Antioxidant, anti-inflammatory and anti-hyperglycemic activity of aqueous and methanolic extract of Houttuynia cordata: an in vitro and in vivo study

Available synthetic antioxidants such as butylated hydroxyl anisole, butylated hydroxyl toluene, propyl gallate, and ascorbic acid exhibit several side effects. To curb these side effects, more effective, less toxic, and cost-effective drugs are required. Therefore, this study aims to screen and evaluate the antioxidant as well as the anti-inflammatory and antidiabetic potential of Houttuynia cordata collected from Mairang village, West Khasi Hills, Meghalaya, India using several standard methods. The aqueous and methanolic extracts of H. cordata were evaluated by screening their ability to scavenge 1,1-diphenyl-2-dipicrylhydrozyl, 2,2-azinobis (3-ethylbenzothiazoline-6-sulfonic acid), hydrogen peroxide, and nitric oxide. Total phenol and flavonoid content was measured by Folin-Ciocalteau and by AlCl3 colorimetric method respectively. The anti-inflammatory activity of the plant was determined using the protein denaturation method. Methanolic and aqueous extracts of Houttuynia cordata exhibit varying free radical scavenging and anti-inflammatory activity. Among the extracts used in the study, the methanolic extract of Houttuynia cordata elicited a higher activity than the aqueous extract. Houttuynia cordata also elicited a marked reduction in blood glucose level of normal and alloxan-induced diabetic mice. Flavonoids, which have been reported to possess anti-inflammatory, enzyme inhibition, antimicrobial, anticancer, antiallergy, and antioxidant properties may contribute towards the free radical scavenging and anti-inflammatory effect of Houttuynia cordata.