Ginseng total saponins enhance neurogenesis after focal cerebral ischemia

Ginseng, the root of Panax ginseng C.A. Meyer, is one of the most commonly used healing herbs for stroke and chronic debilitating conditions in China. Ginsenosides are the main active principles for ginseng's efficacy, but the mechanisms have not been fully clarified.

To test the hypothesis whether or not the administration of Ginseng total saponins (GTS) can enhance neurogenesis after focal cerebral ischemia, and thereby improve neurological deficits.

Male Wistar rats received intraperitoneal injections of GTS dissolved at a dose of 25 mg kg(-1) d(-1) or normal saline (NS) of same volume 3 days before the permanent middle cerebral artery occlusion (MCAO) model establishment until the animals were killed at the time points of 1d, 3d, 7d and 14d. The neurological function was assessed blindly. BrdU immunostaining and double staining were performed by following the 3-steps method.

(A) GTS-treated rats have better neurological scores compared with those in NS group at 14d time point (p<0.05); (B) the number of BrdU(+) cells and BrdU(+)/NeuN(+) cells in GTS group were significantly higher than those in NS group in the ipsilateral subventricular zone and in the ipsilateral infarct area after MCAO, respectively (p<0.05 or p<0.01); (C) the increase of the number of BrdU(+)/NeuN(+) cells highly correlated with the decrease of neurological scores. Coefficient correlation r=-0.828 (p<0.01).

GTS can improve neurological deficits after focal cerebral ischemia by inducing endogenous neural stem cells activation and thereby enhance adult central nervous system regeneration.