Effects of the SGLT-2 inhibitor canagliflozin on adenine-induced chronic kidney disease in rats

Background/Aims: SGLT-2 inhibitors have been shown to be nephroprotective in diabetes. Here, we examined if one of these drugs (canagliflozin) could also ameliorate non-diabetic chronic kidney disease (CKD). Methods: CKD was induced in rats by feeding them adenine (0.25%^w/w for 35 days) and canagliflozin (10 or 25 mg/kg, by gavage) was given with or without adenine. Several conventional and novel plasma and urine biomarkers and tissues morphology were used to investigate the canagliflozin effect on kidney structure and function. Results: Rats fed adenine showed the typical features of CKD that included elevation of blood pressure, decreased food intake and growth, increased water intake and urine output, decrease in creatinine clearance, and increase in urinary albumin/creatinine ratio, liver-type fatty acid binding protein, N-acetyl-beta-D-glucosaminidase, and plasma urea, creatinine, uric acid, calcium, indoxyl sulfate and phosphorus concentrations. Adenine also increased concentrations of several biomarkers of inflammation such as neutrophil gelatinase-associated lipocalin, interleukin-6, tumor necrosis factor alpha, clusterin, cystatin C and interleukin-1β, and decreased some oxidative biomarkers in kidney homogenate, such as superoxide dismutase, catalase, glutathione reductase, total antioxidant activity, and also urinary 8-isoprostane and urinary 8-hydroxy-2-deoxy guanosine. Adenine significantly increased the renal protein content of Nrf2, caused renal tubular necrosis and fibrosis. Given alone, canagliflozin at the two doses used did not significantly alter any of the parameters mentioned above. When canagliflozin was given concomitantly with adenine, it significantly and dose-dependently ameliorated all the measured adenine-induced actions. Conclusion: Canagliflozin ameliorated adenine-induced CKD in rats, through reduction of several inflammatory and oxidative stress parameters, and other indices such as uremic toxins, and by antagonizing the increase in the renal content of the transcription factor Nrf2. The drug caused no overt or significant untoward effects, and its trial in patients with CKD may be warranted.