Efficacy of epigallocatechin-3-gallate against oleic acid-induced acute respiratory distress syndrome

Abstract: OBJECTIVE: The objective is to induce acute respiratory distress syndrome (ARDS) in rats by oleic acid and evaluate the prophylactic and therapeutic effectiveness of epigallocatechin-3-gallate (EGCG) against ARDS. BACKGROUND: ARDS is an acute, severe inflammatory lung injury. Clinically used anti-inflammatory medication and corticosteroids have side effects, infection risk, and increased treatment costs. Epigallocatechin-3-gallate (EGCG) from green tea is a flavonoid possessing antioxidant and anti-inflammatory properties. Intravenous injection of pure oleic acid causes respiratory distress in diverse animal species, leading to inflammation in the lungs. Hence, we used oleic acid to induce ARDS in rats to assess the prophylactic and therapeutic effectiveness of EGCG against ARDS. MATERIALS AND METHODS: A total of four groups were formed, with five animals allocated to each group. The control group (G1) was administered with normal saline 0.2 ml/kg, twice at an interval of 1 h, ARDS group (G2) with oleic acid 0.2 ml/kg intravenously, twice at 1-h interval. The prophylactic group (G3) was administered with EGCG 10 mg/kg i.p. 1 h before the administration of oleic acid, whereas therapeutic group (G4) was administered with same dose of EGCG but, 1 h after the administration of oleic acid. RESULTS: Assessment of animal body and lungs weight, gross macroscopic and microscopic evaluation of lungs did not produce any significant treatment-related changes when compared with the control group. However, a substantial decrease in tumor necrosis factor-alpha levels was observed in G3 and G4 when compared to the G2 group. CONCLUSIONS: EGCG has both prophylactic and therapeutic effectiveness against ARDS.