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

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.

Antityphoid properties and toxicity evaluation of Harungana madagascariensis Lam (Hypericaceae) aqueous leaf extract.

CONTEXT: Harungana madagascariensis Lam is commonly used in Cameroonian folk medicine for the treatment of malaria and typhoid fever. OBJECTIVE: To investigate the therapeutic potentials of H. madagascariensis aqueous leaf extract for the treatment of salmonellosis (e.g. typhoid fever, gastroenteritis). MATERIALS AND METHODS: A Salmonella Typhimurium-infected rat model was used. The faeces of these rats were analysed for viable Salmonella Typhimurium before and after infection, and during the treatment period. The physiological, biochemical and histopathological markers of possible side effects of the extract were also studied using standard methods and kits. RESULTS AND DISCUSSION: The in vivo antisalmonellal study revealed that this extract significantly (P<0.05) reduced the number of viable Salmonella Typhimurium recovered from faeces, and could stop salmonellosis after 10 days of treatment for male and female rats, with non-toxic doses. However, the biochemical and histological analyses revealed that at relatively high-doses (≥100mg/kg for females and 200mg/kg for males) the extract could induce liver damage, as illustrated by a rise of serum transaminases (ALT and AST), significant inflammation of the parenchyma and portal vein, as well as cell necrosis. There were also increases in cholesterol levels in both sexes. No significant unwanted side effect of the extract was observed on the kidney, as shown by both serum and urinary creatinine, and urinary protein levels. CONCLUSION: The results obtained showed that H. madagascariensis has a promising antisalmonellal effect and, therefore, the potential to provide an effective treatment against salmonellosis, including typhoid fever.