Icariin is one of the predominant flavonoids contained in Herba Epimedii (Yin-yang-huo in Chinese), a well-known Chinese medicine for the treatment of cancers and immune system diseases. Although Herba Epimedii has been widely used in China and there are so many and various research reports on the herbal drug and its main flavones, very limited data is available on the tissue distribution and biotransformation of icariin. In the present study, a liquid chromatographic method combined with electrospray ionization tandem mass spectrometry was developed to quantify the concentration of icariin in rat plasma and various tissues collected at different time points after oral administration of the total flavonoid extract of Herba Epimedii at a dose of 0.69 g/kg (corresponding to 42 mg/g icariin). Biological samples were processed by simple protein precipitation. Genistein was chosen as internal standard. The method was successfully applied to plasma pharmacokinetic and tissue distribution studies of icariin in rat. As a result, it was worth noting that the tissue distribution characteristics of icariin exhibited a significant gender difference. Moreover, in vivo metabolism of icariin was also investigated. A total of 11 potential metabolites were found in rat feces collected in different time periods after oral and intramuscular administration of icariin. In vivo metabolic pathways were involved in hydrolysis, demethylation, oxidation, and conjugation. The preclinical data would be useful for fully understanding in vivo disposition of this compound and interpreting the mechanism of its biological response.

BackgroundEpimedium sagittatum (Sieb.et Zucc.) Maxim., Ying-Yang-Huo in Chinese has been used as a traditional Chinese medicine and is deemed to “reinforce the kidney Yang”. Previous studies showed that E. sagittatum could modulate the immune system and treat some chronic disease such as rheumatic arthritis, cardiovascular diseases and osteoporosis. The aim of this study is to evaluate the anti-inflammatory effects of ethyl acetate extracts (YYHs) of E. sagittatum and its mechanisms of action.MethodsIn order to explore the composition of YYHs, YYHs was analyzed using high performance liquid chromatography-mass spectrometry-mass spectrometry (HPLC-MS/MS) and in comparison with reference standards. Anti-inflammatory model was established in LPS-induced RAW264.7 cells. The levels of nitric oxide (NO) were measured with the Griess reagent. Production of tumor necrosis factor-alpha (TNF-α) and interleukin-2 (IL-2) were measured by enzyme-linked immunosorbent assays (ELISA). In addition, expression of p-p65 protein and TLR4/MD-2 complex was detected by western blots and flow cytometric, respectively. Nuclear factor kappa B (NF-κB) nuclear translocation was observed by fluorescence microscope.ResultsA total of eight compounds were identified, of which icariside II was the most abundant compound. YYHs (12.5–50 μg/mL) had no obvious cytotoxic effect on cells, and remarkably inhibited LPS-induced production of NO, TNF-α and IL-2 with a dose-dependent manner. Additionally, YYHs up-regulated expression of p-p65 and TLR4/MD-2 complex. Further research showed that YYHs significantly suppressed NF-κB p65 nuclear translocation.ConclusionIn brief, YYHs contributed to the inhibition of LPS-induced inflammatory response through the TLR4/MD-2-mediated NF-κB pathway and may be a potential choice to combat inflammation diseases.Abstract graphIt includes a schema of pathways at the end of the paper.

Chuan-Ke-Zhi (CKZ), a purified Herba Epimedii extract, is a potent Chinese medicine preparation whose main bioactive components are a class of flavonoid glycosides such as epimedins A, B, and C and icariin. And epimedin C is far more abundant than other flavones in this extract. This study aims to investigate the pharmacokinetic and bioavailability of epimedin C and what effects, if any, other ingredients in CKZ have on its pharmacokinetics. Epimedin C, CKZ, and a combination of epimedins A, B, and C and icariin were, respectively, administrated to rats, and then the pharmacokinetic parameters of epimedin C in the three groups were calculated and compared. The result indicated that CLZ, MRT0–∞, and AUC0–∞ of epimedin C were significantly different among the three groups (P < 0.05), and compared with the epimedin C group, the absorption of epimedin C significantly increased in the CKZ group. Furthermore, in this study the absolute bioavailability of epimedin C was also investigated by comparing intramuscular and intravenous administration of epimedin C. As a result, epimedin C could be quickly absorbed with extremely high absolute bioavailability after intramuscular administration.

It is well known that High-Performance Thin Layer-Chromatography (HPTLC), the off-line planar chromatographic technique, has been employed in the pharmacopoeias of many countries for identification by virtue of its low-cost, less dependent on expensive equipment, flexible mobile phase composition and easy post-derivatization. In particular, the unique merit of HPTLC is able to provide the picture-like images of multiple samples in parallel on the same plate for instant viewing. In addition to the two dimension parameters (migration distance (R f value), integration peak value), the attractive color image, as the third dimension parameter, enhances the potency of HPTLC identification. The bioactivity of herbal medicines released from its compound bioactive ingredients in a holistic manner. Therefore the detected total chemical composition in the image should be reasonably more meaningful to assessing the inherent quality than only any selected single marker constituent of the given herbal drug. A vivid colorful picture-like HPTLC image could be easily recognized but not described properly by words. Hence extending the plate spot/band capacity on the plate for involving the bioactive components as much as possible. Combining digitizing the HPTLC image, the acquired infographic (HPTLC image, the digital scanning profile and the integrated parameters) can be used for establishing the fingerprint common pattern of the given species. It can be coupled with chemometrics analysis for more effectively quantifiable assessing the inherit quality of the herbal drugs. In this paper we reported methodically some Chinese herbal drugs analysis via various levels for demonstration of the practical application in QC.

A simple, sensitive, and specific liquid chromatography tandem mass-spectrometric method was developed and validated for the determination of epimedin B in rat plasma and tissue samples. After being processed with a protein precipitation method, these samples were separated on an Agilent Eclipse XDB-C18 column with an isocratic mobile phase consisting of acetonitrile and 0.1% formic acid aqueous solution (32 : 68, v/v). The calibration curve of epimedin B was linear over the concentration range from 1 to 500 ng/mL in plasma and tissue homogenate. The method was then applied to pharmacokinetic and tissue distribution studies after a single oral administration of Herba Epimedii extract to SD rats. Results showed that epimedin B reached the plasma peak concentration at 0.4 h and the terminal elimination half-life was 1.6 h in rat plasma, and the plasma area under the curve from time zero to infinity (AUC0–∞) was 14.35 μg/L·h. The concentration distribution of epimedin B in rat tissue was in the following order: liver > ovary > womb > lung > kidney > spleen > heart > brain, indicating that the compound could be widely distributed in rat, and the reproductive system may be the principal target of epimedin B for female rat.