Effects of Salvia officinalis Extract and its Nano-Encapsulated Form on Methylmercury Induced Neurotoxic-Stress in Male Rats

Nanoparticles derived from plants known for their high content of flavonoids provide a biologically inspired route to design therapeutic agents and a means of reducing metal nanoparticle toxicity. Little is currently known on the anti-neurotoxicity of Salvia officinalis L. extracts and their corresponding nanoparticles. In the present study, anti-neurotoxic stress activity of S. officinalis extract obtained from aerial parts (leaves) and nanoparticles derived from these extract were investigated against Methylmercury (MeHg). Ten groups of rats were treated with different concentrations of extracts (125 mg/kg bw of non-nanoparticles of S. officinalis, SO; 25, 50 and 125 mg/kg bw of SO nanoparticles, SON) and/or MeHg (10 mg/kg bw) for 8 weeks to determine their anti-neurotoxic effect. After the last injection, rats were sacrificed and brain capsule were collected on ice bath and the cortex were separated in order to investigate the apoptosis, reactive oxygen species (ROS), expression alteration of glutamate transporters (GLAST, GLT-1, SNAT3 and ASCT2 mRNA), DNA fragmentation, 8-OHdG levels and glutathione peroxidase (GPx) activity. The preset study found that the neurotoxic stress of MeHg was markedly inhibited with SO extracts especially with SO nanoparticles. Treatment of male rats with SON50+MeHg decreased significantly the apoptosis rate, ROS production, DNA fragmentation and 8-OHdG levels as well as increased the expression of GLAST, GLT-1, SNAT3, ASCT2 mRNA and GPx activity in the cerebral cortex. The biosynthesized nanoparticles may be further characterized to better evaluate their anti-neurotoxicity potential against other neurotoxic agents.