zeaxanthin and Carcinoma--Hepatocellular

Meso-zeaxanthin was investigated for antimutagenic and anticarcinogenic activity, using the Ames test (Salmonella typhimurium strains TA 98, TA 100, TA 102 and TA 1535) with direct acting mutagens like sodium azide (NaN3) (5 μg/ plate), nitro-o-phenylendiamin (NPD) (20 μg/ plate), N-methyl- N'-nitro-N-nitrosoguanidine (MNNG) (1μg/ plate) and tobacco extract 50 mg/ plate) and with a mutagen needing microsomal activation, acetamidofluorene (AAF) ( 20 μg/ plate). The carotenoid was found to inhibit the mutagenicity induced by NaN3, NPD and MNNG in a concentration dependent manner, as well as that with AAF and the tobacco extract. Concentrations needed for 50 % inhibiton was found to be 50 μg/ plate for the chemical mutagens and 100 μg/ plate for tobacco extract. Using specific resorufin derivatives as substrates in vitro, the concentration of meso-zeaxanthin needed for 50 % inhibition of CYP1A2 (7-methoxyresorufin-O-demethylase) was 5 µg/ml, for CYP2B 1/2 (7- pentoxyresorufin-O-depentylase) was 8 µg/ml and for CYP1A1 (7-ethoxyresorufin-O-deethylase) was 12 µg/ml, while that of CYP 2E1 (aniline hydroxylase) was 7µg/ml and for CYP 1A, 2A, 2B, 2D and 3A (aminopyrene-N-demethylase) was 10.5 µg/ml. Evaluated using nitroso diethyl amine (NDEA) induced hepatocellular carcinoma in rats, treatment with meso-zeaxanthin reduced the tumor incidence when compared to the control group. The activity of glutamate oxaloacetate transaminase, glutamate pyruvate transaminase and alkaline phosphatase was drastically elevated in both serum and liver tissue of NDEA alone treated control animals and meso-Zeaxanthin pretreated animals showed significant decrease to normal levels, in line with histopathological findings.

Topics: Animals; Anticarcinogenic Agents; Antimutagenic Agents; Carcinogens; Carcinoma, Hepatocellular; Cytochrome P-450 CYP1A2; Liver Neoplasms, Experimental; Male; Microsomes, Liver; Mutagenicity Tests; Mutagens; Rats; Rats, Wistar; Salmonella Infections; Salmonella typhimurium; Tumor Cells, Cultured; Xanthophylls; Zeaxanthins

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