Department of Biochemistry, College of Medical Sciences, University of Calabar, P.M.B 1115, Calabar, Nigeria.
Department of Biochemistry, College of Science, Evangel University Akaeze, P.M.B. 129 Abakaliki, Ebonyi State, Nigeria.
Endocr Metab Immune Disord Drug Targets. 2020;20(3):365-379. doi: 10.2174/1871530319666190724114729.
Obesity is characterized by increased body fat and involves an imbalance between the synthesis and degradation of lipids.
The study aimed to investigate the effect of African walnuts (Tetracarpidium conophorum) on lipids storage and the regulatory enzymes of hepatic lipid metabolism in obese rats.
Nuts were extracted in ethanol (WE) and further separated to obtain the ethyl-acetate fraction (ET) and the residue (RES). These were administered orally to 3 groups of monosodium glutamate- obese rats (n = 6), respectively, for 6 weeks. Other groups in the study were: normal (NC), obese control (OC) and standard control (SC) which received orlistat. Hepatic total lipids, total phospholipids, triacylglycerol (TG), total cholesterol (TCHOL), 3-hydroxyl-3-methylglutaryl-CoA (HMG-CoA) reductase and paraoxonase were studied.
Total lipids, TG and TCHOL which increased in OC compared to NC group, decreased. HMG-CoA reductase activity decreased in the 3 study groups relative to OC. Paraoxonase activity which decreased in OC was up-regulated, while the magnitude of hepatic cholesterol decreased from 94.32 % in OC to 52.19, 65.43 and 47.04 % with WE, ET and RES, respectively. Flavonoids, alkaloids, glycosides, tannins and saponins were detected in the nut. GC-MS analysis revealed 16, 18 and 10 volatile components in WE, ET and RES, respectively. Unsaturated fatty acids (linolenic acids: 33.33, 47.95 and 50.93 %, and α-linolenic acids: 25, 19.66 and 26.63 %) in WE, ET and RES, respectively, are the most abundant, and likely to be responsible for the observed activity.
African walnuts can prevent hepatic lipid accumulation through reciprocal actions on HMG-CoA reductase and paraoxonase in obesity.
肥胖的特征是体脂肪增加，并涉及脂质的合成和降解之间的失衡。
本研究旨在探讨非洲核桃（Tetracarpidium conophorum）对肥胖大鼠脂质储存和肝脂代谢调节酶的影响。
用乙醇（WE）提取坚果，并进一步分离得到乙酸乙酯部分（ET）和残渣（RES）。将这些物质分别口服给予 3 组谷氨酸单钠肥胖大鼠（n = 6），持续 6 周。研究中的其他组为：正常组（NC）、肥胖对照组（OC）和标准对照组（SC），它们分别接受奥利司他。研究了肝总脂质、总磷脂、三酰甘油（TG）、总胆固醇（TCHOL）、3-羟-3-甲基戊二酰辅酶 A（HMG-CoA）还原酶和对氧磷酶。
与 NC 组相比，OC 组总脂质、TG 和 TCHOL 增加，而降低。与 OC 组相比，3 个研究组的 HMG-CoA 还原酶活性降低。OC 组对氧磷酶活性降低，上调，而肝胆固醇的幅度从 OC 组的 94.32%降低至 52.19%、65.43%和 47.04%，分别用 WE、ET 和 RES。在坚果中检测到黄酮类、生物碱、糖苷、单宁和皂苷。GC-MS 分析显示 WE、ET 和 RES 分别含有 16、18 和 10 种挥发性成分。WE、ET 和 RES 中的不饱和脂肪酸（亚麻酸：33.33%、47.95%和 50.93%，α-亚麻酸：25%、19.66%和 26.63%）含量最丰富，可能是观察到的活性的原因。
非洲核桃可通过对肥胖症 HMG-CoA 还原酶和对氧磷酶的相互作用防止肝脂质积累。
