title: Regression of experimental oral carcinomas by local injection of beta-carotene and canthaxanthin.
abstract: Regression of 7,12-dimethylbenz[a]anthracene (DMBA)-induced epidermoid carcinomas of hamster buccal pouch was accomplished by local injections of beta-carotene and canthaxanthin. One-hundred male hamsters (2-3 months old) were divided into five groups of 20 animals. All animals had the right buccal pouches painted three times weekly for 14 weeks with a 0.5% solution of DMBA in mineral oil, at which time all animals exhibited gross tumors of variable size and number. Group 1 animals were then injected locally into the right buccal pouch twice weekly for 4 weeks with 250 micrograms-carotene in 0.1 ml minimal essential medium (MEM) per injection. Group 2 animals were similarly injected with 250 micrograms canthaxanthin in 0.1 ml MEM. Group 3 animals were similarly injected with 250 micrograms 13-cis-retinoic acid in 0.1 ml MEM. Group 4 animals were injected only with MEM; Group 5 animals were untreated controls. Animals were killed in a carbon dioxide chamber, and buccal pouches were photographed. Tumors were counted and measured. Tumor burden in each group was compared, and statistical significance between groups was recorded. beta-Carotene was more effective than canthaxanthin in tumor regression. 13-cis-Retinoic acid had no effect in this system.
mesh_terms: D015127:9,10-Dimethyl-1,2-benzanthracene; D000278:Administration, Buccal; D000818:Animals; D016644:Canthaxanthin; D002294:Carcinoma, Squamous Cell / Q000139:chemically induced / Q000188:drug therapy* / Q000473:pathology; D002338:Carotenoids / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000627:therapeutic use*; D002610:Cheek; D006224:Cricetinae; D009062:Mouth Neoplasms / Q000139:chemically induced / Q000188:drug therapy* / Q000473:pathology; D012074:Remission Induction; D019207:beta Carotene
chemical_list: D019207:beta Carotene; D002338:Carotenoids; D016644:Canthaxanthin; D015127:9,10-Dimethyl-1,2-benzanthracene