Induction of Apoptosis by Piper Betel Leaf Extract on 7, 12 Dimethylbenz [a] Anthracene Induced Hamster Buccal Pouch Carcinogenesis

The induction of apoptosis by Piper betel leaf extracts during 7, 12 dimethylbenz [a] anthracene (DMBA) induced hamster buccal pouch (HBP) carcinoma was studied in male Syrian hamsters using DNA fragmentation and the apoptosis-associated proteins, tissue transglutaminase (tTG) and Bcl-2. Hamsters were divided into four groups of six animals each. Animals in group 1 were painted with a 0.5% solution of DMBA in liquid paraffin on the right buccal pouches three times a week for 14 weeks. Group 2 animals painted with DMBA as in group 1, in addition received 500 mg/kg body weight chloroform extract of Piper betel leaves orally on days alternate to DMBA application. Group 3 animals painted with DMBA as in group 1, in addition received 500 mg/kg body weight methonolic extract of Piper betel leaves orally on days alternate to DMBA application. Group 4 animals received neither DMBA nor betel leaf extracts and served as the control. The experiment was terminated at the end of 14 weeks. Administration of Piper betel leaf extracts (500 mg/kg body weight) to animals painted with DMBA inhibited DMBA-induced oral cancer as revealed by the absence of neoplasm, induction of tTG and inhibition of Bcl-2 expression. The results of the present study suggest that Piper betel leaves may exert its chemopreventive effect by inducing apoptosis.