Cytotoxic effect of chlorpyrifos ethyl and its degradation derivatives by Pseudomonas peli strain isolated from the Oued Hamdoun River (Tunisia).

A bacterium was isolated from the river of Oued Hamdoun (Tunisia), and its phenotypic features, physiological and chemotaxonomic characteristics and phylogenetic analysis of 16S ribosomal RNA sequence revealed it as Pseudomonas peli (P. peli). Chlorpyrifos ethyl (CP) was used as the sole source of carbon and energy by P. peli, and it was cometabolised in the presence of glucose. CP was completely degraded by P. peli after 96 h of shake incubation. High-performance liquid chromatography analysis indicated that the biodegradation kinetics was not affected by the addition of glucose into the culture medium. In the present study, only transient accumulation of one major no-identified product was observed after 48 h of incubation, with no other persistent metabolites detected. Cytotoxicity of CP, before and after biodegradation with P. peli, was evaluated in vitro using the MTT-colorimetric assay against three human cancer cell lines (A549, lung cell carcinoma, HT29, colon adenocarcinoma and MCF7, breast adenocarcinoma). CP reduced viability of all human cell lines in a dose-dependent manner. Its activity was very remarkable against A549 cell line. However, cytotoxicity strongly decreased in CP obtained after incubation with P. peli Hence, we conclude that when incubated under appropriate conditions,P. peli has a metabolism that completely detoxifies CP.

Antimalarial and cytotoxic activities of chiral triamines.

Chiral triamine antimalarial compounds have been identified following the screening of mixture-based positional scanning libraries made up of 31,320 compounds against P. falciparum. The library, namely N-methyl triamine (TPI 762) was generated following exhaustive reduction of resin-bound acylated dipeptides. Using the PSCL approach, individual compounds were rapidly identified which were only 10 times less active than the standard drugs chloroquine (CQ) and Artemisinin (Artes).

Evaluation of antiproliferative and antioxidant activities of the organic extract and its polar fractions from the Mediterranean gorgonian Eunicella singularis.

The present study was conducted to evaluate the antiproliferative and antioxidant activities of organic extract and its polar fractions from Eunicella singularis (Esper 1794). Organic extract and two fractions of E. singularis (F2 and F3) were screened for the presence of phenolic compounds, terpenoids and glycosides. The antiproliferative activity of E. singularis organic extract and its polar fractions was evaluated on human cancer cell lines (A549, lung cell carcinoma; HCT15, colon cell carcinoma and MCF7, breast adenocarcinoma), using the MTT colorimetric method and clonogenic assay, as well as the antioxidant activity, using the stable radical 1,1-diphenyl-2-picrylhydrazyl (DPPH), and the FRAP assays. The fractions F2 and F3 showed significant total phenolic content (40 and 35.72mg gallic-acid equivalent/g dried sample), respectively, and important antiproliferative properties against the cancer cell lines. The IC50 values, ranged from 36 to 274µg/ml for A549; 93 to 426µg/ml for HCT15; and 52 to 225µg/ml for MCF7 and in the clonogenic inhibition assay from 18 to 134µg/ml for A549; 43 to 357µg/ml for HCT15; and 17 to 160µg/ml for MCF7. Using the DPPH method, the fraction F2 exhibited the strongest radical scavenging activity, with IC50 0.08mg/ml, which approaches the activity of the powerful antioxidant standard, ascorbic acid (IC50=0.064mg/ml). The reducing power of the samples was in the following order: F2>organic extract>F3. These results suggest that E. singularis fractions might be used as a potential source of natural antioxidant and antitumor agents. The purification and determination of the chemical structures of compounds in these active fractions are under investigation. The results could provide a compound(s) with a promising role in future medicines.

Decolorization does not always mean detoxification: case study of a newly isolated Pseudomonas peli for decolorization of textile wastewater.

The textile industry is a favor to the Tunisian economy by offering several job positions. However, it's not environmentally friendly. In fact, textile industries discharge high volumes of wastewater which contain several toxic pollutants such as dyes, fixator, and whiteness. In our study, Pseudomonas peli, isolated and characterized from Oued Hamdoun (center of Tunisia), was found able to decolorize textile effluent about 81 % after 24 h shaking incubation. On the other hand, the in vitro antiproliferative effects of the untreated and treated effluent was evaluated by their potential cytotoxic activity using the MTT colorimetric method against three human cancer cell lines (A549, lung cell carcinoma; HT29, colon adenocarcinoma; and MCF7, breast adenocarcinoma). Results showed that intact textile effluent and its content azo dyes didn't inhibit the proliferation of all tested cell lines. However, the cytotoxic effect was remarkable when we tested effluent obtained after treatment by P. peli in a dose-dependent manner. This activity was attributed to the presence, in our treated effluent, of some azo products of dyes which are responsible for inhibition of human cell lines proliferation. Thus, the use of this strain for testing on the industrial scale seems impossible and disadvantageous.

Human cell death in relation to DNA damage after exposure to the untreated and biologically treated pharmaceutical wastewater.

Among all the pharmaceutical drugs that contaminate the environment, antibiotics occupy an important place due to their high consumption rates in both veterinary and human medicine. The present study examined the ability of Pseudomonas putida to grow on the antibiotic wastewater, currently expanding in Tunisia, containing amoxicillin and cefadroxil. P. putida was very efficient to grow quickly in pharmaceutical wastewater (PW) and in reducing the total dissolved solids to 80.1 %. Cytotoxicity of PW, before and after biodegradation with P. putida mt-2, was evaluated in vitro, using the MTT assay, against four human tumor cell lines such as A549 (lung cell carcinoma), HCT15 (colon cell carcinoma), MCF7 (breast adenocarcinoma), and U373 (glioma cell carcinoma). The PW reduced all human cell lines viability in a dose-dependent manner. This activity was very remarkable against U373 cell line. For this reason, we have tested the genotoxicity of PW using comet assay for quantification of DNA fragmentation. In fact, PW has statistically significant (p<0.001) influence on DNA. Indeed, the percentage of genotoxicity was 66.87 and 87.5 %, after 24 and 48 h of treatment, respectively. However, cytotoxicity and genotoxicity decreased strongly when tested the PW obtained after incubation with P. putida mt-2. Our results indicate that P. putida is a promising and improved alternative to treating industrial-scale effluent compared to current chemical treatment procedures used by the industrials.

Analgesic and antibutyrylcholinestrasic activities of the venom prepared from the Mediterranean jellyfish Pelagia noctiluca (Forsskal, 1775).

BACKGROUND: Toxins derived from jellyfishes have been exploited as a model for the development of new drug promising applications to treat neurodegenerative diseases. The present work is aimed to evaluate the acute toxicity of crude venom of Pelagia noctiluca and then to screen the analgesic and antibutyrylcholinestrasic (anti-BuChE) activities of the crude venom and its fractions. METHODS: Sephadex G75 gel was used to separate crude venom of Pelagia noctiluca, which led to some fractions. In addition, in vivo analgesic and in vitro plasma antibutyrylcholinestrasic activities were carried out with Pelagia crude venom and its fractions respectively. RESULTS: The crude venom and its fractions displayed analgesic and anti-BuChE activities at different doses without inducing acute toxicity. Fraction 2 possesses the highest analgesic and antibutyrylcholinestrasic properties. The crude venom and fraction 1 had shown to possess less significant inhibitory activity against analgesic and antibutyrylcholinestrasic models. CONCLUSIONS: Based on this study, the crude venom of Pelagia noctiluca is found to be a useful tool for probing pharmacological activity. The purification and the determination of chemical structures of compounds of active fractions of the venom are under investigation.

Evaluation of antiproliferative and anti-inflammatory activities of methanol extract and its fractions from the Mediterranean sponge.

BACKGROUND: Without doubt, natural products have been, and still are, the cornerstone of the health care armamentarium. Of all natural sources, the marine environment is clearly the last great frontier for pharmaceutical and medical research. METHODS: This work progresses in the direction of identifying component(s) from the Mediterranean sponge, Spongia officinalis with pharmacological activities. In the present study we investigated the efficacy of methanol extract and its semi-purified fractions (F2, F3) from Spongia officinalis for their in vivo anti-inflammatory activity using the carrageenan-induced paw edema in rats and their in vitro antiproliferative effects by their potential cytotoxic activity using the MTT colorimetric method and clonogenic inhibition against three human cancer cell lines (A549, lung cell carcinoma, HCT15, colon cell carcinoma and MCF7, breast adenocarcinoma). RESULTS: The fractions F2 and F3 showed interesting anti-inflammatory and antiproliferative activities in a dose dependent manner. CONCLUSIONS: The present study indicates that the methanolic extrac and its fractions from Spongia officinalis are a significant source of compounds with the antiproliferative and anti-inflammatory activities, and this may be useful for developing potential chemopreventive substances.

Anticonvulsant and analgesic activities of crude extract and its fractions of the defensive secretion from the Mediterranean sponge, Spongia officinalis.

This study progresses in the direction of identifying component(s) from the Mediterranean sponge, Spongia officinalis with anticonvulsant and analgesic activities. We investigated the efficacy of crude extract and its semi-purified fractions (F1-F3) of the defensive secretion from Spongia officinalis for their in vivo anticonvulsant activity using the pentylenetetrazole (PTZ) seizure model and analgesic activity using the writhing test in mice. Among the series the crude extract exhibited interesting analgesic activity in a dose dependent manner. Similarly the fraction F2 showed a partial protection of mice from PTZ-induced seizure and interesting analgesic activity in a dose dependent manner. The purification and the determination of chemical structure(s) of compound(s) of this active fraction are under investigation.

Toxicities effects of pharmaceutical, olive mill and textile wastewaters before and after degradation by Pseudomonas putida mt-2.

BACKGROUND: Removal of numerous classes of chemical pollutants from the industrial wastewater such as textile, pharmaceutical and olive mill using conventional wastewater treatment, is incomplete and several studies suggested that improvement of this situation would require the application of biological treatment techniques. Dyes, polyphenols and drugs are an environmental pollutants extremely toxics to plants and other living organisms including humans. These effluents were previously treated by Pseudomonas putida. The main of this work was to evaluate the in vivo toxicity of the three wastewaters. METHODS: Writhes and convulsant effect of effluents were carried out and were compared to the treated effluents. Only pharmaceutical wastewater was exhibited a convulsant effect which observed in mice treated by effluent. On the other hand, all industrial wastewater induced significantly an algogenic effects particularly when mice were treated by the pharmaceutical wastewater (Number of writhes = 44). CONCLUSION: Toxicity was totally removed when mice were treated by the bio remediated effluent. This indicates that P. putida was able to completely detoxify the toxic industrial effluent.

Parallel synthesis and anti-inflammatory activity of cyclic peptides cyclosquamosin D and Met-cherimolacyclopeptide B and their analogs.

We report the parallel synthesis of two natural cyclopeptides, isolated from the seeds of Annona squamosa, cyclosquamosin D (A1), and Met-cherimolacyclopeptide B (B) and their analogs. All of the compounds were screened for anti-inflammatory activity by evaluating their inhibitory effects on the production of pro-inflammatory cytokines using the lipopolysaccharide stimulated macrophage J774A.1 cell line. Compounds having significant anti-inflammatory activity in suppressing the secretion of IL-6 and TNF-α have been identified, some of which exhibit activity superior to that observed with the natural products.

Screening of antimutagenicity via antioxidant activity in different extracts from the flowers of Phlomis crinita Cav. ssp mauritanica munby from the center of Tunisia.

For centuries, plants have been used in traditional medicines, and there has been recent interest in the chemopreventive properties of compounds derived from plants. In the present study, we investigated the free-radical-scavenging, antioxidant, and antimutagenic potential of polar extracts from Phlomis crinita Cav. flowers. Ethyl acetate, chloroform, and methanol extracts were prepared from powdered Phlomis flowers and characterized for the presence of tannins, flavonoids, iridoids, sterols, cardiac glycosides, and anthraquinones. All the extracts showed increased activity in scavenging the ABTS free radical, but only ethyl acetate and methanol extracts were active in scavenging the superoxide anion generated by the xanthine/xanthine oxidase system. In addition, all the extracts significantly decreased the mutagenicity induced by 2-aminoanthracene in the presence of a metabolizing homogenate (S9) and methyl methane sulfonate in the absence of metabolizing system, using the Ames test with Salmonella typhimurium TA102 and TA104. The present study indicates that extracts of P. crinita flowers are a significant source of compounds with antigenotoxic and antioxidant activity (most likely phenolic compounds) and thus may be useful candidates for chemoprevention studies.