Neuroprotective effect of ginsenoside Rg1 prevents cognitive impairment induced by isoflurane anesthesia in aged rats via antioxidant, anti-inflammatory and anti-apoptotic effects mediated by the PI3K/AKT/GSK-3 pathway

Ginsenoside Rg1 is the primary active substance in ginseng, and it has multiple pharmacological actions. Investigations on the pharmacologic action of ginsenoside Rg1 have developed, with a particular focus on the regulation of metabolism. The present study hypothesized that the neuroprotective effects of ginsenoside Rg1 prevent cognitive impairment induced by isoflurane anesthesia via antioxidant, anti-inflammatory and anti-apoptotic effects, mediated by the phosphoinositide 3-kinase (PI3K)/AKT/glycogen synthase kinase-3 (GSK-3) pathway in aged rats. Sprague-Dawley rats were divided into isoflurane and ginsenoside Rg1 groups and were treated with 20 mg/kg ginsenoside Rg1 for 7 days. Morris water maze was performed to analyze the cognitive function of the rats. Enzyme-linked immunosorbent assays were used to analyze the levels of malondialdehyde, glutathione, interleukin (IL)-1, IL-6 and caspase 3. The protein expression levels of AKT, GSK 3, p21WAF1/CIP1 and p53 were measured using western blot analysis. Ginsenoside Rg1 significantly improved cognitive function, and exhibited antioxidant and anti-inflammatory effects, demonstrating the neuroprotective effects of ginsenoside Rg1 against the effect of isoflurane anesthesia in the rats. In addition, ginsenoside Rg1 significantly reduced caspase-3 activity, upregulated the expression of PI3K/AKT/GSK-3 and downregulated the mRNA expression levels of p21WAF1/CIP1 and p53 in the aged rats exposed to isoflurane anesthesia. The data obtained in the present study provided evidence that the neuroprotective effects of ginsenoside Rg1 prevented the cognitive impairment induced by isoflurane anesthesia via antioxidant, anti-inflammatory and anti-apoptotic effects, mediated by the PI3K/AKT/GSK-3 pathway.