Portulaca oleracea L. extract reduces hyperglycemia via PI3k/Akt and AMPK pathways in the skeletal muscles of C57BL/Ksj-db/db mice. (5th October 2020)

• Record Type: Journal Article
• Authors: Lee, Ji Hyun; Park, Jae Eun; Han, Ji Sook
• Is Part Of: Journal of ethnopharmacology. Volume 260(2020)
• Publication Date: 2020-10-05
• Subjects: Db/db mice -- Hyperglycemia -- Insulin resistance -- Portulaca oleracea -- Skeletal muscle; Ethnopharmacology -- Periodicals; Pharmacognosy -- Periodicals; Herbs -- Periodicals; Herbs -- Periodicals; Pharmacognosy -- Periodicals; Pharmacognosie -- Périodiques; Herbes -- Périodiques; 615.1
• DOI: 10.1016/j.jep.2020.112973
• Languages: English
• ISSNs: 0378-8741

Abstract

Abstract: Headings ethnopharmacological relevance: Portulaca oleracea L. is a succulent annual herb, which has various pharmacological effects including antidiabetic property. However, in vivo the reducing effect of P. oleracea on hyperglycemia and its mechanism of action have not been clarified in a mouse model of type 2 diabetes. Aim of the study: The effects of Portulaca oleracea L. extract (POE) on hyperglycemia were investigated in an animal model of type 2 diabetes. Materials and methods: C57BL/Ksj-db/db mice were randomly divided into three groups: db/db-control group was fed a standard semi-synthetic diet (AIN-93 G), db/db-RG group was fed AIN-93 G supplemented with rosiglitazone (RG) (0.005%, w/w), and db/db-POE group was fed AIN-93 G supplemented with POE (0.4%, w/w) for 6 weeks. Diabetes-related physical and biochemical indicators and the phosphorylation of components of PI3k/Akt and AMPK pathways were measured. Results: The blood glucose and the glycosylated hemoglobin levels (HbA1c) in db/db-POE group were significantly lower than those in db/db-control group. In db/db-POE group, The homeostatic index of insulin resistance (HOMA-IR) decreased significantly, whereas the quantitative insulin sensitivity check index (QUICKI) was higher than those in db/db-control group. POE significantly elicited the phosphorylation of IRS-1 Tyr612, Akt Ser473, and AS160 Thr642, and the activation of PI3K in the skeletal muscle of mice. Additionally, POE significantly stimulated the phosphorylation of AMPK Thr172, TBC1D1 Ser231, and ACC Ser79 and elevated the expression of plasma membrane-glucose transporter type 4 (GLUT4). Conclusions: These results indicate that POE reduces hyperglycemia by improving insulin resistance through the PI3k/Akt and AMPK pathways in the skeletal muscle of C57BL/Ksj-db/db mice. Graphical abstract: Extract of Portulaca oleracea L. supplementation improves PI3K/Akt and AMPK signaling activation in the skeletal muscle of C57BL/Ksj-db/db mice. POE supplementation decreases insulin resistance and prevents hyperglycemia, hyperinsulinemia and hyperlipidemia. Image 1