Anti-hepatitis B virus activities of friedelolactones from Viola diffusa Ging.

BACKGROUND: Hepatitis B virus (HBV) infection is the major factor of causing hepatitis B, cirrhosis and liver cancer. Interferon and nucleoside drugs, the main drugs to treat HBV infection, have disadvantages of scavenge difficulty and drug resistance respectively. Viola diffusa Ging is used as a traditional Chinese herbal medicine for the treatment of hepatitis. PURPOSE: The aim of the study is to investigate the chemical constituents of Viola diffusa Ging and their anti-HBV activity. METHODS: Chemical constituents were extracted and purified by ethanol reflux extraction and chromatographic separation technology including D-101 Macroporous resin, silica gel, Sephadex LH-20 and preparative thin-layer chromatography. Their structures were elucidated on the basis of extensive NMR and MS data. Cytotoxicity and inhibiting effects on HBsAg and HBeAg secretion of HepG2.2.15 of all compounds except 10 were studied by MTT method and ELISA method. RESULTS: Three friedelolactones with naturally occurring seco-ring-A friedelane triterpenoids, 2ß-hydroxy-3, 4-seco-friedelolactone-27-oic acid (1), 2ß, 28ß-dihydroxy-3,4-seco-friedelolactone-27-oic acid (2) and 2ß, 30ß-dihydroxy-3,4-seco-friedelolactone-27-lactone (3), and a stigmastane, stigmast-25-ene-3ß,5α,6ß-triol (11) together with nine known compounds were isolated from the whole plant of Viola diffusa G. (Violaceae). Compounds 1-3, 9, 11, 12 exhibited significant activities of blocking both HBsAg and HBeAg secretion, and compound 4, 6, 7, 8 selectively inhibited HBeAg secretion while compound 13 selectively inhibited HBsAg secretion. IC50 values of compounds 1 and 2, 26.2 µM and 33.7 µM for HBsAg, 8.0 µM and 15.2 µM for HBeAg, was significantly lower than that of positive control lamivudine. CONCLUSION: Compounds 1-3, 11 are new compounds never reported before and the promising results demonstrate the potential of compound 1-3, 9, 11, 12 for the treatment of HBV infection.

[Preliminary screening of activity fraction of Alchornea trewioides suppresses expression of subgenomic hepatitis C virus RNA in vitro].

OBJECTIVE: To screen activity fraction of Alchornea trewioides which suppresses expression of subgenomic Hepatitis C Virus (HCV) RNA in vitro. METHODS: Anti-HCV effects in vitro were examined in an HCV subgenomic replicon cell culture system--CBRH7919 (Jneo3-5B). The cells were exposed to different concentrations of A. trewioides initial ethanol extracts, portions of petroleum ether,ethyl acetate and n-butanol extracts with interferon a combined with ribavirin as positive control. The content of HCV RNA was examined by Quantitative PCR. The expression levels of functional proteins NS3 were examined in all groups by Western blot. Cell proliferation test with CCK-8 assay was used to evaluate the cytotoxicity of drugs. RESULTS: The study showed that exposure of CBRH7919 (Jneo3-5B) cells to ethyl acetate extract of A. trewioides resulted in a concentration-dependent inhibition of subgenomic HCV RNA replication and NS3 protein expression ability among the four extracts (P < 0.05). The activity of ethyl acetate extract was increased by 5.71 times than that of the initial ethanol extract. IC50 to subgenomic HCV RNA was 14.60 mg/L, CC50 to CBRH7919 (Jneo3-5B) cells was 40.30 mg/L and the treatment index (TI) was 2. 76. CONCLUSION: The ethyl acetate extract of A. trewioides is the activity fraction which can significantly interfere with subgenomic HCV RNA replication and expression of NS3 protein in vitro. These data suggest that ethyl acetate extract isolated from A. trewioides may have potential use as an anti-HCV compound.

[Determination of vetatramine in Veratrum nigrum by HPLC-ELSD].

OBJECTIVE: To develop an HPLC-ELSD method for determination of vetatramine. in Veratrum nigrum. METHOD: The analy fical column was Shim-pack ODS - C18 (4.6 mm x 250 mm, 4 microm) column, the mobile phase was acetonitrile-water (containing 0.1% triethylamine) (50:50), at a flow rate of 0.8 mL x min(-1). The temperature of drift tube was 90 degrees C and the gas flow was at the rate of 2.5 L x min(-1). RESULT: The calibration curve was linear in the range of 0.36-3.6 microg (r = 0.999 8). The average recovery was 100.9% (RSD 2.3%, n = 6). The contents of veratramine in Veratrum nigrum. from the ten different sources were determined. CONCLUSION: The method may be used as a accurate and reproducible way to determine the content of veratramine in V. nigrum.

[Investigation on the formula of Fuyankang dispersed tablets].

OBJECTIVE: To investigate the preparation technique and optimal formulation of Fuyankang dispersed tablets. METHOD: The formula of Fuyankang dispersed tablets were optimized in terms of disintegrating time by studying single factor and orthogonal design test. RESULT: The products formulated with the optimum techniques met the quality specification of dispersed tablets. The dissolubility of the optimized dispersed tables was obviously faster than that of common tablets. CONCLUSION: This prescription and technology of Fuyankang dispersed tablets are reasonable and effective.