CHEMOPREVENTIVE EFFICACY OF ADHATODA VASICA LEAVES IN 7,12- DIMETHYLBENZ[A]ANTHRACENE INDUCED ORAL CARCINOGENESIS

Abstract

Imbalance in oxidant and antioxidant status is one of the commonly observed
phenomenon in several pathological conditions including cancer. Also, defect in
detoxification cascade leads to accumulation of toxic metabolites, which cause
mutation in DNA and leads to neoplastic transformation. Aim of the present study is
to focus the chemopreventive potential of Adhatoda vasica leaves during DMBA
induced hamster buccal pouch carcinogenesis by analyzing the status of lipid
peroxidation by products (TBARS), antioxidants (Superoxide dismutase (SOD),
catalase (CAT), glutathione peroxidase (GPx) and Vitamin E) and detoxification
agents (cytochrome p450, cytochrome b5, glutathione-s-transferase (GST), reduced
glutathione (GSH), glutathione reductase (GR), DT-diaphorase and oxidized
glutathione (GSSG)). Topical application of DMBA to the buccal pouches of
hamsters, thrice a week for 14 weeks, developed well differentiated squamous cell
carcinoma. At the end of the experimental period, we noticed an imbalance in
oxidant and antioxidant status as well as defect in the detoxification mechanism in
hamsters treated with DMBA alone. Though oral administration of ethanolic extract
of Adhatoda vasica leaves (AVELet) to hamsters treated with DMBA, suppressed the
tumor formation, we noticed hyperplasia and dysplasia. AVELet also modulated the
status of lipid peroxidation, antioxidants and detoxification cascade in favour of
delaying the tumor formation in hamsters treated with DMBA. The present study thus
highlights the tumor preventive potential of AVELet, which could be attributed to its
antioxidant potential during DMBA induced oral carcinogenesis. Further studies are
in progress to isolate and characterize the bioactive principles from the leaves of
Adhatoda vasica.