Hydrogen Sulfide Protects Hippocampal Neurons Against Methamphetamine Neurotoxicity Via Inhibition of Apoptosis and Neuroinflammation

Methamphetamine (METH) known as a highly neurotoxic compound associated with irreversible brain cell damage that results in neurological and psychiatric abnormalities. The mechanisms of METH intoxication mainly involve intraneuronal events including oxidative stress, excitotoxicity, and dopamine oxidation. Based on recent studies, H2S can protect neurons through anti-inflammatory, antioxidant, and antiapoptotic mechanisms. Therefore, we aimed to study the effects of protection of H2S against METH neurotoxicity. The 72 male Wistar rats were randomly allocated into six groups: control (n, 12), H2S (n, 12), METH (n, 12), METH + H2S 1mg/kg (n, 12), METH + H2S 5mg/kg (n, 12), and METH + H2S 10mg/kg (n, 12) groups, (NaHS as a H2S donor; 1, 5, 10mg/kg). METH neurotoxicity was induced by 40mg/kg of METH in four intraperitoneal (IP) injections (e.g., 4x10mg/kgq. 2h, IP). NaHS was administered at 30min, 24h, and 48h after the final injection of METH. Seven days after METH injection, the brains were removed for biochemical assessments, glial fibrillary acidic protein (GFAP), and caspase-3 immunohistochemistry staining. H2S treatment could significantly increase both superoxide dismutase and glutathione (P<0.01), and a reduction was observed in malondialdehyde (P<0.05) and TNF- (P<0.01) versus the METH group. Moreover, H2S could significantly decrease caspase-3 and GFAP-positive cells in the CA1 region of the hippocampus (P<0.01) compared to the METH group. According to the findings, H2S makes significant neuroprotective impacts on METH neurotoxicity due to its antioxidant and anti-inflammatory activities.