Abstract

G.G. Bakari, R.A. Max*, H.R. Mdegela, E.C.J. Phiri and M.M.A. Mtambo

Antiviral effect of resinous extract from Commiphora swynnertonii was investigated using chickens experimentally infected with Newcastle disease (ND) virus. A total of 114 chickens, approx. 5 months old, were assigned into eight experimental groups (G1 – G8). Chickens in G1 and G2 served as negative (not infected, not treated) and positive (infected, not treated) controls. To study the prophylactic effect of the extract, chickens in G3, G4 and G5 received 250, 500 and 1,000 mg resin per kg bodyweight respectively seven days before experimental infection. Chickens in G6, G7 and G8 received 250, 500 and 1,000 mg resin per kg bodyweight respectively seven days after infection with ND virus to assess therapeutic effect of the extract. Clinical signs, bodyweight gain and mortality were monitored. Antibody titers against the virus were measured, postmortem and histopathological lesions were examined. Results revealed significant reduction (P< 0.05) in clinical signs and mortality rates following administration of the resinous extract before and after the infection. Prophylactic administration of the extract was more effective in reducing the severity of the disease compared to the therapeutic approach. Similarly, antibody titers decreased significantly (P< 0.001) in all resin-treated groups irrespective of dose given and on whether the extract was administered before or after ND was evident. These findings indicate that the resinous extract from C. swynnertonii has strong antiviral activity against ND virus in chickens and that prophylactic administration has better protective effect against the disease.