Evidence to Support the Anti-Cancer Effect of Olive Leaf Extract and Future Directions.

Anna Boss,Gareth Marlow,Karen Bishop,Matthew Barnett,Lynnette Ferguson

doi:10.3390/nu8080513

Anna Boss, Gareth Marlow + Show 3 more

Open Access

https://doi.org/10.3390/nu8080513

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Abstract

The traditional Mediterranean diet (MD) is associated with long life and lower prevalence of cardiovascular disease and cancers. The main components of this diet include high intake of fruit, vegetables, red wine, extra virgin olive oil (EVOO) and fish, low intake of dairy and red meat. Olive oil has gained support as a key effector of health benefits and there is evidence that this relates to the polyphenol content. Olive leaf extract (OLE) contains a higher quantity and variety of polyphenols than those found in EVOO. There are also important structural differences between polyphenols from olive leaf and those from olive fruit that may improve the capacity of OLE to enhance health outcomes. Olive polyphenols have been claimed to play an important protective role in cancer and other inflammation-related diseases. Both inflammatory and cancer cell models have shown that olive leaf polyphenols are anti-inflammatory and protect against DNA damage initiated by free radicals. The various bioactive properties of olive leaf polyphenols are a plausible explanation for the inhibition of progression and development of cancers. The pathways and signaling cascades manipulated include the NF-κB inflammatory response and the oxidative stress response, but the effects of these bioactive components may also result from their action as a phytoestrogen. Due to the similar structure of the olive polyphenols to oestrogens, these have been hypothesized to interact with oestrogen receptors, thereby reducing the prevalence and progression of hormone related cancers. Evidence for the protective effect of olive polyphenols for cancer in humans remains anecdotal and clinical trials are required to substantiate these claims idea. This review aims to amalgamate the current literature regarding bioavailability and mechanisms involved in the potential anti-cancer action of olive leaf polyphenols.

Highlights

Cancer is a group of diseases involving proliferation of mutated cells [1]
There is strong evidence from cell models which demonstrates that olive polyphenols, and the combination found in olive leaf, are able to modulate and interact with molecular pathways and in doing so may inhibit the progression and development of cancer
It is important to acknowledge that cell models are very different from the complex human body and applying these findings to cancer outcomes in humans is difficult

Summary

Introduction

Cancer is a group of diseases involving proliferation of mutated cells [1]. In 2012, over 14 million new cases of cancer were reported [2], triggering a push to further develop treatments and preventative strategies. Only higher and variety of polyphenols than olive products and the benefits they provide to human health [39,40,41,42], there are currently no those found in EVOO, but many of the polyphenols contain a glucose moiety. This structural difference in the polyphenols may have important consequences by altering their capacity to improve health outcomes [43,44]. Research into the anti-cancer properties of olive polyphenols is abundant with a focus on the health effects of EVOO. The key components from the research articles pivotal to this review have been summarized in Supplementary Table S1

Olive Leaf Polyphenols

Glycosylation

Bioavailability of Olive Leaf Polyphenols

Olive via an an interaction receptors on

Quinone Hypothesis for Anti-Cancer Properties of Olive Leaf

Conclusions