Safety of natural anthraquinone emodin: an assessment in mice.

BACKGROUND: Emodin, a natural anthraquinone, has shown potential as an effective therapeutic agent in the treatment of many diseases including cancer. However, its clinical development is hindered by uncertainties surrounding its potential toxicity. The primary purpose of this study was to uncover any potential toxic properties of emodin in mice at doses that have been shown to have efficacy in our cancer studies. In addition, we sought to assess the time course of emodin clearance when administered both intraperitoneally (I.P.) and orally (P.O.) in order to begin to establish effective dosing intervals. METHODS: We performed a subchronic (12 week) toxicity study using 3 different doses of emodin (~ 20 mg/kg, 40 mg/kg, and 80 mg/kg) infused into the AIN-76A diet of male and female C57BL/6 mice (n = 5/group/sex). Body weight and composition were assessed following the 12-week feeding regime. Tissues were harvested and assessed for gross pathological changes and blood was collected for a complete blood count and evaluation of alanine transaminase (ALT), aspartate transaminase (AST) and creatinine. For the pharmacokinetic study, emodin was delivered intraperitoneally I.P. or P.O. at 20 mg/kg or 40 mg/kg doses to male and female mice (n = 4/group/sex/time-point) and circulating levels of emodin were determined at 1, 4 and 12 h following administration via liquid chromatography with tandem mass spectrometry (LC-MS/MS) analysis. RESULTS: We found that 12 weeks of low (20 mg/kg), medium (40 mg/kg), or high (80 mg/kg) emodin feeding did not cause pathophysiological perturbations in major organs. We also found that glucuronidated emodin peaks at 1 h for both I.P. and P.O. administered emodin and is eliminated by 12 h. Interestingly, female mice appear to metabolize emodin at a faster rate than male mice as evidenced by greater levels of glucuronidated emodin at the 1 h time-point (40 mg/kg for both I.P. and P.O. and 20 mg/kg I.P.) and the 4-h time-point (20 mg/kg I.P.). CONCLUSIONS: In summary, our studies establish that 1) emodin is safe for use in both male and female mice when given at 20, 40, and 80 mg/kg doses for 12 weeks and 2) sex differences should be considered when establishing dosing intervals for emodin treatment.

Simultaneous quantification of chrysophanol and physcion in rat plasma by ultra fast liquid chromatography-tandem mass spectrometry and application of the technique to comparative pharmacokinetic studies of Radix et Rhei Rhizoma extract alone and Dahuang Fuzi Decoction.

Most herbal medicines are prescribed in combination based on the theory of TCM to obtain synergistic effects or diminish the possible adverse reactions. Compatibility refers to the combination of two or more herbs based on the clinical settings and the properties of herbs. Chrysophanol and physcion are the main effective compounds in Radix et Rhizoma Rhei and Dahuang Fuzi Decoction which is the combination of Radix et Rhizoma Rhei, Radix Aconiti Lateralis Praeparata and Radix et Rhizoma Asari. However, chrysophanol and physcion are difficult to detect in vivo because of their low concentration and interference from endogenous compounds. The aim of this study is to develop a rapid, specific and sensitive ultra high performance liquid chromatography-triple quadrupole tandem mass method to simultaneously quantify chrysophanol and physcion in rat plasma, in order to better understand the pharmacokinetics and compatibility mechanism of Dahuang Fuzi Decoction for the first time. Multiple reaction monitoring (MRM) mode was applied for the quantitation at [M-H](-)m/z 253.0→m/z 225.1 for chrysophanol, [M-H](-) for m/z 283.1→m/z 240.0 physcion and [M-H](-)m/z 239.0→m/z 211.0 for IS. The analytes were separated on an Agilent Eclipse plus C18 column (100mm×2.1mm, 1.8µm) column within a total running time of 6.5min using a mixture of 3mM ammonium acetate in water and methanol (95:5, v/v) with a time program flow gradient according to the "plus gradient chromatography" theory. The inclusion of the ammonium acetate in the UFLC mobile phase dramatically improved the detection limit of the tested compounds and decreased the interference by matrix effects, which have been referred to as "LC-electrolyte effects". Finally, we demonstrated the application of a validated method in a comparative pharmacokinetic study of rats receiving an oral dose of Dahuang Fuzi Decoction or Radix et Rhei Rhizoma, the monarch drug in the prescription. Pharmacokinetic parameters showed significant difference between the two groups. The achieved comparative pharmacokinetic results were helpful to clarify the combination mechanism of Dahuang Fuzi Decoction.

Hepatotoxic assessment of Polygoni Multiflori Radix extract and toxicokinetic study of stilbene glucoside and anthraquinones in rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Polygoni Multiflori Radix (PMR) has been traditionally used as a tonic and an anti-aging remedy for centuries; however, hepatic lesions linked to PMR have been frequently reported. AIM OF THE STUDY: This work attempted to investigate the hepatotoxic potential of PMR extract and the toxicokinetics of stilbene glucoside and anthraquinones in PMR extract following repeated administration. MATERIALS AND METHODS: Histopathological and biochemical tests were performed to assess the hepatotoxicity of PMR extract. A rapid and sensitive liquid chromatography-mass spectrometry (LC-MS) assay was developed for toxicokinetic analysis of the main constituents of PMR extract, including 2,3,5,4'-tetrahydroxystilbene-2-O-ß-D-glucoside (TSG), emodin-8-O-ß-D-glucoside and emodin. RESULTS: The histopathological and biochemical tests indicated that repeated administration of high-dose PMR extract (20 g/kg) for 3 weeks could cause hepatic lesions, while the low-dose treatment (1 g/kg) was safe. Necrosis and steatosis of hepatic cells, inflammatory cell infiltration and mild fibrosis were the main toxicity symptoms caused by high-dose PMR extract in rat liver. The aspartate aminotransferase (AST) levels increased by approximately 17%, from 110.80±0.84 to 129.75±10.83 IU/L, in the high-dose group compared with the control group. The proposed LC-MS method was proven to be suitable for the simultaneous quantification of these three constituents by affording desirable linearity (r(2)>0.998) and satisfactory precision (error less than 10%). The toxicokinetic study showed that emodin could not be detected in the low-dose group, but the AUC and Cmax of emodin displayed a gradual increase with repeated treatments in the high-dose group. The toxicokinetics of TSG in the low- and high-dose groups exhibited similar trends after repeated administration. CONCLUSIONS: Consideration needs to be given to the rational application of PMR in the clinic to balance its benefits and risks. The increased emodin exposure in vivo provided a putative explanation for the observed hepatic lesions induced by PMR extract, although further studies to confirm the potentially causal link between emodin exposure and hepatic lesions are still necessary.

A rapid UFLC-MS/MS method for simultaneous determination of formononetin, cryptotanshinone, tanshinone IIA and emodin in rat plasma and its application to a pharmacokinetic study of Bu Shen Huo Xue formula.

Bu Shen Huo Xue formula (BSHX) is a traditional Chinese medicine prescription used for clinical treatment of chronic kidney diseases. A rapid and selective Ultra fast liquid chromatography with tandem mass spectrometry (UFLC-MS/MS) method was developed for simultaneous determination of four bioactive components of BSHX including formononetin, cryptotanshinone, tanshinone IIA, and emodin in control and unilateral ureteral obstruction (UUO) model rat plasma for the first time. Atorvastatin was used as the internal standard (IS). Plasma samples were extracted by liquid-liquid extraction with ethyl acetate. The chromatographic separation was carried out on a Shim-pack XR-ODS III column with a gradient mobile phase consisting of acetonitrile and 0.1% formic acid. The detection was performed on a triple-quad tandem mass spectrometer by multiple reaction monitoring (MRM) via electrospray ionization (ESI) source with positive ionization mode for formononetin, cryptotanshinone, tanshinone IIA, and negative mode for emodin. The method was linear for four analytes over the range of investigated concentration with all coefficients of determination (R(2)) greater than 0.9938. The lower limits of quantification (LLOQ) for formononetin, cryptotanshinone, tanshinone IIA, and emodin were defined as 0.3, 0.5, 1.5, and 0.3ng/mL, respectively. The rapid and sensitive method was fully validated and successfully applied to the pharmacokinetic study of formononetin, cryptotanshinone, tanshinone IIA and emodin in rats following oral administration of Bu Shen Huo Xue formula.