Oral administration of oleuropein and olive leaf extract has cardioprotective effects in rodents: A systematic review

Oleuropein is a polyphenol found in olive trees that has shown beneficial effects in animal studies and potentially in human health, although few studies have been performed to confirm this hypothesis in the latter population. Previous studies related its antioxidant activity to cardioprotective effects and showed a positive correlation between dose and response. We thus aimed to assess the cardioprotective effect of oleuropein and olive leaf extract in animal experiments. A literature search was conducted in June 2020 in the PubMed, Scopus and Web of Science databases. The descriptors "oleuropein" and "oleuropein aglycone" identified 12 articles for qualitative synthesis. Risk of bias was assessed by SYRCLE's RoB tool for animal studies. The results demonstrate evidence of a positive association between the administration of oleuropein and olive leaf extract and improvement in outcomes in hypertension, heart failure, myocardial infarction. renal hypertension and diabetes. This review presents a positive effect of oleuropein and olive leaf extract administration on cardiovascular parameters in animal studies.