Investigation of the Effects of Chronic L-Arginine Supplementation on Paraoxonase-1 Activity in High-Cholesterol Diet-Induced Hypercholesterolemia Model in Rats

Investigation the effects of chronic oral L-arginine supplementation in hypercholesterolemic rats on serum paraoxonase-1 activity, lipid profile, and oxidative stress levels were aimed in this study. Adult Wistar albino male rats were randomly selected and divided into 4 groups equally (n=9), named as control group (C), L-arginine group (LA), hypercholesterolemia group (HC) and hypercholesterolemia+L-arginine group (HC+LA). The experimental model was performed by feeding subjects with a 3% cholesterol diet for 8 weeks. L-arginine supplementation was performed by containing 3% L-arginine into the drinking water of the subjects. At the end of the study, serum lipids, paraoxonase1 (PON1) activity, and malondialdehyde (MDA) levels of all animals were measured, and the atherogenic index (ATI) was calculated. Atherosclerotic lesions were evaluated histopathologically using aort tissue specimens. It was found that serum PON1, MDA and lipids as well as ATI and PON1/HDL ratio increased in the HC, whereas in the HC+LA, these parameters were decreased statistically significantly compared to the HC. Moreover, a statistically significant increase was found in serum TG, VLDL and PON1 levels in the LA compared to the C. PON1 and MDA levels were found to be strongly correlated in a negative way. 8 weeks of L-arginine administration found to be effective on decreasing ATI, LDL and oxidative status of rats in hypercholesterolemia group, conversely, it didn’t display significant difference for PON1 and HDL levels. In addition, it was determined in the histopathological examination that l-arginine supplementation alleviated the changes of vascular structures due to hypercholesterolemia.

本研究旨在探讨慢性口服L-精氨酸补充对高胆固醇血症大鼠血清脂氧合酶1活性、血脂谱和氧化应激水平的影响。选取成年Wistar白化雄性大鼠，随机分为四组，每组9只，分别命名为对照组（C）、L-精氨酸组（LA）、高胆固醇血症组（HC）和高胆固醇血症+L-精氨酸组（HC+LA）。通过给予受试者含3%胆固醇的饮食8周建立实验模型。L-精氨酸补充通过在受试者的饮用水中添加3%L-精氨酸进行。研究结束时，测量所有动物的血清脂质、脂氧合酶1（PON1）活性和丙二醛（MDA）水平，并计算动脉粥样硬化指数（ATI）。采用主动脉组织标本进行病理学检查以评估动脉粥样硬化病变。研究发现，与对照组相比，HC组血清PON1、MDA和脂质以及ATI和PON1/HDL比值均显著升高，而在HC+LA组，这些指标与HC组相比均显著降低。此外，与C组相比，LA组血清三酰甘油（TG）、极低密度脂蛋白（VLDL）和PON1水平显著升高。PON1和MDA水平被发现呈负相关。8周L-精氨酸给药被证明对降低高胆固醇血症组大鼠的ATI、LDL和氧化应激状态有效，而对于PON1和HDL水平则未显示显著差异。此外，在病理学检查中还确定，L-精氨酸补充减轻了高胆固醇血症导致的血管结构变化。