Wissem Mnif

Effect of Endocrine Disruptor Pesticides: A Review

Endocrine disrupting chemicals (EDC) are compounds that alter the normal functioning of the endocrine system of both wildlife and humans. A huge number of chemicals have been identified as endocrine disruptors, among them several pesticides. Pesticides are used to kill unwanted organisms in crops, public areas, homes and gardens, and parasites in medicine. Human are exposed to pesticides due to their occupations or through dietary and environmental exposure (water, soil, air). For several years, there have been enquiries about the impact of environmental factors on the occurrence of human pathologies. This paper reviews the current knowledge of the potential impacts of endocrine disruptor pesticides on human health.

Estrogenic and anti-estrogenic activity of 23 commercial textile dyes.

The presence of dyes in wastewater effluent of textile industry is well documented. In contrast, the endocrine disrupting effects of these dyes and wastewater effluent have been poorly investigated. Herein, we studied twenty-three commercial dyes, usually used in the textile industry, and extracts of blue jean textile wastewater samples were evaluated for their agonistic and antagonistic estrogen activity. Total estrogenic and anti-estrogenic activities were measured using the Yeast Estrogen Screen bioassay (YES) that evaluates estrogen receptor binding-dependent transcriptional and translational activities. The estrogenic potencies of the dyes and wastewater samples were evaluated by dose-response curves and compared to the dose-response curve of 17β-estradiol (E2), the reference compound. The dose-dependent anti-estrogenic activities of the dyes and wastewater samples were normalized to the known antagonistic effect of 4-hydroxytamoxifen (4-OHT) on the induction of the lac Z reporter gene by E2. About half azo textile dyes have anti-estrogenic activity with the most active being Blue HFRL. Most azo dyes however have no or weak estrogenic activity. E2/dye or E2/waste water ER competitive binding assays show activity of Blue HFRL, benzopurpurine 4B, Everzol Navy Blue FBN, direct red 89 BNL 200% and waste water samples indicating a mechanism of action common to E2. Our results indicate that several textile dyes are potential endocrine disrupting agents. The presence of some of these dyes in textile industry wastewater may thus impact the aquatic ecosystem.

Biological Analysis of Endocrine-Disrupting Compounds in Tunisian Sewage Treatment Plants

Endocrin-disrupting compounds (EDCs) are frequently found in wastewater treatment plants (WWTPs). So far, research has been mainly focused on the detection of estrogenic compounds and very little work has been carried out on other receptors activators. In this study, we used reporter cell lines, which allow detecting the activity of estrogen (ERα), androgen (AR), pregnane X (PXR), glucocorticoid (GR), progesterone (PR), mineralocorticoid (MR), and aryl hydrocarbon (AhR) receptors, to characterise the endocrine-disrupting profile of the aqueous, suspended particulate matter, and sludge fractions from three Tunisian WWTPs. The aqueous fraction exhibited estrogenic and androgenic activities. Suspended particulate matter and sludge extracts showed estrogenic, aryl hydrocarbon and pregnane X receptor activities. No GR, MR, or PR (ant) agonistic activity was detected in the samples, suggesting that environmental compounds present in sewage might have a limited spectrum of activity. By performing competition experiments with recombinant ERα, we demonstrated that the estrogenic activity detected in the aqueous fraction was due to EDCs with a strong affinity for ERα. Conversely, in the sludge fraction, it was linked to the presence of EDCs with weak affinity. Moreover, by using different incubation times, we determined that the EDCs present in suspended particulate matter and sludge, which can activate AhR, are metabolically labile compounds. Finally, we showed in this study that environmental compounds are mainly ER, AR, PXR, and AhR activators. Concerning AR and PXR ligands, we do not to know the nature of the molecules. Concerning ER and AhR compounds, competition experiments with recombinant receptor and analysis at different times of exposure of the AhR activation gave some indications of the compound’s nature that need to be confirmed by chemical analysis.

Endocrine Disrupting Chemicals and Human Health Risk Assessment: A Critical Review

Concerns over the threats posed by a large number of molecules, collectively termed as endocrine disrupting compounds (EDCs) and generally known to alter and disrupt hormone systems and physiological functions, have often been expressed in academic and scholarly debates. From the perspective of classical toxicology, EDCs have genomic mechanisms of actions and exert agonistic or antagonistic effects on steroid receptors. They are also able to alter reproductive function by binding to estrogen or androgen receptors, and the neuroendocrine system by binding to the thyroid receptor. Recently, EDCs have been shown to have equally complex nongenomic mechanisms, altering steroid synthesis or steroid metabolism. As environmental contaminants, these molecules proved disruptively harmful for many wildlife species, particularly those from or depending on the aquatic ecosystem. An increasingly growing body of research has voiced further concerns that human populations are not immune from the dangers of EDCs. Studies from this line of research caution that EDCs can alter hormonal balance and that a whole range of breast and prostate cancers, endometriosis, cryptorchidism, and hypospadias have been linked to exposure to EDCs. This particular area has raised a lot of controversy and the literature on this subject often presents opposing, and sometimes conflicting, perceptions and perspectives. Accordingly, the authors aimed to contribute to the committed academic search for better appreciation of the topic. They first discuss the major natural and synthetic chemicals with endocrine disrupting properties to which humans and wildlife may be exposed. They then describe the key endocrine mechanisms of action and conclude by addressing the main observed effects in human and wildlife populations.

Essential Oils’ Chemical Characterization and Investigation of Some Biological Activities: A Critical Review

This review covers literature data summarizing, on one hand, the chemistry of essential oils and, on the other hand, their most important activities. Essential oils, which are complex mixtures of volatile compounds particularly abundant in aromatic plants, are mainly composed of terpenes biogenerated by the mevalonate pathway. These volatile molecules include monoterpenes (hydrocarbon and oxygenated monoterpens), and also sesquiterpenes (hydrocarbon and oxygenated sesquiterpens). Furthermore, they contain phenolic compounds, which are derived via the shikimate pathway. Thanks to their chemical composition, essential oils possess numerous biological activities (antioxidant, anti-inflammatory, antimicrobial, etc…) of great interest in food and cosmetic industries, as well as in the human health field.

Golimumab and malignancies: true or false association?

Malignancy is one of the comorbidities linked to golimumab, a biological TNF-α blocker. In this systematic review and meta-analysis, we searched different databases and analyzed original publications to elucidate the remaining open question about the real association of malignancies with golimumab therapy. The most frequent cancer in patients treated with golimumab, in association or not with methotrexate, is the lung adenocarcinoma. However, lymphoma is not very commonly represented in these patients. We show that there is no major and evident risk of malignancies associated with golimumab in current scientific literature. An increased risk of malignancies may be associated with golimumab, but this warrants further clinical confirmation. Also, this risk mentioned in different studies must be taken with caution because of number of limits and biases.

Biochemical and histological changes in the liver and gills of Nile tilapia Oreochromis niloticus exposed to Red 195 dye

The present study investigates the biochemical and morphological responses induced in the liver and gills of Nile tilapia Oreochromis niloticus by exposure to various Red 195 dye concentrations (0.05, 0.1 and 0.2 mg L−1) for various durations (7, 14 and 21 days). The histology and antioxidant activities of catalase (CAT), glutathione reductase (GR) and glutathione S-transferase (GST) were monitored and evaluated during exposure and after recovery in clean water. The results revealed that CAT activity decreased after 7 and 21 days of exposure to 0.2 mg L−1 concentrations and increased only after 7 days of exposure to high concentrations compared to the liver and gill control samples, respectively. Both organs were, however, noted to undergo a decrease in GST activity after 7 days of exposure to low Red 195 dye concentrations. Compared to the control, the gills of the tilapia exposed to 0.05 and 0.1 mg L−1 concentrations for longer periods underwent an increase in GST activity. Similarly, GR activity was higher in the liver of tilapia exposed to this dye at the sampling days, except for the highest concentration (0.2 mg L−1) after 21 days of exposure. The GR activity in the gills decreased significantly after 7 and 21 days of exposure to 0.05 and 0.1 mg L−1 concentrations, respectively. The results of the recovery group revealed that the liver and gills displayed insignificant differences in antioxidant enzyme activities. The liver and gill tissues of the fish exposed to Red 195 showed several histopathological changes. Liver damages included an increase in cytoplasmic vacuolization, disruption of endothelial lining, metabolic zonation, necrotic cells, rupture of hepatocyte membrane, and decline of higher eosinophilia. The gills also exhibited some necrotic cells, edema, lifting of filaments and lamellar epithelium, and vascular disorders, such as extreme vasodilatation and proliferation of filament epithelium. A correlation between the biochemical and histological changes of the liver and gill tissues was established, attributing the tissue and cell damages to the accumulation of hydrogen peroxide or production of other radicals via a Fenton reaction.

Identification of A New Chemotye of the Plant Mentha aquatica Grown in Tunisia: Chemical Composition, Antioxidant and Biological activities of its Essential Oil

Abstract This work was carried out in order to valorize a medicinal and aromatic plant of Tunisia: Mentha aquatica. Mentha aquatica dried leaves were submitted to hydrodistillation in a Clevenger apparatus. Their essential oil (EO) composition was analysed by gas chromatography coupled to mass spectrometry (GC-MS). The antioxidant activity of Mentha aquatica Essential oil was evaluated by DPPH free radical -scavenging method. We tested also its biological activity against some microorgnisms : Escherichia Coli ATCC 25922, Staphylococcus aureus ATCC 29213 and Bacillus and also a fungi : candida. Results showed that the most abundant volatile compound of M. aquatica Essential oil was pulegone with a percentage of 39.36 %. It was followed by menthone accounting for 27.69 % of total volatile compounds. Furthermore, oxygenated monoterpenes accounting for 91.4 % of total volatiles constituted the prominent chemical class of this volatile oil. Respective amounts of hydrocarbon monoterpenes and sesquiterpenes were of 3.51 and 5.06 %. The half maximal inhibitory concentration (IC50) of the M. aquatica Essential oil was similar to that of trolox (8 μg /ml ) which is a synthetic molecule with a high antioxidant activity used as a blanck, The antibacterial assay showed that M. aquatia Essential oil was active against Staphylococcus ATCC, E. coli and Bacillus but it doesn’t show an inhibitory effect against Candida.

Chemical Synonyms, Molecular Structure and Toxicological Risk Assessmentof Synthetic Textile Dyes: A Critical Review

Textile industry has been considered for years to be one of the major sources of worldwide pollution problems. Huge amount of wastewater is generated at different stages of textile manufacturing. These waste products are mostly released in the environment without prior consideration. In Fact, they are highly contaminated with lot of chemicals including dyes. For this reason, the investigation of the effects of those compounds over the environment and human health has become a great interest. This review outlines the chemical synonyms, molecular structure and the toxicological effects of 85 textile dyes. The potential fate and effect of those substances on aquatic, human health and ecosystem are discussed in this article.

Influence of drying conditions on the quality of Origanum syriacum L.

The temperature and the speed of drying may affect the quality of the end product of medicinal plants. In addition, ecotypes and chemotypes could be factors influencing this quality. Thus, the aim of our study was to explore various techniques of drying of Origanum syriacum L., which is considered as a main ingredient in the Lebanese diet. For all these reasons, we decided to study two types of O. syriacum originating from Rkai and Ibrine regions on which analyses were carried out. In view of our results, a moderate temperature, in the absence of light, is more favourable for the safeguarding of the flavours and chlorophylls. On the other hand, these conditions seem to be unsuitable for other substances. In order to clarify the optimal conditions for drying of O. syriacum to lead to a product of quality, the choice of a technique of suitable dehydration seems to be delicate.