The Biological Activity of Aqueous and Methanolic Extracts of Juglans regia on Yeasts and Pathologic Bacteria

Abstract

Background: The plant extract can be used as a natural alternative to control of pathogenic yeasts and bacteria in general and to reduce the risk of antibiotic-resistant pathogens. Methods: Diffusion agar method was used to examine the antifungal and antibacterial activity of both aqueous and methanolic Juglans regia extracts. For yeasts, The MIC values were determined by the standard serial dilution assay using serial dilutions of the aqueous and methanolic extracts (300,200,100, 50, 25) µg/L). The MIC for bacteria was done using Muller-Hinton agar. The concentrations of the extracts tested were (500, 250, 100, 50) µg/ml. Results: Juglans regia extracts showed activities against Malassezia furfur yeast, Methanolic extract exhibits more activity than aqueous extract. The Minimum Inhibition Concentrated rate (MIC) for Malassezia furfur methanolic extract was 75 µg/ml. The extracts also examined on Candida albicans opportunistic yeast in the mouth and found to be more active than M. furfur were MIC 50 µg/ml. The biological activity of aqueous and methanolic extracts were also examined against six pathogenic bacteria isolated from patients suffering from different diseases from several hospitals in Basrah, including Staphylococcus aureus, Escherichia coli, Salmonella typhi, Proteus mirabilis, pseudomonas aeruginosa and Vibrio parahaemolyticus. The Methanolic extract showed an effective effect in inhibiting all bacterial species compared with the aqueous extract. Conclusion: This study provides the possibility of using a natural plant such as Juglans regia as antimicrobial agent for many pathogenic yeasts and bacteria.