Antioxidant and Anti-Inflammatory Activities of Thai Traditional Hand and Foot Soaking Formulary and Its Bioactive Compounds

Abstract

Background/Objectives: This study aimed to investigate the antioxidant and anti-inflammatory properties of a Hand and Foot Soaking Formulary composed of ten medicinal plants, with curcumin as a major bioactive marker, to provide scientific validation for its traditional use. Methods: The formulation was evaluated for total phenolic and flavonoid contents, with curcumin quantified using HPLC. Antioxidant activity was assessed using DPPH, ABTS, and FRAP assays. Cytotoxicity was evaluated in RAW264.7 cells using the MTT assay. Anti-inflammatory activity was determined by measuring nitric oxide (NO), PGE<inf>2</inf>, TNF-α, IL-1β, and IL-6 levels in LPS-stimulated RAW264.7 macrophages using ELISA. Results: The Hand and Foot Soaking Formulary exhibited promising antioxidant and anti-inflammatory properties, consistent with its traditional use. Phytochemical analysis confirmed the presence of bioactive compounds, with measurable levels of total phenolics, flavonoids, and significant curcumin content. Antioxidant activity was demonstrated through free radical scavenging and ferric-reducing assays, while cytotoxicity testing in RAW264.7 macrophages indicated low toxicity (IC<inf>50</inf> = 48.61 ± 3.80 µg/mL). The formulary significantly reduced LPS-induced nitric oxide, PGE<inf>2</inf>, TNF-α, IL-1β, and IL-6 production. These effects were comparable to turmeric extract and curcumin, though curcumin displayed higher potency. Conclusions: The Hand and Foot Soaking Formulary demonstrates antioxidant and anti-inflammatory properties in vitro, supporting its traditional use. Its polyherbal composition may offer synergistic effects and holds promise as a safe, natural topical remedy.