Antimicrobial and toxicity studies of different fractions of the aerial parts of the Mikania cordata

Abstract

The methanolic extract along with some organic soluble fractions of the aerial parts of Mikania cordata (Bumr.f.) B.L. Robinson were tested against five Gram-positive and eight Gram-negative bacteria and against three pathogenic fungi. Only dichloromethane fractions showed remarkable activities against all the tested bacteria and the highest activity against Escherichia coli with a zone of inhibition 14 ± 0.75 mm and the minimum activity against Salmonella typhi (zone of inhibition 8 ± 0.73). Other showed moderate or little activity. n-Haxene fractions showed significant activity against Escherichia coli with a zone of inhibition 10 ± 0.15. The highest antifungal activity was shown against Candida albicans (12 ± 1.75 mm, inhibition zone diameter) and the weakest activity against Aspergillus niger (9 ± 0.65mm, inhibition zone diameter) for CH₂Cl₂ fraction whereas n-Haxen fractions had no activity. Significant and highest minimum inhibitory concentration (MIC) values were observed in dichloromethane fraction against Escherichia coli with the value of 1.25 mg/ml.  Lowest LC₅₀ value 0.49 ± 1.16 of n-Haxene fraction indicated the highest toxicity incomparison with the other fractions.