Viral load in 1-day-old ducklings acutely infected with duck hepatitis B virus by different doses and routes of inoculation

In vitro and in vivo anti-hepatitis B virus activities of the lignan nirtetralin B isolated from Phyllanthus niruri L

ETHNOPHARMACOLOGICAL RELEVANCE

Nirtetralin B, a new lignan first reported by our team, is isolated from Phyllanthus niruri L. This plant has long been used in folk medicine for liver protection and antihepatitis B in many Asian countries. This study was designed to evaluate the anti-hepatitis B virus activity of nirtetralin B using HepG2.2.15 cells and duck hepatitis B virus (DHBV) infected ducks as in vitro and in vivo models.

MATERIALS AND METHODS

Nirtetralin B was isolated from Phyllanthus niruri L. (Euphorbiaceae) by extraction and chromatographic procedures and the anti-hepatitis B virus activity was evaluated both in vitro and in vivo. The human HBV-transfected liver cell line HepG2.2.15 was used in vitro assay. And the in vivo anti-hepatitis B virus activity was evaluated on the expression of HBV replication, HBsAg, HBeAg, ALT and AST on day 0, 7, 14, 17 after nirtetralin B was dosed intragastricly (i.g.) once a day for 14 days at the dosages of 25, 50 and 100mg/kg/day in the duck hepatitis B virus (DHBV) infected ducks.

RESULTS

In the human HBV-transfected liver cell line HepG2.2.15, nirtetralin B effectively suppressed the secretion of the HBV antigens in a dose-dependent manner with IC50 values for HBsAg of 17.4μM, IC50 values for HBeAg of 63.9μM. In DHBV-infected ducklings, nirtetralin B significantly reduced the serum DHBV DNA, HBsAg, HBeAg, ALT and AST. And analysis of the liver pathological changes confirmed the hepatoprotective effect of nirtetralin B.

CONCLUSION

The experimental data demonstrated that nirtetralin B exhibits anti-hepatitis B virus activity both in vitro and in vivo.

In vitro and in vivo anti-hepatitis B virus activities of the lignan niranthin isolated from Phyllanthus niruri L

ETHNOPHARMACOLOGICAL RELEVANCE

Niranthin is a lignan isolated from Phyllanthus niruri L. This plant has long been used in folk medicine for liver protection and antihepatitis B in many Asian countries. This study was designed to evaluate the anti-hepatitis B virus activity of niranthin using HepG2.2.15 cells and duck hepatitis B virus (DHBV) infected ducks as in vitro and in vivo models.

MATERIALS AND METHODS

Niranthin was isolated from Phyllanthus niruri L. (Euphorbiaceae) by extraction and chromatographic procedures and the anti-hepatitis B virus activity was evaluated both in vitro and in vivo. The human HBV-transfected liver cell line HepG2.2.15 was used in vitro assay. And the in vivo anti-hepatitis B virus activity was evaluated on the expression of HBV replication, HBsAg, HBeAg, ALT and AST on day 0, 7, 14, 17 after niranthin was dosed intragastricly (i.g.) once a day for 14 days at the dosages of 25, 50 and 100 mg/kg/day in the duck hepatitis B virus (DHBV) infected ducks.

RESULTS

In the human HBV-transfected liver cell line HepG2.2.15, the secretion of HBsAg and HBeAg were significantly decreased after treatment with niranthin for 144 h, with IC50 values for HBsAg of 15.6 µM, IC50 values for HBeAg of 25.1 µM. In DHBV-infected ducklings, niranthin significantly reduced the serum DHBV DNA, HBsAg, HBeAg, ALT and AST. Furthermore, analysis of the liver pathological changes confirmed the hepatoprotective effect of niranthin.

CONCLUSION

The experimental data demonstrated that niranthin exhibits anti-hepatitis B virus activity both in vitro and in vivo.

Development and evaluation of an antigen-capture ELISA for detection of the UL24 antigen of the duck enteritis virus, based on a polyclonal antibody against the UL24 expression protein

An antigen-capture enzyme-linked immunosorbent assay (AC-ELISA) method was developed for the efficient detection of the UL24 antigen of the duck enteritis virus (DEV) using polyclonal antibodies. Ducks and rabbits were immunized, respectively, with expressed UL24 recombinant protein. The IgG antibodies against UL24 from ducks and rabbits were purified and used as the capture antibodies. The specificity of the optimized AC-ELISA was evaluated by use of DEV, duck hepatitis virus (DHV), duck hepatitis B virus (DHBV), gosling plague virus (GPV), Riemerella anatipestifer (R.A.), Escherichia coli (E. coli), Pasteurella multocida (P.M.) and Salmonella Enteritidis (S.E.). Only DEV specimens yielded a specific and strong signal. The limit of the sensitivity of this method for the detection of DEV was 46 ng/100 microl. Compared with PCR and virus isolation, the rate of agreement for the detection of experimentally infected sera was 100%. A comparative test used on clinical specimens between the neutralization test and the AC-ELISA showed that the proportions of true positives and true negatives by the AC-ELISA were 0.90 and 0.67 respectively. These results indicated that the AC-ELISA approach is rapid, sensitive, and reliable for specific detection of DEV antigen.