Beta-Lactamase Inhibitory Potential and Antibacterial Potentiation of Certain Medicinal Plants and Extracts against Extended Spectrum Beta-Lactamase Producers

Beta-lactamase inhibitory potential of fifteen plants was checked by beta-lactamase enzyme inhibition assay wherein inhibition of commercial beta-lactamase by their extracts was determined using a chromogenic substrate. These plant extracts showed considerable beta-lactamase inhibition. All these plant extracts were further checked for their inhibition of Extended Spectrum Beta-lactamase in the screening assay. Eight of the plant extracts showed potentiation of cephalosporins against the Extended Spectrum Beta-lactamase producing Klebsiella pneumoniae strain and were checked for their beta-lactamase (especially Extended Spectrum Beta-lactamase) inhibitory potential against a panel of beta-lactam resistant Gram negative bacterial strains (mainly Extended Spectrum Beta-lactamase producers) and few beta-lactam resistant Gram positive bacterial strains. Four of the plants showed substantial potentiation of the beta-lactams against the beta-lactam resistant bacterial strains and seem to have potential as beta-lactamase inhibitors (including against Extended Spectrum Beta-lactamase producers). The presence of beta-lactamase inhibitory potential in the studied plant extracts warrants further efforts in regard to purification and isolation of bioactive compounds from their extracts for probable development of new beta-lactamase inhibitors.