Anti-tumor promoting activity of Asteracantha longifolia against experimental hepatocarcinogenesis in rats

Vegetables, natural products of plant origin and numerous non-nutritive die tary constituents have been shown to play a salutary role in cancer chemopr evention. The present study aims to evaluate the chemopreventive efficacy o f the methanol fraction of Asteracantha longifolia seed extract against dev elopment of 2-acetylaminofluorene (2-AAF)-selected gamma -glutamyl transpep tidase (gamma -GT)-positive foci following diethylnitrosamine (DEN) initiat ion. Treatment of rats with doses 200 and 400 mg/kg body weight of methanol extract of A. longifolia seeds on alternate days, subsequent to carcinogen treatment, for 6 weeks significantly reduced the incidence and size distri bution of gamma -GT-positive foci and tumor formation. Administration of A. longifolia seeds significantly (P<0.001) ameliorated the activities of ant ioxidant enzymes, glutathione peroxidase (GPx) and catalase (CAT), in a dos e-dependent manner. Prophylactic administration of seed extract simultaneou s to 2-AAF in the diet, at same doses, significantly suppressed 2-AAF and p artial hepatectomy (PH)-induced ornithine decarboxylase (ODC) activity and [H-3]thymidine incorporation into hepatic DNA, in a dose-dependent manner. Assimilation of the quantitative foci data together with the findings of th e modulation of tumor promoting markers give ample evidence to the anti-tum or promoting potential of A. longifolia seeds against chemically-induced he patocarcinogenesis in Wistar rats. (C) 2001 Elsevier Science Ltd. All right s reserved.