Effects of fermented aloe vera mixed diet on larval growth of Protaetia brevitarsis seulensis (Kolbe) (coleopteran: Cetoniidae) and protective effects of its extract against CCl4-induced hepatotoxicity in Sprague-Dawley rats

Abstract

The present study was conducted to evaluate the efficacy of fermented aloe vera mixed diet on larval growth of Protaetia brevitarsis seulensis (Kolbe) (coleopteran: Cetoniidae) and protective effects of extract of larvae of P. brevitarsis seulensis fed fermented aloe vera mixed diet against Carbon tetrachloride (CCl4)-induced hepatotoxicity in Sprague-Dawley rats. To determine whether different diets can affect the larval growth of P. brevitarsis seulensis, six different diets were investigated in the experiment, and the results exhibited that 15% fermented aloe vera with 85% fermented oakwood sawdust was the best diet for larval growth of this insect, followed by 9% fermented aloe vera with 91% fermented oakwood sawdust. Adult male Sprague-Dawley rats (n = 30) were separated into five groups of six each, as follows: control group; CCl4 group; CCl4 plus larval extract group (without fermented aloe vera); CCl4 plus 9% and 15% larval extract groups (with fermented aloe vera). All extract groups were fed with 30 mg/kg extracts of fermented oakwood sawdust only and fermented oakwood sawdust plus 9% and 15% fermented aloe vera, respectively, once every consecutive day, with administration of CCl4 (1.5 mL/kg, 20% CCl4 in olive oil) twice a week for 3 weeks. Administration of CCl4 increased the serum alanine aminotransferase, aspartate aminotranseferase and thiobarbituric acid reactive substance levels in rats and reduced levels of glutathione in the liver. Treatment with extract of larval-fed fermented aloe vera mixed diet significantly alleviated these changes to nearly normal levels. The histopathological changes induced by CCl4 were also significantly attenuated by extract of larval-fed fermented aloe vera mixed diet treatment. The results suggest that the beneficial effect of fermented aloe vera mixed diet on larval growth may be to stimulate the larval life cycle, and 15% larval-fed fermented aloe vera mixed diet exhibits potent hepatoprotective effects on CCl4-induced liver injury in rats, likely due to increased glutathione contents and the inhibition of lipid peroxidation.