The potential role of urbanization in the resistance to organophosphate insecticide in Culex pipiens pipiens from Tunisia

Objective

To examine the effects of urbanization on the resistance status of field populations of Culex pipiens pipiens to organophosphate insecticide.

Methods

Bioassays and biochemical assays were conducted on Tunisian field populations of Culex pipiens pipiens collected in four various areas differing in the degree of urbanization. Late third and early fourth larvae were used for bioassays with chlorpyrifos and adults mosquitoes for biochemical assays including esterase and acetyl cholinesterase (AChE) activities.

Results

The distribution of resistance ratios in this study appears to be influenced by the degree of urbanization. The highest resistance was recorded in the population from most urbanized areas in Tunisia whereas the lowest resistance was found in relatively natural areas. Both metabolic and target site mechanisms were involved in the recorded resistance.

Conclusion

This is the first study in Tunisia showing evidence of the impact of urbanization on the resistance level in Culex pipiens pipiens. Proper management of the polluted breeding sites in the country and effective regulation of water bodies from commercial and domestic activities appear to be critical for managing insecticide resistance.

Evaluation of resistance to temephos insecticide in Culex pipiens pipiens larvae collected from three districts of Tunisia

Background

Mosquitoes are considered as the main groups of arthropods that cause nuisance and public health problems.

Objectives

Evaluation of resistance to temephos insecticide in Culex pipiens pipiens larvae collected from three districts of Tunisia.

Methods

Late third and early fourth instars larvae of Culex pipiens pipiens were collected in three localities of Northern and Southern Tunisia. Field collected populations were tested against temephos insecticide and compared to bioassays of a susceptible reference strain. The cross-resistance between temephos and propoxur, and the polymorphism of over-produced esterases and AChE 1 were investigated.

Results

Studied populations exhibited tolerance to temephos with low and high levels of resistance. The resistance ratio (RR₅₀) values of temephos ranged from 1.34 to 114. Synergists and starch electrophoresis showed that the metabolic resistances were involved in the recorded resistance. Likewise, the resistant target site (acetyl cholinesterase: AChE 1) was responsible for the recorded resistance to temephos compound in Culex pipiens pipiens.

Conclusion

The low and high resistance recorded to temephos insecticides is particularly interesting, because it leaves a range of tools useable by vector control services. However, further studies are needed to determine its spread and anticipate vector control failure where these insecticides are used.

Resistance development and insecticide susceptibility in Culex pipiens pipiens, an important vector of human diseases, against selection pressure of temephos and its relationship to cross-resistance towards organophosphates and pyrethroids insecticides

Background

Culex pipiens pipiens is an important vector of human diseases.

Objective

To determine the insecticide resistance development in Culex pipiens pipiens against selection pressure of temephos..

Methods

A field population of Culex pipiens pipiens was collected from Northwestern Tunisia with a medium level of temephos resistance (LC₅₀ = 0.0069). It was subjected to six generations of temephos pressure selection to evaluate its relationship to cross-resistance towards organophosphates (OPs) and pyrethroids (PYR) insecticides.

Results

The selection was initiated at the dose 0.0266, 0.0748 and 0.0069 which were increased during successive generations up to 0.1488, 3.8747 and 0.0086 after sixth generation for temephos, chlorpyrifos and permethrin insecticides, respectively. It is important to noted that high cross-resistance to chlorpyrifos insecticide (OP) was detected (51.88×). However, little or no cross-resistance to the pyrethroid permethrin (PYR) was recorded (1.24×). Contrary to metabolic resistance, it seemed that acetylcholinesterases AChE 1 was fixed under pressure selection.

Conclusion

The high cross-resistance to temephos and chlorpyrifos is reasonable because they belong to the same class of insecticide (OP). However, the little cross-resistance to the pyrethroid permethrin could support its use alternately for Culex pipiens pipiens control.

Resistance status to deltamethrin pyrethroid of Culex pipiens pipiens (Diptera: Culicidae) collected from three districts of Tunisia

OBJECTIVES

The aim of the present study was to determine the susceptibility status of Culex pipiens pipiens populations against deltamehtrin insecticide.

METHODS

Larvae of Culex pipiens pipiens were collected from three breeding places in Northern and Southern Tunisia between 2003 and 2005. Early third and late fourth instars were tested against deltamethrin pyrethroid insecticide. Cross-resistance with DDT resistance was evaluated in studied samples to estimate the role of target site insensitivity and two synergists including piperonyl butoxide (Pb) and S,S,S-tributyl phosphorotrithioate (DEF) were used to estimate the role of detoxification enzymes.

RESULTS

Our results revealed that the level of deltamehtrin resistance ranged from 0.67 to 31.4. We also showed the non-involvement of kdr resistance in pyrethroid resistance and no cross-resistance with DDT resistance was detected in all studied populations including the most resistant one. Synergists study on the resistant population (sample # 1) showed the involvement of CYP450 in the recorded resistance to the deltamethrin insecticide.

CONCLUSION

The results obtained from this study should be considered in the current control programs to combat mosquitoes in Tunisia.

Poikiloderma with neutropenia in a Tunisian patient with a novel C16orf57 gene mutation

Poikiloderma with neutropenia (PN) is a genodermatosis characterized by poikiloderma, permanent neutropenia, recurrent infections, nail abnormalities, and palmoplantar hyperkeratosis. We report the case of a Tunisian patient with PN. Skin lesions started from the face and spread to the extremities and trunk. Neutropenia was initially periodic and concomitant with infections periods. DNA analysis identified a novel homozygous deletion of a 1-bp (c.161delC, p.P54RfsX60) in the C16orf57gene, presumed to be causative. This report presents the variability of the clinical manifestations and evolution of PN and emphasizes the importance of studying other patients with PN to better delineate mutations profile among populations.

Thymoquinone ameliorates lead-induced suppression of the antioxidant system in rat kidneys

Objective

Alteration of the antioxidant status in the kidneys may be related to lead (Pb) intoxication. The present study aimed to investigate the possible beneficial effect of thymoquinone (TQ), the major active ingredient of the volatile oil of Nigella sativa seeds, on Pb-induced renal antioxidant defense system impairment.

Methods

A total of thirty two healthy adult male Wistar rats were randomly divided into four equal groups as follows: a control group, which received no treatment; a Pb group, which was exposed to 2,000 ppm of Pb acetate in drinking water; a Pb-TQ group, which was cotreated with Pb plus TQ (5 mg/kg/day, per os); and a TQ group receiving only TQ. All treatments were applied for five weeks.

Results

TQ alone did not induce any significant changes in the antioxidant defense system. By contrast, Pb exposure significantly decreased reduced glutathione level and superoxide dismutase, glutathione peroxidase, catalase, and glutathione reductase activities in the renal tissue. Interestingly, supplementation with TQ significantly improved the affected antioxidant parameters.

Conclusion

Our data are the first to provide evidence on the protective effect of TQ against Pb-induced renal antioxidant capacity impairment and suggest that this component might be a clinically promising alternative in Pb nephrotoxicity.

Rosmarinus officinalis L. ameliorates titanium dioxide nanoparticles and induced some toxic effects in rats' blood

Titanium dioxide nanoparticles (TiO₂ NPs) have been widely used as a white pigment in food and drugs. The most important route of human exposure to TiO₂ is through food and drug products containing TiO₂ additives. This study investigates the efficacy of an oral traditional use of rosemary extract in ameliorating some toxic effects induced on blood of TiO₂ NP-intoxicated rats. Rats were given rosemary extract via intragastric administration 1 h before the intragastric administration of 100 mg/kg/day TiO₂ NPs (10 nm) for 60 days. TiO₂ NPs significantly increased serum cholesterol, glucose, and triglyceride levels of rats. They also induced significant oxidative stress and inflammatory and caused DNA damage in peripheral blood leukocytes. The rosemary extract appears to have a significant protective effect by lowering glucose level properties, restoring the lipid profile and showing an antioxidative, anti-inflammatory, and antigenotoxic properties against TiO₂ NPs toxicity. In conclusion, this study gives an encouraging scientific basis for consumers of rosemary leaves to keep on with this culinary habit.

Hematological, biochemical, and toxicopathic effects of subchronic acetamiprid toxicity in Wistar rats

Acetamiprid is one of the most widely used neonicotinoids. This study investigates toxic effects of repeated oral administration of three doses of acetamiprid (1/20, 1/10, and 1/5 of LD₅₀) during 60 days. For this, male Wistar rats were divided into four different groups. Hematological, biochemical, and toxicopathic effects of acetamiprid were evaluated. According to the results, a significant decrease in the body weight gain at the highest dose 1/5 of LD₅₀ of acetamiprid was noticed. An increase in the relative liver weight was also observed at this dose level. The hematological constituents were affected. A significant decrease in RBC, HGB, and HCT in rats treated with higher doses of acetamiprid (1/10 and 1/5 of LD₅₀) was noted. However, a significant increase in WBC and PLT were observed at the same doses. Furthermore, acetamiprid induced liver toxicity measured by the increased activities of aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphates (ALPs), and lactate dehydrogenase (LDH) which may be due to the loss of hepatic membrane architecture and hepatocellular damage. In addition, exposure to acetamiprid resulted in a significant decrease in the levels of superoxide dismutase and catalase activities (p ≤ 0.01) with concomitant increase in lipid peroxidation in rat liver. These findings highlight the subchronic hepatotoxicity of acetamiprid.

The effect of titanium dioxide nanoparticles on neuroinflammation response in rat brain

Titanium dioxide nanoparticles (TiO₂ NPs) are widely used for their whiteness and opacity in several applications such as food colorants, drug additives, biomedical ceramic, and implanted biomaterials. Research on the neurobiological response to orally administered TiO₂ NPs is still limited. In our study, we investigate the effects of anatase TiO₂ NPs on the brain of Wistar rats after oral intake. After daily intragastric administration of anatase TiO₂ NPs (5-10 nm) at 0, 50, 100, and 200 mg/kg body weight (BW) for 60 days, the coefficient of the brain, acethylcholinesterase (AChE) activities, the level of interleukin 6 (IL-6), and the expression of glial fibrillary acidic protein (GFAP) were assessed to quantify the brain damage. The results showed that high-dose anatase TiO₂ NPs could induce a downregulated level of AChE activities and showed an increase in plasmatic IL-6 level as compared to the control group accompanied by a dose-dependent decrease inter-doses, associated to an increase in the cerebral IL-6 level as a response to a local inflammation in brain. Furthermore, we observed elevated levels of immunoreactivity to GFAP in rat cerebral cortex. We concluded that oral intake of anatase TiO₂ NPs can induce neuroinflammation and could be neurotoxic and hazardous to health.

Toxicopathic changes and genotoxic effects in liver of rat following exposure to diazinon

In general, people may come in contact with mixtures of insecticides through domestic use, consumption of contaminated food or drinks, and/or living close to treated areas. We analyzed the toxic effects of diazinon on histological structure of liver and hematological parameters in male rats. DNA-damaging potential of diazinon was also investigated using the comet assay in blood cells and the micronucleus test in bone marrow. Two groups of six male rats orally received different amounts of diazinon: 1/50 and 1/25 LD 50 for 4 weeks (5 day/week). The present study showed that diazinon caused hypertrophy of sinusoids, central vein, and portal triad, in addition to the formation of oedema, vacuoles, hemorrhage, necrosis, and lymphoid infiltration in rats' liver. A significant decrease in red blood cells, hemoglobin, hematocrite levels, and platelet counts was observed in the treated groups. However, the white blood cell count increased. Micronucleus test results revealed aneugenic effects of diazinon. Furthermore, we noticed an increase in comet tail length in treated groups. So, the comet assay confirmed the genotoxic potential of diazinon in vivo. On the assumption that all alterations observed in rats could be observed in human, it is necessary to raise the awareness about the health risk posed by this insecticide.

Protective effect of thymoquinone against lead-induced hepatic toxicity in rats

Lead (Pb) intoxication is a worldwide health problem which frequently affects the liver. This study was carried out to investigate the potential protective effect of thymoquinone (TQ), the major active ingredient of volatile oil of Nigella sativa seeds, against Pb-induced liver damage. Adult male rats were randomized into four groups: Control group received no treatment, Pb group was exposed to 2000 ppm Pb acetate in drinking water, Pb-TQ group was cotreated with Pb plus TQ (5 mg/kg/day, per orally), and TQ group receiving only TQ. All treatments were applied for 5 weeks. Results indicated that Pb exposure increased hepatic Pb content, damaged hepatic histological structure (necrotic foci, hepatic strands disorganization, hypertrophied hepatocytes, cytoplasmic vacuolization, cytoplasmic loss, chromatin condensation, mononuclear cell infiltration, congestion, centrilobular swelling), and changed liver function investigated by plasma biochemical parameters (AST, ALT, ALP, γ-GT, LDH). Pb treatment also decreased total antioxidant status level and increased lipid peroxidation in the liver. Supplementation with TQ remarkably improved the Pb-induced adverse effects without significantly reducing the metal accumulation in the liver. In conclusion, our results indicate, for the first time, a protective effect of TQ against Pb-induced hepatotoxicity and suggest that this component might be clinically useful in Pb intoxication.

Histopathological and genotoxic effects of chlorpyrifos in rats

This study aims to investigate the effects of chlorpyrifos's sub-acute exposure on male rats. Two groups with six animals each were orally treated, respectively, with 3.1 mg/kg b w and 6.2 mg/kg b w of chlorpyrifos during 4 weeks. The genotoxic effect of chlopyrifos was investigated using the comet assay and the micronucleus test. Some hematological and liver's histopathological changes were also evaluated. Results revealed that chlorpyrifos induced histopathological alterations in liver parenchyma. The lymphoid infiltration observed in liver sections and the increase in white blood cells parameter are signs of inflammation. A significant increase in the platelet' count and in polychromatic erythrocytes/normochromatic erythrocytes (PCE/NCE) ratio was observed in chlorpyrifos-treated groups which could be due to the stimulatory effect of chlorpyrifos on cell formation in the bone marrow at lower doses. In addition, the increase of bone marrow micronucleus percentage and the comet tail length revealed a genotoxic potential of chlorpyrifos in vivo.

Malathion-induced hepatotoxicity in male Wistar rats: biochemical and histopathological studies

The increasing use of organophosphorus pesticides in the environment constitutes an ecotoxicological hazard especially for humans and non-target animals. Hereby, we analyzed the toxic effects of malathion on the histological structure of liver and biochemical parameters in male rats. Three groups received daily different amounts of malathion: 1/1000, 1/100, and 1/10 LD50 for 30 days. The weights of treated rat's liver have increased. Analyzed tissues showed centrilobular and sinusoidal congestion, hepatocyte hypertrophy, cellular vacuolization, anucleated hepatocytes, depletion of organelles affecting the majority of cells, and presence of necrotic foci into the hepatic parenchyma. Histological sections of the liver showed important hepatocyte glycogen storage. We conclude that malathion stimulates the filing of glycogen in a dose-dependent manner. Biochemical parameters showed that alanine transaminase (ALT), aspartate transaminase (AST), gamma glutamyl transpeptidase (GGT), lactate dehydrogenase (LDH), and alkaline phosphatase (ALP) levels increased in the treated groups when the level of total protein decreased in intoxicated groups.

Thymoquinone supplementation reverses lead-induced oxidative stress in adult rat testes

The purpose of the present study was to investigate the potential protective effect of thymoquinone (TQ), the major active ingredient of volatile oil of Nigella sativa seeds, against Pb-induced testicular oxidative stress. Adult male rats were randomized into four groups: control group which received no treatment, Pb group was exposed to 2000 ppm Pb acetate in drinking water, Pb-TQ group was co-treated with Pb plus TQ (5 mg/kg b.w./day, p.o.) and TQ group receiving only TQ (5 mg/kg b.w./day, p.o.). All treatments were applied for 5 weeks. Pb treatment induced oxidative stress status in testes as evidenced by a significant decrease in the antioxidant enzymes activities such as superoxide dismutase, glutathione peroxidase and catalase, and in the reduced glutathione content and in a significant increase in the level of malondialdehyde. Interestingly, TQ supplementation completely reversed these biochemical changes caused by Pb to the control values. In conclusion, our results suggest, for the first time, that TQ is very efficient in preventing Pb-induced testicular oxidative stress. This study will open new perspectives for the clinical use of TQ in Pb intoxication.

Thymoquinone supplementation ameliorates lead-induced testis function impairment in adult rats

This study was realized to investigate the possible beneficial effect of thymoquinone (TQ), the major active component of volatile oil of Nigella sativa seeds, against lead (Pb)-induced inhibition of rat testicular functions. Adult rats were randomized into four groups: a control group receiving no treatment; a Pb group exposed to 2000 parts per million (ppm) of Pb acetate in drinking water; a Pb-TQ group co-treated with Pb (as in Pb group) plus TQ (5 mg/kg body weight (b.w.)/day, per orally (p.o.)); and a TQ group receiving TQ (5 mg/kg b.w./day, p.o.). All treatments were for 5 weeks. No significant differences were observed for the body weight gain or for relative testes weight among the four groups of animals. Testicular Pb content significantly increased in metal-intoxicated rats compared with that in control rats. TQ supplementation had no effect on this testicular Pb accumulation. Interestingly, when coadministrated with Pb, TQ significantly improved the low plasma testosterone level and the decreased epididymal sperm count caused by Pb. In conclusion, the results suggest, for the first time, that TQ protects against Pb-induced impairment of testicular steroidogenic and spermatogenic functions. This study will open new perspectives for the clinical use of TQ in Pb intoxication.

A novel insight on chronic AlCl3 neurotoxicity through IL-6 and GFAP expressions: modulating effect of functional food fenugreek seeds

OBJECTIVE

This study was designed to review the effect of chronic aluminium exposure on interleukin-6 (IL-6) secretion in the posterior brain and test the putative modulating effect of fenugreek seeds.

METHODS

Female Wistar rats were divided into four groups: control; AlCl3 during 5 months (500 mg/kg body weight, intragastric for 1 month then 1600 ppm via the drinking water); AlCl3 plus fenugreek seed powder (FSP) (5%) during the last 2 months and FSP alone.

RESULTS

Oral administration of aluminium chloride during 5 months caused hypoproduction of IL-6 together with a decrease in GFAP reactivity and an alteration of antioxidant status in the posterior brain. On the other hand, fenugreek seeds supplementation was able to enhance IL-6 expression, re-increase GFAP reactivity, and modulate the pro-oxidant-related effect.

DISCUSSION

In the context of recent researches, IL-6 hypoproduction in the posterior brain could be a novel mechanism of Al chronic toxicity with a direct effect on glial cells. Using FSP as a diet supplement could offer a neuroprotective effect against Al toxicity. This could be mediated by astroglial cells protection, antioxidant and immunomodulatory actions.

Fenugreek seeds reduce aluminum toxicity associated with renal failure in rats

Despite the reports on safety concerns regarding the relationship between aluminum salts and neurological and bone disease, many countries continue to use aluminum as phosphate binders among patients with renal failure. In search for a diet supplement that could reduce aluminum toxicity related to renal failure, we carried out this prospective animal study in which the fenugreek seeds were assessed for their effects on rats nephrotoxicity induced by aluminum chloride (AlCl₃). Oral AlCl₃ administration during 5 months (500 mg/kg bw i.g for one month then 1600 ppm via drinking water) led to plasma biochemical changes, an inhibition of alkaline phosphatase (ALP), a decrease of total antioxidant status (TAS), and an induction of lipid peroxidation (LPO) in the blood and brain, in addition to kidney atrophy and morphological alterations at the level of Bowman's capsule, the glomerulus and different sorts of tubules, reminiscent of some known kidney disease. The treatment with the whole fenugreek seed powder (FSP) (5% in the diet) during the last 2 months showed its effectiveness in restoring normal plasma values of urea, creatinine, ALP and glucose, as well as re-increasing the TAS, inhibiting LPO and alleviating histopathological changes in the injured kidneys. This study highlights the induced nephrotoxicicity, as well as the related toxicity in the brain and bone, by chronic oral ingestion of the aluminum salts. However, the maintenance of a diet supplemented with fenugreek seeds could offer protection for the kidney, bone and brain, at the same time.

A novel mutation in FGD4/FRABIN causes Charcot Marie Tooth disease type 4H in patients from a consanguineous Tunisian family

Charcot-Marie-Tooth (CMT) disease constitutes a clinically and genetically heterogeneous group of hereditary neuropathies characterized by progressive muscular and sensory loss in the distal extremities with chronic distal weakness, deformation of the feet, and loss of deep tendon reflexes. CMT4H is an autosomal recessive demyelinating subtype of CMT, due to mutations in FGD4/FRABIN, for which nine mutations are described to date. In this study, we describe three patients from a consanguineous Tunisian family, presenting with severe, early onset, slowly progressive, autosomal recessive demyelinating CMT, complicated by mild to severe kyphoscoliosis, consistent with CMT4H. In these patients, we report the identification of a novel homozygous frameshift mutation in FGD4: c.514_515insG; p.Ala172Glyfs*27. Our study reports the first mutation identified in FGD4 in Tunisian patients affected with CMT. It further confirms the important clinical heterogeneity observed in patients with mutations in FGD4 and the lack of phenotype/genotype correlations in CMT4H. Our results suggest that FGD4 should be screened in other early-onset CMT subtypes, regardless of the severity of the phenotype, and particularly in patients of consanguineous descent. In Tunisians, as in other populations with high consanguinity rates, screening of genes responsible for rare autosomal recessive CMT subtypes should be prioritized.

Fenugreek seeds, a hepatoprotector forage crop against chronic AlCl3 toxicity

Background

Having considered how bioavailable aluminium (Al) may affect ecological systems and animals living there, especially cattle, and in search for a preventive dietary treatment against Al toxicity, we aimed to test the protective role of fenugreek seeds against chronic liver injury induced by aluminum chloride (AlCl₃) in Wistar rats.

Results

Five months of AlCl₃ oral exposure (500 mg/kg bw i.g for one month then 1600 ppm via drinking water) caused liver atrophy, an inhibition of aspartate transaminase (AST), alanine transaminase (ALT) and glutamyl transpeptidase (GGT), an enhancement of both lipid peroxidation and lactate dehydrogenase (LDH) activity and an increase of total protein level in liver. Moreover, histopathological and histochemical examinations revealed moderate alterations in the hepatic parenchyma in addition to a disrupted iron metabolism. Co-administration of fenugreek seed powder (FSP) at 5% in pellet diet during two months succeeded to antagonize the harmful effects of AlCl₃ by restoring all tested parameters.

Conclusion

This study highlighted the hepatotoxicity of AlCl₃ through biochemical and histological parameters in one hand and the hepatoprotective role of fenugreek seeds on the other hand. Thus this work could be a pilot study which will encourage farmers to use fenugreek seeds as a detoxifying diet supplement for domestic animals.

Assessment of chromosomal aberrations and micronuclei in peripheral lymphocytes from tunisian hospital workers exposed to ionizing radiation

Epidemiological studies suggest that cytogenetic biomarkers, such as micronuclei (MN) in peripheral blood lymphocytes may predict cancer risk because they indicate genomic instability. The objective of the present study was to evaluate the frequencies of MN and chromosome aberrations (CA) in peripheral blood lymphocytes of hospital workers exposed to ionizing radiation and healthy subjects. The study was conducted using peripheral blood lymphocytes from 30 workers from the radiology department and 30 from the cardiology department. This study included 27 healthy age- and sex-matched individuals as the control group. The assessment of chromosomal damage was carried out by the use of CA and micronucleus assays in peripheral lymphocytes. Our results show that CA and micronucleus frequencies were significantly higher among the exposed groups when compared to controls. Our finding of significant increase of CA and MN frequencies in peripheral lymphocytes in exposed workers indicates a potential cytogenetic hazard due to this exposure. The enhanced chromosomal damage of subjects exposed to genotoxic agents emphasizes the need to develop safety programs.

Study of lipid profile and parieto-temporal lipid peroxidation in AlCl₃ mediated neurotoxicity. Modulatory effect of fenugreek seeds

BACKGROUND

Peroxidation of lipid (LPO) membrane and cholesterol metabolism have been involved in the physiopathology of many diseases of aging brain. Therefore, this prospective animal study was carried firstly to find out the correlation between LPO in posterior brain and plasmatic cholesterol along with lipoprotein levels after chronic intoxication by aluminium chloride (AlCl₃). Chronic aluminum-induced neurotoxicity has been in fact related to enhanced brain lipid peroxidation together with hypercholesterolemia and hypertriglyceridemia, despite its controversial etiological role in neurodegenerative diseases. Secondly an evaluation of the effectiveness of fenugreek seeds in alleviating the engendered toxicity through these biochemical parameters was made.

RESULTS

Oral administration of AlCl₃ to rats during 5 months (500 mg/kg bw i.g for one month then 1600 ppm via the drinking water) enhanced the levels of LPO in posterior brain, liver and plasma together with lactate dehydrogenase (LDH) activities, total cholesterol (TC), triglycerides (TG) and LDL-C (Low Density Lipoproteins) levels. All these parameters were decreased following fenugreek seeds supplementation either as fenugreek seed powder (FSP) or fenugreek seed extract (FSE). A notable significant correlation was observed between LPObrain and LDL-C on one hand and LDHliver on the other hand. This latter was found to correlate positively with TC, TG and LDL-C. Furthermore, high significant correlations were observed between LDHbrain and TC, TG, LDL-C, LPObrain as well as LDHliver.

CONCLUSION

Aluminium-induced LPO in brain could arise from alteration of lipid metabolism particularly altered lipoprotein metabolism rather than a direct effect of cholesterol oxidation. Fenugreek seeds could play an anti-peroxidative role in brain which may be attributed in part to its modulatory effect on plasmatic lipid metabolism.

Genotoxic damage in hospital workers exposed to ionizing radiation and metabolic gene polymorphisms

Of all workers exposed globally to synthetic sources of radiation, medical personnel represent the largest group, but receive relatively low doses. Accidental or therapeutic acute radiation exposure of humans was observed to induce various forms of cytogenetic damage, including the possibility of increasing the incidence of micronuclei (MN) and chromosomal aberrations (CA). The aim of this study was to assess occupationally induced chromosomal damage in a large population of hospital workers exposed to low doses of ionizing radiation (IR). The cytokinesis-block MN and comet assays were used to examine peripheral blood lymphocytes (PBL) of 31 exposed workers to IR and 33 control subjects corresponding in gender, age, and smoking. Glutathione S-transferases (GSTM1, GSTT1, and GSTP1) are postulated to be involved in the detoxification of endogenous and exogenous genotoxicants. The association between these biomarkers and polymorphic genes of xenobiotic metabolizing enzymes was thus also assessed. MN frequency was significantly higher in the exposed subjects compared controls. Comet assay results showed a significant increase of tail length in workers exposed to IR. Data obtained suggest that GSTM1, GSTT1, and GSTP1 polymorphism do not modify significantly the genotoxic potential of IR. Therefore, the exposed medical personnel need to carefully apply radiation protection procedures and minimize, as low as possible, IR exposure to avoid possible genotoxic effects.

Erythrocyte antioxidants enzymes imbalance following subcutaneous pyrethroid treatments in rats of different sex

Permethrin and deltamethrin are insecticides used all over the world in agriculture to control pests. The aim of this work is to investigate the effects of subcutaneous permethrin and/or deltamethrin treatments on erythrocyte antioxidant enzymes activity in rats of different sex. The results obtained show that permethrin decreases SOD and GPx activity in female rats, while it increases SOD activity in male rats. Deltamethrin treatment reduces GPx activity in male rats, while permethrin has a similar effect but only for short time treatments. A catalase activity decrease was observed in both sexes following pyrethroid treatment but when both the pyrethroids were administrated in male rats, the enzyme activity has increased. In conclusion, this study points out for the first time the importance of rat gender on erythrocyte antioxidant enzymes, which are influenced not only by the length and the type of insecticide treatment but importantly by sex.

Genes conferring resistance to organophosphorus insecticides in Culex pipiens (Diptera: Culicidae) from Tunisia

In Tunisia, the mosquito Culex pipiens shows various organophosphate resistance alleles at Ester and ace-1 loci. The characterization and the distribution pattern of these alleles were studied among 20 populations sampled from north to center of Tunisia. At the Ester locus, Ester4, Ester5, and Ester(B12) were present. A new esterase characterized by the same electrophoretic migration as esterase A1 was identified: A13, encoded by Ester(A13) allele. At the ace-1 locus, the presence of the ace-1(R), ace-1(D), and F290V mutated alleles was also detected. A large heterogeneity in allelic frequencies at Ester and ace-1 loci was observed among samples, with a high significant genotypic differentiation considering both loci (F, = 0.077, P < 10(-5)), depicting variations of insecticide treatment intensity between areas. A comparison between populations collected in 1996 and 2005 showed an absence of significant resistance evolution. However, the high frequencies of resistance alleles in 2005 populations suggested that the selection pressures are still important in Tunisia. Strategies for resistance management are discussed in the context of the current knowledge of the Tunisian situation.

Resistance to pyrethroid insecticides in Culex pipiens pipiens (Diptera: Culicidae) from Tunisia

Resistance toward 2 pyrethroïd insecticides (permethrin and deltamethrin), and an organochloric one (DDT) was analyzed in 18 samples of Culex pipiens pipiens common mosquitoes collected from different Tunisian areas between March 2002 and November 2005. Bioassays were performed over different larvae samples. The recorded mortalities, after 24h exposure to increased doses of insecticides, were compared to those obtained on a susceptible reference strain (S-LAB). All samples were resistant to permethrin. However, a large variation in the tolerance to this insecticide was observed between samples. Resistance ratio levels at LC50 (RR50) for the analyzed samples were ranged from 1.5 to 9092 folds. For deltamethrin, 14 among 17 studied samples were resistant. RR50, in the resistant samples, were ranged from 3 to 453 folds. Resistance to the two tested pyrethroids and DDT were correlated. The use of synergists showed that the cytochrome P450-dependent monooxygenases had a major contribution to the permethrin and deltamethrin resistance and that the esterases (and/or glutathione-S-transferases) had only a minor contribution. Results were discussed in relation to resistance mechanisms and mosquito's control.

Characterization of a novel high-activity esterase in Tunisian populations of the mosquito Culex pipiens

AIn the mosquito Culex pipiens (L.) (Diptera: Culicidae) esterases contribute to insecticide resistance by their increased activity. These esterases display a heterogeneous geographical distribution, particularly in Tunisia, where they are very diverse. In this study, we extended the characterization of a highly active esterase first detected in 1996: B12. Esterase B12 displayed the fastest electrophoretic mobility of all the previously described highly active esterases. We showed that it was encoded by the Ester(B12) allele at the Ester locus, and we isolated a strain, TunB12, homozygous for this allele. TunB12 displayed a low (approximately two- to three-fold) but significant resistance to the organophosphates temephos and chlorpyrifos, and to the pyrethroid permethrin. Only temephos resistance was synergized by S,S,S-tributyl-phosphorotrithioate. Real-time quantitative polymerase chain reaction revealed that the Ester(B12) allele was not amplified in TunB12 strain, indicating that B12 high activity could be due to a gene up-regulation mechanism. Ester(B12) allele frequencies also were estimated in 20 Tunisian populations collected in 2005. Analyses revealed a large distribution of this allele all over the country. Finally, sequences of Ester(B12) were acquired and genetic distance trees were constructed with the resistance Ester alleles already published, providing indications about allele's origins. The diverse array of highly active esterases in C. pipiens from Tunisia and the possible scenario of the origin of their coding alleles are discussed in the context of their possible evolution.

Interplay of socio-economic factors, consanguinity, fertility, and offspring mortality in Monastir, Tunisia

AIM

To assess the association among social status, prevalence of consanguineous marriages, and the effects of consanguinity on reproductive behavior and mortality in Tunisia.

METHODS

The study included data on a total of 1741 live-births born from November 1989 to October 1990 in the maternity ward of the University-Hospital Fattouma Bourguiba of Monastir, Tunisia. After delivery, women filled out a questionnaire on the age of the parents at marriage, the number of pregnancies and abortions, the number of neonatal and post-neonatal deaths, and deaths of children under 5 years. Three categories of marriages were distinguished as follows: marriages between first cousins, marriages between cousins of other degree, and non consanguineous marriages.

RESULTS

Consanguineous marriages represented 432 (24.81%) of the unions. Most consanguineous marriages were contracted between first cousins (n=303; 70.13%). Consanguineous couples had a lower age at marriage and a higher fertility index than non-consanguineous couples. The rates of spontaneous abortions and stillbirths were not correlated with consanguinity. However, higher rates of neonatal and post-neonatal deaths, and deaths of children younger than 5 years were observed in consanguineous couples.

CONCLUSION

Fertility index and mortality, especially in the first year of life, were significantly higher in consanguineous marriages. This important socio-economical factor needs to be considered in assessing equity on health in specific social and cultural contexts.

Association among education level, occupation status, and consanguinity in Tunisia and Croatia

AIM

To investigate the association between education level, occupation status (a proxy for socio-economic status), and consanguinity in 2 large data sets from Tunisia and Croatia countries with different attitudes toward consanguinity.

METHODS

The sample of 1016 students, attending 5 university institutions in Monastir, Tunisia, were interviewed about the educational level and occupation status of their parents and the degree of parental relatedness. In Croatia, a sample of 1001 examinees from 9 isolated island populations was interviewed about their own educational level, occupation status, and consanguinity.

RESULTS

Prevalence of consanguinity (offspring of second cousins or closer) among 1016 Tunisian students was 20.1%, and 9.3% among 1001 Croatian isolates. In Tunisia, the association between consanguinity and both parental degree of education and parental occupation status was highly significant in women (P<0.001), but not significant in men. In Croatia, no statistically significant associations were noted, although there was a consistent trend of increased prevalence of consanguinity with lower education level or occupation status in both genders, but more pronounced in women.

CONCLUSION

Association between education level, socio-economic status, and consanguinity needs to be taken into account in inbreeding studies in human populations. The relationship may be specific for each studied population and highly dependent on the cultural context. It is generally more pronounced among women in most settings.