An experimental study on providing a scientific evidence for seven-time alcohol-steaming of Rhei Rhizoma when clinically used

Abstract

BackgroundRhei Rhizoma (RR) has been widely used as laxative and processed to alter its therapeutic actions or reduce its side effects. In this study, we evaluated experimentally the clinical application guideline that RR should be alcohol-steamed seven times before being used in elderly patients, as described in Dongeuibogam, the most famous book on Korean traditional medicine.MethodsUnprocessed RR (RR-U) was soaked in rice wine, steamed and then fully dried (RR-P1). The process was repeated four (RR-P4) or seven times (RR-P7). Reversed-phase high-performance liquid chromatography was used to determine the RR-U, RR-P1, RR-P4 and RR-P7 (RRs) constituents. To evaluate the effect of RRs on liver toxicity, human hepatoma cells (HepG2) were treated with RRs at 100 μg/mL for 4 h and then cell viabilities were measured using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide method. To confirm the effects in vivo, 5-week-old male Sprague–Dawley rats were treated with RRs at 3 g/kg/day for 21 days. Body weight and serum biochemical parameters were measured and liver histology was assessed.ResultsThe levels of sennosides decreased in processed RRs in an iteration-dependent manner, while the emodin level was unaffected. In HepG2 cells, cell viability was reduced with RR-U, while the toxicity decreased according to the number of processing cycles. The changes in body weight, relative liver weight and liver enzymes of RR-U-treated rats were reduced in processed RRs-treated rats. Histopathological analysis indicated swelling and cholestasis improved following seven times alcohol-steaming cycles.ConclusionsThese results provide experimental evidence that RR-P7 almost completely reduces RR hepatotoxicity.Electronic supplementary materialThe online version of this article (doi:10.1186/s12906-015-0922-y) contains supplementary material, which is available to authorized users.

Untargeted Metabolomics Reveals Dose-Response Characteristics for Effect of Rhubarb in a Rat Model of Cholestasis

“…Rhubarb (Rhei Radix et Rhizoma) is a famous medicine officially documented in the Chinese Pharmacopoeia (National Pharmacopoeia Committee, 2010 ), that has been used for the treatment of cholestasis since the time of the Eastern Hang dynasty (25–220 AD) as part of the Yin-Chen-Hao-Tang preparation (Wang et al, 2011b ). Rhubarb has been shown to possess broad spectrum activities, such as antioxidant (Silveira et al, 2013 ), anti-inflammatory (Hu et al, 2014 ), and hepatoprotective activities (Neyrinck et al, 2014 ); moreover, rhubarb encourage bilirubin excretion (Sim et al, 2015 ), and has been applied for the treatment of cholestasis in the clinic (Ho, 1996 ; Huang et al, 1997 ).…”