Canagliflozin provides cardioprotection and renoprotection against isoprenaline‐induced oxidative stress by stimulating AMPK‐Akt‐eNOS‐NO signaling axis

Abstract

The antidiabetic drug canagliflozin, a SGLT2 inhibitor, has been reported to possess protective effects against ischemia‐reperfusion and chemically‐induced cardiac and renal injuries. However, to our knowledge, no studies have investigated the protective effects of canagliflozin in isoprenaline (ISO)‐induced cardiac and renal oxidative damage – a model mimicking sympathetic nervous system (SNS) overstimulation‐evoked organ injuries in humans. Therefore, we investigated effects of canagliflozin in ISO‐induced cardiac and renal oxidative stress, and their underlying molecular mechanisms. Our tissue biochemistry, histology, and Western blotting data showed that ISO administration inflicted pro‐oxidative, pro‐inflammatory and pro‐apoptotic changes in the heart and kidney tissues. In contrast, treatment with canagliflozin at 5 mg/kg body weight attenuated levels of cardiac and renal oxidative stress markers including malondialdehyde (MDA), advanced protein oxidation product (APOP), myeloperoxidase (MPO) and nitric oxide (NO), and restored levels of endogenous antioxidant molecules such as catalase (CAT), superoxide dismutase (SOD) and glutathione (GSH) that were depleted in ISO‐treated rats. Western blot analysis revealed that canagliflozin increased activity of anti‐oxidant/anti‐inflammatory proteins such as AMP‐activated protein kinase (AMPK), Akt and eNOS, and decreased pro‐oxidative/pro‐inflammatory proteins including iNOS and NADPH oxidase isoform 4 (NOX4). Protein expression analysis further revealed that ISO increased the ratio of pro‐apoptotic/anti‐apoptotic protein (Bax:Bcl‐2) expression, which was significantly reduced by canagliflozin treatment. Our histological examination demonstrated that in the heart and kidney tissue sections, canagliflozin attenuated ISO‐induced histopathological changes, including inflammatory cell infiltration, collagen deposition, and fibrosis. Consistent with our biochemical data, canagliflozin augmented heart and kidney functions in ISO rats, further supporting a protective role of this drug in ISO‐induced oxidative stress. In summary, we show that canagliflozin produces cardioprotective and renoprotective actions via suppression of iNOS, NOX4 and Bax, and activation of AMPK‐Akt‐eNOS‐NO signaling axis. Support or Funding Information This work was supported by a start‐up grant from the Mercer University College of Pharmacy to Dr. Raquibul Hasan and a research grant from North South University to Dr. Md Ashraful Alam