Polyphenol-rich pequi extract protects human coronary artery endothelial cells against free radicals: Therapeutic potential of a Brazilian native plant

Author(s): Karla M. S. Braga, Eugenio G. Araujo, Frank W. Sellke, M. Ruhul Abid

The imbalance between production and elimination of free radicals such as Reactive Oxygen (ROS) and nitrogen species compromises endothelial cells and results in Cardiovascular Diseases (CVD). The antioxidant system plays an essential role in maintaining the homeostasis of organic functions, by promoting the balance between cellular oxidants and antioxidants. However, in pathophysiological conditions, the endogenous antioxidant defense mechanisms may be insufficient to control and eliminate free radicals accumulated within the cell. The supplement of external antioxidants is suggested to help fight and prevent oxidative lesions such as lipoperoxidation and oxidative DNA damage. Primary natural antioxidants polyphenols are found in a variety of vegetable sources and can assist cells in the neutralization of free radicals. Resveratrol, a non-flavonoid polyphenol abundant in red wine, is the most investigated compound of this class due to the healthy properties attributed to the Mediterranean Diet. Despite its proven beneficial roles in multiple in vitro and small animal research models, resveratrol supplementation has not yet to produce satisfactory results in human clinical trials. Phenolic compounds are secondary metabolites frequently formed in organisms as a defense mechanism against environmental adverse conditions, like drought and severe UV exposure, typical features of the Brazilian Cerrado biome. The pequi (Caryocar brasiliense, Cambess) is a typical Cerrado tree that produces fruits with polyphenol-rich barks. Recently, we have tested pequi bark’s ethanolic extract efficacy in protecting Human Coronary Artery Endothelial Cells (HCAEC) subject to oxidative stress or conditions that result in increased ROS production. Pequi bark extract increased antioxidative enzyme levels, decreased ROS, and favored Endothelial Cells (EC) proliferation, pointing to a protective effect of pequi extract. The therapeutical potential from native fruits worldwide may support treating and preventing cardiovascular disease and become a sustainable economic activity to low-income communities.