Enhancement Effect of Berberis vulgaris var, integerrima Seeds on the Antibacterial Activity of Cephalosporins against Staphylococcus aureus and Escherichia coli

To evaluate the enhancement effect of Berberis vulgaris var, integerrima seedson the antibacterial activity of cephalexin and ceftizoxime against Staphylococcusaureus and Escherichia coli ethanol extract of the seeds were prepared. Diskdiffusion and broth dilution methods were used to determine the antibacterialactivity of two cephalosporins in the absence and presence of the extract and itsvarious fractions separated by thin layer chromatography. Clinical isolates of S. aureusand E. coli were used as test strains. Total extract and one of its fractions enhancedthe antibacterial activity of cephalexin and ceftizoxime. The active component ofthe extract involved in the enhancement of cephalexin and ceftizoxime antimicrobialactivities had an Rfof 0.47 on TLC and a max of 209 nm. The highest fold decreasein minimum inhibitory concentration was observed for ceftizoxime plus the activefraction of the extract against E. coli. Our preliminary results on the columnchromatography and identification of the active component by high resolutionmass spectroscopy showed that this minor compound may be categorized as aprotoberberine structure compound. Therefore, the ethanolic extract of B. vulgarisvar. integerrima seeds combined with cephalosporins may be useful against S.aureus and E. coli.