Protective Effect of Apigenin on 7, 12- Dimethylbenz (a) Anthracene Induced Glycoconjugates in the Plasma and Buccal Mucosa of Golden Syrian Hamsters

Present study investigated the protective effect of apigenin on cell surface glycoconjugates abnormalities in 7, 12-dimethyldenz(a)anthracene(DMBA) induced hamster buccal pouch carcinogenesis. DMBA painting in the hamster buccal pouch three times per week for 14 weeks developed oral squamous cell carcinoma. The levels of glycoconjugates (Protein bound hexose, Hexosamine, Lipid bound sialic acid, Total sialic acid and Fucose) were analyzed by using specific colorimetric methods. The levels of glycoconjugates were significantly increased both in plasma and buccal mucosa in tumor bearing hamsters as compared to normal hamsters. Oral administration of apigenin at a dose of 2.5mg/kg bw significantly restored the status of glycoconjugates in DMBA treated hamsters. Our results suggest that apigenin protected cell surface glycoconjugates abnormalities during DMBA induced oral carcinogenesis. INTRODUCTION: Oral cancer, a diverse group of tumors arising from lip, cheek, floor of the mouth, hard and soft palate, tongue, pharynx and oral cavity, is the fifth most frequent cancer worldwide . This disfiguring form of cancer assumes a major health problem in terms of patient’s morbidity and mortality in India and accounts for 40-50% of all cancers. Higher prevalence of oral cancer has been associated with chewing of betel quid containing tobacco, in addition to smoking and alcohol consumption . Cancer of the oral cavity can be prevented by avoiding these risk factors. 7, 12-dimethylbenz (a) anthracene (DMBA), a potent site and organ specific procarcinogen, is commonly employed to develop oral cancer in the buccal pouch of golden Syrian hamsters since the precancerous and cancerous lesions as well as biochemical and molecular marker expressions induced by DMBA has marked similarities with human oral cancers . It has been reported that chemical carcinogens increase the expression of cell surface glycoconjugates during cell differentiation . DMBA induced cell surface abnormalities has been reported well in several experimental cancers . Increased levels of protein bound hexose, hexosamine, fucose and sialic acids were reported in DMBA induced hamster buccal pouch carcinogenesis . Glycoconjugates, carbohydrates covalently linked with other chemical species, consist of glycoproteins, glycopeptides, peptidoglycans, glycolipids, and lipopolysaccharides. They are involved in biological recognition processes such as cell-cell recognition, cell growth and differentiation and cell-matrix interaction . Mammalian cell membrane glycoconjugates have also been associated with tumor progression and