Ginsenoside Re, Produces Multi-targeted Potent Antidiabetic Effects Via Estrogen Receptor Signaling Pathway in Rat, an Alternative Multi-Targeted Therapeutic for Type 2 Diabetes

Aims: To identify more effective ginsenoside for type 2 diabetes (T2D) and clarify whether the ginsenoside characterizing estrogenic multi-targeted antidiabetic effects.

Study Design: Identifying more effective ginsenoside through preclinical evaluation of antidiabetic effects of representative ginsenosides with T2D rat model, and further test pharmacological mechanism underlying the potent antidiabetic effects of the ginsenoside in the same model.

Place and Duration of Study: Key laboratory for Pharmacy, Inner Mongolia Medical University, March 2018 to November 2020.

Methodology: Used a total of 240 female adult rats. Rat model of T2D induced by high-fat diet fed and streptozotocin. Five tapes of representative ginsenosides (Rb1, Rd, Rg3, Re, Rg1) administrated at low (20 mg/kg daily) and high (40 mg/ kg daily) doses to T2D rats with orally for 4 weeks. Detect testing indexes with biochemical, histological, Quantitative Real-Time PCR, and western blots analysis.

Results: Ginsenoside Re (Re), very significantly lowered blood glucose (P<0.01), lipids (P<0.001), free fatty acid (P<0.001), and glucagon (P<0.01) levels, markedly improved impaired insulin sensitivity (P<0.01), ameliorated oxidative stress (P<0.01) and inflammation (P<0.01) in T2D rats, exhibited potent antidiabetic effects. Moreover, Re, phosphorylate serine/threonine kinase (Akt) (P<0.01) and endothelial nitric oxide synthase (eNOS) (P<0.01), up regulates B-cell lymphoma-2 (P<0.01) and insulin gene expression (P<0.01), down regulates glucagon gene expression(P<0.01), reverse impaired glucagon-like peptide 1 (P<0.01); exhibits multi-targeted effects; these effects of Re were inhibited by estrogen receptor (ER) inhibitor (ICI-182,780) (P<0.01). Functionally, the antidiabetic effects of Re were sequentially inhibited by inhibitor of ER, Akt, and eNOS, respectively (P<0.01).

Conclusion: These findings, revealed a novel pharmacological property of Re that characterized in multi-targeted potent antidiabetic effects mediated by ER/Akt/eNOS/NO signaling pathway, provide the first evidence for the potential use of Re, as a multi-targeted therapeutic for T2D, particularly, a novel candidate for replacement of estrogen therapy and NO therapy in diabetes.