毒理性
商业膳食补充剂中含有辛酸,已有多起明显的急性肝损伤案例归因于这类补充剂。 “LipoKinetix”就是这样一种被宣传为减肥和健身的补充剂。每片含有辛酸钠(100毫克)、诺乙非君(25毫克)、二碘甲状腺原氨酸(100毫克)、育亨宾(3毫克)和咖啡因(100毫克)。该产品与多起急性肝损伤有关。发病时间为2到12周,临床表现类似于急性病毒性肝炎,起初出现疲劳和恶心,随后出现黄疸。血清酶升高的模式为肝细胞型,血清ALT显著升高,碱性磷酸酶水平略有增加。肝活检显示急性肝细胞坏死和炎症。免疫过敏特征(发热、皮疹和嗜酸性粒细胞增多)并不常见,自身抗体通常不存在。停止服用膳食补充剂后恢复迅速,但有些情况严重,导致急性肝衰竭,需要紧急肝移植或死亡。其他含有辛酸的多成分膳食补充剂也报告了急性肝炎的病例,但比LipoKinetix要少见得多,LipoKinetix在FDA发出警告信后已从市场撤回。基于地衣的Kombucha茶也报告了罕见的肝毒性实例,但没有显示这些是否是由于辛酸或茶中的其他污染物所致。
可能性评分(辛酸):B(很可能是明显临床肝损伤的原因)。
可能性评分(Kombucha茶):C(可能是明显临床肝损伤的原因)。
Several cases of clinically apparent acute liver injury have been attributed to commercial dietary supplements that contain usnic acid. “LipoKinetix” was one such supplement advertised as a weight loss and body building supplement. Each tablet contained sodium usniate (100 mg), norephedrine (25 mg), diiodothyronine (100 mg), yohimbine (3 mg) and caffeine (100 mg). The product has been linked to multiple instances of acute liver injury. The time to onset was 2 to 12 weeks and the clinical presentation resembled acute viral hepatitis with onset of fatigue and nausea, followed by jaundice. The pattern of serum enzyme elevations was hepatocellular, with marked elevations in serum ALT and minimal increases in alkaline phosphatase levels. Liver biopsy demonstrated acute hepatocellular necrosis and inflammation. Immunoallergic features (fever, rash and eosinophilia) were not common and autoantibodies were usually not present. Recovery was rapid with stopping the dietary supplement, but some cases were severe and led to acute liver failure and either death or need for emergency liver transplantation. Instances of acute hepatitis have also been reported with other multi-ingredient dietary supplements that contain usnic acid, but much more rarely than with LipoKinetix which was withdrawn from distribution after a FDA warning letter. Rare instances of hepatotoxicity have also been reported with use of lichen based teas known as Kombucha tea, but whether these were due to usnic acid or another contaminant of the tea was not shown.
Likelihood score (usnic acid): B (highly likely cause of clinically apparent liver injury).
Likelihood score (Kombucha tea): C (probable cause of clinically apparent liver injury).
来源:LiverTox