Aim : In order to promote African traditional pharmacopoeia, studies have been undertaken to evaluate the effects of aqueous extracts of Annona senegalensis (Annonaceae) (EAAs) and Hallea ledermannii (Rubiaceae) (EAHl) in white rats of Wistar strain. Methods: A phytochemical screening and a toxicological study according to the Organisation for Economic Co-operation and Development (OECD) guidelines 423 were carried out. Pharmacological effects on blood glucose were evaluated. The different treatments were performed orally. Results: The aqueous extracts of EAAs and EAHl, respectively at the maximum doses of 3000 and 5000 mg / kg bw, did not cause death in rats. Phytochemical screening revealed the presence of polyphenols, flavonoids and quinonic compounds in both extracts. This study showed that in addition to the common compounds, the Annona senegalensis extract contained sterols, polyterpenes, catechic tannins and alkaloids, while that of Hallea ledermannii showed the existence of saponosides. Annona senegalensis (100 mg/kg bw) and Hallea ledermannii (200 mg/kg bw), provoked more hypoglycemia respectevely of 40 % and 35.34 % in rats. EAAS (27.78 % vs 25.41 %) showed better anti-hyperglycemic effect in pretreated rats while EAHl (40.30 % vs 29.37 %), provoked more anti-hyperglycemic activity in post-treated animals. Conclusion: The effects of EAAs and EAHI on blood glucose value, may be related to the presence of chemical compounds such as flavonoids and saponosides highlighted in phytochemical study. These compounds recall those of certain insulin-secreting agents and justify their use in traditional medicine.
Key words: Annona sengalensis, Hallea ledermannii, Glibenclamide, hypoglycemia, anti-hyperglycemia, rat.
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