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Rim Timoumi
  • Monastir

Rim Timoumi

Background: Among insecticides belonging to the insect growth regulators class, we are interested in this present work in the study of Triflumuron (TFM) which is widely used in the protection of crops, human and animal health against... more
Background: Among insecticides belonging to the insect growth regulators class, we are interested in this present work in the study of Triflumuron (TFM) which is widely used in the protection of crops, human and animal health against diseases caused by certain vector insects. However, the bibliographic data of its toxicity in vitro are almost impossible to find. The increased use of these insecticides has caused severe damage. This prompted us to look for preventive strategies with respect to the toxicity induced by TFM. Objective: Our study aimed to test the effect of an antioxidant substance, the fennel essential oil (FEO) against toxicity induced by TFM using two different cell lines, the human renal embryonic cells (HEK 293) and hepatocytes (Hep G2). Methods and results: According to the MTT assay, and independently of the cell line used, we showed a significant reduction in the cell viability, an increase in reactive oxygen species (ROS) generation, MDA levels and mitochondrial...
Environmental Science and Pollution Research (ESPR) serves the international community in all areas of Environmental Science and related subjects with emphasis on chemical compounds. It reports from a broad interdisciplinary outlook.... more
Environmental Science and Pollution Research (ESPR) serves the international community in all areas of Environmental Science and related subjects with emphasis on chemical compounds. It reports from a broad interdisciplinary outlook. Apart from the strictly scientific contributions as research articles (short and full papers) and reviews, ESPR publishes: news & views from research and technology, legislation and regulation, hardware and software, education, literature, institutions, organizations, conferences. Editorial Policy For maximum benefit to the environmental community, the journal has the following features: ESPR represents the international perspective, with emphasis on the natural sciences but also includes the impacts of legislation, regulation, and the economy on pollution control; and ESPR articles are generally chemically oriented but cover all the broad areas within environmental science. ESPR was conceived as a truly international scientific journal. Information from ESPR should also be useful for planning lectures and university environmental curricula. A global network of editorial board members represents a variety of disciplines and groups of interest: university, industry, administrative bodies, government, consulting companies, public interest groups.
Pesticides have been used to kill pests such as insects, fungi, rodents, and unwanted plants. As these compounds are potentially toxic to the target organisms, they could also be harmful to human health and the environment. Several... more
Pesticides have been used to kill pests such as insects, fungi, rodents, and unwanted plants. As these compounds are potentially toxic to the target organisms, they could also be harmful to human health and the environment. Several chronic adverse effects have been identified even after months or years of exposure. The adverse effects of pesticides on the agricultural ecosystem have been a matter of concern in recent decades. In this review, we present an overview of the studies, including our previous studies, monitoring currently used pesticides in the Tunisian agricultural soils that belong to the class of insect growth regulators (IGRs). Triflumuron (TFM) is a benzoyl phenyl urea insecticide belonging to the class of IGRs. TFM is widely used around the world to increase crop yield by protecting them from damage caused by insects. TFM works by inhibiting the synthesis of chitin, an essential part of the insect cuticle, making it susceptible to pathogens and deformities. Consequently, insects become more susceptible to pathogens and malformations. However, studies revealing its toxicity and its mode of action in mammalian systems remain very limited. The aim of this review is to better inform the community about the impact of TFM on crops, the environment, and human beings by summarizing its toxic effects.
Pesticides have been used to kill pests such as insects, fungi, rodents, and unwanted plants. As these compounds are potentially toxic to the target organisms, they could also be harmful to human health and the environment. Several... more
Pesticides have been used to kill pests such as insects, fungi, rodents, and unwanted plants. As these compounds are potentially toxic to the target organisms, they could also be harmful to human health and the environment. Several chronic adverse effects have been identified even after months or years of exposure. The adverse effects of pesticides on the agricultural ecosystem have been a matter of concern in recent decades. In this review, we present an overview of the studies, including our previous studies, monitoring currently used pesticides in the Tunisian agricultural soils that belong to the class of insect growth regulators (IGRs). Triflumuron (TFM) is a benzoyl phenyl urea insecticide belonging to the class of IGRs. TFM is widely used around the world to increase crop yield by protecting them from damage caused by insects. TFM works by inhibiting the synthesis of chitin, an essential part of the insect cuticle, making it susceptible to pathogens and deformities. Consequen...
Hexavalent chromium (CrVI) compounds are potent toxicants commonly used in numerous industries. Thus, potential toxic effects and health hazards are of high relevance. Selenium (Se) and zinc (Zn) are known for their antioxidant and... more
Hexavalent chromium (CrVI) compounds are potent toxicants commonly used in numerous industries. Thus, potential toxic effects and health hazards are of high relevance. Selenium (Se) and zinc (Zn) are known for their antioxidant and chemoprotective properties. However, little is known about their protective effects against CrVI-induced renal damage during pregnancy. In this context, the present study aimed to investigate the protective efficacy of these two essential elements against potassium dichromate-induced nephrotoxicity in pregnant Wistar Albino rats. Female rats were divided into control and four treated groups of six each receiving subcutaneously on the 3rd day of pregnancy, K2Cr2O7 (10 mg/kg, s.c. single dose) alone, or in association with Se (0.3 mg/kg, s.c. single dose), ZnCl2 (20 mg/kg, s.c. single dose) or both of them simultaneously. The nephrotoxic effects were monitored by the evaluation of plasma renal parameters, oxidative stress biomarkers, DNA damage, and renal Cr content. The obtained results showed that K2Cr2O7 disturbed renal biochemical markers, induced oxidative stress and DNA fragmentation in kidney tissues, and altered renal histoarchitecture. The co-administration of Se and/or ZnCl2 has exhibited pronounced chelative, antioxidant, and genoprotective effects against K2Cr2O7-induced renal damage and attenuated partially the histopathological alterations. These results suggest that Se and Zn can be used as efficient nephroprotective agents against K2Cr2O7-induced toxicity in pregnant Wistar Albino rats.
Hexavalent chromium (CrVI) is an environmental pollutant and an endocrine-disrupting metal. Se and Zn are essential trace elements, known to play a crucial role in thyroid homeostasis. However, there is a lack of data reporting... more
Hexavalent chromium (CrVI) is an environmental pollutant and an endocrine-disrupting metal. Se and Zn are essential trace elements, known to play a crucial role in thyroid homeostasis. However, there is a lack of data reporting thyrotoxicity during gestation. In this study, we investigated the protective effects of selenium and zinc against potassium dichromate–induced thyrotoxicity in pregnant Wistar rats. Thirty pregnant Wistar rats were divided into control and four treated groups receiving subcutaneously (s.c) on the 3rd day of pregnancy, K2Cr2O7 (10 mg/kg, s.c) alone, or in association with Se (0.3 mg/kg, s.c), ZnCl2 (20 mg/kg, s.c), or both of them simultaneously. The hormonal profile, oxidative stress biomarkers, DNA damage, and histological modifications were evaluated. Our main findings showed that K2Cr2O7 promoted hypothyroidism, oxidative stress, genotoxicity, and histological alterations in the thyroid gland. The co-treatment with Se or ZnCl2 has mitigated K2Cr2O7-induced thyrotoxicity in pregnant Wistar rats by exhibiting antioxidant and genoprotective effects. However, the combined co-treatment of both of them was less thyroprotective, and therefore, further investigations on the synergetic interaction of Se and Zn against CrVI toxicity using different doses and exposure routes are required.
Insect growth regulator insecticides are a new class of pesticides, commonly used around the world to control insect damages. Among those compounds, we focused our interest on triflumuron (TFM), which is less toxic than other conventional... more
Insect growth regulator insecticides are a new class of pesticides, commonly used around the world to control insect damages. Among those compounds, we focused our interest on triflumuron (TFM), which is less toxic than other conventional insecticides. However, not much is known about its toxic effects on mammalian systems. Therefore, our study aimed toward evaluating the cytotoxic and genotoxic effects of TFM using two different cell lines, the human renal embryonic cells (HEK 293) and hepatocytes (Hep G2). We showed, according to the 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide assay, that TFM reduced significantly the cell viability and increased the reactive oxygen species generation, malondialdehyde levels, and mitochondrial membrane potential in both cell lines. The antioxidant system was disturbed as assessed by the increased activities in both catalase and superoxide dismutase. We demonstrated also, that TFM is an inductor of DNA damages quantified by the com...
The aim of this study is to evaluate the cytotoxic and the genotoxic effects of triflumuron (TFM) on human colon carcinoma cells (HCT-116). Indeed, TFM is used to protect vegetables, fruits, and domestic animals against a large spectrum... more
The aim of this study is to evaluate the cytotoxic and the genotoxic effects of triflumuron (TFM) on human colon carcinoma cells (HCT-116). Indeed, TFM is used to protect vegetables, fruits, and domestic animals against a large spectrum of parasites causing animal and human disorders. However, studies revealing its toxicity and its mode of action in mammalian systems remain very limited. We monitored our work with the cytotoxicity assay starting with the cell viability test, the ROS generation, the malondialdehyde (MDA) production, the DNA fragmentation, and the measurement of some antioxidant enzymes activities such as catalase, superoxide dismutase, and the glutathione S-transferase. Also, we measured the mitochondrial transmembrane potential. We showed that TFM induced a dose-dependent cell death. This decrease in cell viability was accompanied by a significant reduction in the mitochondrial membrane potential. We also have shown that TFM induced oxidative stress as revealed by t...
The di (2‐ethylhexyl) phthalate (DEHP) is a plasticizer used in the polyvinyl chloride industry. Human exposure to this plasticizer is inevitable and contributes to several side effects. In this study, we examined whether DEHP induces... more
The di (2‐ethylhexyl) phthalate (DEHP) is a plasticizer used in the polyvinyl chloride industry. Human exposure to this plasticizer is inevitable and contributes to several side effects. In this study, we examined whether DEHP induces apoptosis and oxidative stress in embryonic kidney cells (HEK‐293) and whether the nuclear factor E2‐related factor 2 (Nrf‐2)/heme oxygenase‐1 (HO‐1) antioxidant pathway is involved in the pathogenesis of this process. We demonstrated that DEHP is cytotoxic to HEK‐293 cells. It causes oxidative damage through the generation of free radicals, induces lipid peroxidation, and alters superoxide dismutase and catalase activities. Simultaneously, DEHP treatment decreases the expression and the protein level of Nrf‐2 and HO‐1. Inhibition of the Nrf‐2/HO‐1 pathway is related to the mitochondrial pathway of apoptosis. This apoptotic process is characterized by a loss of mitochondrial transmembrane potential (ΔΨm) and upregulation of the expression of caspase‐3 ...
The immunosuppressive drug tacrolimus (TAC) is used clinically to reduce the rejection rate in transplant patients. TAC has contributed to an increased prevalence of cardiovascular disease in patients receiving solid organ... more
The immunosuppressive drug tacrolimus (TAC) is used clinically to reduce the rejection rate in transplant patients. TAC has contributed to an increased prevalence of cardiovascular disease in patients receiving solid organ transplantation. Mycophenolate mofetil (MMF), a potent inhibitor of de novo purine synthesis, is known to prevent ongoing rejection in combination with TAC. In the present study, we investigated the antioxidant and antigenotoxic effect of MMF on TAC-induced cardiotoxicity in rats. Oral administration of TAC at 2.4, 24, and 60 mg/kg b.w. corresponding, respectively, to 1, 10, and 25% of LD50 for 24 h caused cardiac toxicity in a dose-dependant manner. TAC increased significantly DNA damage level in hearts of treated rats. Furthermore, it increased malondialdehyde (MDA) and protein carbonyl (PC) levels and decreased catalase (CAT) and superoxide dismutase (SOD) activities. The oral administration of MMF at 50 mg/kg b.w. simultaneously with TAC at 60 mg/kg b.w. prove...
Insect growth regulator insecticides are a new class of pesticides, commonly used around the world to control insect damages. Among those compounds, we focused our interest on triflumuron (TFM), which is less toxic than other conventional... more
Insect growth regulator insecticides are a new class of pesticides, commonly used around the world to control insect damages. Among those compounds, we focused our interest on triflumuron (TFM), which is less toxic than other conventional insecticides. However, not much is known about its toxic effects on mammalian systems. Therefore, our study aimed toward evaluating the cytotoxic and genotoxic effects of TFM using two different cell lines, the human renal embryonic cells (HEK 293) and hepatocytes (Hep G2). We showed, according to the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, that TFM reduced significantly the cell viability and increased the reactive oxygen species generation, malondialdehyde levels, and mitochondrial membrane potential in both cell lines. The antioxidant system was disturbed as assessed by
Research Interests:
Triflumuron (TFM) is one of the most widely used insecticides over the world. It is a benzoylphenyl urea that belongs to the class of insect growth regulators. This insecticide acts by inhibiting insect's chitin synthesis and by... more
Triflumuron (TFM) is one of the most widely used insecticides over the world. It is a benzoylphenyl urea that belongs to the class of insect growth regulators. This insecticide acts by inhibiting insect's chitin synthesis and by consequences, making insect more susceptible to pathogens and malformations. TFM effects have been reported in mammalians and crops. However, studies that reveal its toxicity mechanisms are limited. In this line, the current study aimed to determine the implication of oxidative stress in the toxicity induced by TFM and particularly in the perturbation of biochemical parameters in male Balb/C mice. Male Balb/C mice were divided into three groups receiving TFM at doses of 250, 350, and 500 mg/kg bw respectively. The occurrence of oxidative stress in both kidney and liver tissues was monitored by measuring of oxidative stress markers. TFM caused an increase as protein carbonyls generation, malondialdehyde induction (MDA) and catalase (CAT), superoxide dismutase (SOD), glutathion peroxidase (Gpx), as well as glutathion S transferase (GST) activities. In the same conditions, we have evaluated the effect of TFM treatment on biochemical parameters. In response to the three TFM doses, we showed significant dose dependent inductions in all tested oxidative stress markers. However, TFM caused an increase in the liver enzyme activities as aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP), g-glutamyltranspeptidase (GTT), and total bilirubin (BILT) in a dose-dependent manner. Equally, renal markers as urea, uric acid, albumin, and creatinine were increased in the same manner. We can conclude that oxidative damage seems to be a key determinant of TFM-induced toxicity in both liver and kidney of male Balb/C mice. Moreover, the oxidative stress is more pronounced in the liver than in the kidney. Thus, TFM may be considered as a hepatotoxic insecticide.
Research Interests:
Research Interests:
The aim of this study is to evaluate the cytotoxic and the genotoxic effects of triflumuron (TFM) on human colon carcinoma cells (HCT-116). Indeed, TFM is used to protect vegetables, fruits, and domestic animals against a large spectrum... more
The aim of this study is to evaluate the cytotoxic and the genotoxic effects of triflumuron (TFM) on human colon carcinoma cells (HCT-116). Indeed, TFM is used to protect vegetables, fruits, and domestic animals against a large spectrum of parasites causing animal and human disorders. However, studies revealing its toxicity and its mode of action in mammalian systems remain very limited. We monitored our work with the cytotoxicity assay starting with the cell viability test, the ROS generation, the malondialdehyde (MDA) production, the DNA fragmentation, and the measurement of some antioxidant enzymes activities such as catalase, superoxide dismutase, and the glutathione S-transferase. Also, we measured the mitochondrial transmembrane potential. We showed that TFM induced a dose-dependent cell death. This decrease in cell viability was accompanied by a significant reduction in the mitochondrial membrane potential. We also have shown that TFM induced oxidative stress as revealed by the generation of reactive oxygen species, the increase of the MDA levels, and the activation of the antioxidant enzymes. Moreover, our results indicated that TFM induced DNA damage in HCT-116 cells as monitored by the comet assay. We demonstrate, for the first time, the cytotoxic and the genotoxic potentials of TFM on human cultured cells.
Research Interests:
The aim of this study is to evaluate the cytotoxic and the genotoxic effects of triflumuron (TFM) on human colon carcinoma cells (HCT-116). Indeed, TFM is used to protect vegetables, fruits, and domestic animals against a large spectrum... more
The aim of this study is to evaluate the cytotoxic and the genotoxic effects of triflumuron (TFM) on human colon carcinoma cells (HCT-116). Indeed, TFM is used to protect vegetables, fruits, and domestic animals against a large spectrum of parasites causing animal and human disorders. However, studies revealing its toxicity and its mode of action in mammalian systems remain very limited. We monitored our work with the cytotoxicity assay starting with the cell viability test, the ROS generation, the malondialdehyde (MDA) production, the DNA fragmentation, and the measurement of some antioxidant enzymes activities such as catalase, superoxide dismutase, and the glutathione S-transferase. Also, we measured the mitochondrial transmembrane potential. We showed that TFM induced a dose-dependent cell death. This decrease in cell viability was accompanied by a significant reduction in the mitochondrial membrane potential. We also have shown that TFM induced oxidative stress as revealed by the generation of reactive oxygen species, the increase of the MDA levels, and the activation of the antioxidant enzymes. Moreover, our results indicated that TFM induced DNA damage in HCT-116 cells as monitored by the comet assay. We demonstrate, for the first time, the cytotoxic and the genotoxic potentials of TFM on human cultured cells.
Research Interests:
Background: Among insecticides belonging to the insect growth regulators class, we are interested in this present work in the study of Triflumuron (TFM) which is widely used in the protection of crops, human and animal health against... more
Background: Among insecticides belonging to the insect growth regulators class, we are interested in this present work in the study of Triflumuron (TFM) which is widely used in the protection of crops, human and animal health against diseases caused by certain vector insects. However, the bibliographic data of its toxicity in vitro are almost impossible to find. The increased use of these insecticides has caused severe damage. This prompted us to look for preventive strategies with respect to the toxicity induced by TFM. Objective: Our study aimed to test the effect of an antioxidant substance, the fennel essential oil (FEO) against toxicity induced by TFM using two different cell lines, the human renal embryonic cells (HEK 293) and hepatocytes (Hep G2). Methods and results: According to the MTT assay, and independently of the cell line used, we showed a significant reduction in the cell viability, an increase in reactive oxygen species (ROS) generation, MDA levels and mitochondrial membrane potential in both cell lines after their treatment with TFM. Moreover, we showed an increased in both catalase and superoxide dismutase activities. We demonstrated also, that TFM is an inductor of DNA damages quantified by the comet assay accompanied by apoptosis, highlighted by the evaluation of the expression of pro and anti-apoptotic proteins (Bax and Bcl2). Conclusion: However, the use of FEO reversed completely the cytotoxicity induced by TFM.
Research Interests:
Research Interests:
Triflumuron induces genotoxicity in both mice bone marrow cells and human colon cancer cell line, Toxicology Mechanisms and Methods,