Postprandial Glucose and Triglyceride Increases Along with the Endothelial Malfunction were Attenuated by the Administration of SGLT2 Inhibitor, Empagliflozin

Dual A1 and A2A adenosine receptor antagonists, methoxy substituted 2-benzylidene-1-indanone, suppresses intestinal postprandial glucose and attenuates hyperglycaemia in fructose-streptozotocin diabetic rats

BACKGROUND/AIM

Recent research suggests that adenosine receptors (ARs) influence many of the metabolic abnormalities associated with diabetes. A non-xanthine benzylidene indanone derivative 2-(3,4-dihydroxybenzylidene)-4-methoxy-2,3-dihydro-1 H-inden-1-one (2-BI), has shown to exhibit higher affinity at A₁/A_2A ARs compared to caffeine. Due to its structural similarity to caffeine, and the established antidiabetic effects of caffeine, the current study was initiated to explore the possible antidiabetic effect of 2-BI.

METHODS

The study was designed to assess the antidiabetic effects of several A₁ and/or A_2A AR antagonists, via intestinal glucose absorption and glucose-lowering effects in fructose-streptozotocin (STZ) induced diabetic rats. Six-week-old male Sprague-Dawley rats were induced with diabetes via fructose and streptozotocin. Rats were treated for 4 weeks with AR antagonists, metformin and pioglitazone, respectively. Non-fasting blood glucose (NFBG) was determined weekly and the oral glucose tolerance test (OGTT) was conducted at the end of the intervention period.

RESULTS

Dual A₁/A_2A AR antagonists (caffeine and 2-BI) decreased glucose absorption in the intestinal membrane significantly (p < 0.01), while the selective A_2A AR antagonist (Istradefylline), showed the highest significant (p < 0.001) reduction in intestinal glucose absorption. The selective A₁ antagonist (DPCPX) had the least significant (p < 0.05) reduction in glucose absorption. Similarly, dual A₁/A_2A AR antagonists and selective A_2A AR antagonists significantly reduced non-fast blood glucose and improved glucose tolerance in diabetic rats from the first week of the treatment. Conversely, the selective A₁ AR antagonist did not reduce non-fast blood glucose significantly until the 4th week of treatment. 2-BI, caffeine and istradefylline compared well with standard antidiabetic treatments, metformin and pioglitazone, and in some cases performed even better.

CONCLUSION

2-BI exhibited good antidiabetic activity by reducing intestinal postprandial glucose absorption and improving glucose tolerance in a diabetic animal model. The dual antagonism of A₁/A_2A ARs presents a positive synergism that could provide a new possibility for the treatment of diabetes.

Empagliflozin Regulates the AdipoR1/p-AMPK/p-ACC Pathway to Alleviate Lipid Deposition in Diabetic Nephropathy

BACKGROUND

Abnormal lipid deposition in the progress of diabetic nephropathy (DN) plays an important role in a number of studies that have shown that SGLT2 inhibitor (SGLT2i) empagliflozin plays an important role in lipid metabolism, but its mechanism is still unclear.

METHODS

We aimed to explore the effect of empagliflozin on lipid levels in kidney cancer patients with DN and postoperative patients without DN kidney carcinoma; the patients with DN showed ectopic lipid deposition. In type 2 diabetes model mice induced by streptozotocin (STZ) and a high-fat diet, combined AMPK plus empagliflozin or empagliflozin inhibitor plus compound C was applied, followed by analyses of the blood, urine and kidney indexes to observe the correlation between SGLT2i and AMPK and lipid metabolism in diabetic kidney disease. We determined whether DN in patients with renal tubular atrophy involved lipid metabolism.

RESULTS

In clinical specimens, the adiponectin receptor AdipoR1 was reduced, and the phosphorylation acetyl-CoA carboxylase (p-ACC) was increased. In vitro and in vivo pathological immunofluorescence and Western blotting confirmed that, under the condition of high glucose, malpighian tubules displayed ectopic lipid deposition and expressed related lipid parameters accompanied by fibrosis. Empagliflozin intervention reduced lipid deposition fibrosis and renal tubular atrophy, and the addition of compound C promoted disease progression. Moreover, siAdipoR1 transfection proved that AdipoR1 affected P-AMPK and then p-ACC affected lipid metabolism in renal tubular cells.

CONCLUSION

According to the above experimental results, empagliflozin could reduce lipid metabolism of DN through AdipoR1/P-AMPK/P-ACC pathway and delay DN progress.