In vitro antimicrobial activity of Harungana madagascriensis and Euphorbia prostrata extracts against some pathogenic Salmonella sp.

Harungana madagascariensis Lam (Hypericaceae) and Euphorbia prostrata Ait (Euphorbiaceae) are commonly used in Cameroon as traditional medicines for the treatment of typhoid fevers. Aqueous extracts were prepared from the leaves of H. madagascariensis and the whole plant of E. prostrata and tested in vitro for antibacterial activity against Salmonella Typhi, Salmonella Paratyphi A, Salmonella Paratyphi B and Salmonella Typhimurium, using broth dilution technique. Phytochemical screening was performed using standard methods. Acute toxicity study of the various extracts was also done on mice. Results obtained showed that H. madagascariensis extract exhibited minimum inhibitory concentrations (MICs) ranging from 390.625 to 1562.5 μg/ml. The median lethal dose (LD50) of H. madagascariensis extract as shown by the acute toxicity studies were 11.6 g/kg and 13.2 g/kg body weight for female and male mice, respectively. The MIC values of E. prostrata extract varied from 1024 to 2048 μg/ml. The LD50 values obtained for this extract were 23.2 g/kg and 26.4 g/kg body weight for female and male mice, respectively. Phytochemical analysis showed the presence of phenols, tannins, saponins, anthraquinones, anthocyanins, triterpenoids, flavonoids and alkaloids in both plant extracts. These data suggest that the aqueous extracts of H. madagascariensis and E. prostrata contain antibacterial principles which may be non toxic.Keywords: Harungana madagascariensis, Euphorbia prostrata, antibacterial activity, Salmonella sp., phytochemical screening, acute toxicity

Purification and characterization of circulating Onchocerca volvulus antigens from epileptic and non-epileptic onchocerciasis patient sera

Studies conducted during the past 25 years to investigate the possible relationship between onchocerciasis and epilepsy have led to contradictory results. In the present study aimed at contributing to the investigation of a possible relationship between onchocerciasis and epilepsy, we proceeded to purify and characterize circulating O. volvulus antigens from sera of onchocerciasis patients with and without epilepsy. Out of 539 onchocerciasis patients included in the study, sera from 78 epileptics and 20 non epileptics with high antigen titres were separately pooled and subjected to affinity purification using immunosorbent columns prepared using human and rabbit anti-O. volvulus IgG antibodies. Eluates of purified circulating O. volvulus antigens were concentrated, and then the protein contents were determined using the Bradford method. The antigenicity of the purified antigens was evaluated in a direct ELISA using onchocerciasis patient sera. Finally, the molecular composition of the purified proteins was determined by SDS-PAGE. The purified antigens were highly antigenic and there was no significant difference in the reaction profiles of the two groups or categories of patients. SDS-PAGE analysis showed that the purified antigens ranged from 31.63 to 102.40 KDa and there was no difference in the molecular composition of antigens purified from sera of the two classes of patients. Based on this antigen profiling between epileptic and non-epileptic onchocerciasis patients, we cannot conclude with certainty whether onchocerciasis is really a cause of epilepsy in areas where it is hyperendemic as predicted by some epidemiological studies.Keywords: Antigen-detection ELISA, Immunoadsorbent columns, Affinity chromatography, Antigenicity, SDS-PAG

In vitro evaluation of the antimicrobial properties of Mallotus oppositifolium decoction leaf extracts and fractions

In order to verify the in vitro antimicrobial properties of Mallotus oppositifolium (Euphorbiaceae), the qualitative phytochemical screening and the antimicrobial activities on Shigella dysenteriae A2, Salmonella typhi, Escherichia coli, Enterococcus faecalis, Staphyllococcus aureus and Candida albicans strains of the aqueous decoction (DEMO) hexane (HEMO) and methanol (MEMO) fractions of leaves were assessed. The screening was performed using colorimetric methods. The antimicrobial activity was carried out using disc diffusion assays. The minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) were determined by the dilution methods. The screening revealed the presence of metabolites such as alkaloids, flavonoids, phenolic compounds, tannins, saponins, lipids, carbohydrates, mucilages, proteins, triterpens and steroids. DEMO, HEMO, MEMO showed a concentration-dependent activity against Shigella dysenteriae A2 and Salmonella typhi, with inhibition zone ranging from 9.44±0.44 to 19.00±0.24 mm, 8.94±0.05 to 20.03±0.17 mm and 8.13±0.17 to 16.76±0.11 mm respectively. The MIC showed ranges from 0.25 to 1.00 mg.mL-1, 0.20 to 0.50 mg.mL-1 and 1.00 to 3.00 mg.mL-1, while the MBC ranged from 1.00 to 5.00 mg.mL-1, 0.50 to 1.00 and 3.00 to 10.00 mg.mL-1 respectively. The leaves decoction and fractions activity on the two strains showed promising activities to justify the use of the plant against diarrhoea in folk medicine.Keywords: Folk medicine, phytochemical analysis, Mallotus oppositifolium diarrhea, antimicrobial

Antibacterial agents from the leaves of Crinum purpurascens herb (Amaryllidaceae)

Background: Typhoid fevers and urogenital infections continue to be serious health problems in developing countries. In our search for therapeutic agents from natural sources with potential for the treatment of typhoid fevers and urogenital infections, extract and compounds were obtained from Crinum purpurascens and tested. Methods: Two alkaloids (4,5-ethano-9,10-methylenedioxy-7-phenanthridone or hippadine (1) and 4,5-ethano-9-hydroxy-10-methoxy-7-phenanthridone or pratorimine (2)) and one steroid (â-D -glucopyranoside of sitosterol (3)) were isolated from the CH2Cl2/MeOH (1:1) leaf extract of Crinum purpurascens and screened for antibacterial activity using both agar diffusion and broth dilution techniques. Results: For the CH2Cl2/MeOH extract, the MIC values obtained were 3 mg/ml (against P. aeruginosa), 4 mg/ml (against E. coli, K. pneumoniae and S. aureus) and 6 mg/ml (against S. typhi and S. paratyphi B), whereas the MBC values varied between 7 and 12 mg/ml. For compound 1, the MIC values varied between 200 and 250 µg/ml, whereas the MBC value was 300 µg/ml against all the bacteria strains used. Compound 2 did not show any antimicrobial activity against these bacteria strains. For compound 3, the MIC values varied between 250 and 300 µg/ml, whereas the MBC values were 300 µg/ml (against S. typhi and S. paratyphi B) and > 300 µg/ml (against the other bacteria strains). Conclusion: These data suggest that C. purpurascens leaf extract contains antibacterial agents which could be used in the treatment of typhoid fevers and urogenital infections

Biovailability of the antisalmonellal active ingredients contained in Allium sativum bulbs

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