Submitted to: Carotenoid Symposium
Publication Type: Abstract Only
Publication Acceptance Date: 10/15/2001
Publication Date: 1/6/2002
Citation: CHONGVIRIYAPHAN, N., LIU, C., LIPMAN, R., SMITH, D.E., RUSSELL, R.M., WANG, X. BETA-CAROTENE IN THE PRESENCE OF ALPHA-TOCOPHEROL AND VITAMIN C PROTECTS AGAINST LUNG SQUAMOUS METAPLASIA IN FERRETS EXPOSED TO TOBACCO SMOKE. INTERNATIONAL CAROTENOID SYMPOSIUM. 2002;97. Interpretive Summary:
Technical Abstract: There is a discrepancy between the observational studies and the intervention trials using beta-carotene (BC) as a chemopreventive agent against the risk of lung cancer in smokers. Several lines of evidence indicate the possibilities that the carcinogenesis induced by BC may be related to the dosage used and/or to the instability of BC in the antioxidant-poor environment of the lungs of smokers. In the present study, we evaluated the effects of BC at low dose (LBC, equivalent to an intake of 6 mg/day in human) vs. BC at high dose (HBC, equivalent to 30 mg/day in human) supplement in either the presence or absence of alpha-tocopherol (AT, equivalent to100 mg/day in human) and ascorbic acid (AA, equivalent to 210 mg/day in human) on lung pathological changes after exposed to smoke (SM) for 6 weeks. The results show that cigarette smoke exposure for six weeks induced squamous metaplasia in the lung tissues of SM, SM+HBC, and SM+HBC+AT+AA groups but not in the SM+LBC or SM+LBC+AT+AA groups. The lung BC concentration increased in the BC supplement groups in a dose-dependent manner. There was no difference on lung concentrations of AT and AA among the treatment groups. However, lung BC levels decreased significantly in the presence of AT and AA in the BC supplement groups. We conclude that LBC in the presence or absence of AT and AA protects against the smoke-induced lung squamous metaplasia in ferrets.