PHYTOCHEMICAL SCREENING and ANTIMICROBIAL ACTIVITIES OF STINGING NETTLE (Urtica dioica L.) LEAF, FRUIT AND ROOT EXTACTS

Abstract

Medicinal plants have been used for centuries to treat diseases. Differences in antimicrobial activities may affected by geographical area and other conditions.This study was carried out to screen the phytochemical composition and antimicrobial activities of leaf,friut and root extracts of U.dioca against pathogenic bacteria and fungus. U.dioca is a medicinal plant which belongs to the family Urticaceae.The Leaf,friut and root of this plant were collected. The phytochemical screening was conducted using methanol as an extraction solvent. The antibacterial and antifungul activities of these extracts against Four bacterial pathogen (E. coli, S. typhi, S. aureus and S. pyogenes and two fungi pathogens (A. versicolor and A. niger) were evaluated using the disc diffusion method at three different concentrations (100, 150 and 200 mg/mL) in the presence of positive and negative controls.The MIC,MBCand the MFC of these crude extracts against Four bacterial pathogen and two fungial pathogens were assessed using the broth dilution method. In this study, qualitative analysis of the composition of the leaf extract has revealed the presence of tannins, saponins, flavonoids, terpenoids, and alkaloids. However, the fruit extract revealed the presence of steroids in addition to saponins, flavonoids, and terpenoids. As tannins, phlobatannins, saponins, flavonoids, terpenoids and alkaloids were detected as the active phytoconstituents of root extract. From the antibacterial activity, S. aureus were the most susceptible bacterial species to 200 mg/mL concentration with maximum zone of inhibition (16.83mm) form root extract. While the least susceptible was E.coli at 200 mg/mL concentration with minimum inhibition zone (13.57mm) for fruit extract. Contrastingly, the 200 mg/mL concentration of the extract revealed maximum antifungal activity with the highest zone of inhibition (16.00mm) for leaf extract against A. versicolor showing its susceptibility whereas the weakest antifungal activity with minimum zone of inhibition (13.17mm) at 200 mg/mL concentration of the extract was recorded for fruit extract against A. niger. A. versiclor was more susceptible than A. niger by all of the crude extracts at a concentration of 200 mg/ml. The extract from U. dioica (L.) root demonstrated strongest bactericidal activity with MIC of 1.5mg/ml and corresponding MBC of 3.125mg/ml against S.aureus. The antifungal activity of the extracts demonstrated the strongest antifungal activity with MIC of 6.25mg/ml and corresponding MFC of 12.5mg/ml in leaf extract against A. versicolor. It can be concluded from the result antimicrobial activity that the root extract of U. dioica (L) had exhibited the strongest antibacterial potential while the fruit extract had the least antibacterial. The antifungal activity, the leaf extract presented the highest antifungal potential while the fruit extract had the least antifungal. The findings of this current study suggested that the crude extracts of U.dioca have the potential to be used as a source of alternative antimicrobial agents. However, further extensive studies have to be undertaken for developing concrete recommendations for antimicrobial agents to reduce the effects of bacterial and fungal pathogenic activities.