Protective Effect of Propolis (Bee Glue) in Mice Bearing Ehrlich Ascites Carcinoma

Cancer is considered one of the most common causes of morbidity and mortality worldwide. Many studies were carried out to investigate the discovery of natural and synthetic compounds that can be used in the prevention and/or treatment of cancer. Natural products of either plant or animal origin that exhibit antitumour activity have been discovered. The present study was undertaken to evaluate the protective effect of ethanolic extract of propolis without or with radiation exposure in Ehrlich ascites carcinoma- bearing female albino mice. The animals were randomly distributed into three major groups as follows: group A (control group): consists of 10 mice kept on normal standard rodent diet without any treatment and housed in two cages: mice of the first cage served as control for non tumour-bearing group and the second cage served as control for tumour-bearing group. Group B (non tumour-bearing group): consists of 15 mice and used to study the effect of the vehicle solution (gum acacia), propolis and gamma irradiation on normal mice. Mice of this group were equally distributed into three subgroups receiving gum acacia, propolis for two weeks and gamma irradiated. Group C (tumour bearing group): consists of 20 mice randomly and equally distributed into 4 subgroups: Ehrlich ascites carcinoma, Ehrlich ascites carcinoma and 2 Gy irradiated, Ehrlich ascites carcinoma and propolis treated, and Ehrlich ascites carcinoma and propolis irradiated. Plasma and hepatic lipid peroxidation index (TBARS), superoxide dismutase (SOD) and glutathione (GSH) were assessed in RBC and liver together with hepatic aspartate amino transferase (AST) and alanine amino transferase (ALT) and histopathological examination of liver sections. There was decrease in the levels of SOD and GSH as well as an increase in TBARS in mice bearing EAC in addition to increase in hepatic levels of AST and ALT. The microscopical examination of liver sections of mice bearing EAC showed various histopathological alterations including vacuolar degeneration of hepatocytes with sporadic cell necrosis of hepatocytes having deeply pyknotic nuclei, congestion and dilatation of the portal blood vessel and central vein with brown pigment deposition associated with areas of hemorrhage. Treatment of EAC-bearing mice by propolis without or with radiation exposure was found to improve the adverse changes in the liver functions and histopathological changes in liver sections with an increase in antioxidants activities and reduction of lipid peroxidation. It could be concluded that propolis extract supplementation have the ability to provide protective effects against Ehrlich ascites carcinoma- induced biochemical and histopathological changes without harmful side effects.