Inhibitory Effect of Hydroalcoholic Extract of Olive Leaf (Olea europaea) on Growth of Candida albicans

Introduction and Aim: Candida albicans is the most common and pathogenic species of Candida genus, known to be the fourth most common cause of blood infections. The present study investigates the inhibitory effect of hydroalcoholic extract of Olive leaf on growth of this yeast in vitro.

Materials and Methods: In this experimental study, fresh Olive leaf were collected from its natural habitat in Gotvand city and after washing the leaves were dried in a sterile environment. After verifying the plant species and receiving the herbarium code, the leaf of the plant was completely ground and the 80% hydroalcoholic extract of the plant was prepared by maceration method. Serial dilutions of extract were then prepared in RPMI 1640 medium from 256 to 1 mg/mL. Afterwards, minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) of this extract for fungus was achieved after 48 hours exposure of the extract to the yeast Suspension using micro broth dilution method and re-culturing on Sabouraud dextrose agar (SDA) medium and colony counting.

Results: After counting the yeast colonies grown on Sabouraud dextrose agar and performing one-way ANOVA statistical analysis at the significance level less than 0.05, Although all concentrations of equal to or greater than 4 mg / mL of extract had a significant difference from positive control colonies count, according to the concepts of MIC and MFC, concentrations of 8 and 32 mg / mL were considered as them, respectively.

Conclusion: Olive seems to be a proper complementary drug in the treatment of Candida albicans. Needless to say, this requires extensive pharmacological studies and the evaluation of the possible toxicity of the derivatives and compounds of this plant.