Cardioprotective Effects of Bosentan in Rats Subjected to Lung Ischemia–Reperfusion Injury

TL;DR

Bosentan, a drug, protects the heart in rats undergoing lung injury by reducing damage and inflammation.

Contribution

This study demonstrates bosentan's cardioprotective effects in a novel rat model of lung ischemia–reperfusion injury.

Findings

Bosentan reduced histopathological changes like inflammation and edema in heart tissue.

Bosentan lowered oxidative stress markers and increased antioxidant enzyme activities in myocardial tissue.

Bosentan significantly decreased levels of ET-1, NF-κB, p53, and TGF-β1 in I/R-injured rats.

Abstract

Background and Objectives: This study aimed to investigate the cardioprotective effects of bosentan, an endothelin receptor antagonist, in a rat model of lung ischemia–reperfusion (I/R) injury, with a focus on myocardial tissue involvement. Materials and Methods: Twenty-four male Wistar rats were randomly assigned to four groups: sham, bosentan, I/R, and I/R + bosentan. Lung I/R injury was induced by hilar clamping for 45 min, followed by 60 min of reperfusion. Bosentan (30 mg/kg) was administered intraperitoneally 30 min prior to the procedure. Myocardial tissue was evaluated histopathologically for structural disorganization, inflammation, fibrosis, and edema. TGF-β1 protein levels in myocardial tissue were compared across the groups using β-actin as the loading control. ELISA was used to quantify ET-1, NF-κB, and p53 levels, while spectrophotometric analysis was employed to assess MDA levels and the activities of SOD and CAT enzymes in heart tissue. Results: The I/R group exhibited significant myocardial disorganization, inflammation, and interstitial edema compared to the sham and bosentan groups. Bosentan treatment markedly ameliorated these histopathological alterations. Additionally, the I/R group showed elevated levels of ET-1, NF-κB, p53, and MDA, along with reduced SOD and CAT activities; these changes were significantly attenuated by bosentan administration. Bosentan treatment significantly reduced myocardial ET-1 levels (from 136.88 ± 5.02 to 120.18 ± 2.67 nmol/g, p = 0.003), NF-κB levels (from 0.87 ± 0.04 to 0.51 ± 0.03 ng/mg, p = 0.002), and TGF-β1 expression (from 1.72 ± 0.10 to 0.91 ± 0.08 relative units, p = 0.001). Moreover, bosentan increased antioxidant enzyme activities, elevating SOD levels from 21.45 ± 1.23 to 32.67 ± 1.45 U/mg protein (p = 0.001) and CAT levels from 15.22 ± 0.98 to 25.36 ± 1.12 U/mg protein (p = 0.002). Conclusions: Bosentan exerts cardioprotective effects in rats subjected to lung I/R injury by reducing myocardial damage, inflammation, and oxidative stress. These findings suggest that bosentan may serve as a potential therapeutic agent for preventing remote organ injury associated with pulmonary I/R.

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