@article {124, title = {Anti-Fibrotic Effect of Irbesartan via Attenuation of Endoplasmic Reticulum stress in Isoprenaline-Induced Myocardial Fibrosis}, journal = {International Journal of Pharmacology and Clinical Sciences}, volume = {4}, year = {2015}, month = {Dec 2015}, pages = {76-82}, type = {Research Article}, chapter = {76}, abstract = {

Background: Angiotensin receptor blockers are the new class of compounds used for the treatment of fibrotic diseases. Objectives: The purpose of this study was to investigate cardioprotective effect of irbesartan in isoproterenol induced endoplasmic reticulum stress, which results in myocardial fibrosis. Materials and Methods: Thirty wistar rats were assigned to study, 6 rats in a group. Myocardial fibrosis was induced by isoproterenol (5 mg/kg, s.c. for 15 days) which can cause cardiac toxicity. Irbesartan (10, 20 and 30 mg/kg, p.o.) was administered for 15 days after administration of isoproterenol. Post-treatment with irbesartan, cardiac functional measurements and the left and right ventricular weight indices were analyzed. Pathological alteration of levels of soluble collagen was determined. Results: The administration of irbesartan resulted in a significant (p\<0.01) improvement in cardiac function and reduced levels of soluble collagen. Irbesartan also showed decrease in the level of malondialdehyde and an increase in defensive antioxidant enzymes (SOD, CAT, and GSH) thus, exerts antioxidant activity. Conclusion: Irbesartan possesses anti-fibrotic activity and offers protection against myocardial fibrosis, due to regulation of angiotensin II activity through blockade of AT1 receptors which might attenuate the endoplasmic reticulum stress and thus inhibit myocardial fibrosis via inhibition of oxidative stress. The regulation of antioxidant defensive enzymes may be involved in anti-fibrotic effect of irbesartan

}, keywords = {Endoplasmic Reticulum Stress, Irbesartan, Isoproterenol, Myocardial Fibrosis, Oxidative Stress, Soluble Collagen}, doi = {10.5530/ijpcs.4.4.2}, author = {Vandana Shamrao Nade and Pranita Pradip Dharmadhikari and Laxman Ashok Kawale} } @article {128, title = {Comparison of In vitro Antioxidant Activity of Olmesartan and Amlodipine}, journal = {International Journal of Pharmacology and Clinical Sciences}, volume = {4}, year = {2015}, month = {Dec 2015}, pages = {90-93}, type = {Research Article}, chapter = {90}, abstract = {

Introduction: Free radical oxidative stress has been implicated in the pathology of a wide variety of clinical disorders. Antioxidants are agents which scavenge the free radicals and prevent the damage caused by them. Angiotensin II receptor blockers used in the treatment of hypertension, have also been reported to protect organs such as kidney and heart. Althoug, the mechanisms of these protective effects are not fully understood, it is generally thought that their antioxidant effects likely play a role. Amlodipine, a calcium channel blocker, seems to exert atheroprotective effects through its antioxidant properties related to its chemical structure and independent of its calcium channel-blocking effect. Though research has proved that olmesartan and amlodipine exhibit antioxidant activity independent of their antihypertensive effects, there are not many in vitro studies to analyse which drug is a better antioxidant. Objective: This in vitro study was done to compare the antioxidant activity of olmesartan and amlodipine. Materials and Methods: In this study, we demonstrated the antioxidant activities of 10 mg/ml stock solutions of olmesartan and amlodipine in vitro. DPPH (1,1 Diphenyl 2-picryl hydrazide) and Nitric oxide free radical scavenging assays were done. Results: Olmesartan showed significant (49.48\%) and consistent free radical scavenging activity by DPPH and Nitric oxide radical scavenging assays. Free radical scavenging activity of amlodipine was more significant (56.89\%) than olmesartan but was inconsistent and non-concentration dependent. Conclusion: Hence this in vitro study has proved that olmesartan has better antioxidant activity than amlodipine.

}, keywords = {Amlodipine, DPPH, Free radicals, Nitric Oxide, Olmesartan, Oxidative Stress}, doi = {10.5530/ijpcs.4.4.4}, author = {Rajathilagam Thiruvengadam and Seethalakshmi Sankar} }