, Cultured

Topics: Animals; Animals, Laboratory; beta Carotene; Carcinogens; Disease Models, Animal; Ferrets; Liver Neoplasms; Lung Neoplasms; Marmota; Mice; Mutation; Neoplasms; Phenotype; Sciuridae; Skin Neoplasms; Zebrafish

To assess the degree of oxidative stress, we measured plasma ubiquinone-10 percentage (%CoQ-10) in total amounts of ubiquinone-10 in patients with chronic active hepatitis, liver cirrhosis, and hepatocellular carcinoma, and in age-matched control subjects, %CoQ-10 values were 12.9 +/- 10.3 (n = 28), 10.6 +/- 6.8 (n = 28), 18.9 +/- 11.1 (n = 20), and 6.4 +/- 3.3 (n = 16), respectively, showing a significant increase in oxidative stress in patient groups as compared to control subjects. There were no differences in total amounts of ubiquinone-10 and ubiquinol-10 among the four groups. We next measured %CoQ-10 in plasmas obtained from nine patients treated with percutaneous transluminal coronary angioplasty (PTCA). Plasmas were collected when hospitalized, and at the time (0, 4, 8, 12, 16, and 20 hr, and 1, 2, 3, 4, and 7 days) after the PTCA. %CoQ-10 values before and right after PTCA were 9.9 +/- 2.8 and 11.4 +/- 2.0, respectively, reached a maximum (20-45) at 1 or 2 days later, and decreased to 7.9 +/- 2.7 at 7 days after PTCA, indicating an increase in oxidative stress in patients during coronary reperfusion.

Topics: Adult; Aged; Aged, 80 and over; Angioplasty, Balloon, Coronary; Ascorbic Acid; beta Carotene; Bilirubin; Biomarkers; Carcinoma, Hepatocellular; Carotenoids; Female; Hepatitis; Humans; Liver Cirrhosis; Liver Neoplasms; Lycopene; Male; Middle Aged; Oxidative Stress; Reference Values; Ubiquinone; Uric Acid; Vitamin E

We have applied our method for the simultaneous detection of plasma ubiquinol-10 (reduced form) and ubiquinone-10 (oxidized form) (S. Yamashita and Y. Yamamoto, Anal. Biochem. 250, 66-73, 1997) to plasmas of normal subjects (n = 16) and patients with chronic active hepatitis (n = 28), liver cirrhosis (n = 16), and hepatocellular carcinoma (n = 20) to evaluate the pressure of oxidative stress in these patients. The average ubiquinone-10 percentages (+/- S.D.) in total ubiquinone-10 and ubiquinol-10 in the four groups were 6.4 +/- 3.3, 12.9 +/- 10.3, 10.6 +/- 6.8, and 18.9 +/- 11.1, respectively, indicating a significant increase in ubiquinone-10 percentage in patient groups in comparison to normal subjects. These results and a significant decrease in the plasma ascorbate level in patient groups indicate that oxidative stress is evident after the onset of hepatitis and the subsequent cirrhosis and liver cancer.

Topics: Adult; Aged; Aged, 80 and over; Antioxidants; Ascorbic Acid; beta Carotene; Biomarkers; Carcinoma, Hepatocellular; Carotenoids; Cholesterol; Cholesterol Esters; Female; Hepatitis, Chronic; Humans; Liver Cirrhosis; Liver Diseases; Liver Neoplasms; Lycopene; Male; Middle Aged; Oxidative Stress; Ubiquinone; Vitamin E

Highly differentiated human cell lines represent a useful in vitro model for the study of carotenoid uptake, metabolism, and function. Carotenoids are usually introduced into tissue culture media either in organic solvents or as micelles, whereas carotenoids are localized in lipoproteins in vivo. Initially, the stability of beta-carotene and alpha-tocopherol in micelles and human lipoproteins under standard tissue culture conditions was compared. Recovery of beta-carotene and alpha-tocopherol was 27% +/- 2% and 73% +/- 2%, respectively, after overnight incubation of micellar beta-carotene and alpha-tocopherol in serum-free medium without cells. This marked loss of beta-carotene was attenuated by inclusion of alpha-tocopherol in micelles. In contrast, recovery of beta-carotene and alpha-tocopherol was 88%-95% when medium containing the total lipoprotein fraction isolated from beta-carotene supplemented individuals was incubated overnight without cells. Cellular accumulation of beta-carotene and alpha-tocopherol from medium containing total lipoproteins (1 mg/ml) was proportional to their concentrations in the lipoprotein fraction (r = 0.94 for beta-carotene and 0.74 for alpha-tocopherol). Cells exhibited similar capability of acquiring beta-carotene and alpha-tocopherol from medium containing either low- or high-density lipoproteins. These data show that lipoproteins represent a stable vehicle for delivery of beta-carotene and alpha-tocopherol to HepG2 human liver cells.

Topics: Adult; beta Carotene; Carcinoma, Hepatocellular; Culture Media, Serum-Free; Drug Carriers; Humans; Lipoproteins; Liver; Liver Neoplasms; Male; Micelles; Middle Aged; Tumor Cells, Cultured; Vitamin E

The high incidence of hepatocellular carcinoma (HCC) in cirrhosis, where previous studies have indicated a severe reduction in several antioxidant vitamin factors, prompted us to compare plasma liposoluble vitamins with tocopherol content in healthy and neoplastic liver tissue in humans. This, with a view to a more positive preventive dietary approach, given the conflicting results obtained by liposoluble vitamin dietary supplementation in different malignancies. Eleven patients with cirrhosis, 18 patients affected by cirrhosis with HCC, and 10 patients with liver metastases (LM) from digestive tract adenocarcinomas were compared with controls who had undergone perlaparoscopic cholecistectomy. Plasma alpha- and beta-carotene, retinol and tocopherol, together with liver tocopherol, from both nonmalignant portions and malignant nodules of the same organ, were determined by high-performance liquid chromatography following a well-assessed technique. The results confirm a trend towards a reduction in circulating carotenoids and tocopherol in cirrhosis and in patients affected by cirrhosis with HCC. Tocopherol content in liver tissue is significantly decreased in cirrhosis (0.26 + 0.03 micromol/g prot., mean + SEM, P < .001) and in cirrhotic areas of the HCC group (0.31 + 0.02, P < .002), with respect to its content in liver specimens of healthy controls (0.46 + 0.03) and in healthy areas of the same organ in patients with LM (0.41 + 0.03). Tocopherol concentration is further reduced by 50% in malignant liver nodules of HCC, with respect to surrounding cirrhotic tissue, whereas in metastatic liver nodules from digestive neoplasms the tocopherol content is almost twice that of healthy surrounding areas. This unpredictable tocopherol behavior in liver specimens, of secondary as opposed to primary malignancies of the liver, affords further insight into the conflicting effects of liposoluble vitamins employed in the chemopreventive treatment of different malignant diseases, where hepatic tocopherol concentration show opposite trends: halved in primary HCC and doubled in LM of digestive adenocarcinomas, with respect to healthy controls.

Topics: Aged; beta Carotene; Carcinoma, Hepatocellular; Carotenoids; Female; Humans; Lipids; Liver; Liver Neoplasms; Male; Middle Aged; Vitamin A; Vitamin E

Epidemiological evidence indicates that aflatoxin B1 (AFB1) intake is associated with an increased risk of hepatocellular carcinoma (HCC). The hepatocarcinogenesis is initiated by covalent binding of AFB1 to cellular DNA. To determine whether nutritional factors and hormonal status may influence the binding of AFB1 to hepatic DNA, a cross-sectional study was performed on a total of 42 male asymptomatic hepatitis B surface antigen (HBsAg) carriers and 43 male non-carriers in a cohort study on the multistage development of HCC in Taiwan. The major AFB1-DNA adduct in vivo, AFB1-N7-guanine, was measured by high-performance liquid chromatography in urine. Urinary AFB1-N7-guanine was detectable in 40% of the subjects. HBsAg carriers had a higher detection rate of urinary AFB1-DNA adducts than non-carriers and the difference was statistically significant after multivariate adjustment. After taking into account the total AFB1 urinary metabolite level, chronic HBsAg carrier status, and other potential confounders, plasma levels of cholesterol, alpha-tocopherol, and alpha- and beta-carotene were positively associated with the detection rate of the AFB1-DNA adducts in a dose-dependent manner, whereas plasma lycopene level was inversely related to the presence of the adducts in urine. The association of urinary AFB1-DNA adducts with the plasma levels of cholesterol, alpha-tocopherol, lycopene, and alpha- and beta-carotene was observed at both low and high exposure levels of AFB1. There was a synergistic interaction of plasma alpha-tocopherol with alpha- and beta-carotene on the adduct levels. No association with the adducts was found for plasma levels of retinol and testosterone. This study demonstrated different associations of antioxidant vitamins with AFB1-DNA adduct formation. The data consistent with our previous finding in cultured woodchuck hepatocytes that alpha-tocopherol and beta-carotene enhanced AFB1-DNA adduct formation suggest that prospective investigation of the relationship between plasma micronutrients and risk of AFB1-related HCC is warranted.

Topics: Adult; Aflatoxin B1; Aged; Antioxidants; beta Carotene; Carotenoids; Chronic Disease; DNA; DNA Adducts; Guanine; Hepatitis B; Hepatitis B Surface Antigens; Hepatitis B virus; Humans; Liver; Liver Neoplasms; Male; Middle Aged; Testosterone; Vitamin E; Vitamins

The inhibitory effects of beta-carotene or vitamin A on preneoplastic lesions induced in rats were compared, when specifically administered during early promotion of hepatocarcinogenesis. Initiation was performed by diethylnitrosamine. During the selection/promotion period 2-acetylaminofluorene was administered, and a partial hepatectomy was performed. Afterwards, the rats were divided into 3 groups. To two groups, beta-carotene or vitamin A were given for five weeks. Another group served as control and received corn oil. At the end of the study, beta-carotene reduced the incidence and total number of hepatocyte nodules. Vitamin A rats exhibited a lower number of nodules, but the incidence was 100%. Moreover, beta-carotene reduced the total number of gamma GT-positive preneoplastic lesions, as well as the morphometric parameters of persistent gamma GT-positive lesions. In contrast, morphometric parameters of persistent lesions remained almost unaffected in vitamin A animals. Furthermore, beta-carotene significantly increased the number of remodeling gamma GT-positive preneoplastic lesions. Vitamin A administration, however, resulted only in a small increase in the number of remodeling lesions. These results suggest that the inhibitory effects of beta-carotene during early promotion of hepatocarcinogenesis can be attributed not only to an inhibitory effect on persistent lesions, but also to a striking stimulatory activity on remodeling gamma GT-positive lesions.

Topics: Animals; Anticarcinogenic Agents; beta Carotene; Diterpenes; gamma-Glutamyltransferase; Liver; Liver Neoplasms; Male; Precancerous Conditions; Rats; Rats, Wistar; Retinyl Esters; Vitamin A

To test whether beta-carotene or canthaxanthin can modulate the initiation of liver preneoplasia by diethylnitrosamine (DEN) in a sequential protocol of hepatocarcinogenesis, for three weeks male weanling rats were fed diets containing beta-carotene or canthaxanthin (300 mg/kg diet) or excess vitamin A (70,000 IU/kg diet) or were given beta-carotene by injection (9 injections at 10 mg/kg body wt ip). On Day 15, all rats were injected with 200 mg DEN/kg body wt ip; later they were submitted to 2-acetylaminofluorene treatment and to two-thirds hepatectomy, then to phenobarbital treatment, after which gamma-glutamyltranspeptidase- and placental glutathione-S-transferase-positive liver foci were histologically detected. Neither beta-carotene (fed or injected), canthaxanthin, nor an excess of dietary vitamin A had an influence on the number and size of preneoplastic liver foci, despite a significant incorporation and persistence in liver of both carotenoids, especially canthaxanthin, and of supplemental vitamin A. These results are in conflict with another report in which beta-carotene, given to rats during the initiation phase, was found to strongly inhibit DEN-induced hepatocarcinogenesis.

Topics: Animals; Anticarcinogenic Agents; beta Carotene; Canthaxanthin; Carcinogens; Diet; Diethylnitrosamine; gamma-Glutamyltransferase; Glutathione Transferase; Liver; Liver Neoplasms; Male; Precancerous Conditions; Rats; Rats, Wistar

Inhibitory effects of naturally occurring antioxidants on the initiation stage of hepatocarcinogenesis were studied. Group 1 rats were given a diet containing beta-carotene (beta-CT, 0.02%), alpha-tocopherol (alpha-TP, 1.5%), glutathione (GLT, 5%), vanillin (VNL, 1%), quercetin (QCT, 1%) or ellagic acid (ELA, 1%), or 3 doses of diallyl sulfide (DAS, 200 mg/kg, i.g.) over an 8-day period. On day 7, the animals received a single dose of 2-amino-3-methylimidazo[4,5-f] quinoline (IQ, 100 mg/kg, i.g.), 12 h after two-thirds partial hepatectomy for initiation and 2 weeks thereafter, were placed on promotion regimen comprising phenobarbital (0.05% in diet) and a single dose of D-galactosamine (100 mg/kg, i.p.). Groups 2 and 3 were treated as described for Group 1, but without test material or IQ, respectively. Survivors were killed at week 11 and antioxidant influence was assessed by comparing values for preneoplastic glutathione S-transferase placental form-positive (GST-P+) foci between Groups 1 and 2. All lesions larger than 70 microns in diameter consisting of approximately 5 cells in cross section were counted. Numbers of GST-P+ foci/cm2 in Group 1 were: beta-CT, 7.99; alpha-TP, 8.21; GLT, 9.71; DAS, 10.37; VNL, 10.57; QCT, 11.1; ELA, 12.5 (n = 11-15). All, except ELA, showed a significant decrease as compared with the Group 2 value of 14.54 (n = 15). Only beta-CT showed a significant decrease for the area value. This is the first report to show that beta-CT, alpha-TP, GLT, DAS, VNL, QCT exert inhibitory effects on initiation of hepatocarcinogenesis by the food carcinogen IQ, suggesting that these antioxidants might find application as chemopreventive agents. Furthermore, the current protocol proved practical for the assessment of chemopreventive agents within 11 weeks, a relatively short period.

Topics: Allyl Compounds; Animals; Anticarcinogenic Agents; Antioxidants; Benzaldehydes; beta Carotene; Carcinogens; Carotenoids; Food Contamination; Glutathione; Liver Neoplasms; Male; Quercetin; Quinolines; Rats; Rats, Inbred F344; Sulfides; Vitamin E

A case-control study was carried out in 59 patients with newly diagnosed hepatocellular carcinoma and 101 control subjects, who were all male hepatitis B carriers. The odds ratios of hepatocellular carcinoma occurring among hepatitis B carriers in the lowest quartile and those highest quartile of dietary and serum status were 5.3 (1.9 to 15.0) and 86.9 (20.0 to 377.2), respectively. The odds ratios for hepatitis B carriers in the lowest quartile and those in the highest quartile of dietary and serum beta-carotene status were 1.7 (0.7 to 4.1) and 5.0 (1.9 to 13.2). Vitamin E status did not differ in case patients and control subjects. Low education level, heavy consumption of alcohol, and smoking status were also associated with increased odds of hepatocellular carcinoma. Serum retinol, positively associated with dietary retinol, demonstrated an independent effect on hepatocellular carcinoma. This effect may reflect changes in the physiologic condition of the patients at the time of entering the hospital.

Topics: Adult; beta Carotene; Carcinoma, Hepatocellular; Carotenoids; Case-Control Studies; Diet; Hepatitis B; Humans; Liver Neoplasms; Male; Middle Aged; Odds Ratio; Risk Factors; Socioeconomic Factors; Vitamin A; Vitamin E

Although beta-carotene has been considered to be a key cancer preventive agent in green and yellow vegetables, other types of carotenoids, such as alpha-carotene, may also contribute to anticarcinogenic action, since these carotenoids usually coexist with beta-carotene and are detectable in human blood and tissues. In this study, we compared the inhibitory effect of natural alpha-carotene, obtained from palm oil, with that of beta-carotene on spontaneous liver carcinogenesis in C3H/He male mice. The mean number of hepatomas per mouse was significantly decreased by alpha-carotene supplementation (per os administration in drinking water at a concentration of 0.05%, ad libitum) as compared with that in the control group (P < 0.001, Student's t test). On the other hand, beta-carotene, at the same dose as alpha-carotene, did not show any such significant difference from the control group. Furthermore, we also compared the antitumor-promoting activity of alpha-carotene with that of beta-carotene against two-stage mouse lung carcinogenesis (initiator, 4-nitroquinoline 1-oxide; promoter, glycerol). alpha-Carotene, but not beta-carotene, reduced the number of lung tumors per mouse to about 30% of that in the control group (P < 0.001, Student's t test). The higher potency of the antitumor-promoting action of alpha-carotene compared to beta-carotene was confirmed in other experimental systems; e.g., alpha-carotene was also found to have a stronger effect than beta-carotene in suppressing the promoting activity of 12-O-tetradecanoylphorbol-13-acetate on skin carcinogenesis in 7,12-dimethylbenz[a]anthracene-initiated mice. These results suggest that not only beta-carotene, but also other types of carotenoids, such as alpha-carotene, may play an important role in cancer prevention.

Topics: 4-Nitroquinoline-1-oxide; 9,10-Dimethyl-1,2-benzanthracene; Administration, Oral; Animals; beta Carotene; Carotenoids; Drug Screening Assays, Antitumor; Humans; Liver Neoplasms; Lung Neoplasms; Male; Mice; Mice, Inbred C3H; Ornithine Decarboxylase; Papilloma; Skin Neoplasms; Specific Pathogen-Free Organisms; Tetradecanoylphorbol Acetate