Affiliations 

  • 1 Department of Life Sciences, School of Pharmacy, International Medical University (IMU), Bukit Jalil, 57000, Kuala Lumpur, Malaysia. jestin_chellian@imu.edu.my
  • 2 School of Postgraduate Studies and Research, International Medical University, Kuala Lumpur, Malaysia
  • 3 Department of Life Sciences, School of Pharmacy, International Medical University (IMU), Bukit Jalil, 57000, Kuala Lumpur, Malaysia
  • 4 Division of Pathology, School of Medicine, International Medical University, Kuala Lumpur, Malaysia
  • 5 Department of Pharmaceutical Chemistry, School of Pharmacy, International Medical University, Kuala Lumpur, Malaysia. mallikarjunarao_pichika@imu.edu.my
Sci Rep, 2022 Dec 10;12(1):21393.
PMID: 36496468 DOI: 10.1038/s41598-022-25739-5

Abstract

The antidiabetic effects of quercetin and metformin are well known. However, their synergistic effect in reversing the symptoms of diabetes-induced endothelial dysfunction remains unknown. In this study, we have investigated their synergistic effect in streptozotocin (STZ)-nicotinamide induced diabetic rats. Seventy-five rats were divided into five groups; normal control, diabetic control, treatment groups (10 mg/kg quercetin, 180 mg/kg metformin, and combined). The plasma glucose and lipid levels, liver enzymes, ex-vivo studies on aortic rings, histology of liver, kidney, pancreas, abdominal aorta and thoracic aorta, and immunohistochemical studies were carried out. The findings revealed that the combination of quercetin and metformin showed a greater antidiabetic effect than either drug, and rendered protection to the endothelium. The combination effectively reversed the hyperglycemia-induced endothelial dysfunction in diabetic rats. Furthermore, it also reversed the dysregulated expression of eNOS, 3-nitrotyrosine, VCAM-1, CD31 and SIRT-1. Overall, the present study's findings demonstrate that quercetin potentiates the activity of metformin to control the complications associated with diabetes.

* Title and MeSH Headings from MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.