Ameliorating effect of Withania somnifera root extract in Escherichia coli-infected broilers.

The present study was undertaken to investigate the effect of aqueous Withania somnifera root (WSR) extract in broiler chicks experimentally infected with Escherichia coli O78 @ 10⁷ CFU/0.5 ml intraperitoneally. Clinical signs and mortality due to colibacillosis observed in infected chicks were mild and lasted for short duration in WSR extract supplemented group as compared with the nonsupplemented group. A significant increase in serum alanine transaminase, aspartate transaminase, lactate dehydrogenase, and creatine phosphokinase activities and a decrease in total protein and albumin concentrations were observed in the infected groups, though these changes were of lower magnitude in WSR extract supplemented group. A significantly higher activity of oxidative blood parameters such as superoxide dismutase, catalase, glutathione reductase, and glutathione-S-transferase enzymes were noticed in WSR extract supplemented group. The WSR extract supplemented group revealed significantly higher E. coli-specific antibody titer and enhanced lymphocyte proliferation response as compared with the nonsupplemented group. The gross and histopathological lesions of colibacillosis were mild in the WSR extract-supplemented infected group as compared with the nonsupplemented infected group. Withania somnifera root extract supplementation produced 31.48 and 34.38% protection in the gross and histopathological lesions in E. coli infected chicks, respectively. It is concluded that supplementation of 20% WSR extract @ 20 ml/L of water caused a reduction in the severity, mortality, and recovery period of E. coli infection and enhanced the humoral and cellular immune responses suggesting its protective effect on limiting the pathology of E. coli infection in broiler chickens.