Curcumin attenuates renal ischemia and reperfusion injury-induced restrictive respiratory insufficiency

Pulmonary failure, instead of kidney failure, is one of the leading causes of acute kidney injury (AKI)-related death. Volume overload was previously regarded as the primary cause of lung injury, presumably by impaired renal fluid clearance. Recent evidence suggested that proinflammatory cytokines, chemokines, and free radicals released during AKI are playing a crucial role in the lung injury. We aimed to examine the protective efficacy of lung function with curcumin pretreatment.

AKI was induced by 45 minutes of kidney ischemia (bilateral occlusion of renal pedicles) followed by 3 hours of reperfusion. Rats were divided into 3 groups: sham-operated, kidney ischemia and reperfusion (I/R), and a group with 2 days of oral pretreatment with curcumin (12.5 mg/kg/d) before I/R injury. The pulmonary function test (PFT) was conducted at baseline and after 3 hours of reperfusion, yielding parameters of lung volumes, chord compliance (Cchord), inspiratory resistance (RI), and forced expiratory volume at the first 200 millisecond (FEV200). We also examined levels of protein concentration (PC), methylguanidine (MG), tumor necrosis factor-α (TNF-α), and malondialdehyde (MDA) in the bronchoalveolar lavage (BAL).

Ischemic AKI-induced restrictive lung disease was demonstrated by the decreased Cchord, total lung capacitance (TLC), and FEV200, in addition to the increased lavage PCBAL, MG, TNF-α, and MDA level. Curcumin pretreatment ameliorated lung function impairment and alveolar vascular protein leak and attenuated lung inflammation.

The protective effect of curcumin pretreatment against restrictive lung disease is most likely associated with decreasing hydroxyl radical, lipid peroxidation, and inflammation in the lungs and improving alveolar vascular permeability.