Glutathione-S-transferase genetic polymorphism and risk of hepatotoxicity to antitubercular drugs in a North-African population: A case-control study.

INTRODUCTION: GST non-functional genotypes can lead to the accumulation of toxic intermediates, resulting in liver damage and increasing susceptibility to ATDH. AIM: To investigate the impact of GST Mu (GSTM1), GST Theta (GSTT1) null genotypes, and GST Pi (GSTP1; adenosine (A) > guanine (G), rs1695) variant allele on the development of ATDH in Tunisian patients treated with anti-tuberculosis therapy. METHODS: This was a case-control study including patients receiving anti-tuberculosis regimen. Cases (n = 23) were tuberculosis patients presenting ATDH during two months of anti-tuberculosis drug therapy. Controls (n = 30) were patients treated for tuberculosis, but presenting no ATDH. Genotyping was performed using a polymerase chain reaction-restriction fragment length polymorphism. RESULTS: No statistically significant association was observed between GSTM1 and GSTT1 homozygous null genotypes, and the risk of ATDH. A statistically significant association between GSTM1 and GSTT1 double null genotypes, and the risk of ATDH was found (p = 0.033) between cases and controls. For GSTP1, the distribution of GG homozygous mutant genotype was significantly associated with ATDH compared with the wild and the transition A to G (AA + AG) genotypes. CONCLUSION: Double deletion of GSTM1 and GSTT1 may predispose to ATDH in a Tunisian population. Moreover, GSTP1 rs1695 (A > G) genotyping can predict susceptibility to developing ATDH.

GC-MS Based Metabolic Profiling of Parkinson's Disease with Glutathione S-transferase M1 and T1 Polymorphism in Tunisian Patients.

AIM AND OBJECTIVE: Parkinson's disease (PD) is the second most common neurodegenerative disease. It is a multifactorial disorder (caused by aging, environmental, and genetic factors). Metabolomics can help explore the biomarker profiles for aging. Recent studies showed an association between the glutathione S-transferases (GSTs) polymorphisms and PD risk. The purpose of this study was to evaluate the association of this genetic polymorphism and the metabolomic profile in PD Tunisian patients, in order to identify effective biomarkers in the genetic differentiation. MATERIALS AND METHODS: In this study, the metabolomic profile changes related to GSTs polymorphism were searched in 54 Tunisian PD patients treated with L-dopa, using a gas chromatography-mass spectrometry (GC-MS) technique. RESULTS: The study results showed that mannose, methyl stearate, and three other unknown metabolites, increased in patients with GSTM1 positive genotype, while glycolic acid, porphine, monomethyl phosphate, fumaric acid, and three other unknown metabolites decreased in patients with GSTM1 positive genotype. Subsequently, the levels of glycolic acid, erythronic acid, lactic acid, citric acid, fructose, stearic acid, 2-amino-2-methyl-1,3-propanediol and three other unknown metabolites increased in patients with GSTM1 positive genotype, while the levels of proline, valine and two unknown metabolites decreased with GSTT1 positive genotype. CONCLUSION: All these altered metabolites are related to energy metabolism and it can be concluded that GSTs polymorphism based the shifting in energy metabolism and led to oxidative stress.

Evaluation of Daily Laurus nobilis Tea Consumption on Lipid Profile Biomarkers in Healthy Volunteers.

Introduction:Laurus nobilis is known in the field of herbal medicine and in vitro studies that it has beneficial effects such as antibacterial, antifungal, antidiabetes, and anti-inflammatory properties.Objective: We investigated whether L. nobilis tea consumption affects the plasma levels of lipid biomarkers in healthy volunteers.Methods: Thirty healthy Tunisian volunteers aged between 20 and 57 years old consumed L. nobilis infusion, prepared from 5 g of dried L. nobilis leaves in 100 ml boiled water, once a day during 10 days. Plasma concentrations of serum low-density lipoprotein (LDL) cholesterol, triglycerides and HDL (high-density lipoprotein) cholesterol were measured by Beckman Coulter D × 600 analyzer before L. nobilis consumption and at the end of the experiment.Results:L. nobilis tea consumption significantly increased the concentration of HDL cholesterol ([HDL cholesterol] D0 = 1.34 ± 0.25 pg/mL, D11=1.42 ± 0.29, p = 0.01). However, a slight decrease that was statistically non-significant in LDL cholesterol and triglycerides levels was observed (p < 0.05).Conclusions: These findings highlight the improving blood lipidic profiles, which means a possible positive effect on reducing the risk of cardiovascular disease of L. nobilis tea consumption in healthy volunteers. However, more powerful studies with an extended treatment period are required.

Glutathione S-transferase M1 and T1 polymorphisms and the risk of mild hepatotoxicity induced by carbamazepine in a tunisian population study.

BACKGROUND: The aim of this study was to evaluate whether the glutathione S-transferase M1 (GSTM1) and T1 (GSTT1) null alleles may contribute to carbamazepine-induced hepatotoxicity. METHODS: A cross-sectional prospective study was conducted to identify the frequency distribution of GSTM1 and GSTT1 alleles in 129 Tunisian epileptic patients treated with carbamazepine. Null alleles were determined using a Polymerase Chain Reaction. Serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were measured by standard methods. RESULTS: Our results showed that the frequencies of GSTM1 (-) null allele and GSTT1 null (-) allele were 74.4 and 17.8% respectively. The ALT and AST levels were elevated in 46 (35.7%) and 33 (25.6%) cases. The mean values of ALT and AST were approximately 1.32 and 3.61 times higher than the upper limit of normal levels, respectively. The values of ALT and AST were significantly higher in GSTM1 (-) allele than in GSTM1 (+) (p = 10-3.and 0.004, respectively). The level of ALT was significantly higher in combination of GSTM1 (-)/T1(-) than in combined GSTM1(-)/T1(+) and combined GSTM1(+)/T1(+) (p = 0.2 and 0.03, respectively), and that of AST was significantly higher in combination of GSTM1(-)/T1(-) and in combination of GSTM1(+)/T1(-) than in combination of GSTM1(+)/T1(+) (p = 10-3 and 10-3, respectively). CONCLUSIONS: Our findings suggest that the GSTM1 (-) allele may be considered as a key factor for the development of carbamazepine-induced hepatotoxicity. Results related to GSTT (-) allele and elevation in AST levels should be considered with caution as AST may be elevated in other pathophysiological conditions.

The relationship between pharmacokinetic parameters of carbamazepine and therapeutic response in epileptic patients.

INTRODUCTION: The prescribed dose and carbamazepine plasma concentration to achieve the optimal therapeutic efficacy are highly variable from one patient to the other. Our study aimed to determine whether biological parameters may be used as plasma markers that can individually adjust the carbamazepine dose necessary to optimize therapeutic efficacy. MATERIAL AND METHODS: Ninety-four epileptic patients under carbamazepine monotherapy and who have never used combination therapy were recruited from the consecutive admissions at the Department of Neurology "CHU Sahloul" of Sousse Central Hospital in Tunisia from February 2010 to April 2011. The patients were monitored for epilepsy for three years on average. Carbamazepine and 10,11-epoxide-carbamazepine concentrations were analyzed through high-performance liquid chromatography. Simultaneously, therapeutic efficacy was assessed through the annual number of seizures in each patient. RESULTS: Our results showed the absence of any significant correlations between specific dose (mg/kg/day), carbamazepine plasma concentrations and therapeutic efficacy (r = 0.0025, p = 0.30; r = 0.1584, p = 0.38 respectively), whereas both plasma 10,11-epoxide-carbamazepine concentration and 10,11-epoxide-carbamazepine to plasma carbamazepine ratio were closely correlated with therapeutic efficacy (r = 0.34, p = 0.03; r = 0.45, p = 0.008 respectively). The optimum therapeutic response was observed among patients who simultaneously had a plasma concentration of 0.8 µg/ml of metabolite and 5.5 µg/ml of carbamazepine. CONCLUSIONS: The results suggest that plasma levels of both carbamazepine and of 10,11-epoxide-carbamazepine must be set to achieve an optimum therapeutic response.

Effects of glutathione S-transferase M1 andT1 deletions on bipolar disorder risk among a Tunisian population.

Glutathione S-transferases (GSTs) enzymes are involved in the detoxification of several endogenous and exogenous substances. In this study, we evaluated the effects of two glutathione S-transferase polymorphisms, (GSTM1 and GSTT1) on bipolar disorder (BPD) risk susceptibility in a Tunisian population. These polymorphisms were analyzed in 229 healthy subjects and 109 patients with BPD, using a polymerase chain reaction. Statistical analysis was performed using SPSS 18.0. The relative associations between the GSTs genotypes and BPD were assessed by calculating odds ratios (ORs) and 95% confidence intervals (CLs). The study results demonstrated that individuals with GSTM1 [OR=1.51, 95% CI: 0.93-2.45, p=0.081] or GSTT1 [OR=1.65, 95% CI: 0.95-2.88, p=0.060] were not associated with the risk of BPD, whereas a significant association was found between individuals with both GSTM1/T1 null genotype and BPD risk [OR=2.96, 95% CI (1.26-7.03), p=0.005]. These genotyping finding revealed that the absence of both GSTM1 and GSTT1 activity could be a contributor factor for the development of BPD.

Effects of EPHX1 and CYP3A4*22 genetic polymorphisms on carbamazepine metabolism and drug response among Tunisian epileptic patients.

The aim of this study was to evaluate the impact of polymorphisms in the EPHX1 (c.416A > G, c.337T > C) and CYP3A4*22 genes involved in carbamazepine (CBZ) metabolism and pharmacoresistance among 118 Tunisian patients with epilepsy under maintenance dose of CBZ. These genetic polymorphisms were analyzed by PCR-RFLP. Associations between plasma CBZ concentration, CBZ-E concentration, maintenance doses and metabolic ratio (CBZ-E:CBZ, CBZ-D:CBZ-E) were analyzed with each polymorphism. Both variants of EPHX1 c.416A > G and c.337T > C are significantly associated with higher metabolic ratio CBZ-E:CBZ and seem to decrease the activity of the epoxide hydrolase. The CYP3A4*22 variant allele is significantly associated with lower CBZ-D:CBZ-E ratio and seems also to be associated with less activity of the cytochrome. Our data suggest that certain polymorphisms of metabolizing enzyme genes could influence inter-individual variability of CBZ metabolism.

Relationships between pharmacokinetic parameters of carbamazepine and therapeutic response in patients with bipolar disease.

This study aimed to assess the relationship between plasma levels of carbamazepine and its active metabolite 10,11-epoxide-carbamazepine, and the therapeutic response in patients with bipolar disease. Thirteen patients were kept on a fixed individual dose of carbamazepine for 19 weeks under psychiatric care. Steady-state plasma concentrations of carbamazepine and its metabolite 10,11-epoxide-carbamazepine were measured at weeks 4, 12, and 20 by HPLC essay. Simultaneously, the psychopathologic state was assessed using the Brief Psychiatric rating scale (BPRS). Upon correlational analysis, mean BPRS scores did not correlate with the plasma levels of carbamazepine, whereas both mean plasma levels of 10, 11-epoxide-carbamazepine concentrations and 10,11-epoxide-carbamazepine to plasma carbamazepine ratio were closely correlated with mean values of BPRS scores (r = 0.80, p =10(-4), r= -0.89, p =10(-3) respectively). Optimum therapeutic response was observed among patients who had a plasma metabolite level of 1.4 µg/mL and a plasma carbamazepine concentrations of 7 µg/mL simultaneously. These results suggest that both plasma carbamazepine and 10,11-epoxide-carbamazepine levels must be fixed to achieve optimum therapeutic response. In order to reach these conditions, inhibitor drugs (such as valproic acid) or inductor drugs (such as phenobarbital) of epoxyde-hydrolase might be coadministered with the carbamazepine in order to adapt the plasma level of 10,11-epoxide-carbamazepine.

[Cytogenetics study of chromosomal instability in Fanconi anemia in Tunisia]. / Étude cytogénétique de l'instabilité chromosomique dans la maladie de Fanconi en Tunisie.

Cells of Fanconi anemia (FA) is characterized by cellular and chromosomal hypersensitivity to DNA cross-linking agents. We tested mitomycin C at 25 ng/mL, 40 ng/mL and diepoxybutane 0.1 µg/mL in order to select a reference technique in the diagnosis of AF. We also studied the mitotic segregation of sex chromosomes. Our study focused on 73 patients with aplastic anemia suspecting AF and also 17 healthy controls. Thus, the MMC 25 ng/mL with a sensitivity to detect AF cells. DEB, by contrast, showed better specificity. FISH study shows the presence of instability in the AF mitotic cells. The association for routine diagnosis of MMC 25 ng/mL and DEB 0.1 mcg/mL, and the search for a mitotic instability by FISH is the best way of cytogenetic diagnosis of AF.

Effects of glutathione S-transferase M1 and T1 deletions on epilepsy risk among a Tunisian population.

Glutathione-S-transferases enzymes are involved in the detoxification of several endogenous and exogenous substances. In this present study, we evaluated the effects of two glutathione-S-transferase polymorphisms, (GSTM1 and GSTT1) on epilepsy risk susceptibility in a Tunisian population. These polymorphisms were analyzed in 229 healthy subjects and 98 patients with epilepsy, using a polymerase chain reaction (PCR). Odds ratio (ORs) was used for analyzing results. The study results demonstrated that individuals with the GSTM1 null genotype were at an increased risk of developing epilepsy [OR=3.80, 95% confidence interval (CI) (2.15-4.78)], whereas no significant effects were observed between individuals with GSTT1 null genotype and epilepsy risk [OR=1.15, 95% CI (0.62-2.12)]. These genotyping finding revealed that the absence of GSTM1 activity could be contributor factor for the development of epilepsy disease.

Analysis of thiopurine S-methyltransferase phenotype-genotype in a Tunisian population with Crohn's disease.

This study was conducted to investigate the thiopurine S-methyltransferase TPMT activity distribution and gene mutations in Tunisian population with positive diagnostic for Crohn's disease. TPMT activity was measured in Tunisian population (n = 88) by a high performance liquid chromatography assay. Polymerase chain reaction-based methods were used to determine the frequency of TPMT mutant alleles TPMT*2, TPMT*3A, TPMT*3B and TPMT*3C. TPMT activity was normally distributed, ranging from 4.58 to 35.27 nmol/(h ml) RBC with a mean of 18.67 ± 7.10 nmol/(h ml) RBC. Seven TPMT*3A heterozygotes and one TPMT*3C homozygote were found in 88 patients, with allele frequencies of 0.039 and 1.13, respectively. TPMT*3A and the TPMT*3C, which cause the largest decrease in enzyme activity, were both variant alleles detected in the Tunisian population.