Chemical Identification, In vitro Antidiarrheal Potential, and Toxicological Study of the Leaves of Combretum grandiflorum G. Don (Combretaceae), a Beninese Medicinal Plant

Combretum grandiflorum G. Don is traditionally used in ethnic medicines for the treatment of different diseases in Benin. Despite its wide use, no studies have been undertaken on its potential toxicity. The study was designed to assess the antimicrobial activity and potential toxicity of aqueous and hydroethanolic extracts of C. grandiflorum.

Qualitative phytochemistry was carried out by a differential staining or precipitation method. The antibacterial and antifungal effects were evaluated by the solid medium diffusion method. Cytotoxicity was evaluated on Artemia salina larvae while acute toxicity was evaluated with Wistar strain rats via the oral route. The qualitative screening revealed the presence in the plants of Polyphenols, Flavonoids, Tannins, catechic and gallic tannins. Both types of extracts inhibited microbial growth. The hydroethanolic extract was active on all the bacterial strains used with a high inhibition diameter compared to the aqueous extract. On strains of Shigella Sonnei and Salmonella spp, the antibacterial effect of the hydroethanolic extract is significantly (p˂0.05) better compared to that of the aqueous extract. Cytotoxicity tests showed no toxic effects at the doses evaluated. At a dose of 2000 mg/kg, the aqueous and hydroethanolic extracts of C. grandiflorum induced neither mortality nor alteration of the physiological parameters of Wistar rats (renal, hepatic parameters, hematological constants, body weight). These extracts therefore do not present acute oral toxicity for Wistar rats at the limit dose of 2000 mg/Kg/bw in Wistar rats. These results justify some therapeutic indications for these plants. They could therefore be used for the development of improved phytomedicines.