Effects of dietary protein content on oxidative stress and uric acid decomposition in Blattella germanica (Blattaria: Blattellidae)

Author of the article:ZHANG Bi-Yao, CHEN Jian-Hua, LUO Xian-Mei, WANG Guo-Hong

Author's Workplace：College of Life Sciences, Fujian Normal University, Provincial University Key Laboratory of Cellular Stress Response and Metabolic Regulation, College of Life Sciences, Fuzhou 350108, China

Key Words：Blattella germanica, protein content, uric acid decomposition, antioxidant

Abstract：[Objectives]  To investigate effects of diet protein content on oxidative stress and uric acid decomposition pathways in the German cockroach (Blattella germanica), thereby providing a theoretical basis for the development of novel cockroach baits. [Methods]  German cockroaches were randomly assigned to one of four treatment groups which were fed diets with a protein content of either 5%, 25%, 45% or 65%. Ultraviolet spectrophotometry was then used to determine the superoxide dismutase activity and malondialdehyde content of each treatment group. In addition, RT-PCR was used to determine the gene expression levels of the urate oxidase, allantoinase, allantoidase, urease, and glutamine synthesis enzyme, genes. [Results]  Superoxide dismutase activity in adult males fed the 45% protein diet was significantly higher than that of those fed the 5%, 25% and 65% protein diets, but was not significantly different to that of larvae fed the 5%, 25% and 65% protein diets（P<0.05）. There was no significant difference in SOD activity between male and female cockroaches（P>0.05）. Cockroaches fed the 65% protein diet had the lowest survival rate, the lowest SOD activity and urate oxidase gene expression, but the highest in vivo malondialdehyde content and allantoidase, urease and glutamine synthase gene expression. [Conclusion] German cockroaches store uric acid under high protein conditions, which can reduce their antioxidant capacity and survival rate.