Panax notoginseng saponins promotes cerebral recovery from ischemic injury by downregulating LINGO-1 and activating the EGFR/PI3K/AKT signaling pathways in vivo

Abstract

Objective: Panax notoginseng saponins (PNS), extracted from rhizome of the herb Radix et Rhizoma Notoginseng (Panax notoginseng (Burk.) F.H. Chen), was recently discovered to have beneficial effects against neurological damage. This study investigated the effects of PNS on cerebral ischemia and elucidated the molecular mechanisms underlying these effects. Methods: Middle cerebral artery occlusion rats were treated with PNS (3.6 mg/100 g or 7.2 mg/100 g per day) for 7 days, the gene of LINGO-1 was measured and the expression of protein synaptophysin, postsynaptic density protein 95, LINGO-1 and p-EGFR/p-PI3K/p-AKT were investigated. The weight and mNSS score of Sprague–Dawley rats in each group were recorded every day during the 7 days. Results: PNS promoted middle cerebral artery occlusion rats' weight and the recovery of neural function. PNS significantly decreased ischemia-induced LINGO-1 protein expression. PNS also elevated EGFR/PI3K/AKT phosphorylation levels. Conclusion: PNS promoted cerebral recovery from ischemic injury by accelerating synapse reconstruction and inhibiting the neuron growth negative regulatory protein LINGO-1 and activating the epidermal growth factor receptor (EGFR)/PI3K/AKT signaling pathway in vivo. Keywords: Panax notoginseng saponins, Cerebral ischemia, LINGO-1, EGFR, PI3K/AKT