In Vitro Antimicrobial Assessment of Selected Plant Extracts from Pakistan

Screening of ethno-medicinal plants is a pre-requisite for discovery of new drug components. Polar as well as non-polar extracts from four important plants (Cedrela serrata, Hedera helix, Hedera nepalensis and Cuscuta reflexa) were tested against two gram positive (Staphylococcus epidermidis, Staphylococcus aureus) and three gram negative (Escherichia coli, Pseudomonas sp. and Klebsiella pneumoniae) bacterial strains as well as two pathogenic fungal strains (Fusarium oxysporum and Penicillium sp.). Bacterial and fungal pathogens were tested by using agar well diffusion and agar tube dilutions methods, respectively. Methanol extracts from all selected plant species showed activity against all tested bacterial strains. Maximum inhibition was shown by Cuscuta reflexa methanol extract (19.2 mm) against Klebsiella pneumoniae. Inhibition ranges observed for other methanol extracts were 12–15, 12–16 and 9–16 mm in Hedera nepalensis, Hedera helix and Cedrela serrata, respectively. Chloroform extract of Cuscuta reflexa inhibited all bacterial strains with maximum inhibition zone of 21 mm against Klebsiella pneumoniae. Chloroform extract from other plant species proved inactive against all bacterial strains except Escherichia coli and Pseudomonas sp. In the case of fungal strains Fusarium oxysporum was inhibited maximum (78%) by chloroform extract of Hedera helix; however, other extracts showed moderate or low activity. In conclusion, active extracts of present study can be suitable candidates for new drug discovery in future.