The possible protective effect of magnolol on triolein-induced lung structural changes in rats: Histological and immunohistochemical study

Abstract

Introduction: Triolein is a neutral fat derives from an oleic acid. It has been used as a textile lubricant, a plasticizer and present in cocoa butter. Its occupational exposure lead to health hazards especially lung injury. Magnolol is a Chinese herbal complex with anti-inflammatory, antioxidant and antifibrotic actions. Aim: The present research aimed to evaluate the possible protective effect of magnolol on triolein-induced lung structural changes in rats using histological and immunohistochemical study. Materials & methods: 45 male Wistar rats were used. Their weights were from 120 to 150 gm. They were divided into Group 1 (15 rats as control group); Group 2: 15 rats that received 0.2 ml triolein at the caudal vein then were sacrificed after 2, 4 and 21 days; Group 3: 15 rats that received 50 mg/kg oral dose of magnolol daily 60 minutes before giving triolein then were sacrificed after 2, 4 and 21 days. Results: Group 2 showed significant thickened inter-alveolar septa, inflammatory cellular infiltrations, congested blood vessels, luminal inflammatory exudates, disorganized sloughed epithelium and lost cilia. Group 2 also showed significantly increased deposition of collagen fibers, significantly increased expression of alpha –Smooth muscle actin (α-SMA) in the interalveolar septa, wall of the blood vessels and bronchioles and significant increase in the number of macrophages with positive CD68 (Cluster of Differentiation 68) immunohistochemical reaction. Group 3 showed improvements of the previous pathological findings. Conclusion: Magnolol could protect the lung from the injurious effect of triolein possibly due to its anti-inflammatory, antioxidant and antifibrotic actions. This may favor the use of magnolol for the treatment of lung injuries.