Heat Treatment Enhances the Neuroprotective Effects of Crude Ginseng Saponin by Increasing Minor Ginsenosides

Ginsenoside is the primary active substance of ginseng and has many pharmacological effects, such as anti-cancer, immune- sugar- and lipid metabolism-regulating, and antioxidant effects. It also protects the nervous and cardiovascular systems. This study analyzed the effects of thermal processing on the bioactivities of crude ginseng saponin. Heat treatment increased the contents of minor ginsenosides in crude saponin, such as Rg3, and heat-treated crude ginseng saponin (HGS) had better neuroprotective effects than non-treated crude saponin (NGS). HGS reduced glutamate-induced apoptosis and reactive oxygen species generation in pheochromocytoma 12 (PC12) cells significantly more than NGS. HGS protected PC12 cells against glutamate-induced oxidative stress by upregulating Nrf2-mediated antioxidant signaling and downregulating MAPK-mediated apoptotic signaling. HGS has potential for the prevention and treatment of neurodegenerative disorders, such as Alzheimer's and Parkinson's disease.