Ganoderic acid A potentiates antioxidant effect and protection of mitochondrial membrane and reduction the apoptosis rate in primary hippocampal neurons treated with magnesium free medium

Ganoderma lucidum extracts have shown antiepileptic effects in in vivo and in vitro studies. In this work, primary hippocampal neurons cultured in magnesium-free medium were used to study the neuroprotective effects of ganoderic acid A and B (GA-A and GA-B) on superoxide dismutase (SOD) activity and mitochondrial membrane potential, to improve our understanding of their antiepileptic effect. The activity of SOD was determined by the xanthine oxidase assay, the variations of mitochondrial membrane potential and cell apoptosis were measured by JC-1 fluorescent staining and flow cytometry. It was found that the SOD activity and mitochondrial membrane potential (118.84 U/mg protein and 244.08 Δψm) of the epileptic hippocampal neurons were significantly lower than control values (135.95 U/mg protein and 409.81 Δψm), associated with an increase of cell apoptosis (31.88% vs. 8.84%). These circumstances can be improved by treatment of GA-A/GA-B (for SOD, 127.15±3.82 / 120.52±4.30 U/mg protein; for membrane potential (Δψm), 372.35 / 347.28; and for cell apoptosis (%), 14.93 / 20.52). Results indicated that GA-A significantly improved SOD activity, while both GA-A/GA-B tranquillized the mitochondrial membrane potential of hippocampal neurons, and thereby protected these neurons by inhibiting apoptosis.