beta-carotene and Nasopharyngeal-Neoplasms

This study demonstrates the analysis of nasopharyngeal cancer (NPC) in human blood sera using Raman spectroscopy combined with the multivariate analysis technique. Blood samples of confirmed NPC patients and healthy individuals have been used in this study. The Raman spectra from all these samples were recorded using 785 nm laser for excitation. Important Raman bands at 760, 800, 815, 834, 855, 1003, 1220-1275, and 1524 cm

Topics: Aged; Amino Acids; beta Carotene; Early Detection of Cancer; Humans; Lipids; Middle Aged; Nasopharyngeal Neoplasms; Principal Component Analysis; Spectrum Analysis, Raman

The structures of three triterpene alcohols isolated from the latex of Euphorbia antiquorum were established to be eupha-7,9(11),24-trien-3beta-ol (2; antiquol C), 19(10-->9)abeo-8alpha,9beta,10alpha-eupha-5,24-dien-3beta-ol (3; antiquol B), and 24-methyltirucalla-8,24(24(1))-dien-3beta-ol (4; euphorbol) on the basis of spectroscopic methods. Compounds 3 and 4 have previously been assigned the erroneous structures of 10alpha-cucurbita-5,24-dien-3alpha-ol and 24-methyleupha-8,24(24(1))-dien-3beta-ol, respectively. Compounds 2-4 and four other known compounds isolated from the latex, euphol (1), lemmaphylla-7,21-dien-3beta-ol (5), isohelianol (6), and camelliol C (7), showed potent inhibitory effects on Epstein-Barr virus early antigen (EBV-EA) activation induced by the tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA).

Topics: Antigens, Viral; Antiviral Agents; Chromatography, High Pressure Liquid; Euphorbia; Herpesvirus 4, Human; Humans; Latex; Molecular Conformation; Molecular Structure; Nasopharyngeal Neoplasms; Nuclear Magnetic Resonance, Biomolecular; Spectrophotometry, Infrared; Spectrophotometry, Ultraviolet; Sri Lanka; Stereoisomerism; Tetradecanoylphorbol Acetate; Tumor Cells, Cultured; Virus Replication

Seven labdane-type diterpenoids from the stem bark of Thuja standishii (Gord.) Carr. (Cupressaceae) and their analogues showed strong inhibitory effects on Epstein-Barr virus early antigen (EBV-EA) activation induced by 12-O-tetradecanoylphorbol-13-acetate (TPA). Among these compounds, 15,16-bisnor-13-oxolabda-8(17), 11E-dien-19-oic acid was revealed to have the strongest inhibitory effect on the EBV-EA activation, being stronger than that of beta-carotene which has been intensively studied in cancer prevention using animal models. 15,16-bisnor-13-Oxolabda-8(17), 11E-dien-19-oic acid was also found to exhibit the excellent anti-tumor promoting activity in two-stage mouse skin carcinogenesis test using 7,12-dimethylbenz[a]anthracene and TPA.

Topics: 9,10-Dimethyl-1,2-benzanthracene; Animals; Antigens, Viral; beta Carotene; Carboxylic Acids; Carcinogens; Diterpenes; Female; Humans; Mice; Mice, Inbred ICR; Naphthalenes; Nasopharyngeal Neoplasms; Neoplasms; Papilloma; Plant Extracts; Plant Stems; Skin Neoplasms; Tetradecanoylphorbol Acetate; Trees

Asian studies have reported that risk of nasopharyngeal cancer (NPC) is increased in individuals who frequently consume salted fish, which contains high levels of N-nitroso compounds. As part of a collaborative, population-based, case-control study in the U.S., where the annual incidence of the disease is low, we investigated whether dietary intake of preformed nitrosamines or nitrosamine precursors, or of antioxidants including vitamin C and carotenoids, was associated with altered risk of NPC overall, or of specific histologic subtypes of disease. Cases (n = 133) identified at 5 population-based cancer registries and controls (n = 212) identified through random digit dialing completed a telephone interview and self-administered food frequency questionnaire. Dietary exposures were expressed as quartiles of intake, and odds ratios (ORs) calculated using the lowest quartile of intake as the reference category. Risk of non-keratinizing and undifferentiated tumors of the nasopharynx was increased in frequent consumers of preserved meats, which contain high levels of added nitrites. ORs in the 2nd, 3rd and highest quartile were 1.99, 4.35 and 4.59, although 95% confidence intervals did not exclude 1.0. Risk of differentiated squamous cell carcinoma, but not other histologic types, was significantly reduced in individuals with vitamin C intake above the lowest quartile (ORs 0.30, 0.33 and 0.30 in the 2nd, 3rd and highest quartiles, respectively). This association was markedly stronger among non-smokers and former smokers than among current smokers. Finally, individuals who reported consuming supplemental vitamins were at an approximately 50% reduced risk of NPC. Our results indicate that future studies should consider the effects of dietary risk factors on the risk of specific histologic subsets of NPC, and not assume that the disease is etiologically homogeneous.

Topics: Adolescent; Adult; Aged; Alcohol Drinking; Antioxidants; Ascorbic Acid; beta Carotene; Black or African American; Case-Control Studies; Diet; Educational Status; Energy Intake; Female; Humans; Male; Middle Aged; Nasopharyngeal Neoplasms; Nitrosamines; Odds Ratio; Risk; Smoking; Surveys and Questionnaires; White People

The association between the consumption of preserved foods in infancy, childhood and adulthood and the risk of nasopharyngeal carcinoma was investigated in a case-control study among Singapore Chinese: 200 cases (73% male) were compared with 406 hospital controls (71% male). Significantly increased risks were observed in association with frequent adult consumption of salted soy beans (OR 7.3 for consumption 4 or more times per week, compared with never), canned pickled vegetables (p = 0.01; OR 4.5 for 4 or more times per week), "sze chuan chye", a salted Chinese tuber, (OR 2.4 for 4 or more times per month) and "kiam chye", salted mustard greens (OR 2.7 for 4 or more times per week). A protective effect of high vitamin-E intake in adulthood was observed (OR 0.5 for the highest third of the control range, as compared with the lowest).

Topics: Adult; Ascorbic Acid; beta Carotene; Carotenoids; Case-Control Studies; Female; Fish Products; Food Preservatives; Glycine max; Humans; Male; Nasopharyngeal Neoplasms; Pregnancy; Risk Factors; Singapore; Vegetables; Vitamin E

Topics: Animals; Antibodies, Viral; Antiviral Agents; beta Carotene; Carotenoids; Herpesvirus 4, Human; Humans; Immunoglobulin A; Interferons; Nasopharyngeal Neoplasms; Nasopharynx; Precancerous Conditions; Risk; Tumor Virus Infections