Evaluation of the Biological Activities of Olea europaea L. Leaves Aiming at the Utilization of a Natural Resource

RAVETTI, SOLEDAD; BUSTOS, PAMELA SOLEDAD; ORTEGA, MARÍA GABRIELA; HERGERT, L.Y.; TURCATTO, A.; RAVETTI, L.M; ACIAR, ROXANA MÓNICA

San Juan

Simposio; VIIth INTERNATIONAL SYMPOSIUM ON OLIVE GROWING; 2012

International Society for Horticultural Science

Given the increasing relevance of olive growing in Argentina and the fact that most scientific studies have been focused on olive oil benefits and its characteristics, it has been considered necessary to initiate research activities studying the presence of compounds of interest in some the least analysed aspects of the crop such as the leaf components with medicinal and pharmaceutical properties. Furthermore, it is important to highlight that growers are experiencing serious problems to deal with the olive processing wastes (specially the leaves). A proposal to study those leaves with the objective of trying to find active principles with potential use in the pharmaceutical industry starting from a natural raw material of low cost is considered of interest. This work shows the evaluation of the antioxidant activity of the olive leaf ethanol and hexane extracts against Artemia saline and the microbiological bioassays against different phytopathogenic fungi strains. The toxicity assay on Artemia saline is used to predict the citotoxic activity of a number of substrates with possible application on bioassays on carcinogenic cells at a later stage. The antioxidant activity determined by the free radical neutralising capacity with the reagent DPPH was carried out on the ethanol and hexane extracts at concentrations of 0.02, 0.015, 0.01 and 0.005 g/mL. The fungicide activity was evaluated according to modified Bondi et al. method, as the tests have been carried out by inoculating the surface of an agar dish with the studied microorganisms adding over those inoculations solutions with 20 mg/mL solutions of the ethanol extract, hexane extract and ketoconazole, respectively. The results of the present investigation demonstrated that both olive leaf extracts show an important antioxidant activity. There was no activity on Artemia saline for both extracts and there was no in vitro inhibition of the development of any of the eight selected strains. These preliminary results are encouraging and further work should continue focusing on the isolation of the different compounds responsible for the antioxidant activity of olive leaves.