OBJECTIVE: To investigate the in vivo anti-salmonella activity and the safety of aqueous extract of Euphorbia prostratra (E. prostratra), a plant commonly used in Cameroon by traditional healers. METHODS: A Salmonella typhimurium-infected rat model was used for the study. The physiological, biochemical and histopathological markers of possible side effects of this extract were studied using standard methods. RESULTS: The extract had a significant effect on the number of viable Salmonella typhimurium recovered from faeces, and could stop salmonellosis after 8 and 10 days of treatment for male and female rats, respectively, with non-toxic doses. However, the biochemical and histopathological analyses revealed that at relatively high doses (≥ 73.48 mg/kg for female and ≥ 122.71 mg/kg for male) the extract could induce liver damage, as illustrated by a rise of serum transaminases' levels and significant inflammation of the parenchyma and portal vein. Side effects were also observed on the kidneys, as shown by both serum and urinary creatinine, and urinary proteins. CONCLUSIONS: The overall results indicate that the aqueous extract of E. prostrata has the potential to provide an effective treatment for salmonellosis, including typhoid fever. However, it is necessary to extrapolate these results in large animals, in further studies.

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.