Pomegranate Peel Extract Reduces Diabetes-induced Collagen Turnover and Biochemical Imbalance in Rat Lung

Diabetes causes lung function disorders. However, pulmonary collagen turnover under diabetes has not been well studied. The purpose of this study was to investigate collagen turnover in lung and to evaluate protective effect of pomegranate peel extract (PPE). Diabetes model in rat was induced by alloxan (250 mg/kg, i.p.). PPE treated rats received 100 mg/kg of PPE for 30 days. PPE was characterized by Gas chromatography–mass spectrometry (GC-MS). Hydroxyproline was determined by colourimetric assay kit, total collagen using ELISA kit and by histopathological assay. Collagenases (MMP-1,-8,-13) wereanalyzed by fluorometric method. Antioxidant enzyme activities and inflammatory marker C-reactive protein (CRP) were evaluated. Diabetes decreases SOD activity and increases CRP level by 33% (p < 0.05) and 125% (p < 0.01), respectively, when compared to the control group. PPE abrogated diabetesinduced SOD activity and CRP level disturbance. Collagenase activity was lower in diabetes and PPE group by 38% (p < 0.05) and 34% (p < 0.05), respectively, when compared to control. Diabetes increased significantly collagen and hydroxyproline by 32% (p < 0.05) and 192% (p < 0.01), respectively, and restored at similar level than controls in PPE group. Lung histopathological assay showed distended alveoli and peribronchial inflammatory cell infiltration in diabetic group. Compared to diabetic, PPE limits inflammatory cell infiltration in lung tissue. Diabetes causes ECM imbalance and enhances inflammation in lung wall, which can be abrogated by PPE.