Journal of Evidence-Based Integrative Medicine (May 2019)

Methanol-Extract/Fractions of Leaves Ameliorate Hyperglycemia and Associated Oxidative Stress in Streptozotocin-Induced Diabetic Wistar Rats

  • Chimaobi J. Ononamadu MSc,
  • Adamu J. Alhassan PhD,
  • Aminu Ibrahim PhD,
  • Abdullahi A. Imam PhD,
  • Godwin O. Ihegboro MSc,
  • Tajudeen A. Owolarafe MSc,
  • Mohammed S. Sule PhD

DOI
https://doi.org/10.1177/2515690X19843832
Journal volume & issue
Vol. 24

Abstract

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The present study evaluated the antidiabetic and antioxidant potential of the methanolic extract/solvent fractions of the leaves of Dacryodes edulis using a streptozotocin (STZ)-induced diabetic Albino Wistar rat model. The fasting blood glucose/insulin levels and inhibition of α-amylase and α-glucosidase were determined. Antioxidant activity was assessed in vitro by 2,2-diphenyl-1-picrylhydrazyl, hydroxyl, superoxide scavenging, reducing power, and total antioxidant capacity assays and in vivo by monitoring catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) activities and reduced glutathione (GSH) and malondialdehyde (MDA) levels. The aqueous-methanol fraction exhibited the highest and significant ( P < .05) reduction in fasting blood glucose (FBG; 54.03%) with a concomitant inhibition of α-amylase and α-glucosidase activities. The ethyl acetate fraction also exhibited a significant ( P < .05) reduction in FBG and an increase in insulin levels in the treated diabetic Wistar rats. A significantly ( P < .05) higher reducing power and radical scavenging activity was observed in the aqueous-methanol and ethyl acetate fractions. The aqueous-methanol and ethyl acetate fractions also significantly ( P < .05) reversed the alterations in oxidative stress markers (GSH, MDA, CAT, and SOD) observed in the diabetic control group. In conclusion, the study demonstrated that the methanol extract of Dacryodes edulis ameliorates hyperglycemia and the associated oxidative stress in STZ-induced diabetic Wistar rats. These observed activities are largely due to the compounds that partitions into the aqueous-methanol (55:45) solvent fraction. This provides scientific evidence for the use of this plant extract in folk medicine and also a baseline data for its further characterization. Further work should be carried out to characterize the aqueous-methanol solvent fractions for the active compounds.