Screening of some medicinal plants from cameroon for β‐Lactamase inhibitory activity

In efforts to find new bioactive β-lactamase inhibitors, this study investigated 16 Cameroonian plants belonging to 10 families which were evaluated for anti-β-lactamase activity. The investigation showed that extracts 2, 6, 3 and 5 of the 16 plants investigated presented interesting in vitroβ-lactamase inhibition (over 90%), respectively, of the β-lactamases TEM-1, OXA-10, IMP-1 and P99. These extracts were from Mammea africana (all β-lactamases), Garcinia lucida, G. kola (OXA-10, IMP-1 and P99), Bridelia micrantha (OXA-10, P99), Ochna afzelii (OXA-10, P99), Prunus africana (IMP-1) and Adenia lobata (TEM-1). After elimina tion of tannins (according to the European Pharmacopoeia) the extracts from B. micrantha, G. lucida and M. africana were tested further for their anti-β-lactamase activity. The extracts from B. micrantha and G. lucida exhibited potent inhibitory activity, respectively, of β-lactamase OXA-10 (IC50 = 0.02 mg/mL) and P99 (IC50 = 0.01 mg/mL). The anti-β-lactamase activity of M. africana extract was weak. The isolation and the structural elucidation of the active constituents of G. lucida and B. micrantha will provide useful leads in the development of β-lactamase inhibitors. Copyright © 2007 John Wiley & Sons, Ltd.