Antimicrobial Effects of Hydroxytyrosol Extracted From Olive Leaves, on Propionibacterium Acnes

Introduction: The olive tree consists of twenty species that belong to the olive genus (olea). These trees are always green and have small, seamless leaves that are facing each other. Acne vulgaris is one of the most common skin diseases and the most common cause for referral of patients to dermatologists. Propionibacterium acnes is a gram-positive bacteria, anaerobic rod that is found on the human skin surface as a natural flora, causing acne. It can also cause chronic blepharitis and endophthalmitis in the eye.& para;& para;Materials and Methods:& para;& para;Standard well assay method in Mueller-Hinton agar based on CLSI protocol was used to evaluate the zone of inhibition of different hydroxytyrosol concentrations. Then the result of this assay was compared with standard antibiogram test by antibiotics choice for acne treatment such as Clindamycin. Tetracycline and Erythromycin.& para;& para;To determine MIC and MBC. a sterile micro plate was first prepared from hydroxytyrosol 20 dilutions consecutively from 10 fold serial dilution in sterilized Mueller-Hinton Broth from 200mg/ml until 0.00038 mg/ml. Standard suspension of Propionibacterium acnes opposite 5x105 cfu/ml was prepared and equally added to the tubes containing different dilutions of hydroxytyrosol.& para;& para;Findings: Until the fifth dilution, growth was observed: the concentration of 12.5 mg/ml of the tested com- pound had the minimum bactericidal concentration. MBC converted unit to 12500 mu g/ml.& para;& para;In the 6th dilution (6.25 mg/ml) growth was observed, therefore this concentration was introduced as minimum inhibitory concentration (MIC) and the convert- ed unit to 6250 mu g/ml.& para;& para;Conclusion: In this study, it was found that hydroxytyrosol has an antibacterial effect against Propionibacterium acnes. But it is weaker than existing standard antibiotics.