In vitro Antimicrobial Activities of Hygrophila schulli (Buch.-Ham) Leaf and Root Extracts Against Clinically Important Human Pathogens

Hygrophila schulli is an important medicinal plant in Indian systems of medicine. The purpose of the present study was to examine the antibacterial and antifungal activities of H. schulli collected from Kuttand wetlands, Kerala state, India. Hot and cold extracts of leaf and root in seven solvent each (hexane, chloroform, dichloromethane, ethyl acetate, acetone, methanol and water) were tested against clinically important bacterial and fungal pathogens. Ciprofloxacin (5 µg/ml) and Amphotericin B (10 µg/ ml) was used as a standard drugs for analyzing antibacterial and antifungal activity respectively. The cold methanolic leaf extract showed the highest inhibition zone against Staphylococcus epidermidis (16 mm) and Klebsiella pneumoniae (15 mm) and the hot ethyl acetate leaf extract showed an inhibition zone of 13 mm against Pseudomonas aeruginosa. Different concentrations of cold methanolic extracts were tested against S. epidermidis and K. pneumoniae and they showed the highest inhibition zones of 27 mm and 26 mm respectively at 400 mg/ml. The results revealed that the leaf extracts of H. schulli have promising antibacterial activity than the root extracts. The leaf and root extracts did not show antifungal activity against the tested fungal pathogens.