In vitro effects of 1-(4-dimethylaminobenzylidene)-2-(2-hydroxybenzylidene) hydrazine and its copper complex on lymphocyte proliferation and function in the presence of free radical generator.

In this study, the in vitro effects of 1-(4-dimethylaminobenzylidene)-2-(2-hydroxybenzylidene) hydrazone (L1) and its corresponding copper complex [Cu(L1)], synthesized in our laboratory, were investigated on the proliferative responses, Th1 (interleukin-2 (IL-2), interferon-γ (INFγ)) and Th2 (IL-4) cytokine secretion, adenosine triphosphate (ATP) levels and intracellular redox status of T lymphocytes submitted to H2O2/FeSO4-mediated oxidative stress. T cells were isolated on histopaque density gradient by differential centrifugation, and were cultured with the mitogen concanavalin A (Con A), free radical generator (H2O2/FeSO4) and with different concentrations of L1 and [Cu(L1)] (1 - 100 µM). Proliferation (MTT assay), cytokines (Elisa kits), ATP levels, cytotoxic effect (micronucleus test) and oxidative markers (glutathione, catalase, superoxide dismutase, hydroperoxide and carbonyl protein contents) were investigated after 48-h incubation. Our results showed that H2O2/FeSO4 treatment induced a reduction in T lymphocyte proliferation, cytokine secretion and ATP levels associated to an evident intracellular oxidative stress, inflammatory profile and DNA damage. Addition of L1 at 100 µM was able to increase cell proliferation, IL-2, IL-4 and INFγ secretion and ATP contents and to reduce hydroperoxide and carbonyl protein contents, catalase activity and micronuclei number in lymphocytes under oxidative stress, with a partial protection. The [Cu(L1)] exhibited protective effects in T lymphocytes by inhibiting H2O2/FeSO4 - induced cell proliferation suppression, inflammatory status, ATP loss and oxidative stress generation, whatever the concentration used. In conclusion, in the situation of excessive oxidative stress, [Cu(L1)] treatment improved T lymphocyte proliferation, cytokine production, ATP contents and oxidant/antioxidant status. [Cu(L1)] could be effective at improving oxidative stress and T cell abnormalities.

[Effect of N-3 polyunsaturated fatty acids on the modulation of T lymphocytes in vitro and redox status in obese women with hypertension]. / Effet des acides gras polyinsaturés N-3 sur la modulation in vitro des lymphocytes T et le statut redox chez les femmes obèses hypertendues.

OBJECTIVES: Deepen our knowledge of the immune system alterations associated with obesity-related hypertension and demonstrate that polyunsaturated fatty acids can enhance the proliferation and their profile oxidant/antioxidant and subsequently involved in the strategy prevention and treatment in obese hypertensives. METHODS: T cells are isolated from the blood of the control and obese women with hypertension the University Hospital of Tlemcen (Algeria), these cells are incubated in the presence of a synthetic mixture of PUFA to 30µM (DHA/EPA/LA) and stimulated by mitogens for 48hours. The cells are counted and used to assess intracellular oxidative status. The biochemical parameters are determined by the use of plasma. RESULTS: In obese women with hypertension, a significant increase in plasma levels of (glucose, uric acid, creatinine, urea, total cholesterol and triglycerides) compared to controls. In addition, decreased cell proliferation, basal or stimulated by Con A was observed in obese women with hypertension compared with controls. The mixture of PUFA to 30µM reduced lymphoproliferation as well in obese women with hypertension than in controls. The rates in malondialdéhyde (MDA) and protein carbonyl lymphocytes are elevated in hypertensive obese women. PUFA supplementation to 30µM seems correct this redox status in hypertensive obese since rates in protein carbonyl, are similar to those of controls. CONCLUSION: The mixture of PUFA (n-3 and n-6) can modulate the activity of T lymphocyte proliferation and correct the intracellular redox status in hypertensive obese women.

Effect of dietary n - 3 polyunsaturated fatty acids on oxidant/antioxidant status in macrosomic offspring of diabetic rats.

The aim of this work was to determine the effect of dietary n - 3 PUFA on oxidant/antioxidant status, in vitro very low and low density lipoprotein (VLDL-LDL), and VLDL-LDL-fatty acid composition in macrosomic pups of diabetic mothers. We hypothesized that n - 3 PUFA would improve oxidative stress in macrosomia. Diabetes was induced in female Wistar rats fed with the ISIO diet (control) or with the EPAX diet (enriched in n - 3 PUFAs), by streptozotocin. The macrosomic pups were killed at birth (day 0) and at adulthood (day 90). Lipid parameters and VLDL-LDL-fatty acid composition were investigated. The oxidant/antioxidant status was determined by measuring plasma oxygen radical absorbance capacity (ORAC), hydroperoxides, carbonyl proteins, and VLDL-LDL oxidation. Macrosomic rats of ISIO fed diabetic mothers showed an increase in plasma and VLDL-LDL-triglycerides and VLDL-LDL-cholesterol levels and altered VLDL-LDL-fatty acid composition. Plasma ORAC was low with high hydroperoxide and carbonyl protein levels. The in vitro oxidizability of VLDL-LDL was enhanced in these macrosomic rats. The EPAX diet corrected lipid parameters and improved oxidant/antioxidant status but increased VLDL-LDL susceptibility to oxidation. Macrosomia is associated with lipid abnormalities and oxidative stress. n - 3 PUFA exerts favorable effects on lipid metabolism and on the oxidant/antioxidant status of macrosomic rats. However, there are no evident effects on VLDL-LDL oxidation.

Oxidative stress and maternal obesity: feto-placental unit interaction.

OBJECTIVE: To determine oxidative stress markers in maternal obesity during pregnancy and to evaluate feto-placental unit interaction, especially predictors of fetal metabolic alterations. PATIENTS AND METHODS: 40 obese pregnant women (prepregnancy BMI > 30 kg/m²) were compared to 50 control pregnant women. Maternal, cord blood and placenta samples were collected at delivery. Biochemical parameters (total cholesterol and triglycerides) and oxidative stress markers (malondialdehyde, carbonyl proteins, superoxide anion expressed as reduced Nitroblue Tetrazolium, nitric oxide expressed as nitrite, reduced glutathione, catalase, superoxide dismutase) were assayed by biochemical methods. RESULTS: Maternal, fetal and placental triglyceride levels were increased in obese group compared to control. Maternal malondialdehyde, carbonyl proteins, nitric oxide and superoxide anion levels were high while reduced glutathione concentrations and superoxide dismutase activity were low in obesity. In the placenta and in newborns of these obese mothers, variations of redox balance were also observed indicating high oxidative stress. Maternal and placental interaction constituted a strong predictor of fetal redox variations in obese pregnancies. DISCUSSION: Maternal obesity compromised placental metabolism and antioxidant status which strongly impacted fetal redox balance. Oxidative stress may be one of the key downstream mediators that initiate programming of the offspring. CONCLUSION: Maternal obesity is associated with metabolic alterations and dysregulation of redox balance in the mother-placenta - fetus unit. These perturbations could lead to maternal and fetal complications and should be carefully considered.

5,6-dihydro-2H-pyranones and 5,6-dihydro-2H-pyridones and their derivatives modulate in vitro human T lymphocyte function.

The aim of this work was to study the in vitro effects of δ-lactone 1, δ-lactam 3 and their enaminone derivatives 2 and 4, synthesized in our laboratory, on the proliferative responses of human lymphocytes, Th1 and Th2 cytokine secretion and intracellular redox status. Peripheral blood lymphocytes were isolated using differential centrifugation on a density gradient of Histopaque. They were cultured with mitogen concanavalin A (Con A) and with different concentrations of the compounds 1, 2, 3 and 4 (0.1-10 µM). Proliferation (MTT assay), IL-2, INFγ and IL-4 (Elisa kits), oxidative markers (intracellular glutathione, hydroperoxide and carbonyl protein contents) and cytotoxic effect (micronucleus test) were determined. The compounds 1 and 2 are immunosuppressive and decrease IL-2, INFγ and IL-4 secretion with a shift away from Th2 response to Th1 phenotype. The compounds 3 and 4 were immunostimulant and increased cytokine secretion with a shift away from Th1 response to Th2. The introduction of an enamine group to 1 and 3 to provide 2 and 4 seemed to attenuate their immunological properties. These immunomodulatory properties were, however, accompanied by an increase in lymphocyte intracellular oxidative stress, especially with 1 and 2 at high concentrations. In conclusion, the compounds 1, 2, 3 and 4 could be used to provide cell-mediated immune responses for novel therapies in T-cell mediated immune disorders.

Effects of N-acyl-2-hydroxymethyl aziridines on in vitro proliferative responses of human lymphocytes stimulated by mitogens.

Aziridines have been shown to possess marked immunotropic activity. The aim of this work was to study the in vitro effects of different concentrations of three novel aziridines, 2-hydroxy-methyl-1-(N-phtaloylglycyl) aziridine (aziridine 1), 2-hydroxy-methyl-1-(N-phtaloylalanyl) aziridine (aziridine 2) and 2-hydroxy-methyl-1-(N-phtaloylphenylalanyl) aziridine (aziridine 3), on the proliferative responses of human lymphocytes stimulated by mitogens (concanavalin A (Con A) and lipopolysaccharide (LPS)), and interleukin-2 (IL-2), interleukin-6 (IL-6) secretion. The results showed that aziridines 1 and 3 significantly stimulated the resting and Con A or LPS lymphocyte proliferation at concentrations between 1 micromol/l and 1 mmol/l, in a dose-dependent manner, the action of aziridine 3 being the highest. They also increased IL-2 and IL-6 secretion. However, aziridine 2 had no effect on the resting lymphocyte proliferation in the absence of mitogens, at any concentration used, reduced Con A-stimulated T lymphocyte proliferation and LPS- stimulated B lymphocyte proliferation in a dose dependent manner and diminished IL-2 and IL-6 production. None of the three aziridines affected cell viability. In conclusion, the three aziridines used in this study displayed immunomodulatory properties. Aziridines 1 and 3 are potentially immunostimulant while aziridine 2 is immunosuppressive and could be used to provide nonspecific cell-mediated immune responses.