The non-saponin fraction of Korean Red Ginseng (KGC05P0) decreases glucose uptake and transport in vitro and modulates glucose production via down-regulation of the PI3K/AKT pathway in vivo

Abstract

Background: The non-saponin fraction of Korean Red Ginseng has been reported to have many biological activities. However, the effect of this fraction on anti-diabetic activity has not been elucidated in detail. In this study, we investigated the effects of KGC05P0, a non-saponin fraction of Korean Red Ginseng, on anti-diabetic activity in vitro and in vivo. Methods: We measured the inhibition of commercially obtained α-glucosidase and α-amylase activities in vitro and measured the glucose uptake and transport rate in Caco-2 cells. C57BL/6J mice and C57BLKS/Jdb/db (diabetic) mice were fed diets with or without KGC05P0 for eight weeks. To perform the experiments, the groups were divided as follows: normal control (C57BL/6J mice), db/db control (C57BLKS/Jdb/db mice), positive control (inulin 400 mg/kg b.w.), low (KGC05P0 100 mg/kg b.w.), medium (KGC05P0 200 mg/kg b.w.), and high (KGC05P0 400 mg/kg b.w.). Results: KGC05P0 inhibited α-glucosidase and α-amylase activities in vitro, and decreased glucose uptake and transport rate in Caco-2 cells. In addition, KGC05P0 regulated fasting glucose level, glucose tolerance, insulin, HbA1c, carbonyl contents, and proinflammatory cytokines in blood from diabetic mice and significantly reduced urinary glucose excretion levels. Moreover, we found that KGC05P0 regulated glucose production by down-regulation of the PI3K/AKT pathway, which inhibited gluconeogenesis. Conclusion: Our study thereby demonstrated that KGC05P0 exerted anti-diabetic effects through inhibition of glucose absorption and the PI3K/AKT pathway in in vitro and in vivo models of diabetes. Our results suggest that KGC05P0 could be developed as a complementary food to help prevent T2DM and its complications. Keywords: Diabetes mellitus, Korean Red Ginseng, Non-saponin fraction, Glucose regulation