SCREENING ANTIBACTERIAL AND ANTIFUNGAL ACTIVITIES AND EVALUATION OF THE EXHAUSTIVE EXTRACTIONS YIELDS FOR VERBASCUM SINUATUM L.

Abstract

T his study aimed to evaluate antibacterial and antifungal activities and exhaustive extraction yields of the aqueous and organic extract s of V erbascum sinuatum L . , against possible human pathogens, which are the fungus Candida albicans , gram positive bacteria Bacillus subtilis, Staphylococcus aureus , Staphylococcus epidermidis and the gram negative bacteria Eschrichia coli and Pseudomonas aeruginosa . Well diffusion method was used in screening of antimicrobial activity for the plant extracts, in which the diameters of inhibition zones were measured and compared to a positive control. S erial dilution method wa s used for measuring the minimum inhibition concentrations for each microorganism. In well diffusion method, the plant’s aqueous extract has antimicrobial activity to all the tested organisms except Pseudomonas aeruginosa and C andida albicans, with variabl e diameters of inhibition zone. The percent inhibition c o mpared to the positive control imipene m was 39.13 % for Staphylococcus aureus , 37.5 % for Staphylococcus epidermidis, 30.55 % for Eschrichia coli and the least 30.43 % for Bacillus subtilis . The orga nic extract exhibited inhibition activity 26.08 % against Bacillus subtilis and 50 % against Eschrichia coli . In the serial dilution method, the aqueous extract exhibited inhibition for all the test microorganisms. At initial concentration of 20 mg/ml, the lowest MIC value was for Staphylococcus aureus 1.28 µg/ml, and highest for S taphylococcus epidermidis 4000 µg/ml. The MIC values for P seudomonas aeruginosa 160 µg/ml, 800 µg/ml for B acillus subtilis , 800 µg/ml for Eschrichia coli and 32 µg/ml for C andida albicans respectively . This study showed that V . sinuatum extract has a broad spectrum activity against gram positive and gram negative bacteria, as well as anti candidal activity.