Antibacterial activity of ethanolic extract of leaves of the blessed thistle (Cnicus benedictus L.)

Abstract

The aim of this study is to investigate the activity of the ethanolic extract of Cnicus benedictus L. on pathogenic bacteria such as Escherichia coli , Bacillus pumillus , Staphylococcus aureus and Micrococcus . In the clinical significance of these characteristics being causing the infections . The results of this study are showed that the ethanol extract of leaves has an affective impact by inhibiting the growth of these microorganisms in Vitro. The highest rate of inhibition of the ethanol extract for the leaves against Bacillus pumillus is reached to (18) mm at the concentration (75) mg/ml, but the least inhibition is (9) at the concentration (25)mg/ml compared to the inhibition of the both antibiotics Gentamicin (CN) (18)mm and Ceftriaxone (CRO) (Zero)mm as control, Whereas the (MIC) for Staph.aureus is reached to (13) mm at the concentration (25)mg/ml compared to the both antibiotics (CRO) and (CN) respectively (19 and 6)mm. The results also showed that the (MIC) to inhibit the  E.coli is (8)mm at concentration (50)mg/ml compared to the both antibiotics (CRO) and (CN) respectively (Zero and Zero)mm whereas the (MIC) to inhibit Micrococcus bacteria is  (11)mm at the concentration (25)mg/ml compared to the two antibiotics (CRO) and (CN)  respectively (22 and 27 )mm. The results shown that the ethanol extract for the leaves has a significant inhibitory effect against some species of pathological bacteria using in the study.  In addition, the results of the primary chemical investigation are indicated that the ethanol  extract of the Cnicus benedictus L. leaves contained many active compounds alkaloids ,  flavonoids , Phenoles , tannins and the terpenes.