Effect of thymol and propolis extract on genotoxicity, biochemical activities and expression profile of some genes on honey bee, Apis mellifera, infected with Vairimorpha (Nosema) ceranae

Abstract

Background: Nosema ceranae, the predominant microsporidian parasite, weakens Apis mellifera honey bee colonies and reduces their productivity and reproduction. This research aims to detect the impact of thymol and propolis extracts on genotoxicity repair, oxidative enzymes, expression of some antimicrobial genes and some hypopharyngeal glands genes in N. ceranae-infected bees. Experimentally, infected honeybee colonies were divided into four groups: (1) untreated, (2) for propolis (3 g/L) treatment, (3) for thymol (0.1 g/L) treatment and (4) for mixed treatment with thymol and propolis. Workers from adult honeybee colonies, treated and untreated, were randomly sampled. The collected samples were used in studying the genotoxicity effect, the concentration of oxidative enzymes (superoxide-dismutases, glutathione S transferase, catalase and malondialdehyde (MDA)), measuring the relative expression of antimicrobial genes and hypopharyngeal glands genes major royal proteins 1 & 2 (MJRP1 and MJRP2). Results: The results show that thymol and propolis extract decreased genotoxicity effect, increased expression of antimicrobial genes, increased expression levels of MJRP1 and MJRP2 genes and decreased activities of oxidative enzymes when applied to Nosema-infected bees. Conclusion: Thymol and propolis extract positively affect honey bee health and mix of them. This study reveals that natural product extracts and their mixture may fight Nosema and prevent honey bee colonies decline and sudden death.