Modifying influences of betel quid ingredients on B(a)P-induced carcinogenesis in the buccal pouch of hamster.
The present study evaluates the incidence of tumors in hamster buccal pouches following short-term (10 days) and long-term (6 months) topical exposures to graded doses of benzo(a)pyrene, B(a)P (25 micrograms, 50 micrograms and 100 micrograms per pouch either daily for 10 days or thrice weekly for 6 months) alone or in combination with extract of tobacco (1 mg/pouch, twice daily), betel nut (1 mg/pouch, twice daily) or betel leaf (5 mg/pouch, twice daily). Given alone, the three doses of B(a)P respectively yielded, 6 months after the last treatment, 4%, 8.7% and 16.7% tumors in the short-term study, and 20%, 35% and 61% tumors in the long-term study. Short-term treatments with individual ingredients of betel quid did not produce any tumors while long-term treatments produced tumors only with tobacco (17.6%) and betel nut (10.5%). When B(a)P, and betel quid ingredients were painted concomitantly for 10 days, there was, depending upon the dose of B(a)P, complete or partial suppression of tumor production. But when B(a)P-plus-tobacco or B(a)P-plus-betel nut treatments were given for 6 months, there was a considerable increase in tumor incidence. Betel leaf extract, in both short-term and long-term studies, expressed its inhibitory influence on B(a)P-induced tumorigenesis.
D000818:Animals; D001114:Areca / Q000032:analysis; D001564:Benzo(a)pyrene; D001580:Benzopyrenes; D002273:Carcinogens; D002610:Cheek; D006224:Cricetinae; D005260:Female; D008647:Mesocricetus; D009062:Mouth Neoplasms / Q000139:chemically induced*; D010936:Plant Extracts / Q000633:toxicity*; D010946:Plants, Medicinal; D010947:Plants, Toxic; D011230:Precancerous Conditions / Q000139:chemically induced; D014026:Nicotiana / Q000032:analysis
D001580:Benzopyrenes; D002273:Carcinogens; D010936:Plant Extracts; D001564:Benzo(a)pyrene