Mechanism Study on Gymnema Sylvestre Total Saponins Alleviating Insulin Resistance via Regulation of PI3κ/AKT Signal Transduction Pathway in Adipose Tissues / 世界科学技术-中医药现代化

ABSTRACT

This study was aimed to observe the effects of gymnema sylvestre total saponins (GA) on insulin resistance (IR) in adipose tissues of KKay mice,in order to discuss the action mechanism from the PI3K/AKT signal transduction pathway.A total of 27 KKay mice were randomly divided into the model group (DM),Pioglitazone group (BG) and GA group.Nine normal C57BL/6J mice were used as the normal control group (NC).Intragastric administration of drugs was given for eight weeks.The bodyweight and food intake of all mice were tested each week.After the experiment was completed,fasting plasma insulin (Fins) and fasting plasma glucose (FPG) were detected and the insulin sensitive index (ISI) was calculated.Expressions of PDK-1,AKT,P-AKT (Ser473),P-AKT (Thr308) in adipose tissues of epididymis in mice were detected.And expressions of PI3K-p85 mRNA,PTEN mRNA,APN mRNA were also measured.The results showed that compared with DM group,bodyweight of BG and GA groups were decreased (P＜0.05,P＜0.05);FPG and Fins level of BG and GA groups were decreased (P＜0.05,P＜0.05,P＜0.05,P＜0.05),ISI increased (P＜0.05,P＜0.05);APN mRNA increased in BG and GA group (P＜0.01,P＜0.01);PI3K-p85 mRNA increased in GA group (P＜0.05);P-AKT (Thr308) protein expression increased in BG and GA group (P＜0.05,P＜0.01);P-AKT (Ser473) protein expression increased in GA group (P＜0.05);the phosphorylation of AKT (Thr 308) was enhanced in BG and GA group (/9＜0.01,P＜ 0.01);the phosphorylation of AKT (Ser473) was enhanced in GA group (P＜0.01,P＜0.01).PDK-1 protein expression was decreased in BG and GA group (P＜0.05);PTEN mRNA decreased in BG and GA group (P＜0.05,P＜0.01).It was concluded that GA can ameliorate IR by sensitizing PI3κ/AKT signal pathway in adipose tissues of KKAy mice.