Research progress on variations of endogenous metabolites and intestinal bacteria in ulcerative colitis / 中国药理学与毒理学杂志

Ulcerative colitis(UC)is a common chronic intestinal inflammation and one of the modern diseases that are difficult to cure effectively.Increasing attention is paid on UC based on metabonomic and microbe analysis. In this article, we review the recent advances in endogenous metabolites including amino acid, energy metabolism and lipid metabolism, intestinal bacteria including Firmicutes, Bacte-roidetes, Proteobacteria and Actinobacteria as well as covariation between metabolites and intestinal bacteria in UC.Short chain fatty acid and tryptophan are used as examples to ecaborate on the important functions of metabolism of nutrients and intestinal bacteria in diseases and illustrate the contributions of intestinal bacteria to diseases.

Comparative pharmacokinetics of bergenin, a main active constituent of Saxifraga stolonifera Curt., in normal and hepatic injury rats after oral administration / 中国天然药物

Bergenin, isolated from the herb of Saxifrage stolonifera Curt. (Hu-Er-Cao) has hepatoprotective, anti-inflammatory, antitussive, and neuroprotective activities. The aim of the present study was to establish a simple, rapid, and sensitive RP-HPLC method for determination of bergenin in rat plasma and compare its oral pharmacokinetic behaviors in normal and CCl-induced hepatic injury rats. With norisoboldine as an internal standard, chromatographic separation was performed on a C analytical column with acetonitrile and water (11 : 89, V/V) containing 0.1% formic acid as the mobile phase. A good linearity was obtained over the range of 100-10 000 ng·mL. The lower limit of quantification was 50 ng·mL. The developed method was successfully applied to a study of the pharmacokinetic difference of bergenin (100 mg·kg) between normal and hepatic injury rats after oral administration. Marked alterations of pharmacokinetic parameters in hepatic injury rats were observed. Compared to normal rats, the AUC of bergenin in hepatic injury rats was elevated to 2.11-fold and C was increased by 130%, whereas CL value was only 55% of the normal rats, suggesting that the systemic exposure of bergenin was significantly increased under hepatic injury status.

Tetrandrine inhibits migration and invasion of rheumatoid arthritis fibroblast-like synoviocytes through down-regulating the expressions of Rac1, Cdc42, and RhoA GTPases and activation of the PI3K/Akt and JNK signaling pathways / 中国天然药物

Tetrandrine (Tet), the main active constituent of Stephania tetrandra root, has been demonstrated to alleviate adjuvant-induced arthritis in rats. The present study was designed to investigate the effects of Tet on the migration and invasion of rheumatoid arthritis fibroblast-like synoviocytes (RA-FLS) and explore the underlying mechanisms. By using cultures of primary FLS isolated from synoviums of RA patients and cell line MH7A, Tet (0.3, 1 μmol·L(-1)) was proven to significantly impede migration and invasion of RA-FLS, but not cell proliferation. Tet also greatly reduced the activation and expressions of matrix degrading enzymes MMP-2/9, the expression of F-actin and the activation of FAK, which controlled the morphologic changes in migration process of FLS. To identify the key signaling pathways by which Tet exerts anti-migration effect, the specific inhibitors of multiple signaling pathways LY294002, Triciribine, SP600125, U0126, SB203580, and PDTC (against PI3K, Akt, JNK, ERK, p38 MAPK and NF-κB-p65, respectively) were used. Among them, LY294002, Triciribine, and SP600125 were shown to obviously inhibit the migration of MH7A cells. Consistently, Tet was able to down-regulate the activation of Akt and JNK as demonstrated by Western blotting assay. Moreover, Tet could reduce the expressions of migration-related proteins Rho GTPases Rac1, Cdc42, and RhoA in MH7A cells. In conclusion, Tet can impede the migration and invasion of RA-FLS, which provides a plausible explanation for its protective effect on RA. The underlying mechanisms involve the reduction of the expressions of Rac1, Cdc42, and RhoA, inhibition of the activation of Akt and JNK, and subsequent down-regulation of activation and/or expressions of MMP-2/9, F-actin, and FAK.

A LC-ESI-MS method for the simultaneous determination of madecassoside and its metabolite madecassic acid in rat plasma: comparison pharmacokinetics in normal and collagen-induced arthritic rats / 中国天然药物

To develop a simple and highly sensitive high performance liquid chromatography with electrospray ionization mass spectrometric (LC-ESI-MS) method for the simultaneous determination of madecassoside and its major metabolite madecassic acid in rat plasma, and compare the pharmacokinetics of the two compounds in normal and collagen-induced arthritis (CIA) rats. Glycyrrhetinic acid was used as the internal standard (IS). Chromatographic separation was accomplished on an Inertsil ODS-3 column, using a gradient elution with the mobile phase composed of acetonitrile and water acidified with 0.1% (V/V) formic acid. Detection was achieved by ESI-MS under the negative selected ion monitoring (SIM) mode. In normal and CIA rats, madecassoside (30 mg·kg(-1)) was orally administered for 21 consecutive days from the day of arthritis onset. For madecassoside, the linear range was 10-1 000 ng·mL(-1) with the square regression coefficient (r) of 0.998 9, while for madecassic acid, the linear range was 10-500 ng·mL(-1) with the square regression coefficient (r) of 0.996 1. The lower limit of quantification was 10 ng·mL(-1) for both analytes. The intra- and inter-day precision ranged from 1.78% to 13.42% for madecassoside and 2.30% to 14.90% for madecassic acid, and the accuracy was between -0.95% and 6.30% for madecassoside and between -1.48% and 5.34% for madecassic acid. The average recoveries of madecassoside, madecassic acid and IS from spiked plasma samples were > 81%. The developed method was successfully applied to the pharmacokinetic study of madecassoside and madecassic acid in rats after an oral administration of madecassoside. During initial 7 days of dosing, the cmax and AUC of madecassoside were greatly decreased and Vd/F was markedly increased in CIA rats, and no significant difference was observed on the first day of dosing. In contrast, the T1/2, cmax and AUC of madecassic acid were significantly increased, and Ke of madecassic acid was greatly decreased in CIA rats compared with normal rats. Along with repeated administration of madecassoside, the differences of pharmacokinetic parameters of both madecassoside and madecassic acid between CIA and normal rats gradually subsided. The pharmacokinetic characteristics of both madecassoside and madecassic acid in rats were significantly altered by arthritis status, and the differences of pharmacokinetic parameters between arthritis and normal rats coincide with the severity of arthritis.

Studies on absorption kinetics of scopoletin in rat stomachs and intestines / 中国中药杂志

<p><b>OBJECTIVE</b>To study absorption kinetics of scopoletin in rat stomachs and intestines.</p><p><b>METHOD</b>Rats was cannulated for in situ recirculation. UV and HPLC methods were used to determine the concentrations of phenolsulfonphthalein and scopoletin, respectively.</p><p><b>RESULT</b>The absorption rates in rat stomachs at 2 h after administration was 76.31%; The absorption rates at colon, duodenum, ileum and jejunum were 46.25%, 40.54%, 38.21%, 32.77%, respectively. The absorption rate constant (Ka) at concentrations of 10.0144, 20.0288-40.0576 mg x L(-1) in intestine were 0.6434, 0.6137, 0.5970 h(-1), respectively. The Ka of scopoletin at pH of 6.0, 6.8 and 7.4 in intestine were 0.6217, 0.6033, 0.6137 h(-1), respectively.</p><p><b>CONCLUSION</b>The concentrations and pH values of scopoletin solution had no distinctive effect on the absorption kinetics. The absorption of scopoletin was a first-order process with passive diffusion mechanism. Scopoletin was well absorbed at stomachs and intestines in rats. Colon was the best absorption site of scopoletin, which suggest that a sustained-release preparation should be suitable for this compound.</p>

Determination of the content of saponin in Kochia scoparia fruits from different producing areas / 中国中药杂志

<p><b>OBJECTIVE</b>To compare the content of momordin Ic and total saponin in K. scoparia fruits from eleven producing areas.</p><p><b>METHOD</b>HPLC-ELSD and colorimetric method were used to determine the content of momordin Ic and total saponin, respectively.</p><p><b>RESULT</b>The content of momordin Ic in K. scoparia fruits was related to that of total saponin. In the eleven kinds of K. scoparia fruits tested, those produced in Bozhou, Baoding Anguo and Heilongjiang contained more saponins.</p><p><b>CONCLUSION</b>The content of saponin in K. scoparia fruits from various areas is different, and attention must be paid to the effects of environment on the quality of herbs.</p>