Anti‐inflammatory and anti‐insulin resistance activities of aqueous extract from Anoectochilus burmannicus

This study investigated biological activities including antioxidative stress, anti‐inflammation, and anti‐insulin resistance of Anoectochilus burmannicus aqueous extract (ABE). The results showed abilities of ABE to scavenging DPPH and ABTS free radicals in a dose‐dependent manner. Besides, ABE significantly reduced nitric oxide (NO) production in the lipopolysaccharide (LPS)‐treated RAW 264.7 via inhibition of mRNA and protein expressions of nitric oxide synthase (iNOS). The LPS‐induced mRNA expressions of cyclooxygenase‐2 (COX‐2) and interleukin 1β (IL‐1β) were suppressed by ABE. Moreover, ABE exerted anti‐insulin resistance activity as it significantly improved the glucose uptake in tumor necrosis factor (TNF)‐α treated 3T3‐L1 adipocytes. In addition, ABE at the concentration of up to 200 μg/mL was not toxic to human peripheral blood mononuclear cells (PBMCs) and did not induce mutations. Finally, the results of our study suggest the potential use of A. burmannicus as anti‐inflammatory, anti‐insulin resistance agents, or food supplement for prevention of chronic diseases.