Evaluation of Phyllanthus amarus and Phyllanthus maderaspatensis as agents for postexposure prophylaxis in neonatal duck hepatitis B virus infection

Abstract

The therapeutic potential of plant extracts of Phyllanthus amarus and Phyllanthus maderaspatensis for postexposure prophylaxis against infection by Hepadnaviruses was studied in ducklings infected by the duck hepatitis B virus (DHBV). Forty‐four Pekin ducklings were inoculated intraperitoneally with DHBV at 24 hr posthatch. They were treated by intraperitoneal injection of Phyllanthus amarus (aqueous extract) (100 mg/kg body weight) or Phyllanthus mad eraspatensis (alcoholic extract) (100 mg/kg body weight) for a period of 4 weeks. Infected ducklings treated with saline served as controls. Weekly serum samples obtained before, during, and after treatment were analysed for the presence of DHBV DNA in serum by dot blot hybridisation using α ³²P‐labelled probes. Liver tissue was collected after killing the ducks at various time intervals and was studied for replicative status of the viral DNA and liver histopathology; 17 of 21 ducks were viraemic on completion of treatment with Phyllanthus amarus. At 16 week posttreatment follow‐up four of seven animals remained viraemic. Similar results were obtained with Phyllanthus maderaspatensis. There was no alteration in DHBV replication in the liver. No toxicity was observed with this treatment. These observations suggest that Phyllanthus amarus and Phyllanthus maderaspatensis are not useful as therapeutic agents for postexposure prophylaxis against DHBV infection.