African walnuts attenuate ectopic fat accumulation and associated peroxidation and oxidative stress in monosodium glutamate-obese Wistar rats

Biomed Pharmacother. 2020 Apr:124:109879. doi: 10.1016/j.biopha.2020.109879. Epub 2020 Jan 25.

Abstract

Aims: African walnuts were previously shown to modulate hepatic lipid bio-accumulation in obesity. Herein, we investigated the impact of the nuts on fat accumulation in adipose and ectopic regions, and associated oxidatiive stress status in obese rats.

Materials and methods: Whole ethanol extract (WE) of the nuts, and its liquid-liquid fractions-ethyl acetate (ET) and residue (RES) were separately administered to obese rats for 6 weeks. The normal (NC) and obese (OC) controls received normal saline and the standard control (SC), orlistat (5.14 mg/kg b.w.), during the same period. Thereafter, the animals were euthanized and the adipose, brain, kidneys and heart tissues were studied.

Results: The change in body weight to naso-anal length which increased by 63.52 % in OC compared to NC (p < 0.05), decreased by 57.88, 85.80 and 70.20 % in WE, ET and RES-treated groups, respectively, relative to the OC (p < 0.05). Also, adipose tissue weights were lowered upon treatment with the extracts and fractions versus OC (p < 0.05). Total lipids, phospholipids, triacylglycerol and cholesterol concentrations in the studied tissues which were higher in OC (p < 0.05) were lowered (p < 0.05) and compared favorably with SC. Further, malondialdehyde levels in the tissues were lowered upon treatment, compared to the OC (p < 0.05). Glutathione level and activities of glutathione peroxidase, superoxide dismutase and glutathione-S-transferase which were decreased (p < 0.05) in OC, were restored upon treatment with the extracts, relative to the obese control (p < 0.05).

Significance: African walnuts assuaged lipogenesis, oxidative stress and peroxidation in extra-hepatic tissues of obese rats, hence, may attenuate ectopic fat accumulation and its associated pathogenesis.

Keywords: Extra-hepatic lipids; Obesity; Tetracarpidium conophorum; Tissue anti-oxidants; Tissue peroxidation.

MeSH terms

  • Adipose Tissue / metabolism
  • Animals
  • Female
  • Glutathione / metabolism
  • Juglans / chemistry*
  • Lipid Metabolism
  • Lipid Peroxidation / drug effects
  • Male
  • Malondialdehyde / metabolism
  • Obesity / metabolism*
  • Oxidative Stress / drug effects*
  • Plant Extracts / pharmacology*
  • Rats
  • Rats, Wistar
  • Sodium Glutamate / toxicity

Substances

  • Plant Extracts
  • Malondialdehyde
  • Glutathione
  • Sodium Glutamate