Analysis of Free Radical Activities and Phenolic Contents of Spilanthes filicaulis Flower-Head and Leaf Extracts

Background and Objective: Spilanthes filicaulis is a medicinal plant commonly used in traditional remedies and known for its diverse therapeutic properties, particularly its anti-inflammatory, analgesic and antimicrobial effects. However, its antioxidant potential, which plays a crucial role in combating oxidative stress linked to various chronic diseases, requires further exploration. The study aimed to investigate the antioxidant capacity of Spilanthes filicaulis flower-head and leaf extracts. The methanol extracts of the flower-head and leaf of Spilanthes filicaulis has been analyzed as well as phenolic content through different assays like DPPH, ABTS, FRAP and TAC. Materials and Methods: The study utilized analytical reagent-grade chemicals, including methanol and flavonoids like DPPH and ABTS. The 3 kg samples of Spilanthes filicaulis were air-dried, triturated and extracted with 80% methanol. The extracts were analyzed for phenolic content, antioxidant activities (DPPH, ABTS, FRAP and TAC) and phytochemical contents (Phenolics, Tannins, Flavonoids) using SPSS version 20 and ANOVA, with significance set at p<0.05. Results: The extracts’ antioxidant activities the flower-head extract showed higher DPPH radical scavenging activity (EC₅₀ = -0.32±0.04 µg/mL) and ABTS radical scavenging activity (EC₅₀ = -2. 91±0.032). On the other hand, the identity and quantity of the phenolic and flavonoids which are related to the antioxidant potential were comparatively more significant in the leaf extract: Phenolic content had 1411.29±27.93 mg of GAE/mg of dry plant extract and flavonoids with 21.50±0.866 mg quercetin equivalent/mg dry weight. Conclusion: It can be concluded that extracts of Spilanthes filicaulis, especially the flower-head extract may be used as efficient natural sources of antioxidants. This research focuses on the pharmacological possibilities of Spilanthes filicaulis and opens the doors for other researcher to identify the different active compounds and analyze on how they work.