Effects of caffeine and caffeic acid on selected biochemical parameters in L‐NAME‐induced hypertensive rats

Biologically active compounds such as caffeine and caffeic acid can be obtained in plants especially cocoa and coffee. Hence, the combinatory effect of caffeine and caffeic acid as well as their individual effect were assessed on the activities of arginase, angiotensin‐1‐converting enzyme (ACE) as well as nitric oxide (NOx), and malondialdehyde (MDA) level in the Nω‐Nitro‐L‐arginine‐methylester (L‐NAME)‐induced hypertensive rats. The individual and combinatory effect of caffeine and caffeic acid were investigated in L‐NAME‐induced rats. Animals were grouped into eleven containing six animals each. Hemodynamic parameter was determined by tail‐cuff plethysmography. Furthermore, the result showed a notable rise in ACE and arginase activities of L‐NAME‐induced group compared with the control group. However, pretreatment with test compounds lowered ACE, arginase activities, and MDA content with rise in NOx. This study supports that caffeine and caffeic acid combinations demonstrated antihypertensive properties by lowering the systolic blood pressure in L‐NAME‐induced rats. PRATICAL APPLICATIONS: This duo bioactive compounds; caffeine (alkaloid) and caffeic acid (phenolic acid) are lavishly distributed in coffee. Their cardiopotective and cardiomodulatory roles have been investigated due to their biological activities. As far as we are aware, this could be foremost in‐depth study on the antihypertensive and cardioprotective effect of the combinations of caffeine and caffeic acid targeting the key enzymes system relevant to hypertension. Decreased ACE and arginase activities as well as high nitric oxide (NOx) and low MDA level may be associated with its antihypertensive effect. This present study suggests that the combinations of this phenolics and alkaloid compound might proffer a therapeutic strategy in the management of hypertension.