Caffeic acid and chlorogenic acid: Evaluation of antioxidant effect and inhibition of key enzymes linked with hypertension

This study aimed to evaluate and compare the effect of structure of phenolic acids on antihypertensive and antioxidant properties of caffeic acid and chlorogenic acid. The antihypertensive property was studied by evaluating interactions of caffeic acid and chlorogenic acid with some key enzymes (ectonucleoside triphosphate diphosphohydrolase [E-NTPDase], 5ʹ-ectonucleotidase, adenosine deaminase, angiotensin converting enzyme, acetylcholinesterase, and arginase) relevant to high blood pressure. Also, the protective effects of caffeic acid and chlorogenic acid against prooxidants-induced oxidative damage in the rat's heart were determined. Results from this work confirm that caffeic acid and chlorogenic acid exhibited inhibitory effects on key enzymes linked with hypertension and prevented prooxidant-induced oxidative damage in rat's heart. Nevertheless, esterification of caffeic acid with quinic acid might have been responsible for the stronger inhibitory effects exhibited by chlorogenic acid on some enzymes relevant to hypertension. We conclude that esterification of caffeic acid with quinic acid could influence the antihypertensive property of the resultant chlorogenic acid. Practical applications Caffeic acid and its ester; chlorogenic acid are the most common hydroxycinnamic acids present in fruits, spices, vegetables, wine, olive oil, coffee, and dietary supplements. Since caffeic and chlorogenic acid possess pharmacological properties, consuming foods and grains rich in these phenolic acids might provide therapeutic benefits. Thus, caffeic acid and chlorogenic acid stand as promising candidates for drug discovery, and further investigation in this area is required.