N-nitrosamines have been linked with cancer in humans due to their presence in drinking water and diets. This study evaluated the role of betulinic acid (BA) in abating oxidative stress, inflammation, and hyperlipidemia in rats treated with N-nitrosodimethylamine (NDMA). Twenty-four male rats were assigned into four equal groups. Group I served as the control, Group II received BA (25 mg/kg), Group III received NDMA (5 mg/kg) and, Group IV received BA (25 mg/kg) and NDMA (5 mg/kg). Results showed that the administration of NDMA significantly (p < 0.05) elevated malondialdehyde in the liver and kidney relative to controls. Activities of superoxide dismutase, catalase, glutathione peroxidase, and glutathione-S-transferase, and the level of glutathione were significantly (p < 0.05) decreased by NDMA, while treatment with BA elevated the activities of these enzymes in the liver and kidney. The BA lowered serum interleukin-6 and tumor necrosis factor-alpha levels against the NDMA effect. Furthermore, NDMA increased hepatic and renal triglyceride while phospholipids levels were decreased. NDMA significantly modulated the activities of drug-metabolizing enzymes (aniline hydroxylase, aminopyrine-N-demethylase, and uridyldiphosphoglucuronyltransferase), while BA was able to restore these enzymes to values close to controls. Histology revealed the presence of infiltration and fibroplasia in the liver, while cortical degeneration was noticed in the kidney in NDMA-administered rats. These lesions were reduced in the NDMA rats treated with BA. The findings suggest that BA improves NDMA-induced damage in the liver and kidney of rats through reactions that can be linked with antioxidant, anti-inflammatory, and lipid-lowering pathways.

中文翻译：

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白桦脂酸减轻 N-亚硝基二甲胺诱导的 Wistar 大鼠肝脏和肾脏脂质代谢、氧化应激和炎症的变化

N-亚硝胺与人类癌症有关，因为它们存在于饮用水和饮食中。本研究评估了桦木酸 (BA) 在减轻用N-亚硝基二甲胺(NDMA)治疗的大鼠的氧化应激、炎症和高脂血症中的作用。二十四只雄性大鼠被分成四个相等的组。第 I 组作为对照，第 II 组接受 BA (25 mg/kg)，第 III 组接受 NDMA (5 mg/kg)，第 IV 组接受 BA (25 mg/kg) 和 NDMA (5 mg/kg)。结果表明，与对照组相比，NDMA 的施用显着（p  < 0.05）升高了肝脏和肾脏中的丙二醛。超氧化物歧化酶、过氧化氢酶、谷胱甘肽过氧化物酶和谷胱甘肽-S的活性NDMA显着降低了β-转移酶和谷胱甘肽水平（p  < 0.05），而BA治疗提高了这些酶在肝脏和肾脏中的活性。BA 降低了抗 NDMA 效应的血清白细胞介素 6 和肿瘤坏死因子 α 水平。此外，NDMA 增加肝脏和肾脏甘油三酯，而磷脂水平降低。NDMA 显着调节药物代谢酶（苯胺羟化酶、氨基比林-N-去甲基化酶和尿苷二磷酸葡萄糖醛酸转移酶），而 BA 能够将这些酶恢复到接近对照的值。组织学显示肝脏中存在浸润和纤维增生，而 NDMA 给药大鼠的肾脏中发现皮质变性。这些损伤在用 BA 治疗的 NDMA 大鼠中减少。研究结果表明，BA 通过与抗氧化、抗炎和降脂途径相关的反应改善了 NDMA 引起的大鼠肝脏和肾脏损伤。