Antimicrobial activity of Tunisian Euphorbia paralias L

Objective: To examine the potential antimicrobial activity of Euphorbia paralias L. (Euphorbiaeae) leaves and stems extracts. Methods: The antimicrobial activity was tested against six microbial strains:Escherichia coli ATCC 8739, Bacillus subtilis ATCC 6633, Salmonella enterica CIP 8039, Staphy-lococcus aureus ATCC 6538, Pseudomonas aeruginosa ATCC 9027 and Candida albicans ATCC 90028 by two different methods, the disk method and the dilution method. Results: Our results showed the important antimicrobial activity of the chloroform extract of the stems towards the majority of the strains by using both methods. Bacillus subtilis was the most sensitive strain (MIC=MBC=15μg/mL). Conclusion: Thus, some extracts of Euphorbia paralias can be used in the treatment of infectious diseases caused by microbes.

Comparative evaluation of the analgesic activity of several populations of Tunisian Citrullus colocynthis Schrad. immature fruits.

Plant extracts are some of the most attractive sources of new drugs and have shown promising results for the treatment of pains, inflammations and immune-related diseases. Citrullus colocynthis Schrad., (cucurbitaceae) endemic in Tunisia, is widely used in folk medicine to treat many inflammation disorders. The aim of this study is to quantify the alkaloid level and to evaluate the acute toxicity of different populations of Citrullus colocynthis fruit aqueous extracts at immature state and then to screen their analgesic activities. After identification and acute toxicity essay, different populations of Citrullus colocynthis Schrad. aqueous fruit extracts were screened for analgesic activity using the acetic acid writhing test in mice. Yields of prepared extracts and alkaloid level are gravimetrically determined. Results show that alkaloid level vary upon the Citrullus colocynthis population. All extracts displayed analgesic activity at different doses without inducing acute toxicity. Topic results were obtained with immature fruits from south Tunisia. Experimental results have revealed that Citrullus colocynthis Schrad. is a potentially useful drug suitable for further evaluation, and its folk medicinal use, in all Tunisia, as an analgesic agent is validated for all tested Tunisian populations.

Comparative evaluation of the analgesic activity of several populations of Tunisian Citrullus colocynthis Schrad. immature fruits.

Plant extracts are some of the most attractive sources of new drugs and have shown promising results for the treatment of pains, inflammations and immune-related diseases. Citrullus colocynthis Schrad., (cucurbitaceae) endemic in Tunisia, is widely used in folk medicine to treat many inflammation disorders. The aim of this study is to quantify the alkaloid level and to evaluate the acute toxicity of different populations of Citrullus colocynthis fruit aqueous extracts at immature state and then to screen their analgesic activities. After identification and acute toxicity essay, different populations of Citrullus colocynthis Schrad. aqueous fruit extracts were screened for analgesic activity using the acetic acid writhing test in mice. Yields of prepared extracts and alkaloid level are gravimetrically determined. Results show that alkaloid level vary upon the Citrullus colocynthis population. All extracts displayed analgesic activity at different doses without inducing acute toxicity. Topic results were obtained with immature fruits from south Tunisia. Experimental results have revealed that Citrullus colocynthis Schrad. is a potentially useful drug suitable for further evaluation, and its folk medicinal use, in all Tunisia, as an analgesic agent is validated for all tested Tunisian populations.

Assessment of the cytotoxic effect and in vitro evaluation of the anti-enteroviral activities of plants rich in flavonoids.

Nanoparticles derived from plants known for their high content of flavonoids provide a biologically inspired route to designing therapeutic agents and a means of reducing nanoparticle toxicity. Little is currently known on the antiviral activity of Salvia officinalis L. and Washingtonia filifera H.Wendl aqueous extracts and their corresponding nanoparticles. In the present study, antiviral activity of subset extracts obtained from aerial parts of Salvia officinalis L. and Washingtonia filifera H.Wendl and nanoparticles derived from these plants were investigated against coxsackievirus B3 (CVB3). Different concentrations of extracts (7.8, 15.6, 31.25, 62.5, 125, 250, 500, and 1000 μg/mL) were tested for their cytotoxic effect and the antiviral activity was carried out using three non cytotoxic concentrations against CVB3 in Vero cells. The cell viability was carried out using tetrazolium dye (MTT). The experiment was carried out by incubating the extracts with either virus or cells prior to infection. The silver nanoparticles derived from the tested plant extracts enhance antiviral activity at non cytotoxic concentrations. The biosynthesized nanoparticles may be further characterized to better evaluate their antiviral potential against other viral pathogens.

Evaluation of dimethylthiazol diphenyl tetrazolium bromide and propidium iodide inclusion assays for the evaluation of cell viability by flow cytometry.

The natural products are widely used in many fields as pharmaceutical, flavor, industrial, and additive compounds. In many cases, there is a need to evaluate the cytotoxic effect of these products and to determine the non cytotoxic concentration at which they can be used in a safe manner. The objective of the present study was to compare two methods of evaluation the cytotoxic effect of a plant extract. The MTT assay and the PI dye-inclusion assay were used to carry out the experiments. The results were then evaluated by calorimetric and flow cytometry assays. The obtained results showed that a clear difference between the two methods and the cell death using the MTT assay seem to be overestimated. To better evaluate the cytotoxic effect of natural product, we need to carry out several in vitro and in vivo tests before the judgment that a compound is safe to use and at which concentration.

Characterization of outbreak hepatitis a isolates in five Tunisian childcare centers

In the present study, epidemiological survey and molecular characterization of hepatitis A virus during an outbreak in five Tunisian childcare centers in El-Mahres during October and November 2006 were carried out. Five well-water and five drinking water samples were included in the present study. Serological investigation and molecular characterization were carried out. All patients were IgM seropositive and the viral genome was detected in all clinical and well-water samples whereas it was not detected in drinking water from the five childcare centers. Sequence analysis showed that all Tunisian strains belong to sub-genotype IA. The genetic profile of the VP1/2A junction showed that the outbreak isolates underwent an amino acid substitution which was absent in virus's strains detected previously in Tunisia. Further studies need to be conducted to evaluate the emergence of the virus's strains in clinical and water samples and more epidemiological data need to be collected about the risk factors which may contribute to acute hepatitis.

Antimicrobial activities of four Tunisian Chrysanthemum species.

BACKGROUND & OBJECTIVE: Tunisian Chrysanthemum species are known to have medicinal activity and some of the species are used in traditional medicine. We have earlier shown the use of C. trifurcatum flowerheads in Tunisian traditional medicine to treat constipation. In the present study we investigated the anti microbiol activity of four Tunision Chrysanthemum species. METHODS: Different parts (flowers, leaves, stems, roots, leaves and flowers and leaves and stems) of four Tunisian Chrysanthemum species, were extracted with solvents of increasing polarity to obtain aqueous and organic extracts. These extracts were tested in vitro for their antimicrobial activity against 14 bacteria and four yeasts, using agar diffusion and microdilution methods. Activity was evaluated by measuring the zones of inhibition against the tested organisms and minimum inhibitory concentrations (MIC) were determined from the lowest concentrations of extracts to inhibit the growth of microorganisms. Cytotoxity and antiviral activities against Herpes simplex virus type 1 (HSV-1), were evaluated using the neutral red incorporation method. RESULTS: Extracts of the 4 Chrysanthemum species showed some degree of activity against one or more of the microbial strains with MIC ranging from 0.625 to 1.25 mg/ml. Most of the extracts were well tolerated by Vero cells with CC(50) > 500 microg/ml. The petroleum ether extract of C. trifurcatum stems and leaves protected infected cells with EC(50) of 100 microg/ml. INTERPRETATION & CONCLUSION: Our findings showed that some Chrysanthemum extracts exhibited antimicrobial and/or anti-HSV-1 activities. Further studies aimed to the isolation and identification of active substances from the extracts which exhibited interest activities, need to be done.