Amelioration of renal carcinogenesis by bee propolis: a chemo preventive approach

The present study was designed to investigate the chemo preventive efficacy of bee propolis (BP) against diethylnitrosamine (DEN) initiated and ferric nitrilotriacetate (Fe-NTA) promoted renal carcinogenesis in Wistar rats. Chronic treatment of Fe-NTA induced oxidative stress, inflammation and cellular proliferation in Wistar rats. BP is a resinous material collected by bees from various plants which has been used from centuries in folk medicine.

Renal cancer was initiated by single intraperitoneal injection of N-nitrosodiethylamine (DEN 200 mg/kg body weight) and promoted by twice weekly administration of Fe-NTA 9 mg Fe/kg body weight for 16 weeks. The chemo preventive efficacy of BP was studied in terms of lipid peroxidation (LPO), renal anti-oxidant armory such as catalase, superoxide dismustase, glutathione S-transferase, glutathione peroxidase, glutathione reductase and glutathione (GSH), serum toxicity markers, cell proliferation, tumor suppressor protein and inflammation markers.

Administration of Fe-NTA enhances renal LPO, with concomitant reduction in reduced GSH content and antioxidant enzymes. It induces serum toxicity markers, viz., blood urea nitrogen, creatinine and lactate dehydrogenase. Chemo preventive effects of BP were associated with upregulation of antioxidant armory and down regulation of serum toxicity markers. BP was also able to down regulate expression of proliferative cell nuclear antigen, cyclooxygenase-2, tumor necrosis factor-alpha and upregulated p53 along with induction of apoptosis. Histopathological changes further confirmed the biochemical and immunohistochemical results.

These results provide a powerful evidence for the chemo preventive efficacy of BP against renal carcinogenesis possibly by modulation of multiple molecular pathways.