Traditional medicinal uses, phytochemistry, bioactivities and toxicity of the genus Maesa (Primulaceae): A comprehensive review

Introduction: The genus Maesa, belonging to the Primulaceae family, comprises approximately 150 species that are widely distributed in Western Asia, New Guinea, Philippines, China, Indonesia, and Malesia. This review aims to represent the traditional use, pharmacological activity, phytochemical composition, and toxicological profiles of Maesa species along with the botanical description, taxonomical classification, and geographical distribution.Methods: The literature search was performed from January 1975 to December 2020 through electronic databases (Web of Science, Scopus, Google Scholar, PubMed, Science Direct, Sci Finder, and Research Gate) using the following keywords: "Maesa", "phytochemistry", "pharmacology". All the selected manuscripts were investigated for reported plant species, plant parts used in traditional medicine, isolated chemical compounds, and evaluated biological activities.Results: This review includes information on 169 naturally occurring compounds present in Maesa, such as triterpenoid saponins (1-57), benzoquinones (58-72), terpenoids (73-90), flavonoids (91-107), steroids (108-120), alkanes (121-126), phenolics (127-142) and other compounds (127-169). The genus possesses a broad spectrum of ethnopharmacological activities like antibacterial, antifungal, antioxidant, analgesic, antiinflammatory, cytotoxic, antiviral, and haemolytic effects.Conclusions: Maesa species are commonly used as traditional medicines and possess a variety of chemical constituents with conspicuous biological activities. However, only a few species of this genus have been studied in detail and yet to explore the pharmacological activities of the isolated phytochemicals of many species that are summarised in this review work that may be used as background literature for further pharmacological and drug discovery programs using secondary metabolites of genus Maesa.