Kaempferia parviflora Rhizome Extract Improves Skeletal Muscle Glucose Homeostasis by Upregulating the GLUT4 Signaling Pathway In Vitro and In Vivo.

Background/Objectives:Kaempferia parviflora (KP), also known as black ginger, has been reported to exert metabolic regulatory effects, yet its influence on skeletal muscle glucose handling remains unclear. Because impaired glucose uptake in skeletal muscle is a major contributor to insulin resistance and type 2 diabetes mellitus (T2DM), this study investigated the effects of KP on glucose uptake and the GLUT4 signaling pathway both in vitro and in vivo. Methods: The effects of KP extract on glucose uptake and GLUT4-related signaling proteins were evaluated in differentiated C2C12 myotubes. In parallel, C57BL/6J and db/db mice were orally administered KP extract at varying doses for six weeks to evaluate its metabolic effects in vivo. Results: KP significantly increased glucose uptake in C2C12 myotubes, accompanied by increased GLUT4 expression and upregulation of GLUT4-related signaling proteins. In diabetic mice, KP administration improved fasting glucose, glucose tolerance and GLP-1 level while lowering insulin and HbA1c levels. Skeletal muscle tissues exhibited increased GLUT4 expression and modulation of downstream regulators involved in glucose homeostasis. Conclusions: These findings indicate that KP improves skeletal muscle glucose metabolism primarily through activation of the GLUT4 pathway. Taken together, KP may serve as a potential functional ingredient for regulating muscle glucose utilization and mitigating metabolic disturbances associated with T2DM.