Department of Physiology, School of Medicine, Wuhan University, Wuhan, 430071, PR China.
Department of Pathophysiology, School of Medicine, Wuhan University, Wuhan, 430071, PR China.
Toxicol Lett. 2018 Dec 15;299:56-66. doi: 10.1016/j.toxlet.2018.09.003. Epub 2018 Sep 16.
Cadmium exposure is closely associated with a variety of diseases including cancers and the accumulation of cadmium has been long recognized as a public health problem. It is therefore of high importance to find methods to reduce cadmium accumulation in the human body. Herein, we report that administration of betulinic acid (BA) protects mice from cadmium chloride (CdCl2)-induced toxicity by inhibiting cadmium-induced apoptosis in both kidney and liver. Mice were given oral doses of 3 mg/kg, 10 mg/kg and 30 mg/kg of BA daily for ten consecutive days, and were injected with one dose of 1 mg/kg CdCl2 after one hour of BA administration every day. The levels of serum alanine aminotransferase (ALT), aspartate aminotransferase (AST) and blood urea nitrogen (BUN) were assessed by ELISA. Residual cadmium was determined by atomic absorption analysis. Protein expression was evaluated by western blotting. Pretreatment with BA significantly reduced residual cadmium levels in the liver, kidney and testis, increased the cadmium output in urine, and reduced tissue damage induced by CdCl2. Moreover, BA prevented body weight loss by CdCl2 in a dose dependent manner. Furthermore, BA treatment increased the expression levels of B-cell lymphoma 2 (Bcl-2), decreased Bcl-2-associated X (Bax), and inhibited the levels of active caspase-3. Importantly, BA within a dose of 30 mg/kg did not induce any signs of toxicity, and protected mice from the toxicity induced by CdCl2 in a dose-dependent manner. Our findings suggest that BA inhibits CdCl2 induced apoptosis in the kidney and liver, and BA may be an effective agent for the prevention and treatment of cadmium-induced diseases in humans.
镉暴露与多种疾病密切相关,包括癌症,镉的积累长期以来被认为是一个公共卫生问题。因此,寻找减少人体内镉积累的方法非常重要。在此,我们报告桦木酸(BA)通过抑制镉诱导的肾和肝细胞凋亡,保护小鼠免受氯化镉(CdCl2)诱导的毒性。小鼠连续 10 天每天口服 3mg/kg、10mg/kg 和 30mg/kg 的 BA,在 BA 给药 1 小时后每天注射 1mg/kg 的 CdCl2。通过 ELISA 评估血清丙氨酸氨基转移酶(ALT)、天冬氨酸氨基转移酶(AST)和血尿素氮(BUN)的水平。通过原子吸收分析测定残留镉的含量。通过 Western blot 评估蛋白表达。BA 预处理显著降低了肝、肾和睾丸中的残留镉水平,增加了尿中的镉排泄量,减轻了 CdCl2 诱导的组织损伤。此外,BA 以剂量依赖的方式防止了 CdCl2 引起的体重减轻。此外,BA 处理增加了 B 细胞淋巴瘤 2(Bcl-2)的表达水平,降低了 Bcl-2 相关 X(Bax)的水平,并抑制了活性 caspase-3 的水平。重要的是,30mg/kg 剂量的 BA 不会引起任何毒性迹象,并以剂量依赖的方式保护小鼠免受 CdCl2 引起的毒性。我们的研究结果表明,BA 抑制了肾和肝中 CdCl2 诱导的细胞凋亡,BA 可能是预防和治疗人类镉诱导疾病的有效药物。