Ethnomedicinal uses, phytochemistry, pharmacological activities, and toxicology of Enicostema axillare (Lam.) A. Raynal: A review

• Published in: South African journal of botany 2023-08, Vol.159, p.252-262
• Main Authors: Adetunji, Tomi Lois, Padi, Patricia Mmapule, Olatunde, Ahmed, Akuru, Eunice Amaka, Adegbaju, Oluwafunmilayo Dorcas, Adetunji, Ademola Emmanuel, Siebert, Frances
• Format: Article
• Language: English
• Subjects: Bioactivity; Forb; Gentianaceae; Indian whitehead; Pharmacology; Phytochemical constituents; Traditional uses
• ISSN: 0254-6299
• DOI: 10.1016/j.sajb.2023.06.002

•Enicostema axillare has a long history of medicinal use in south Africa.•It is used to treat cough, congestion, alleviation of fever, diabetes, and a range of other diseases.•This review summarizes its botany, traditional uses, phytochemistry, pharmacology, and toxicology.•Swertiamarin, a secoiridoid glycoside, is considered the major chemotaxonomical marker.•E. axillare subsp. littorale studied in clinical trials showed potential treatment for diabetes. Enicostema axillare (Lam.) A. Raynal, commonly known as the Indian whitehead, has a long history of medicinal use in India and some parts of Africa, including South Africa. In ancient times, the plant was often used to treat cough, congestion, alleviation of fever, diabetes, and a range of other diseases. The plant has also demonstrated various pharmacological activities. However, these reports have not been reviewed. Therefore, this review aims to comprehensively summarize the botany, traditional medicinal uses, phytochemistry, pharmacology, and toxicology of E. axillare, providing reference to discover its therapeutic values for further research. To this end, relevant information on E. axillare was retrieved from scientific databases, including Science Direct, Web of Science, Google Scholar, PubMed, Scopus, and World Flora Online. At present, 60 phytoconstituents have been identified and isolated from E. axillare, including flavonoids, steroids, saponins, triterpenoids, flavonols, phenolics, glycosides, volatile oil, and other compounds. Swertiamarin, a secoiridoid glycoside, is considered the major chemotaxonomical marker of the plant responsible for its diverse bioactivities. The extracts and the active constituents of E. axillare have been investigated and reported to demonstrate some pharmacological activities in preclinical studies, including but not limited to antioxidant, anti-inflammatory, anticancer, antidiabetic, antihyperlipidemic, antipyretic, hepatoprotective, and antinociceptive activities. In addition, E. axillare subsp. littorale has undergone some clinical trials with effective outcomes on diabetes. The phytoconstituents and diverse pharmacological activities of E. axillare and its subspecies (littorale) reported in this study provide researchers with a valued context and reference on the current research status of this medicinal plant and direction for further investigation.