Effect of rice bran extract on immunological and physiological parameters of Biomphalaria alexandrina snails infected with Schistosoma mansoni

Abstract

The present study was undertaken to evaluate the effect of rice bran extract on immunological and physiological parameters of Biomphalaria alexandrina snails and Schistosoma mansoni infection. Rice bran methanolic extract showed the strongest antioxidant activity. IC50 values for scavenging DPPH was 344.22 µg/ml and reducing power was increased with increasing amounts of the extract. Total phenolic and flavonoid contents were 4.23 mg gallic acid-equivalent (GAE)/g bran and 2.11 mg quercetin-equivalent (QE)/g bran, respectively. The presence of rice bran during infection causes reduction in infection rate by 33.3%. The exposure of snails to infection for 24 h followed by treatment with 500 ppm of rice bran for 24 h caused a reduction in infection rate by 56.5% as compared to the control (80%). The reduction in infection rate of Schistosoma haematobium may be due to the increase in immune activity response, activation and vacuolation of haemocytes distributed in hemolymph of snails which represent the important system in immunity defense against any invaders. These results could provide useful information for control of Schistosomiasis in integrated pest management program and environmental protection. Key words: Schistosomiasis, antioxidant, rice bran, control, immunological and physiological parameters, snail.