Wedelolactone from Eclipta prostrata (L) L. suppresses inflammation and improves insulin resistance

Abstract

Objective: To evaluate the effects of wedelolactone, a major flavonoid from Vietnamese Eclipta prostrata (L) L., on inflammation and insulin resistance. Methods: Wedelolactone was extracted from the leaves of Vietnamese Eclipta prostrata (L.) L. with methanol by Soxhlet. The effects of wedelolactone on lipopolysaccharide (LPS)-induced cytokine production, reactive oxygen species (ROS) generation, and nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activities in Raw 264.7 cells were measured by enzyme-linked immunosorbent assay (ELISA), specific immunofluorescent dyes and luminometric analysis, respectively. In addition, its effects on glucose uptake and the protein expression of insulin receptor substrate 1 (IRS1) and glucose transporter 4 (GLUT4) were examined in 3T3-L1 cells by immunofluorescent dyes and Western blot. Results: Wedelolactone at 30 μg/mL significantly inhibited LPS-induced production of tumor necrosis factor-α, interleukin (IL)-6, and IL-8 (P<0.01) with no noticeable effects on IL-10 level. It also reduced ROS generation and NADPH oxidase activities in LPS-stimulated Raw 264.7 cells (P<0.01). Furthermore, wedelolactone showed anti-insulin resistance activity, as evidenced by improved glucose uptake and the upregulated expression of IRS1 and GLUT4 in 3T3-L1 cells (P<0.01). Conclusions: Wedelolactone exhibits anti-inflammation and anti-insulin resistance effects, which may be used for the treatment of diabetes and inflammation-associated diseases.