Abstract

RADICAL SCAVENGING ACTIVITY OF TELMISARTAN IN NITRITE-INDUCED HEMOGLOBIN OXIDATION: IN VIVO STUDY

Ruaa Fadhil Abbas*, Saad Abdulrahman Hussain and Amal Ajaweed Sulaiman

Abstract

A large number of therapeutic and environmental agents may cause methemoglobinemia like nitrite. Several free radical species are generated during the course of nitrite-induced methemoglobin formation. Telmisartan, a highly selective antagonist of Angiotensin II type 1(AT1) receptors, is widely used in the treatment of hypertension and congestive heart failure. The study was designed to evaluate the expected protective activity of telmisartan against nitrite-induced hemoglobin oxidation. 18 male rats were randomly allocated into 3 groups. Rats in group I served as control and were given distilled water. In group II (long term exposure), telmisartan (10 mg/kg) was given once daily orally for 7 days; on the seventh day, sodium nitrite (100 mg/kg body weight) was given orally. In group III, telmisartan (10 mg/kg) was given as a single oral dose; thereafter, toxic dose of sodium nitrite (100 mg/kg) was given orally. Blood samples were obtained for measurement of methemoglobin level for each group. The results showed that telmisartan significantly decreased nitrite-induced methemoglobin formation compared with control. Telmisartan attenuates sodium nitrite-induced hemoglobin oxidation and maintain integrity of red blood cells through free radical scavenging activity.

Keywords: Telmisartan, radical scavenger, sodium nitrite.