Adansonia digitata L. (baobab) from Mali: phytochemical profile, antioxidant and antidiabetic activities of its fruit pulp and leaves

Adansonia digitata L. (Malvaceae), commonly called baobab, is a tree widespread in most of Sub-Saharian semi-arid and sub-humid region. Recently, its fruits attract a lot of interest as a food complement for their high nutritional value; in fact, the fruit pulp can be recommended for the daily intake of carbohydrates and proteins for children and pregnant women. The flour of baobab fruit pulp is popularly used in Africa to prepare refreshing drinks, sweets, and sauces, while in Mali is also used to treat the diarrhea of children and to stimulate the milk production in women. In African traditional medicine, the baobab fruit pulp is used as an antipyretic of febrifuge, anti-dysenteric, diaphoretic, immunostimulant, anti-inflammatory, analgesic, and probiotic remedy; baobab leaves are also known as antipyretic or febrifuge. Although these interesting features, only few studies are reported on its secondary metabolite content, with a high variability depending on the geographic region. The aim of this study was to investigate the phenolic profiles of three sample fruits of malian commercial baobab obtained from three different rural markets by HPLC-PDA/UV-ESI-MS/MS. Moreover, these samples were analyzed for thir total phenolic content (TPC), antioxidant activity, and in vitro α-glucosidase inhibition. Results showed that all fruit pulp n-butanolic extracts exhibited a significant antioxidant activity and a higher α-glucosidase inhibition than acarbose used as standards. Baobab fruit pulps were found to be rich in procyanidins and flavonol glycosides, with tiliroside as the major constituent, while the leaves showed a similar profile respect to the fruits, but with more detected phenolics. These results indicated that Malian species baobab has a great potential as source of substances with high biological value. Furthermore, the different chemical compositions of pulp fruits compared to those from other African countries highlighted the influence of growing region on the chemical profile in terms of secondary metabolites.