Kefir milk alleviates benzene-induced immunotoxicity and hematotoxicity in rats.

The adverse health effects of benzene occupational and circumstance pollution exposure are an increasing concern. It leads to damage to various human tissues including bone marrow and ovarian tissues and many vital physiological processes. Previous studies showed that kefir is a rich probiotic, having protective effect, thanks to its antioxidant, anti-inflammatory, and immunomodulatory capacity. The purpose of this study was to evaluate the potential efficacy of kefir to remediate benzene toxicity in rat. Thirty-two female rats were randomly allocated and administered orally with benzene and/or kefir during a period of 21 consecutive days. At the end of the experiment, hematological and bone marrow cell changes were estimated. The animals exposed to benzene exhibited anemia and a significant decrease in the levels of white blood cell. Moreover, benzene led to the activation of gene expression of the pro-inflammatory cytokines interleukin-1ß (IL-1ß) and interleukin-6 (IL-6), a myelotoxicity in bone marrow cells. Our data showed that kefir treatment alleviated benzene-associated weight loss and increased the number of whole blood cells in peripheral blood and nucleated cells in the bone marrow. Furthermore, these physiological results were observed with animals showing high concentrations of lactic acid bacteria (LAB) determined from fecal samples, which are considered an indicator of kefir-associated microorganisms. Our study suggests that kefir is a potential nutritional supplement target to attenuate hematotoxicity induced by benzene.

Factor VII levels, R353Q and -323P0/10 Factor VII variants, and the risk of acute coronary syndrome among Arab-African Tunisians.

The importance of the extrinsic haemostatic system, of which factor VII/VIIa (FVII/FVIIa) is a key constituent, in acute coronary syndrome (ACS) is well recognized. The contribution of FVII gene variants R353Q and -323P0/10, and altered FVII plasma levels to the risk of ACS was investigated in a North African Tunisian Arab cohort consisting of 308 ACS cases and 312 age-, gender- and ethnically-matched control subjects; FVII antigen levels were determined by ELISA. Regression analysis was used in assessing the association of FVII variants and changes in FVII levels to the overall risk of ACS. Significantly higher FVII antigen levels were seen in ACS patients (P < 0.001), and were associated with ACS and with ACS severity, and this association was confirmed by multivariate regression analysis, after adjusting for a number of confounders (BMI, smoking, systolic blood pressure, hypertension, diabetes, and glucose, cholesterol, and triglycerides levels). While the carriage of 353Q allele, was associated with significant reduction in FVII plasma levels, the distribution of the R353Q genotypes was comparable between cases and control subjects, thereby indicating that altered FVII levels, independent of R353 variant, were associated with increased risk of ACS. In contrast, the -323Ins variant, while not associated with altered FVII plasma levels, was associated with ACS, following adjustment for BMI, smoking, systolic blood pressure, hypertension, diabetes, and glucose, cholesterol, triglycerides and FVII levels. In summary, elevated FVII levels, and the -323P0/10 but not R353Q polymorphism, constitute risk factors for ACS.

Contribution of coagulation factor VII R353Q, -323P0/10 and HVR4 polymorphisms to coronary artery disease in Tunisians.

We examined the contribution of two factor VII (FVII) bi-allelic (R353Q, -323P0/10) and one tandem repeat (HVR4) polymorphisms to the risk of coronary artery disease (CAD) in Tunisians. Study subjects comprised 308 CAD patients and 312 age-, gender- and ethnically-matched controls. Regression analysis was used in assessing the FVII association to CAD risk. While the distribution of -323P0/10 alleles and genotypes were comparable between cases and controls, marginal association of the R353Q variant was noted, with the Q allele (19.1 vs. 23.8%; P = 0.05) and Q allele-containing genotypes (R/Q + Q/Q; 33.8 vs. 48.0%) being slightly under-represented in cases than in controls. On the other hand, four alleles of FVII microsatellite HVR4 were detected at variable frequencies in Tunisians, and comprised H6 (63.2%), H7 (33.8%), and to lesser extents H5 (1.9%) and H8 (0.8%). Of these, the H7 variant was under-represented in patients [P = 0.038; OR (95%CI) = 0.75 (0.58-0.97)]. Of the major genotypes detected (H6/H6, H6/H7, H7/H7) only H6/H6 was positively associated with CAD [P = 0.047; OR (95%CI) = 1.39 (1.00-1.94)]. In conclusion, our study underscores the role of polymorphisms in the FVII gene in modulating the susceptibility to CAD in (North African) Tunisian Arabs.

Effect of thymoquinone on 1,2-dimethyl-hydrazine-induced oxidative stress during initiation and promotion of colon carcinogenesis.

We evaluated pre- and post-thymoquinone (TQ) treatment on 1,2-dimethyl-hydrazine (DMH)-induced oxidative stress during initiation and promotion of colon carcinogenesis. Wistar rats were induced with DMH (20mg/kg) for 10 or 20 weeks, and treated with TQ (5mg/kg). Following sacrifice, the colons were analysed for tumour development, reactive oxygen species (ROS) generation, lipid peroxidation [conjugated diene (CD) and malondialdehyde (MDA)], antioxidants [glutathione peroxidase (GPx), catalase (CAT), superoxide dismutase (SOD) and reduced glutathione (GSH)], and histological changes. Increased ROS levels and lipid peroxidation were seen during tumour initiation and promotion. All ROS-scavenging enzyme activities were increased upon shorter DMH treatment but not following longer treatment, while GSH amount was increased upon both treatments. Oxidative state perturbations were associated with moderate colon dysplasia and 30% tumour incidence at initiation and marked dysplasia and 100% tumour incidence at promotion. TQ pre-treatment restored completely DMH-induced oxidative stress at initiation and established histological changes and tumour development. It also abrogated oxidative status aggravation at promotion, and significantly reduced tumour incidence (67%). By comparison, TQ post-treatment corrected oxidative status and attenuated tumour development at initiation. It slightly reduced MDA and antioxidant level at promotion, with a slight reduction in tumour state and dysplasia degree. TQ is efficacious in protecting and curing DMH-induced initiation phase of colon cancer, while exerting a protective role at promotion. TQ effect seems to be related to its capacity in preventing DMH-induced oxidative stress. These in vivo results support the notion that TQ may be of value as a chemo-preventive alternative in colorectal cancer patients.

Anticoagulant properties of the anti-inflammatory cytokine IL-10 in a factor Xa-activated human monocyte model.

BACKGROUND: Monocytes and factor Xa (FXa) are procoagulant agents implicated in the physiopathological processes of atherosclerosis and thrombosis. OBJECTIVE: we evaluated the anticoagulant effect of the anti-inflammatory cytokine IL-10 on an FXa-activated human monocyte (Hu-monocyte) procoagulant phenotype. METHODS: Hu-monocytes were purified by elutriation and activated by FXa. The effect of IL-10 was assessed by means of a 2 h pre-incubation step with recombined human IL-10 (0.5 and 1 ng/mL). Real-time RT-PCR and Western blotting were used to evaluate the effect of IL-10 on tissue factor (TF) mRNA and protein synthesis. A thrombin generation (TG) assay was used as a functional test to assess the effect of IL-10 on TF-dependent TG. RESULTS: we showed that IL-10 inhibited both TFmRNA and TF protein expression in a dose-dependant manner.We showed, as a functional consequence, that IL-10 inhibited Hu-monocyte-triggered TG and that this inhibition was concentration-dependant, and significant for all TG phases. The rate index of the propagation phase (rate index) was the most sensitive parameter while the endpoint of TG decay (S-tail) and the endogenous thrombin potential (ETP) were the least sensitive (inhibition of 80, 40 and 30% respectively). The IL-10 pattern of TG inhibition was similar to TF-Ab-induced inhibition: IC(50) were not reached by ETP and S-tail, and the lowest IC(50) values were reached by the rate index (0.61 ± 0.12 ng/mL and 1.87 ± 0.35 µg/mL respectively). CONCLUSION: the anticoagulant effect of the anti-inflammatory cytokine IL-10 in an FXa-activated Hu-monocyte model is an additional illustration of the cross-talk between inflammation and coagulation, opening new approaches in the field of arteriosclerosis and thrombosis.

Mutational screening of SF1 and WNT4 in Tunisian women with premature ovarian failure.

BACKGROUND: WNT4 and SF1 genes play an important role in ovarian development. They constitute coherent candidate genes associated with premature ovarian failure (POF) pathogenesis. METHODS: We sequenced the coding region of WNT4 and SF1 in 55 Tunisian women with POF and 100 healthy controls. RESULTS: We identified a synonymous variation in WNT4 (c.99G>A, p.Ser33Ser) and a substitution (c.G437C) in SF1 gene inducing G146 to Ala (GGG-GCG) missense mutation. WNT4 (c.99G>A, p.Ser33Ser) was not associated with POF pathology. However, a positive association of SF1 Gly146Ala polymorphism was noted. Gly146Ala minor allele frequency was significantly higher (p=0.029) in POF patients versus controls and Ala allele containing genotypes (p=0.005) were positively associated with POF pathology. The carriage of 146Ala allele was also associated with a significant reduction in estradiol plasma levels. CONCLUSIONS: SF1 Gly146Ala polymorphism seems to be associated with POF pathology in the Tunisian population likely by reducing estradiol levels.

IL-10 modulates fondaparinux inhibition of monocyte-induced thrombin generation.

In addition to its established immuno-regulating capacity, the anti-inflammatory cytokine interleukin (IL)-10 exerts direct effects on coagulation. IL-10 down regulates the expression of tissue factor (TF) and thrombin generation (TG). Thus, we hypothesised that IL-10 could enhance the effect of anticoagulants. To evaluate in vitro the potential additive effect of IL-10 on fondaparinux-induced anticoagulation. Human monocytes were purified by elutriation, and were activated by factor Xa (FXa). Real-time RT-PCR and Western blotting were used to evaluate FXa-induced TF synthesis. TG test was used as a functional test to assess TF-dependent monocyte procoagulation, and to evaluate the effects of IL-10 (200 and 500 pg/ml) and fondaparinux (0.0, 0.1, 0.4, 0.7 and 1.2 µg/ml), separately and in combination. We confirmed that FXa induced TF mRNA and protein synthesis by monocyte in a concentration dependent manner. We showed that FXa-activated monocytes triggered TG via TF expression. We reported that IL-10 inhibited TG with a marginal effect seen at 200 pg/ml. Results with fondaparinux showed a concentration-dependent TG inhibition. The combination of IL-10 and fondaparinux effects demonstrated that IL-10: (i) potentiates the inhibitory effect of fondaparinux on TG by 10-30%, and (ii) dramatically modifies fondaparinux IC50 for each TG parameter. IL-10 enhances in vitro the extent of anticoagulation induced by fondaparinux.

Differential coagulation inhibitory effect of fondaparinux, enoxaparin and unfractionated heparin in cell models of thrombin generation.

Anticoagulants, including unfractionated heparin (UFH), enoxaparin and fondaparinux, are approved drugs in acute coronary syndrome (ACS). Monocytes and monocyte-derived microparticles (MMPs) play an important procoagulant role in ACS by expressing high tissue factor (TF) levels, which in turn triggers thrombin generation. The objective of our study is to compare the in-vitro inhibitory effect of UFH, enoxaparin and fondaparinux in monocytes and MMP models. Human-elutriated monocytes were activated for 5 and 18 h by lipopolysaccharide to obtain activated monocytes (ac-M) or MMPs, respectively. Thrombin generation inhibition was assessed using ac-M or MMPs mixed with platelet-poor plasma containing increased concentrations of anticoagulants. Thrombin generation inhibition was dose-dependent with a differential effect according to the drug: the highest for UFH, the lowest for fondaparinux. Rate index was the most sensitive parameter. For fondaparinux, its IC50 values (anti-Xa IU/ml) were 0.59±0.05 for ac-M and 0.17±0.03 for MMPs. For enoxaparin, rate index IC50 values were 0.27±0.03 for ac-M and 0.19±0.02 for MMPs. Our data support the notion that cell-induced thrombin generation assay may be a reliable alternative to anti-Xa assessment in determining patient anticoagulation level.

-174G>C interleukin-6 gene polymorphism in Tunisian patients with coronary artery disease.

BACKGROUND AND OBJECTIVES: A state of low-grade inflammation accompanies the pathogenesis of atherosclerotic events. Interleukin-6 (IL-6) is a pleotropic pro-inflammatory cytokine that modulates the development of acute coronary syndromes (ACSs), partly by destabilizing coronary atherosclerotic plaques. We have examined the contribution of the -174G>C IL-6 promoter variant on the risk of coronary artery disease (CAD) among Tunisians. PATIENTS AND METHODS: Study subjects included 418 CAD patients and 406 age- and sex-matched controls. IL-6 genotyping was done by PCR-restriction fragment length polymorphism. RESULTS: The frequency of the -174C allele (mutant) was lower in Tunisians than in Europeans, and the distribution of -174 G>C genotypes was similar between CAD patients and control subjects. Moreover, compared to GG genotype carriers, -174C allele carriage did not increase the CAD relative risk (odds ratio and 95% confidence interval=1.09 and 0.80-1.49), which remained nonsignificant after adjusting for traditional risk factors for CAD (age, smoking, hypertension, diabetes and obesity). CONCLUSION: The -174G>C IL-6 promoter variant is not associated with an increased risk of CAD among Tunisians.

Evaluation of the contribution of renin angiotensin system polymorphisms to the risk of coronary artery disease among Tunisians.

Recent studies have identified genetic markers that may directly influence the risk of the coronary artery disease (CAD), in particular the renin angiotensin system genes. Since there are no existing data for the Tunisian population, we investigated the association between these polymorphisms (angiotensin-converting enzyme [ACE] insertion/deletion [Ins/Del]; the angiotensinogen T174M and M235T; and the angiotensin II type 1 receptor A1166C polymorphisms) and CAD in Tunisians. Study subjects comprised 341 cases and 316 age- and sex-matched healthy individuals. Clinical characteristics and other biochemical and environmental risk factors were collected for both. The distribution of the Ins/Del genotypes was significantly different between cases and controls (p = 0.049) with the genotype Ins/Ins identified as a risk, p = 0.02. Similarly, the distributions of the T174M and M235T genotypes were significantly different between cases and controls (p = 0.037 and 0.047, respectively) with 174 M/M and 235 T/T as the risky genotypes (p = 0.001 and 0.026, respectively). However, A1166C genotype frequencies were not significantly different between patients and controls. In conclusion, our results suggest that a significantly higher risk of CAD was associated with the Ins/Del, the M235T, and T174M polymorphisms; other environmental variables such as body mass index; and biochemical variables such as cholesterol.

Functional interleukin-10 promoter variants in coronary artery disease patients in Tunisia.

OBJECTIVES: The contribution of interleukin (IL)-10 promoter variants -1082G/A, -819C/T, and -592C/A to the risk of coronary artery disease (CAD) was investigated in 291 CAD patients and 291 age- and gender-matched control subjects. METHODS AND RESULTS: IL-10 genotyping was performed using PCR-allele-specific amplification (PCR-ASA). Regression analysis was employed in assessing the contribution of the IL-10 variants to the overall CAD risk. A higher frequency of the -592A allele (p = 0.004), but not the -1082A (p = 0.828) or -819T (p = 0.952) alleles, was seen in CAD patients. A higher frequency of -592C/A (p = 0.011), and a lower frequency of -592C/C (p = 0.015) genotypes was noted in patients compared to healthy controls. Regression analysis demonstrated an association of -592C/A [OR (95% CI) = 1.82 (1.02-3.23)] and -592A/A [OR (95% CI) = 3.33 (1.27-9.09)] genotypes with 1-artery disease. Haplotype analysis revealed that none of the eight possible IL-10 haplotypes was associated with CAD or with the severity of CAD, and was confirmed by multivariate regression analysis, after adjusting for a number of confounders (smoking, systolic and diastolic blood pressure, hypertension, diabetes, glucose, cholesterol, and triglycerides). CONCLUSIONS: Our results suggest that the -592C/A, more so than the -1082G/A or the -819C/T IL-10 promoter variant alleles, may be considered to be a risk factor for CAD in Tunisians.

TNF-alpha -308G>A and IL-6 -174G>C polymorphisms in Tunisian patients with coronary artery disease.

OBJECTIVE: Our aim was to evaluate the contribution of tumor necrosis factor (TNF)-alpha -308G>A and interleukin (IL)-6 -174G>C gene promoter variants to the presence of coronary artery disease (CAD) in Tunisians. DESIGN AND METHODS: Study subjects comprised 418 angiographically proven CAD patients and 406 age-, gender-, and ethnic origin-matched controls. Genotyping was performed using polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) analysis. RESULTS: There were no significant differences in the allelic distribution of TNF-alpha -308A (19.6% vs. 19.0%, P=0.73), and IL-6 -174C (15.6% vs. 14.3%, P=0.47) promoter polymorphisms between CAD patients and control subjects, respectively. In addition, single locus analysis revealed no differences in genotype frequencies between the two study groups, and the combined distribution of both genotypes did not differ significantly between controls and CAD patients (P>0.05). CONCLUSION: There is no allelic or genotypic association of TNF-alpha -308G>A and IL-6 -174G>C promoter polymorphisms with CAD in Tunisians, thereby confirming an ethnic-selective contribution of both gene variants to CAD presence.

Association of PAI-1 4G/5G and -844G/A gene polymorphisms and changes in PAI-1/tissue plasminogen activator levels in myocardial infarction: a case-control study.

BACKGROUND: Myocardial infarction (MI) is induced by acquired and inherited risk factors, including the plasminogen activator inhibitor-1 (PAI-1) -844G/A and -675G/A (4G/5G) gene variants. OBJECTIVE: The aim of this study was to investigate the association between PAI-1-844G/A and 4G/5G polymorphisms and changes in PAI-1 and tissue plasminogen activator (tPA) levels in MI in a Tunisian population. METHODS: This was a case-control study involving 305 patients with MI and 328 unrelated healthy controls. PAI-1 genotyping was done by polymerase chain reaction-restriction fragment length polymorphism (RFLP) (-844G/A) or by polymerase chain reaction-allele specific amplification. PAI-1 and tPA levels were assayed by serological assays. RESULTS: In contrast to tPA levels, mean plasma PAI-1 antigen levels were higher in cases than in control subjects. The elevation in PAI-1 levels was more pronounced in -844A and 4G allele carriers. Significantly higher frequencies of (mutant) 4G and -844A alleles and 4G/4G and -844A/-844A genotypes, and corresponding lower frequencies of (wild-type) 5G and -844G alleles and 5G/5G and -844G/-844G genotypes were seen in patients than in controls. Increased prevalence of 4G/-844A and decreased prevalence of 5G/-844G haplotypes were seen in patients than in controls, thereby conferring a susceptibility and protective nature to these haplotypes, respectively. Regression analysis confirmed the independent association of 4G/4G and -844A/A with MI, after controlling for a number of covariates. CONCLUSION: This study indicated that the risk of MI was notably high in 4G and -844A carriers with elevated plasma PAI-1 and were associated with reduced tPA levels.

Human platelet alloantigens HPA-1, HPA-2, and HPA-3 polymorphisms associated with extent of severe coronary artery disease.

The contribution of human platelet antigen (HPA)-1 (GPIIb/IIIa), HPA-2 (GPIb/IX), and HPA-3 (GPIIb/IIIa) polymorphisms to the risk of coronary artery disease (CAD) was investigated in 341 CAD patients and 316 matched control subjects. HPA genotyping was performed by PCR-SSP. Regression analysis was employed in assessing the contribution of these variants to CAD risk. The frequency of HPA-1b (P = .009) and HPA-3b (P = .004) alleles, and HPA-1a/1b (P = .045), HPA-1b/1b (P = .007), and HPA-3b/3b (P = .008) genotypes were higher in patients than control subjects. No significant association was demonstrated between the HPA variants and 1-, 2- and 3-vessel disease. HPA-1b/2a/3b (Pc = .021) and HPA-1b/2b/3a (Pc = .002) haplotypes were positively associated with CAD, thereby conferring a disease susceptibility nature to these haplotypes. Multivariate analysis confirmed the positive association of HPA-1b/2a/3b (aOR = 3.72; 95% CI = 1.49-9.28), and in addition identified HPA-1b/2a/3a (aOR = 2.49; 95% CI = 1.06-5.86) to be positively associated with CAD, after adjusting for a number of covariates. Our results demonstrate positive association of HPA variants and specific HPA-1/HPA-2/HPA-3 haplotypes with CAD in Tunisians.