ABSTRACT
Objective: To evaluate the anti-infectious and antioxidant activities of hydroethanolic extract of Canarium schweinfurthii on broiler chickens infected by Salmonella enterica serovar Typhimurium, known to be threatening public health. Methods: Animals were divided into six groups of eight animals per group: the normal control group, negative control group, positive control group and three test groups receiving the plant extract at 5, 19 and 75 mg/kg bw, respecively. The evolution of the disease as well as the effectiveness of the treatment were monitored by stool culture from the second day post infection until the end of the treatment. In addition, the effects of treatment on growth performances and feed conversion efficiency of broilers were evaluated. For the assessment of antioxidant status, enzymatic and non-enzymatic biomarkers such as catalase, glutathione peroxidase, malondialdehyde and nitric oxide were evaluated in the serum and tissues of animals. Results: The infected chickens treated with oxytetracycline recovered on day 7 after treatment, while animals treated with 19 and 75 mg/kg of Canarium schweinfurthii extract recovered on day 9 and those with 5 mg/kg of the extract on day 10. Salmonella infection caused a decrease on catalase and glutathione peroxidase activities; the administration of various doses of Canarium schweinfurthii extract increased these enzymatic activities. Animals receiving the extract at 5 mg/kg showed a significant increase in catalase activity in serum, heart and lungs while all concentrations of the extract significantly increased glutathione peroxidase activity in the serum, liver and spleen. Concerning non-enzymatic biomarkers, Salmonella infection caused a significant increase of nitric oxide and malondialdehyde concentration in the liver and lungs. Treatment with 75 mg/kg of the extract significantly reduced nitric oxide concentration in the heart and lungs while each dose of the extract reduced and normalized the malondialdehyde level in the serum. Additionally, malondialdehyde production was significantly decreased in the liver, heart and lungs after administration of Canarium schweinfurthii extract at all doses. Conclusions: The hydroethanolic extract of Canarium schweinfurthii attenuates oxidative stress, and is effective in the treatment of avian salmonellosis.