**Oleuropein, a Bioactive Compound from** *Olea europaea* **L., as a Potential Preventive and Therapeutic Agent in Non-Communicable Diseases**

#### **Chiara Nediani 1,\*, Jessica Ruzzolini 1, Annalisa Romani 2 and Lido Calorini 1,3**


Received: 3 October 2019; Accepted: 19 November 2019; Published: 22 November 2019

**Abstract:** Growing scientific literature data sugges<sup>t</sup> that the intake of natural bioactive compounds plays a critical role in preventing or reducing the occurrence of human chronic non-communicable diseases (NCDs). Oleuropein, the main phenolic component of *Olea europaea* L., has attracted scientific attention for its several health beneficial properties such as antioxidant, anti-inflammatory, cardio- and neuro-protective, and anti-cancer. This article is a narrative review focused on the current literature concerning the e ffect of oleuropein in NCDs, such as neuro- and cardiovascular diseases, diabetes mellitus, chronic kidney diseases, and cancer, by its putative antioxidant and anti-inflammatory activity, but also for its other peculiar actions such as an autophagy inducer and amyloid fibril growth inhibitor and, finally, for its anti-cancer e ffect. Despite the increasing number of published studies, looking at the beneficial e ffects of oleuropein, there is limited clinical evidence focused on the benefits of this polyphenol as a nutraceutical product in humans, and many problems are still to be resolved about its bioavailability, bioaccessibility, and dosage. Thus, future clinical randomized trials are needed to establish the relation between the beneficial e ffects and the mechanisms of action occurring in the human body in response to the intake of oleuropein.

**Keywords:** *Olea europaea* L.; oleuropein; extra-virgin olive oil; health e ffects; non-communicable diseases; oxidative stress; inflammation; autophagy; amyloid
