The influence of Nigella sativa essential oil on proliferation, activation, and apoptosis of human T lymphocytes in vitro.

In previous work, we tested the immunomodulatory effect of Nigella sativa (NS) fatty oil. Our results demonstrated that unrefined, obtained by cold pressing black cumin seed oil inhibited lymphocytes' proliferation and induced their apoptosis in a dose-dependent manner. In this study, we examined the immunomodulatory properties of essential oil (EO) obtained from the NS seeds by hydrodistillation and its two main constituents: thymoquinone (TQ) and p-cymene. We analyzed the proliferation, activation phenotype, and apoptosis rates of human T lymphocytes stimulated with an immobilized monoclonal anti-CD3 antibody in the presence of serial ethanol dilutions of tested oil or serial distilled water dilutions of tested compounds with flow cytometry. Our results showed that NSEO significantly inhibited the proliferation of CD4+ and CD8+ T lymphocytes, induced cell death in a dose-dependent manner, and reduced the expression of CD28 and CD25 antigens essential for lymphocyte activation. TQ inhibited the proliferation of T lymphocytes and induced cell death, particularly in high concentrations. Meanwhile, p-cymene did not influence lymphocyte proliferation. However, its high concentration induced cell necrosis. These results show that the essential oil from Nigella sativa has powerful immunomodulatory properties, which, at least partially, are related to the TQ component.

Nigella sativa oil inhibits proliferation and stimulates apoptosis of human lymphocytes in vitro.

The study aimed to examine the in vitro influence of Nigella sativa oil on human lymphocytes. Cells were stimulated with a monoclonal anti-CD3 antibody in the presence of serial oil ethanol dilutions. Then their proliferation and apoptosis rates were assessed using flow cytometry. Our results demonstrate that the lowest dilutions (1:1 and 1:10) of Nigella sativa oil inhibited lymphocytes' proliferation. The number of cell divisions was 8, 1.25, 1.88 after stimulation with anti-CD3, or its combination with 1:1 and 1:10 oil dilution. The percentage of proliferating cells was 92.48%, 8.75%, 24.3% after stimulation with anti-CD3 antibody, or its combination with 1:1 and 1:10 oil dilution. The mean percentage of living cells was 81% after stimulation with anti-CD3, 13.6%, 19.9% in the presence of 1:1 and 1:10 oil dilution. The preliminary studies show that black seed oil has a potent antiproliferative and proapoptotic effect on human lymphocytes in vitro.

The Influence of Antidepressants on the Immune System.

Depression is one of the most frequently diagnosed condition in psychiatry. Despite the availability of many preparations, over 30% of treated patients do not achieve remission. Recently the emphasis is put on the contribution of the body's inflammatory response as one of the causes of depression. The interactions between nervous and immune systems are the main issue addressed by psychoneuroimmunology. In patients suffering from depression changes in the plasma concentrations of cytokines and in the number and level of activation of immune cells has been found. Attention is paid to the high levels of pro-inflammatory cytokines, the prevalence of Th1 responses to Th2, weakening of NK cell cytotoxicity and changes in lymphocyte proliferation and apoptosis. A number of studies focus on influence of antidepressants and non-standard methods of depression treatment, such as ketamine infusion, on patients' immunology. Many of them seem to regulate the immune responses. The study results encourage to look for new ways to treat depression with immunomodulatory drugs. In this article authors present the current knowledge about immune system changes accompanying depression as well as the study results showing the influence of drugs on the immune system, especially in the context of reducing the symptoms of depression.

Proliferation and apoptosis of T lymphocytes in patients with bipolar disorder.

The aim of the study was to evaluate proliferation capacity and susceptibility to apoptosis of T lymphocytes of patients with bipolar disorder (BD) and to investigate in vitro influence of two standard mood stabilizers: lithium and valproic acid on these parameters using flow cytometry. Our results show that T lymphocytes of BD patients, especially those treated with lithium, have reduced proliferation capacity compared to healthy people. In vitro studies showed that valproic acid reduces the number of cell divisions and percentages of proliferating cells regardless of health status but mainly in very high dose, while lithium has no significant influence on proliferation capacity of patients' T lymphocytes. Lymphocytes of BD patients are also more prone to apoptosis compared with healthy individuals which is related to high expression of Bax, a pro-apoptotic protein. In vitro lithium protected patients' lymphocytes from apoptosis proportionally to dose used. Valproic acid protected lymphocytes of patients from apoptosis mainly in therapeutic concentration. Our results show that mood stabilizers used to prevent relapses of the disease have anti-apoptotic effect on T lymphocytes of BD patients but they are not able to improve their proliferation capacity.