Fadia Mahmoud

Cardioprotective effects of the calcineurin inhibitor FK506 and the PAF receptor antagonist and free radical scavenger, EGb 761, in isolated ischemic/reperfused rat hearts

Effects of the calcineurin inhibitor FK506, the platelet-activating factor (PAF) antagonist, and free radical scavenger Ginkgo biloba extract, EGb 761, and their combination on reperfusion-induced ventricular fibrillation (VF), ventricular tachycardia (VT), and recovery of cardiac function were studied after 30 min of global ischemia followed by 2 h of reperfusion in isolated rat hearts. In the first series of studies, rats received a daily (oral) dose of 0, 1, 5, 10, 20, or 40 mg/kg/day FK506 for 10 days. FK506 dose-dependently reduced the incidence of reperfusion-induced total (irreversible plus reversible) VF from a value of 92% for untreated animals to 92% (NS), 83% (NS), 67% (NS), 33% (p<0.05), and 25% (p<0.05), for doses of 1-40 mg/kg/day, respectively, with effects on incidence of VT showing the same pattern. FK506, between 20 and 40 mg/kg/day, also resulted in significant recovery of postischemic cardiac function. In the second series of studies, rats were treated with EGb 761 alone or in combination with FK506. Whereas no significant reduction in arrhythmias or improvement in cardiac function resulted from a single intervention of EGb 761 at 25 mg/kg/day, combined treatment of rats with 25 mg/kg/day of EGb 761 and 1 or 5 mg/kg/day of FK506 resulted in a reduction in total and irreversible VF of 92% and 92% to 42% (p<0.05) and 33% (p<0.05), 25% (p<0.05) and 8% (p<0.05), respectively, versus untreated control animals, paralleled by similar effects on the incidence of VT and accompanied by significant improvements in postischemic cardiac function. Our results demonstrate a novel cardioprotective characteristic of FK506 and suggest that combination therapy by using FK506 plus EGb 761 synergistically improves postischemic cardiac function, while reducing the incidence of reperfusion-induced VF and VT, which may expand the clinical utility of FK506 and allow therapy with FK506 at lower doses than are currently useful.

Lymphocyte subpopulations in pregnancy complicated by hypertension

The immune responsiveness of women is altered during pregnancy in order to retain protective properties against disease and at the same time allow tolerance of the fetus. Diseases such as pre-eclampsia (PE) have been suggested to arise as a result of maladaptations in these immune alterations. Here we evaluate the effect of PE on the composition of peripheral blood lymphocyte subpopulations using lymphocyte surface antigen expression. Fifty-four women of various parities with pregnancy-induced hypertension (PIH) (39 non-proteinuric and 14 proteinuric) and matched controls (30 normotensive pregnant women (NTP) and 15 healthy non-pregnant women (NP)) were investigated. Monoclonal antibodies specific for human T lymphocytes and subpopulations: CD2, CD3, CD4, CD8, CD19 and activation markers: CD25, CD45RA, CD45RO, CD54 AND HLA m DR were used and detected using a two-colour fluorescence analysis with an automated flow cytometer. The total number of T lymphocytes: CD2, CD3, CD4, CD8 and CD19 were significantly decreased in PIH particularly PE ( P <0.05). T cells expressing NK surface markers (CD3/CD16 + CD56) and CD4 cells expressing HLA m DR were higher in PE. CD8 + HLA m DR + cells and T-helper cells expressing adhesion molecules) CD4 + CD54 + ) were higher in NTP than in NP and PE ( P <0.05, 0.05). PE is associated with elevated levels of CD4 + HLA m DR + , and CD3 + NK cells but decreased total numbers of T lymphocytes, and the CD3 + CD25 + subpopulation. These findings indicate systemic alterations in maternal immunity associated with the PE state. This feature of the disease may contribute to abnormal adaptation to pregnancy resulting in PE and PIH, promoting adverse outcomes including pregnancy loss.

Decreased Total Numbers of Peripheral Blood Lymphocytes with Elevated Percentages of CD4+CD45RO+ and CD4+CD25+ of T-Helper Cells in Non-Segmental Vitiligo

Vitiligo is a disorder involving progressive skin depigmentation caused by host mediated destruction of melanocytes. Its pathogenesis is known to correlate with elevated levels of activated skin‐infiltrating T lymphocytes and is presumed to be autoimmune in nature. In the present study, we characterize the immunophenotype of peripheral blood T cells from vitiligo patients, with the objective of developing an investigative and diagnostic tool for the disease, using analysis of peripheral blood. Subjects for this investigation included 32 patients diagnosed with non‐segmental vitiligo and 28 age‐and gender‐matched, normal, healthy control participants. Whole venous blood taken from each subject was analyzed using 2‐color flow cytometry for immunologically‐relevant lymphocyte subsets. When compared with healthy control subjects, peripheral blood from individuals with vitiligo was found to have lower total numbers of lymphocytes (p<0.039). Vitiligo patients also had elevated percentages of memory (CD4+CD45RO+) T cells; (p<0.05), but NK‐T cells (CD3+CD16+CD56+) and naive T cells (CD4+CD45RA+) were present at lower total numbers and percentages than in healthy controls (p<0.01 and 0.05 respectively). Blood from severely afflicted subjects exhibited elevated CD3+HLADR+ and CD4+CD45RO+ as well as lower percentages of NK‐T cells (p<0.05) when compared with mild cases. In conclusion, disease‐associated, peripheral blood lymphocyte immunophenotypic profiles of vitiligo patients are consistent with the hypothesis of T cell activation as a major feature of the disorder. These include elevated memory and reduced naive T cell percentages and increased expression of the activation‐associated surface antigen CD25. These changes presumably reflect increased antigen‐mediated activation. Moreover, because a corollary effect is increased activation‐induced cell death (AICD), lower overall lymphocyte counts observed in vitiligo‐afflicted subjects is also expected.

Summative interaction between astaxanthin, Ginkgo biloba extract (EGb761) and vitamin C in suppression of respiratory inflammation: a comparison with ibuprofen.

In this study, combinations of Ginkgo biloba leaf extract (EGb761) plus the carotenoid antioxidant astaxanthin (ASX) and vitamin C were evaluated for a summative dose effect in the inhibition of asthma‐associated inflammation in asthmatic guinea‐pigs. Ovalbumin‐sensitized Hartley guinea‐pigs challenged with ovalbumin aerosol to induce asthma, were administered EGb761, ASX, vitamin C or ibuprofen. Following killing, bronchoalveolar lavage (BAL) fluid was evaluated for inflammatory cell infiltrates and lung tissue cyclic nucleotide content. Each parameter measured was significantly altered to a greater degree by drug combinations, than by each component acting independently. An optimal combination was identified that included astaxanthin (10 mg/kg), vitamin C (200 mg/kg) and EGb761 (10 mg/kg), resulting in counts of eosinophils and neutrophils each 1.6‐fold lower; macrophages 1.8‐fold lower, cAMP 1.4‐fold higher; and cGMP 2.04‐fold higher than levels in untreated, asthmatic animals (p < 0.05). In conclusion, EGb761, ASX and vitamin C are shown here to interact summatively to suppress inflammation with efficacy equal to or better than ibuprofen, a widely used non‐steroidal antiinflammatory drug (NSAID). Such combinations of non‐toxic phytochemicals constitute powerful tools for the prevention of onset of acute and chronic inflammatory disease if consumed regularly by healthy individuals; and may also augment the effectiveness of therapy for those with established illness. Copyright

Sour cherry seed kernel extract increases heme oxygenase-1 expression and decreases representation of CD3+ TNF-α+ and CD3+IL-8+ subpopulations in peripheral blood leukocyte cultures from type 2 diabetes patients.

The present study evaluates a hypothesis that sour cherry (Prunus cerasus) seed extracts (SCE) modulate CD3+ T lymphocyte activity in ways predictive of potential for uses of SCE in management of inflammatory diseases. Peripheral blood mononuclear cells (PBMC) from 12 type 2 diabetes (T2DM) patients and eight healthy control subjects were cultured 24 h with 100 ng/ml lipopolysaccharide (LPS) to increase inflammatory signaling and co‐incubated with 0.5–100 µg/ml SCE. Cultures were evaluated by two‐color flow cytometry for percent representation of CD3+ IL8+ and CD3 + TNF‐α + cells which express interleukin‐8 (IL‐8), and tumor necrosis factor‐α, (TNF‐α+) respectively, and by enzyme‐linked immunoassay for lymphocyte‐associated heme oxygenase‐1 (HO‐1, known to be induced by SCE). SCE dosage ranges of 0.5–100 µg/ml in cell cultures significantly suppressed LPS‐increased CD3 + TNF‐α + and CD3 + IL8+ representation from all participants (p < 0.05), with greater pharmacological effect noted in suppression of CD3 + TNF‐α + noted in cells from T2DM patients versus healthy control subjects. These effects correlated with increased HO‐1 expression in SCE‐treated PBMC from all subjects (p < 0.05). Since TNF‐α and IL‐8 are diagnostic/prognostic biomarkers for many inflammatory syndromes, the capacity of SCE to down‐regulate representation of cells that express them suggests potential for therapeutic use of SCE in T2DM and other diseases. Copyright

Inflammatory Cytokines and the Risk of Cardiovascular Complications in Type 2 Diabetes

This study evaluates peripheral blood T lymphocyte expression of inflammatory and proinflammatory cytokines as well as T regulatory (Treg) (FOXP3+CD25+CD4+) cells in type 2 diabetes (T2DM). Participants included 40 T2DM and 30 healthy control subjects. Twenty-four patients had no complications while 16 were afflicted with coronary heart disease (CHD). Relative to healthy subjects, all T2DM patients showed a significant increase in expression of CD4+IFN-ϒ+, CD4+TNF-α+, and CD4+IL-8+ T cells (P < 0.001) as well as CD4+IL-6+, CD4+IL-1β+, and IL-17+ T cells (P < 0.05) while the ratios of Treg/Th1(CD4+IFN-ϒ+) and Treg/Th-17(CD4+IL-17+) cells were significantly decreased (P < 0.05 and P < 0.01). T2DM patients with CHD showed a significant increase in CD4+IFN-ϒ+, CD4+TNF-α+, and CD4+IL-17+ T cells and a significant decrease in Treg/Th1 and Treg/IL-17 cells compared to T2DM patients without CHD (P < 0.05). In CHD-afflicted T2DM, HbA1c correlated positively with CD4+IFN-ϒ+ T cells (P < 0.01), HDL correlated negatively with each of CD4+IL-8+ T cells and CD4+IL-17+ T cells (P < 0.05), and LDL correlated positively with CD4+IL-1β+ T cells (P < 0.05). Conclusion. This study shows that hyperglycemia and dyslipidemia correlate with increased inflammatory cytokine expression and suggests the involvement of T cells in the development of diabetes and its complications.

Butyrylcholinesterase activity and pregnancy-associated differences in immunologically relevant peripheral blood leukocyte populations.

Problem:  Toxic anticholinesterases (AC) are known contributors to negative pregnancy outcome. Impairment of detoxification mechanisms may correlate with occurrence of pregnancy disorders in Kuwait.

Butyrylcholinesterase activity in gestational diabetes: correlation with lymphocyte subpopulations in peripheral blood.

Problem  Inefficient clearance of pregnancy‐threatening toxins may contribute to gestational diabetes (GD) and Type II diabetes mellitus (DM) through mechanisms involving immune dysregulation.

Effect of Black Tea Consumption on Intracellular Cytokines, Regulatory T Cells and Metabolic Biomarkers in Type 2 Diabetes Patients.

The present study was undertaken to evaluate the effects of black tea intake on inflammatory cytokines and metabolic biomarkers in Type 2 diabetes mellitus (T2DM). Thirty patients with T2DM were randomly assigned either to a High Intake (HI) group, consuming three cups (600 mL) of black tea per day; and a Low Intake (LI) group, administered 1 cup (200 mL) per day, each during a 12‐week period. Intracellular cytokine expression, regulatory T cells (Treg), glycemic and lipid profiles were measured at baseline and following the tea intake period. Tea consumption correlated with major effects measured in peripheral blood of subjects that included significantly reduced glycated hemoglobin (HbA1c) levels, along with increased regulatory T cells CD3+ CD4+ CD25+ FOXP3, CD3+ CD4+ IL‐10+ cells (an immunosuppressive phenotype), reduced (pro‐inflammatory) CD3+ CD4+ IL‐17+ cells and reduced Th1‐associated CD3+ CD4+ IFN‐Υ+ cells. Tea consumption was also observed to abolish the significance of an inverse correlation between total serum cholesterol and representation of CD4+ IL‐4+ T cells, which may reflect protection against atopy‐related oxidative stress. Outcomes of this study describe both advantages and limitations to consumption of black tea as an aid to sustained health maintenance by persons at‐risk for TD2M and related obesity‐associated metabolic syndromes. Copyright

Sour cherry (Prunus cerasus) seed extract increases heme oxygenase-1 expression and decreases proinflammatory signaling in peripheral blood human leukocytes from rheumatoid arthritis patients

Sour cherry seed extract (SCE) was evaluated for its capacity to inhibit lipopolysaccharide-treated human peripheral blood T cells expressing tumor necrosis factor-alpha, and the chemokine interleukin-8. Both proteins are diagnostic biomarkers for inflammatory pathologies. Peripheral blood leukocytes from 11 rheumatoid arthritis (RA) patients and 8 healthy control subjects were co-cultured for 24h in lipopolysaccharide and the extract, then evaluated by flow cytometry for T cell activation and by enzyme-linked immunoassay for lymphocyte-associated heme oxygenase-1 (HO-1) expression. There was a dose-dependent decrease in expression of the immunophenotypes: CD3+TNF-α+, and CD3+IL8+ in cultures from RA patients to a greater extent than in cells from healthy participants. These results suggest that the extract may have a modulatory roll in RA and other inflammatory disorders via the induction of HO-1, thus abating oxidative stress and strengthening regulation of pro-inflammatory signaling pathways.