Review on ethnobotany, phytochemistry and pharmacology of Malagasy medicinal Aloe L. (Asphodelaceae)

Abstract

Background: The genus Aloe L. (Asphodelaceae) represents a highly diverse group of succulent plants widely distributed in Africa and particularly rich in Madagascar. Despite their recognized importance in traditional medicine, cosmetics, and pharmacology, Malagasy Aloe spp. remains insufficiently studied, especially regarding their traditional uses, phytochemical composition and biological activities.

 Methods: This study is based on a bibliographic review of published data on Malagasy medicinal Aloe and follows the PRISMA style. Scientific articles and books were collected from online databases such as Google Scholar and ResearchGate using targeted keywords. A total of 35 ethnobotanical, 15 phytochemical, and 12 pharmacological papers were compiled and analyzed. Data were organized into a database, and diseases were classified according to the International Classification of Diseases. A correspondence analysis was performed using the MO Excel and the software R to determine the relationship between biological activities and Malagasy Aloe species.

 Results: The review identified 20 Aloe species used in traditional medicine in Madagascar. Aloe vera is the only naturalized species, eleven are endemic, and eight remain unidentified. These species are used to treat 112 ailments grouped into 17 disease categories. Digestive, infectious, and injury-related diseases are the most represented. Phytochemical investigations identified 26 endemic species and revealed 48 chemical compounds belonging to 6 families. However, only 13 endemic species have been pharmacologically evaluated, revealing 10 biological activities and highlighting a significant gap between traditional use and scientific validation.

 Conclusions: This study highlights the richness of ethnobotanical knowledge on Malagasy Aloe alongside a critical lack of integrated phytochemical and pharmacological research. Urgent multidisciplinary efforts are required to explore under-studied species, validate their therapeutic potential, and ensure sustainable conservation of this unique biodiversity.

Keywords: Madagascar, medicinal Aloe, Ethnobotany, phytochemistry, pharmacology.