In vivo anti-salmonella activity of aqueous extract of Euphorbia prostrata Aiton (Euphorbiaceae) and its toxicological evaluation

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

Antibacterial activities and toxicological study of the aqueous extract from leaves of Alchornea cordifolia (Euphorbiaceae)

Abstract Background A. cordifolia is a plant widely used in Africa to solve many health problems. In Cameroon, it is used in the treatment of urogenital infections. As a continuation of our search for pharmacologically active agents from natural sources, the antimicrobial activity of A. cordifolia leaf extracts against E. coli and the toxicity of this extract were investigated. Methods The antibacterial activity of the aqueous extract from leaves of Alchornea cordifolia was carried out in vitro on Escherichia coli, as well as in vivo on E. coli-infected rat model. Phytochemical screening was performed using standard methods. The acute toxicity was investigated in mice, while at the end of treatment of infected rats, some biochemical, hematological and histological markers of toxicity were evaluated. Results The extract exhibited a bacteriostatic activity with MIC value of 1500 μg/ml. Phytochemical screening revealed the presence of phenols, tannins, triterpens, flavonoids, alkaloids, anthraquinones, anthocyanins, saponins and coumarins in the extract. The acute toxicity study showed LD50 values of 8.6 g/kg and 3.8 g/kg in male and female mice respectively. In vivo, the oral administration of the extract showed a dose-dependent decrease of the bacterial load as the extract at 232, 112 and 58 g/kg were able to eradicate the infection after 9, 11 and 13 days of treatment. The infected rats showed a significant (p < 0.05) increase in the level of serum creatinine, ALAT, white blood cells, and a significant (p < 0.05) decrease in the level of food and water intake, the relative weight of lungs, heart and spleen. In the treated rats, a significant (p < 0.05) increase in food and water intake and ALAT was observed at the doses of 116 and 232 mg/kg. A decrease in the red blood cells count and serum protein levels was also observed. These observations corroborate liver damages as revealed by the histopathological examination of the cross sections of this organ. Conclusion The results of this assay thus showed that the extract of A. cordifolia is bacteriostatic, therapeutic at 58 g/kg bw and may be considered as slightly and almost non-toxic on females and males mice respectively