Noa Miriam, Mendoza Sarahí, Más Rosa, Mendoza Nilda
Center of Natural Products from the National Center for Scientific Research, Havana City, Cuba.
Drugs R D. 2003;4(1):29-35. doi: 10.2165/00126839-200304010-00003.
Policosanol is a cholesterol-lowering drug purified from sugarcane (Saccharum officinarum, L.) wax. Beneficial pleiotropic effects of policosanol, such as inhibition of the susceptibility of low density lipoprotein to lipid peroxidation, have been shown. Policosanol has a good safety profile and well tolerated and, to date, no drug-related adverse effects have been demonstrated. Specifically, policosanol has not been shown to affect liver function or to increase liver enzyme levels in experimental or clinical studies.
This study was conducted to determine whether policosanol prevents liver damage induced by carbon tetrachloride (CCl4) in rats, since this model has been associated with an increased rate of lipid peroxidation.
Male Sprague-Dawley rats were randomised to four experimental groups: negative controls (no CCl4 or policosanol, group 1); positive controls (CCl4 but no policosanol, group 2); policosanol 25 mg/kg (group 3) and policosanol 100 mg/kg (group 4). Acute liver injury was induced in groups 2, 3 and 4 by CCl4 suspended in olive oil and administered at a dose of 1590 mg/kg via intraperitoneal injection. Eighteen hours after CCl4 dosing, the rats were anaesthetised and their livers removed for histopathological studies.
Policosanol 25 and 100 mg/kg dose dependently and significantly (p < 0.01) decreased the percentage of ballooned cells and hepatocytes with lipid inclusions and increased the percentage of normal hepatocytes compared with positive controls. The percentage inhibition of the occurrence of ballooned cells and hepatocytes with lipids was marked, reaching 71 and 49%, respectively, with the higher dose (100 mg/kg). The percentage of swollen hepatocytes was unchanged by policosanol compared with positive controls. No histological alterations in liver sections were found in the negative control group. Necrotic areas and inflammatory infiltrates were observed in the liver of seven of eight (87.5%) animals in the positive control group. However, only one of eight (12.5%) animals treated with policosanol 25 mg/kg and none (0%) treated with the higher dose (100 mg/kg) showed such a pattern.
Policosanol protected against the histological changes characteristic of CCl(4)-induced hepatic injury in rats, a model of hepatotoxicity in which the process of lipid peroxidation plays a role. Further studies aimed at demonstrating the connection between such hepatoprotective and antioxidant effects of policosanol must be initiated.
聚廿烷醇是一种从甘蔗(甘蔗属,L.)蜡中提纯的降胆固醇药物。已证实聚廿烷醇具有有益的多效性作用,如抑制低密度脂蛋白对脂质过氧化的易感性。聚廿烷醇具有良好的安全性且耐受性良好,迄今为止,尚未证实有与药物相关的不良反应。具体而言,在实验或临床研究中,聚廿烷醇未显示会影响肝功能或增加肝酶水平。
本研究旨在确定聚廿烷醇是否能预防四氯化碳(CCl4)诱导的大鼠肝损伤,因为该模型与脂质过氧化速率增加有关。
将雄性Sprague-Dawley大鼠随机分为四个实验组:阴性对照组(不给予CCl4或聚廿烷醇,第1组);阳性对照组(给予CCl4但不给予聚廿烷醇,第2组);聚廿烷醇25mg/kg组(第3组)和聚廿烷醇100mg/kg组(第4组)。第2、3和4组通过腹腔注射给予悬浮于橄榄油中的CCl4,剂量为每千克体重1590mg,诱导急性肝损伤。给予CCl418小时后,将大鼠麻醉并取出肝脏进行组织病理学研究。
与阳性对照组相比,聚廿烷醇25mg/kg和100mg/kg剂量依赖性且显著地(p<0.01)降低了气球样细胞和有脂质包涵体的肝细胞的百分比,并增加了正常肝细胞的百分比。高剂量(100mg/kg)时,对气球样细胞和有脂质的肝细胞出现的抑制百分比显著,分别达到71%和49%。与阳性对照组相比,聚廿烷醇对肿胀肝细胞的百分比无影响。阴性对照组肝脏切片未发现组织学改变。阳性对照组8只动物中有7只(87.5%)的肝脏观察到坏死区域和炎性浸润。然而,聚廿烷醇25mg/kg组治疗的8只动物中只有1只(12.5%)出现这种情况,高剂量(100mg/kg)组治疗的动物均未出现(0%)。
聚廿烷醇可预防CCl4诱导的大鼠肝损伤的组织学变化特征,在该肝毒性模型中脂质过氧化过程起作用。必须开展进一步研究以证实聚廿烷醇的这种肝保护作用与抗氧化作用之间的联系。