Spilanthes filicaulis (Schumach. &Thonn.) C. D. Adams: An insights into ethnopharmacologically important but scientifically understudied species.

Spilanthes filicaulis (Schumach. & Thonn.) C. D. Adams is synonymous to Acmella caulirhiza Delile. The plant, also known as cock's eye or African cress, is a medicinal herb that belongs to the Asteraceae family. In this paper, the holistic and current applications of S. filicaulis were synthesized and critically discussed by summarizing, for the first time, its botany, traditional medicinal uses, active components, and pharmacological properties. We employed the databases of ScienceDirect, Scopus, Online Wiley library, PubMed, and Google Scholar to retrieve data on S. filicaulis from inception till February 2024, resulting in more than 70 electronic references. Based on literature reports, S. filicaulis has rich ethnopharmacological uses in different disease areas but their scientific validations are still in early stage, or not verified yet. In general, 16 phytochemicals have been identified so far. They include spilanthol, piperine, erucic acid, and isoquinoline derivative among others. The plant extracts possess anticancer, antioxidant, antimicrobial, anti-inflammatory, hepato-protective, anthelminthic, and analgesic activities. In the future, the phytochemical components, and biological activities of S. filicaulis need to be further investigated. Similarly, mechanistic studies need to be incorporated to the biological testing, to uncover the modes of actions of the species extracts and active components. Considering the species' rich ethnopharmacological applications, and the dearth of robust and established toxicity reports, the study on the safety of S. filicaulis would be an interesting and rewarding approach for further research.