Kousar B Mian, Muzammil Hasan Najmi.
Antioxidant effects of Antihypertensive Drugs: A new insight.
J Rawal Med Coll Jan ;7(1):3-7.

Background: To assess the antioxidant effects of antihypertensive drugs: Angiotensin-converting enzyme inhibitors (ACE inhibitors: captopril, lisinopril, perindopril and ramipril), Angiotensin receptor antagonists (losartan and valsartan), Calcium channel blocker (nifedipine) and Beta blocker (carvedilol). Methods: This experimental study was conducted at the Department of Pharamcology and Pakistan-US Laboratories for Seroepidemiology, Army Medical College, Rawalpindi, from 15 March to 31 May, 2002. The antioxidant acitivity of antihypertensive drugs was measured in vitro using DPPH (1, 1-diphenyl-2-picrylhydrazyl) assay. Results: Among the ACE inhibitors studied, captopril (a sulphydryl (SH)-containing ACE inhibitor) exhibited maximum antioxidant activity (99.93 ± 2.43% at 100 ug(ml) followed by lisinopril (non-SH-containing ACE inhibitor, 29.57 ± 5.7% at 400 ug(ml). The other two non-SH-containing ACE inhibitors perindopril and ramipril were devoid of such activity. Angiotensin II receptor antagonists losartan and valsartan were also without any antioxidant activity. Furthermore, nifedipine (a dihydropyridine calcium antagonist) and carvedilol (a non-specific beta-blocker) showed antioxidant activity of 29.82 ± 4.8% and 29.97 ± 3.9%, respectively, at a concentration of 800 ug/ml. Conclusion: The antioxidant activity present in some ACE inhibitors, calcium channel blockers and beta blockers may play a role in the antihypertensive action of these drugs by inhibiting free radical production.

PakMediNet -Pakistan's largest Database of Pakistani Medical Journals - http://www.pakmedinet.com