Traditional uses and Chemical Characterisation of Strophanthus sarmentosus DC (Apocynaceae), a Medicinal Plant Harvested in Mali

Abstract

Strophanthus sarmentosus is a medicinal plant used in African traditional medicine, but its ethnobotanical uses and phytochemical characteristics remain insufficiently documented in Mali. This study investigated the traditional uses and chemical profile of the leaves and stems of S. sarmentosus harvested in the Koutiala region. Plant material was collected in May 2025, and an ethnobotanical survey was conducted in July 2025 among 40 traditional healers and herbalists in Bamako District and the regions of Sikasso, Koutiala and Bougouni. The dried leaves and stems were powdered and processed by aqueous decoction, hydroethanolic extraction and saponin-oriented maceration. Chemical groups were screened using colour and precipitation reactions, while thin-layer chromatography was used to examine alkaloids, flavonoids and saponosides. The survey identified 15 therapeutic indications. Preparations combining leaves and stems accounted for 52.17% of cited preparation methods, compared with 30.43% for leaves and 17.39% for stems. Aqueous extract yields were 9.02% for leaves and 8.62% for stems, and the saponin extract from leaves represented 5.65%. Phytochemical screening showed alkaloids, flavonoids, tannins, saponins, sterols and triterpenes, free quinones and terpenoids in both plant parts, with differences for anthraquinones, reducing sugars and amines. Chromatographic observations supported the presence of alkaloids, flavonoids and saponosides. These findings document traditional use patterns and provide a preliminary phytochemical profile of S. sarmentosus in Mali.