Abstract
Aims: The purpose of this study is to determine the antimicrobial activity of aqueous and alcoholic extract of grapefruit (Citrus Paradisi Rutaceae) seeds. Materials and Methods: Aqueous and alcoholic (ethanol) extracts of grapefruit seeds "GSE" in 20% (w/v) concentration were investigated for activity against Staphylococcus aureus, Proteus vulgaris, Klebsiella pneumonia, Candida albicans and a mixed oral flora. The level of antimicrobial effects was established using in vitro disc diffusion method. Their antibacterial and antifungal activity was compared to the activity of Chlorhexidine (CHX) solution in two concentrations (0.12 and 0.2%) as a control. Results: The aqueous GSE (20%) solution used in this study gave positive results with lethal effect on the tested organisms with zones of inhibition ranging from 10mm-18mm in diameter, which is comparable to that of chlorhexidine (7mm - 22mm) and (13mm - 20mm) for 0.12% and 0.2% solutions respectively. Ethanolic GSE did not show any antimi-crobial activity. Conclusions: Aqueous GSE has a good antimicrobial effect, which makes it a good natural preparation for use as antiseptic or disinfectant.