Beneficial role of vanillin, a polyphenolic flavoring agent, on maneb-induced oxidative stress, DNA damage, and liver histological changes in Swiss albino mice.

Vanillin, a widely used flavoring agent, has antimutagenic and antioxidant properties. The current study was performed to evaluate its beneficial role against hepatotoxicity induced by maneb, a dithiocarbamate fungicide. Mice were divided into four groups of six each: group 1, serving as negative controls which received by intraperitoneal way only distilled water, a solvent of maneb; group 2, received daily, by intraperitoneal way, maneb (30 mg kg-1 body weight (BW)); group 3, received maneb at the same dose of group 2 and 50 mg kg-1 BW of vanillin by intraperitoneal way; and group 4, serving as positive controls, received daily only vanillin. After 10 days of treatment, mice of all groups were killed. Our results showed that vanillin significantly reduced the elevated hepatic levels of malondialdehyde, hydrogen peroxide, and advanced oxidation protein product and attenuated DNA fragmentation induced by maneb. In addition, vanillin modulated the alterations of antioxidant status: enzymatic (superoxide dismutase, catalase, and glutathione peroxidase) and nonenzymatic (reduced glutathione, nonprotein thiol, and vitamin C) antioxidants in the liver of maneb-treated mice. This natural compound was also able to ameliorate plasma biochemical parameters (aspartate aminotransferase, alanine aminotransferase, gamma glutamyl transpeptidase, alkaline phosphatase, total bilirubin, and total protein). The protective effect of vanillin was further evident through the histopathological changes produced by maneb in the liver tissue. Thus, we concluded that vanillin might be beneficial against maneb-induced hepatic damage in mice.

Comprehensive insight into functional interaction between GNB3 C825T and eNOS T-786C, G894T gene polymorphisms and association with susceptibility to diabetic erectile dysfunction.

BACKGROUND: No study has assessed the possible involvement of endothelial nitric oxide synthase (eNOS) T-786C and G894T and G-protein ß3 subunit (GNB3) C825T polymorphisms with susceptibility to diabetic vasculogenic erectile dysfunction (VED) in North African subjects. OBJECTIVES: Our aim was to evaluate the interaction and association between these gene polymorphisms and this disorder. MATERIALS AND METHODS: A total of 164 type 2 diabetes patients with VED diagnosed with penile color Doppler ultrasonography and 148 age-matched healthy volunteers were genotyped for the rs1799983 (G894T) and rs2070744 (T-786C) of the eNOS gene and the rs5443 (C825T) of the GNB3 gene using the PCR-RFLP method. RESULTS: A significant association of the eNOS G894T (p = 0.005) and T-786C (p = 0.02) with altered susceptibility to VED was observed. The risk also holds for the G894T and T-786C eNOS gene polymorphisms when excluding patients with dyslipidemia and cardiovascular diseases (p = 1.7·10-4 and p = 3.2·10-5 , respectively). The univariate odds ratio associated with CC alleles of the eNOS T-786C revealed a four times increased risk for VED (OR = 4.04; 95% CI = 1.53-10.67; p = 0.006). VED risk was also associated with the G894T variant under dominant model (p = 0.002) and the T-786C variant under recessive model (p = 0.004). Furthermore, the concomitant presence of the combined genotypes of the 894T and 786T strongly affected the predisposition to VED (p = 0.007). DISCUSSION AND CONCLUSION: Our study gave a comprehensive insight into functional interaction between GNB3 and eNOS gene polymorphisms and suggests that the eNOS G894T and T-786C variants are strong predisposing factors of VED susceptibility within men with type 2 diabetes.

Investigation of larvae digestive ß-glucosidase and proteases of the tomato pest Tuta absoluta for inhibiting the insect development.

The tomato leaf miner Tuta absoluta is one of the most devastating pests for tomato crops. Digestive proteases and ß-glucosidase enzymes were investigated using general and specific substrates and inhibitors. Maximal ß-glucosidase and proteolytic activities occurred at temperature and pH optima of 30 and 40°C, 5 and 10-11 unit of pH, respectively. Zymogram analysis showed the presence of distinguished ß-glucosidase exhibiting a specific activity of about 183 ± 15 µmol min-1 mg-1. In vitro inhibition experiments suggested that serine proteases were the primary gut proteases. Gel based protease inhibition assays demonstrated that the 28 and 73 kDa proteases might be trypsin-like and chymotrypsin-like enzymes, respectively. Overall gut trypsin-like and chymotrypsin-like activities were evaluated to be about 27.2 ± 0.84 and 1.68 ± 0.03 µmol min-1 mg-1, respectively. Sodium dodecyl sulfate polyacrylamide gel electrophoresis analysis showed that T. absoluta gut serine proteases are responsible for Bacillus thuringiensis Cry insecticidal proteins proteolysis. Additionally, bioassays showed that T. absoluta larvae development was more affected by the ß-glucosidases inhibitor (D-glucono-δ-lactone) than the serine proteases inhibitor (soybean trypsin inhibitor). These results are of basic interest since they present interesting data of ß-glucosidases and gut serine proteases of T. absoluta larvae.

Male hypogonadism and metabolic syndrome.

The role of androgens in cardiovascular disease is still controversial in men. In this study, we investigated metabolic disorders in Tunisian hypogonadal men compared with healthy controls. Forty hypogonadal men and 80 control subjects were enrolled. Patients with a history of pre-existing panhypopituitarism, thyroid dysfunction or inflammatory disease were excluded. Glycaemia, glycated haemoglobin (HbA1c), high-sensitive C-reactive protein (hsCRP), lipid profile, insulin, testosterone and gonadotrophins were measured. Insulin resistance was assessed by homoeostasis model assessment of insulin resistance (Homa IR). Waist circumference, body mass index and blood pressure were significantly higher in patients compared with controls. Glycemia, HbA1c, fasting serum insulin and Homa IR were significantly increased among hypogonadal men. In univariate analysis, testosterone levels were inversely correlated with body mass index, waist circumference, blood pressure, glycaemia, HbA1C, insulin, Homa IR and hsCRP. In multivariate analysis including all significant variables, initial testosterone level was the only independent risk factor for developing dyslipidaemia. With logistic regression, male hypogonadism was an independent risk factor for MS (P < 0.001). We conclude that low testosterone level plays a central role in the development of metabolic syndrome. Further prospective data are required to establish the causative link.

Methylenetetrahydrofolate reductase C677T and A1298C polymorphisms and variations of homocysteine concentrations in patients with Behcet's disease.

BACKGROUND: Behcet's disease (BD) is a chronic, relapsing, multi-systemic inflammatory disorder of unknown causes. This disease is mainly characterized by mucocutaneous, ocular, vascular, and central nervous system manifestations. The aim of this study is to investigate the associations between C677T and A1298C polymorphisms in the methylenetetrahydrofolate reductase (MTHFR) gene and the plasma homocysteine (Hcy), folate, and B12 levels in a relatively large cohort of Tunisian patients with BD. METHODS: The study included 142 patients with BD and 172 healthy controls. The C677T and A1298C polymorphisms were genotyped using PCR-RFLP. Serum Hcy level was determined using a fluorescence polarization immunoassay. Serum folate and vitamin B12 levels were measured by electrochemiluminescence immunoassay. RESULTS: Genotype and allele frequencies of the two studied MTHFR polymorphisms did not show any significant differences among BD patients compared to controls. Patient carriers of the 677TT variant and the 677T allele displayed significantly higher Hcy concentration. Moreover, no significant association was found between neither A1298C polymorphism nor the C allele and Hcy, folate, and B12 levels. In multivariate analyses, we reported that 677T allele, male gender, and creatinine level were independent risk factors for hyperhomocysteinemia (HHC). CONCLUSIONS: In the present study, we report the absence of any significant differences between genotype and allele frequencies for both studied polymorphisms among BD patients compared to healthy controls. Besides, we showed that the T allele of MTHFR C677T polymorphism influenced the Hcy level which is an independent risk factor for HHC in Tunisian BD patients.

Oxidative stress and hepatotoxicity in rats induced by poisonous pufferfish (Lagocephalus lagocephalus) meat

This study was undertaken to evaluate the effect of pufferfish (Lagocephalus lagocephalus) meat poisoning on hepatic functions of Wistar rats. For this purpose, groups of rats (Lcr, Lcu+b and Lcu-b) received diet supplemented with 10 percent of raw or cooked meat, respectively, with or without cooking water of L. lagocephalus while groups Mcr and Mcu+b received diet supplemented with 10 percent of raw or cooked meat of Liza aurata, which were used as a negative control. In Lcu+b group, ALT, AST and ALP rates (hepatic enzyme markers) decreased after two months of treatment, indicating liver damage. We also observed an increase of 54 and 65 percent of thiobarbituric acid reactive substances (TBARS) in their livers respectively 48 hours and two months after treatment compared to controls. The catalase (CAT) activity in group Lcu+b decreased (p < 0.05) after two periods of treatment, whereas metallothionein (MT) level significantly increased and decreased, respectively after 48 hours and two months. In fact, in the histological analysis of the livers from Lcu+b treated group, we observed an increase in vacuolisation, necrosis, hepatocytes ballooning and sinusoids dilation. These results indicate that L. lagocephalus meat cooked with water produces hepatotoxicity and oxidative damage.(AU)

Hematological toxicity associated with tissue extract from poisonous fish Lagocephalus lagocephalus--influence on erythrocyte function in Wistar rats.

The puffer fish Lagocephalus lagocephalus represents serious public health problems in the world. The relative toxicity of each organ (liver and flesh) was determined by the relation dose-death time "mouse bioassay." The average liver toxicity of the puffer fish was the highest when compared with flesh giving 14.32 and 10.88 MU/g, respectively. A mouse unit is the amount of toxin (extract of fish organ) that kills a 20 g male mouse in 30 min after intraperitoneal injection. One mouse unit is equivalent to 0.22 microg of TTX. For the rat bioassay tests, Wistar rats were daily i.p. injected, for 10 d, with extracts of liver (LT) or flesh (FT) (muscles + skin) of L. lagocephalus. Control rats received injection of NaCl (0.9%). During the experiment, a significant reduction in red blood cell number (RBC), hemoglobin (HGB) concentration, and hematocrit (HCT) was observed essentially after 10 d of treatment in the FT and LT-exposed groups. Consequently, treatment led to severe anemia and hemolytic action as indicated by a significant reduction in the total number of erythrocytes. In fact, our study revealed a significant increase in erythrocyte lipid peroxidation (LPO) in FT and LT groups compared with controls after experimental exposure. The flesh and liver tissue extracts also altered antioxidative enzymes activities: catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px). Histopathological alterations in the spleen occurred exclusively at the end of treatment. We marked also an increase in reticulo-endothelial cells, which led to remove damaged erythrocytes.

Inhibitory effects of 1á, 25dihydroxyvitamin D3 and Ajuga iva extract on oxidative stress, toxicity and hypo-fertility in diabetic rat testes

The aim of the current study is to investigate the therapeutic and preventive effectsof 1á, 25dihydroxyvitaminD3 (1,25 (OH)2 D3) and Ajuga iva (AI) extract on diabetestoxicity in rats testes. Thus diabetic rats were treated with 1á, 25dihydroxyvitaminD3or Ajuga iva extract as both therapeutic and preventive treatments on diabetestoxicity in rats testes. Our results showed that diabetes induced a decrease intestosterone and 17â-estradiol levels in testes and plasma. Besides, a fall in testicularantioxidant capacity appeared by a decrease in both antioxidant (superoxide dismutase(SOD), catalase (CAT) and glutathione peroxidase (GPx) activities) and nonenzymaticantioxidant (copper (Cu), magnesium (Mg) and iron (Fe) levels). All theseschanges enhanced testicular toxicity (increase in testicular aspartate aminotransaminase (AST), alanine amino transaminase (ALT), lactate dehydrogenase(LDH) activities and the lipid peroxidation and triglyceride (TG) levels). In addition,a decrease in testicular total cholesterol (TCh) level was observed in diabetic ratstestes. All the changes lead to a decrease in the total number and mobility of epididymalspermatozoa. The administration of 1á,25dihydroxyvitaminD3 and Ajugaiva extract three weeks before and after diabetes induction interfered and preventeddiabetes toxicity in the reproductive system. 1,25 (OH)2 D3 and Ajuga iva extractblunted all changes observed in diabetic rats. To sum up, the data suggested that 1,25(OH)2 D3 and Ajuga iva extract have a protective effect on alloxan-induced damagein reproductive system by enhancing the testosterone and 17â-estradiol levels, consequentlyprotecting from oxidative stress, cellular toxicity and maintaining the numberand motility of spermatozoids (AU)

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Inhibitory effects of 1alpha, 25dihydroxyvitamin D3 and Ajuga iva extract on oxidative stress, toxicity and hypo-fertility in diabetic rat testes.

The aim of the current study is to investigate the therapeutic and preventive effects of 1alpha, 25dihydroxyvitaminD3 (1,25 (OH)2 D3) and Afuga iva (AI) extract on diabetes toxicity in rats testes. Thus diabetic rats were treated with 1alpha, 25dihydroxyvitaminD3 or Ajuga iva extract as both therapeutic and preventive treatments on diabetes toxicity in rats testes. Our results showed that diabetes induced a decrease in testosterone and 17beta-estradiol levels in testes and plasma. Besides, a fall in testicular antioxidant capacity appeared by a decrease in both antioxidant (superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) activities) and nonenzymatic antioxidant (copper (Cu), magnesium (Mg) and iron (Fe) levels). All theses changes enhanced testicular toxicity (increase in testicular aspartate amino transaminase (AST), alanine amino transaminase (ALT), lactate dehydrogenase (LDH) activities and the lipid peroxidation and triglyceride (TG) levels). In addition, a decrease in testicular total cholesterol (TCh) level was observed in diabetic rats testes. All the changes lead to a decrease in the total number and mobility of epididymal spermatozoa. The administration of 1alpha,25dihydroxyvitaminD3 and Ajuga iva extract three weeks before and after diabetes induction interfered and prevented diabetes toxicity in the reproductive system. 1,25 (OH)2 D3 and Ajuga iva extract blunted all changes observed in diabetic rats. To sum up, the data suggested that 1,25 (OH)2 D3 and Ajuga iva extract have a protective effect on alloxan-induced damage in reproductive system by enhancing the testosterone and 17beta-estradiol levels, consequently protecting from oxidative stress, cellular toxicity and maintaining the number and motility of spermatozoids.

[Lipid profile in maintenance haemodialysis]. / Profil lipidique dans l'insuffisance rénale chronique au stade d'hémodialyse.

INTRODUCTION: The chronic kidney failure is a source of dyslipidemia and accelerated atherosclerosis. No changes in the lipoprotein profile could be reversed by dialysis. OBJECTIVE: Our aim was to study the lipid disturbances characteristics in end stage renal disease in order to assess their theorical atherogenic potential. SUBJECTS AND METHODS: The patient population consisted of 36 patients on maintenance haemodialysis. Matched control subjects were recruited among apparently healthy normolipidemic Tunisians. Total cholesterol, triglycerides, high-density-lipoprotein cholesterol, low-density-lipoprotein cholesterol, apolipoprotein AI and apolipoprotein B concentrations were measured. RESULTS: The triglycerides levels were significantly higher in patient group, unlike the high-density-lipoprotein cholesterol and apolipoprotein AI levels that were significantly reduced. We saw no increase in the levels of low-density-lipoprotein cholesterol and apolipoprotein B. The low-density-lipoprotein cholesterol/high-density-lipoprotein cholesterol ratio result wasn't helpful in the evaluation of the atherogenic risk. CONCLUSION: We confirm the quantitative lipid disorders associated with maintenance haemodialysis. The assessment of cardiovascular risk on the basis of these disorders seems difficult.

Critical base substitutions that affect the splicing and/or homing activities of the group I intron bi2 of yeast mitochondria.

The second intron (bi2) of the cyt b gene from related Saccharomyces species has an extraordinarily conserved sequence and can have different functions in wild-type cells. The protein encoded by the S. cerevisiae intron functions as a maturase to promote intron splicing, while the homologous S. capensis intron encodes a bifunctional protein that acts both as a maturase and as a homing endonuclease (I-ScaI) promoting intron mobility. The protein encoded by intron bi2 belongs to a large gene family characterized by the presence of two conserved LAGLIDADG motifs (P1 and P2). In this study, we analysed a set of splicing-deficient mutants of the S. cerevisiae intron bi2 that carry non-directed mutations affecting the maturase activity, and a set of directed missense mutations introduced into the bifunctional protein encoded by the S. capensis intron. Analysis of these mutations has allowed identification of the residues in the conserved P1 and P2 motifs which are crucial for splicing and homing activities. Moreover, several mutations which are located in the C-terminal part of the protein have been found to affect both functions.

Intragenic suppressors that restore the splicing and homing activities of the protein encoded by the second intron of the Saccharomyces capensis cyt b gene.

The second (bi2) intron of the mitochondrial cyt b gene from Saccharomyces capensis encodes a bifunctional protein which acts both as a maturase, promoting intron splicing, and as a homing-endonuclease, I-ScaI, promoting intron mobility. In this work we isolated and characterized revertants from a respiratory-deficient mutant in which both functions of the protein have been lost. Intragenic revertants resulted mainly from monosubstitutions in the mutated codon and in one case from a distant second site mutation. All novel variants of the S. capensis bi2 intron-encoded protein are competent for the maturase activity but only two of them can partially complement the homing function.

[Free radicals and antioxidants: physiology, human pathology and therapeutic aspects (part II)]. / Radicaux libres et anti-oxydants: physiologie, pathologie humaine et aspects thérapeutiques (ilème partie).

Although they are considered as destructive agents, free radicals can sometimes become useful. Their presence is intimately coupled with the activity of certain hemal oxydases which insert an atom of oxygen into their substrate by a stereospecific radical mecanism. The cytochromes P450 and the enzymes of the eicosanoide metabolism are some examples. The free radicals can act as second cellular messengers, especially to modulate the metabolism of arachidonic acid and the prostaglandin tract or to infer a myorelaxation. They can even play the role of neurotransmitters such as azote monoxyde. The activation of phagocytes, which is an essential event in the inflammatory reaction, integrates these notions at several levels: in the mechanisms of bacterial death, in the spread of the inflammatory reaction and in the alteration of the extra-cellular matrix. The inflammatory reaction is initiated by interactions between vascular endothelium, platelets and leukocytes including signal exchanges, adhesion molecule expression and secretion of chimiotactic mediators. Activation of vascular endothelium is a key event in the initiation of the phenomenon. The cells intervening in the precocious inflammatory phase were tissular mastocytes and platelet-liberating mediators (histamine) and neutrophile cells responsible for vascular injuries induced by oxygen free radicals and nitric oxide. Reactive oxygen intermediates play a critical role, primarily to limit tissue damage and prevent or inhibit infection, secondary to enhancing and prolonging reaction. The monocytes and platelets liberate cytokines early, which appears to be important in activation and production of an inflammatory response. In fact, cytokines, especially TNF alpha and IL-1, induce synthesis and secretion endothelial adhesion molecules such as ICAM-1, VCAM-1 and E-selectin, which have been demonstrated to mediate leukocyte recruitment to sites of inflammation. The cytokines also activate the fibroblasts and endothelial cells that produce, among others, free radicals and other chimiotactic cytokines of which some (IL-8 and related) can induce neutrophil degranulation and stimulate oxidative stress and formation of free radicals. Furthermore, endothelial cells have been shown to make use of a broad repertoire of cytokines including IL-1, IL-6, IL-8, MCP-1 and gro/MGSA, which may be secreted during an inflammatory response and exercise pro-inflammatory functions. Under the influence of the inflammatory mediators, other enzymes are also activated. The inducible isoforms of cyclo-oxygenase (COX-2) and nitric oxide synthase (iNOS) play an important role in inflammatory reactions via the production respectively of prostaglandins and nitric oxide. The induction of cell adhesion molecules (ICAM-1, VCAM-1 and E-selectin), cytokines, acute phase proteins, growth factors, COX-2 and iNOS expression is mediated by the activation of transcriptional factors, especially the nuclear factor kappa B (NF-kappa B). The NF-kappa B system is essentially involved in immediate early expression of various immunoregulatory genes and has been demonstrated to represent an important regulatory system of endothelial activation. The target genes for NF-kappa B comprise a growing list of genes intrinsically linked to a coordinated inflammatory response. The NF-kappa B is a heterodimer composed of two subunits (p65 and p50). In non-stimulated cells, NF-kappa B resides in the cytoplasm as an inactive complex bound to its inhibitor, I kappa B. Upon stimulation with various agents including cytokines, mitogenes, viruses and reactive oxygen intermediates, I kappa B dissociates from the NF-kappa B-I kappa B complex and translocates to the nucleus, binding with high affinity to specific sites in the promoter regions of target genes and stimulating their transcription. In the case of any weakness of this anti-oxidizing defence or any over-production of radical species, a state of oxidative stress occurs. (ABSTRACT TRUNC

[Free radicals and antioxidants: human physiology, pathology and therapeutic aspects]. / Radicaux libres et anti-oxydants: physiologie, pathologie humaine et aspects thérapeutiques.

Oxygen has invaded progressively, and through the ages, an initially anaerobic world. Living organisms had to invent, in the course of evolution, diverse and ingenious defence systems, to survive the toxicity of this element, which was new for them. Strengthened by this experience over billions of years, the present superior organisms, and particularly human species, are thoroughly adapted to 21 per cent of atmospheric oxygen. Nevertheless, the equilibrium is fragile and the menace of oxygen hovers continually. This deleterious potential of oxygen is attributed to the formation, in vivo, of free radicals, a free radical being, by definition, any chemical species possessing one or several mismatched electrons. These free radicals are, in general, very active. They trigger chain reactions able to damage the different constituents of the living organism. Basic oxygen, must be pre-activated to manifest its toxicity. Such an activation can be achieved in two ways: it can be photodynamic, ending mainly in singlet oxygen, it can be reducing, followed by the formation of the anion hydrogen peroxide and of radical hydroxyl; the latter is the most reactive chemical species in the biological world. The reductive process is accelerated in the presence of transition metals, such as iron and copper, and/or specific enzymes (monoxygenase and certain oxydases). This activation takes place in different cellular compartments: mitochondria, microsomes, peroxysomes, cytoplasmic membrane. To this potential toxicity of oxygen the organism opposes different anti-oxidant defence systems. A first group works up the radical chain, inhibiting activation mechanisms. Such a group, as a consequence, warns of the initiation of radical reactions. The second group neutralizes the free radicals already formed and thus stops the chain of propagation. In this group can be found detoxifying enzymes, notably superoxide dismutase and catalase, producing jointly peroxidases, particularly peroxidase glutathions. Such enzymes for the most part have trace elements as cofactors. In this second group can also be found various molecules which act like 'substrate suicide', or as an anti-oxidant shield. Among these molecules, some can act in the lipidic phase, such as tocopherols, carotenoïds and ubiquinones. Other molecules which are lipophobic, mainly ascorbic acid and uric acid, are active in a hydrated environment. In the case of a weakening of such an antioxidant defence or excess production of radicals, a state of oxidative stress occurs. Uncontrolled, these radicals will damage different biological targets: lipids, DNA, proteins. Disturbances of cellular metabolism will occur, unless corrective defences intervene. The identification of these radical phenomena is an obligatory stage. But because of the very short life span of free radicals, identification poses a real analytical problem. However, three approaches are possible: identification of free radicals, either directly by means of paramagnetic electron resonance, or indirectly by identifying some more stable intermediates. evaluation of the traces of radical attack on biological molecules, for example by high performance liquid chromatography, gas-liquid chromatography, colorimetric tests, estimation of the antioxidant status, for example by colorimetric tests, immunoenzymatic methods, high performance liquid chromatography.