Anti-Oxidant and Anti-Inflammatory Capacities of Herbal Tea Made of Osbeckia octandra (Heen Bowitiya)

Abstract

Oxidative stress and chronic inflammation are key mediators in the pathogenesis of chronic degenerative diseases. Osbeckia octandra plant is widely used as an effective medicine in Sri Lankan traditional and Ayurvedic medicine to treat liver diseases which are the consequences of oxidative stress and chronic inflammation. Thus, the present study aimed to determine the antioxidant and anti-inflammatory effects of herbal tea made of O. octandra plant powder purchased from an authenticated seller (6g/250 mL infusion). The qualitative phytochemical screening was performed to identify the presence of phytochemicals in the herbal tea. Free radical scavenging and antioxidant potentials of the herbal tea were investigated by 2, 2-diphenyl-picrylhydrazyl radical scavenging (DPPH), 2,2'-casino-bis (3-ethylbenzothiazoline-6-sulfonic acid (ABTS) assay and ferric reducing antioxidant power assay (FRAP). The total phenolic and total flavonoid contents of the extracts were estimated using the Folin-Ciocalteu and Aluminum chloride colorimetric assays respectively. Anti-inflammatory activity was determined by egg albumin denaturation inhibition assay. Results are expressed as mean±SD (n=3 or 5) and significances calculated at 95% confidence interval (T-test). Total phenolic and total flavonoid contents in the herbal tea were (174.61±0.64) mg gallic acid equivalents/dry g weight and (133.39± 2.72) mg quercetin equivalents/dry gram weight, respectively. The IC50 of the herbal tea were 13.33±2.34 μg·mL-1 and 137.84±0.37 μg·mL-1 for DPPH and ABTS assays against standard ascorbic acid (67.89±4.36 and 67.65±1.32) μg·mL-1 respectively. The herbal tea exhibited potent reducing power when compared to standard, ascorbic acid at lower concentrations in the FRAP assay. A dose-dependent anti-inflammatory activity was apparent where 500 μg· mL-1 herbal tea and Aspirin exhibited 41.5% and 56.5% inhibition of protein denaturation respectively. The O. octandra herbal tea prepared as in the present study contains phenols & flavonoids and possesses potent dose-dependent anti-inflammatory activity and considerable antioxidant capacity.