beta-carotene and Vaginal-Neoplasms

The inhibitory effects of the newly-developed forms of beta-carotene--water-soluble and liposomal--have been studied in rats and mice bearing tumors induced in 4 models of carcinogenesis. Mammary tumors were induced by single injections of 1 mg methylnitrosourea into each gland. Esophageal tumors were induced in male rats by intragastric administration of 3 mg/kg methylbenzylnitrosoamine, thrice a week for 4 weeks. Tumors of the vagina and cervix uteri were induced by intravaginal painting with 25 mkg dimethylbenz(a)anthracene, twice a week for 6 weeks. Tumors of the lung were induced in female mice by intraperitoneal injection of 1 g/kg urethane, once a week for 6 weeks. With models I-III, animals received water-soluble beta-carotene (Aquiton-10) with drinking water (200 mg/I), on completion of carcinogen treatment and for another 9-12 months until the end of experiment. Urethane-treated mice received liposomal beta-carotene with drinking water (60 mg/l) 10 days before the beginning of carcinogen treatment and for another 6 months until the end experiment. Water-soluble beta-carotene failed to influence the carcinogenesis in the mammary gland and esophagus in rats; however, it significantly inhibited carcinoma development in murine vagina and cervix uteri (47.0%). Liposomal beta-carotene significantly inhibited lung adenomas (46.4%) and mammary carcinomas (55.6%) in urethane-treated mice.

Topics: Animals; Anticarcinogenic Agents; beta Carotene; Esophageal Neoplasms; Female; Liposomes; Lung Neoplasms; Male; Mammary Neoplasms, Experimental; Mice; Neoplasms, Experimental; Rats; Solubility; Uterine Cervical Neoplasms; Vaginal Neoplasms; Water