Assessment of the Quality and Evaluation of the Antioxidant Potential of a Novel Sri Lankan Ayurvedic Polyherbal Formulation

Abstract

Background. In Sri Lanka, a Polyherbal Ayurvedic Formulation (PHAF), which consists of powders of seven medicinal plants, is being trialed for use as an anti-inflammatory drug. In general, anti-inflammatory drugs have good antioxidant properties. Therefore, in the present study, an attempt was made to assess the quality and evaluate the antioxidant potential of PHAF. Methods. Physicochemical parameters such as ash content, extractable matter, phytochemical screening for secondary metabolites, levels of heavy metals, and microbes were determined according to standard protocols. Antioxidant activity was evaluated using five in vitro assays: total polyphenolic content (TPC), total flavonoid content (TFC), ORAC (oxygen radical absorbance capacity), DPPH (1,1-diphenyl-2-picryl-hydrazyl), and ABTS (2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt. Results. PHAF contained 5.6 ± 0.2% of moisture, 6.5 ± 0.1% of total ash, 1.4 ± 0.1% of water soluble ash, 0.9 ± 0.0% of acid insoluble ash, 7.7 ± 0.2% of hot water extractable matter, 3.9 ± 0.1% of cold water extractable matter, 10.5 ± 4.1% of hot-ethanol extractable matter, and 8.4 ± 0.2% of cold-ethanol extractable matter. Phytochemical screening revealed the presence of phenolic compounds, tannins, flavonoids, coumarins, and saponins in both aqueous and ethanolic extracts of the drug. TPC, TFC, ORAC, DPPH, and ABTS of aqueous and ethanol extracts of PHAF were 103.65 ± 4.94 and 327.07 ± 9.65 mg gallic acid equivalents/g extract, 76.6 ± 5.83 and 224.6 ± 8.42 mg quercetin equivalents/g of extract, 481.11 ± 17.30 and 1481.44 ± 30.20 mg trolox equivalents/g of extract, 79.50 ± 4.42 and 227.17 ± 6.16 mg trolox equivalents/g of extract, and 198.20 ± 4.55 and 577.08 ± 5.48 mg trolox equivalents/g of extract, respectively. Conclusion. Ethanolic extract of PHAF is better than aqueous extract in terms of antioxidant properties.