Extraction Methodologies, Phytochemical Constituents, and Biological Activities of Senna alata Linn: A Review

Background: Senna alata (L.) Roxb, which belongs to the family of Fabaceae, is a herbal plant that has been used for the treatment of skin diseases, ringworm infection, and constipation since ancient times. In recent decades, various conventional and non-conventional methodologies such as maceration, decoction, and supercritical fluid extraction have been examined by researchers in order to determine the phytochemical constituents potentially found in S. alata. Objective: This review paper aims to provide a detailed discussion of traditional uses, extraction methodologies, phytochemical constituents, and biological activities of S. alata. Methods: The review is based on previous studies obtained from various accessible library databases and electronic search engines, including Google Scholar, PubMed, Science Direct, Research Gate, Scopus and Hindawi. Results: Several non-conventional extraction methods, such as microwave-assisted and ultrasonicassisted, have been found to be better techniques for extracting bioactive compounds from S. alata when compared to conventional extraction methods such as Soxhlet, steam distillation, and maceration in terms of the quality of the yield. Tannins, saponins, flavonoids, anthraquinones, and cardiac glycosides are the common compounds found in S. alata. Among these anthraquinone, the most frequently reported as a major phytochemical constituent, is used as a laxative and possesses antibacterial, antifungal, and antimicrobial properties. Conclusion: Despite various claims for S. alata, very limited non-conventional extraction technology has been reported for its bioactivity study on skin diseases, ringworm infection, and constipation. Thus, this review may stimulate new applications and a clearer future perspective. In addition, the pros and cons of each extraction technology are also reviewed in this paper.