Microbiological and Antioxidant Activity of Phenolic Compounds in Olive Leaf Extract

Abstract

According to many reports, phenolic compounds isolated from olive leaves have very good biological activities, especially antimicrobial. Presently, the resistance of microorganisms to antibiotics is greater than ever. Therefore, there are numerous recent papers about alternative solutions for inhibiting their influence on human health. Olive leaf is studied as an important source of antimicrobials with low cost and used in medicine. Numerous publications on involving green technologies for isolation of active compounds from olive leaves have appeared over the past few decades. The present review reports on current knowledge of the most isolated phenolic compounds from olive leaf extract as well as methods for their isolation and characterization. This paper uses recent research findings with a wide range of study models to describe the antimicrobial potential of phenolic compounds. It also describes the vast range of information about methods for determination of antimicrobial potential focusing on effects on different microbes. Additionally, it serves to highlight the role of olive leaf extract as an antioxidants and presents methods for determination of antioxidant potential. Furthermore, it provides an overview of presence of enzymes. The significance of olive leaves as industrial and agricultural waste is emphasized by means of explaining their availability, therapeutic and nutritional effects, and research conducted on this field.

Keywords: antimicrobial activity; antioxidant activity; enzymatic activity; olive leaf extract; phenolic compounds; supercritical fluid extraction.

Figure 1

Olive (Olea europaea L.) leaves [5].

Figure 2

Chemical structures of phenolic compounds already identified in Olea europaea L. leaf extract.

Figure 3

Scheme of N,N-Dimethyl-p-phenylenediamine dihydrochloride method [83].