Vitamin A Decreases Cytotoxicity of Oxidized Low-Density Lipoprotein in Patients with Atherosclerosis.

BACKGROUND: Oxidized low-density lipoprotein (ox-LDL) is implicated in initiation and progression of atherosclerosis. Previously, we found that ox-LDL increases vulnerability of peripheral blood mononuclear cells (PBMCs) in atherosclerotic patients compared to controls. Vitamin A induces proliferation of PBMCs. The aim of this study was to determine the effect of vitamin A supplementation on PBMC survival against LDL and different doses of ox-LDL. METHOD: In this double-blind placebo-controlled trial, we recruited 35 atherosclerotic patients and 38 healthy controls and randomly allocated them into placebo and vitamin A groups, which received either placebo or 25,000 IU/day of vitamin A for 3 months. PBMCs were isolated, cultured, and stimulated by 1 µg/mL LDL as well as 1 µg/mL and 50 µg/mL ox-LDL. The stimulation indexes (SIs) of PBMCs were calculated to identify cell viability. Additionally, the circulating ox-LDL levels were measured by ELISA. RESULTS: Viability of PBMCs stimulated by 50 µg/mL ox-LDL significantly increased following vitamin A supplementation in patients (p < 0.01). The levels of circulating ox-LDL were not changed by vitamin A treatment. Ox-LDL levels were strongly and positively correlated to SI of PBMCs stimulated by 1 µg/mL LDL and1 µg/mL ox-LDL in all groups. CONCLUSION: Vitamin A decreases cytotoxicity of high-dose ox-LDL and improves PBMC viability. The protective effect of vitamin A is not mediated by an antioxidative mechanism, but may instead have been due to intracellular protection of the apoptotic machinery or induction of proliferation of the cells. Higher levels of ox-LDL increase PBMC irritability in all participants.

Relation between nitrate and nitrite food habits with lung cancer.

Nitrites, a probable human carcinogen, generate reactive nitrogen species that may cause damage to the lung. We evaluated the association between nutritional habits related to nitrite and nitrate intake and risk of lung cancer in Mazandaran, Northern Province of Iran. In this case-control study the two groups were matched for gender and age (+/- 5 years). A semi -quantitative food frequency questionnaire (FFQ) was used to collect dietary data about nutritional habits related to nitrate, nitrite, vitamins E and C intake, from 40 lung cancer cases and 40 control subjects admitted at Mazanaran hospitals. We calculated odds ratios (ORs) and 95% confidence intervals (CIs) for the risk of lung cancer using logistic regression. Mean score of nutritional habits in case group was significantly lower than that in control group (P less than or equal 0.001). We observed a positive association between animal sources of nitrate and nitrite intake (OR = 2.7, 95% CI: 0.13-0.96) and risk of lung cancer. Decreased risk of lung cancer was also observed with fruit intake (OR = 0.26, 95% CI: 1.3-11). Our results indicate a probable association between nutritional habits related to animal sources of nitrate and nitrite intake and the risk of lung cancer that requires to be confirmed by other studies.

A case control study on the lung cancer risk factors in north of Iran.

In this case control study, the risk factors of lung cancer was assessed in the north of Iran. Two groups were matched for gender and age (+/- 5 years). Data were collected from 40 cases and 40 controls attending to hospitals. A public information questionnaire was used for data collection. Incidence odds ratios (OR) and corresponding 95% confidence intervals calculated using logistic regression analyses. Results showed that in adjusted odd ratio positive family history of cancer (OR = 0/19, 95% CI: 0/04-0/8) was associated with a reduction, and consumption of baked bread in traditional oven (OR = 22/6, 95% CI: 1/9-270), was associated with increase in lung cancer risk. Based on the results, smoking was not correlated with lung cancer. In conclusion, the data offers consumption of traditional oven-baked bread may enhance the risk of lung cancer but positive family history of cancer may reduce it.

Effect of Genistein and L-carnitine and Their Combination on Lipid Profile and Inflammatory Cytokines in Experimental Nephrotic Syndrome.

BACKGROUND: Nephrotic syndrome is a disorder caused by kidney damage that results in severe leakage of protein from blood into urine. Hyperlipidemia is one complication of nephrotic syndrome. L-carnitine and genistein can control cardiovascular diseases by causing changes in lipid metabolism and cytokine production. This study was designed to examine the effects of genistein and L-carnitine on serum lipid and cytokine profiles in experimental nephrotic syndrome. METHODS: In this study, 50 male Sprague-Dawley rats were randomly divided into five groups of 10 animals each with similar mean body weights (300±50 g). The five groups were NC (normal-control), PC (patient-control), LC (L-carnitine), G (genistein), and LCG (L-carnitine-genistein). Serum HDL-cholesterol (HDL) LDL-cholesterol (LDL), triglyceride, cholesterol, IL-6, and TNF-α were measured. Statistics were analyzed using SPSS 18.0. RESULTS: At the end of the study, of the patient groups, HDL was significantly greater in the LC than in the PC or G groups (P<0.001). LDL was significantly less in the G than in the PC, LC, or LCG groups (P<0.001). Interleukin-6 was significantly greater in the PC than in the LC, G, or LCG groups, and significantly greater in the LC than in the G group. (P<0.001), but no significant differences were found for triglyceride, cholesterol, or TNF-α between the patient groups. CONCLUSION: Genistein had less effect on HDL and triglyceride levels than LC or LCG. Regarding inflammatory cytokines, genistein and L-carnitine had less effect on TNF-α than on IL-6.

Effect of Genistein and L-Carnitine and Their Combination on Gene Expression of Hepatocyte HMG-COA Reductase and LDL Receptor in Experimental Nephrotic Syndrome.

BACKGROUND: Nephrotic syndrome is a disorder that leads to hyperlipidemia. L-carnitine and genistein can effect on lipid metabolism and the syndrome. In the present study, we have delved into the separate and the twin-effects of L-carnitine and genistein on the gene expressions of HMG-COA reductase and LDL receptor in experimental nephrotic syndrome. METHODS: In this controlled experimental study, 50 male Sprague-Dawley rats were randomly divided into five groups: NC (normal-control), PC (patient-control), LC (L-carnitine), G (genistein), LCG (L-carnitine-genistein). Adriamycin was used for inducing nephrotic syndrome and the spot urine samples and urine protein-to-creatinine ratio were measured. Hepatocytic RNA was extracted and real-time PCR was used for HMG-COA Reductase and LDL receptor gene Expression measurement. RESULTS: The final weight of the patients groups were lower than the NC group (P=0.001), and weight gain of the NC group was higher than the other groups (P<0.001). The proteinuria and urine protein-to-creatinine ratio showed significant differences between PC group and LC, G and LCG groups at week 7 (P<0.001). The expression of HMGCOA Reductase mRNA down regulated in LC, G and LCG groups in comparison with PC group (P<0.001). ΔCT of LDLr mRNA showed significant differences between the PC group and the other patient groups (P<0.001). CONCLUSION: This study shows a significant decreasing (P<0.001) and non-significant increasing trend in HMG-COA Reductase and LDLr gene expression, respectively, and synergistic effect of L-carnitine and genistein on these genes in experimental nephrotic syndrome.

The effect of vitamin A supplementation on disease progression, cytokine levels and gene expression in multiple sclerotic patients: study protocol for a randomized controlled trial.

Multiple Sclerosis (MS) is a chronic inflammatory disease that leads to degeneration of the brain and spinal tissue. Imbalances of CD4+ T cells including Thelper1 (Th1)/Thelper2 (Th2) and Thelper17 (Th17)/Tregulatory (Treg), their secreted cytokines and gene expressions, are important aspects of in immunopathogenesis of MS. Vitamin A and its metabolites can regulate the immune system and appears to be effective in preventing progression of the autoimmune disease such as MS. Disease progression was evaluated By Magnetic Resonance Imaging (MRI), Expanded Disability States Scale (EDSS) and Multiple Sclerosis Functional Composite (MSFC) tests. Cytokine levels were measured using ELISA kits and gene expression was quantified by Real time PCR (RT-PCR) system. According to the difference between the epidemiological and clinical data on the relationship between vitamin A and immune system regulation, this study of the first time assesses Immune function as well as gene expression and progression of the disease following administration of vitamin A supplement.

The effect of vitamin a supplementation on biochemical parameters in multiple sclerosis patients.

BACKGROUND: Vitamin A has different functions in the body and after being converted to acid form; it can play many roles in immune system regulation. Therefore, this vitamin can be used as a supplement in the treatment of diseases, such as cancer and autoimmune diseases. Vitamin A is a fat-soluble compound and its long-term consumption in high doses can have some adverse effects. OBJECTIVE: The current study aimed to investigate the possible complications and find solutions to minimize the adverse effects. PATIENTS AND METHODS: This study was a double blind randomized clinical trial. In the main study, vitamin A (as retinyl palmitate) was given to 35 multiple sclerosis (MS) patients in order to regulate their immune system with a dose of 25000 IU/day for a period of six months. To investigate the possible biochemical complications, lipid profiles, fasting blood sugar (FBS), liver enzymes, and C-reactive protein (CRP) were tested. RESULTS: Vitamin A did not have a significant difference in lipid profiles, FBS and liver enzymes between the two groups receiving vitamin A and the placebo, but CRP increased in patients who were taking vitamin A, 1.65±0.43 (mg/L) and 2.88±0.67, (Mean±SEM), before and after the intervention respectively (P=0.029), and statistical analysis showed significant differences with the group receiving placebo (P=0.011) and CRP level in vitamin A group was 1.3 mg/L more than those of the placebo group after intervention (P=0.011). CONCLUSIONS: Considering that no significant difference was found in the proven vitamin A side effects, due to the increase in CRP, frequent clinical and biochemical controls are required along with vitamin A supplementation.

In vitro effect of human serum and fetal calf serum on CD4+ T cells proliferation in response to myelin oligodendrocyte glycoprotein (MOG) in correlation with RBP/TTR ratio in multiple sclerotic patients.

Myelin oligodendrocyte glycoprotein (MOG) is one of the autoantigens used in evaluation of the CD4(+) T cells proliferation response in multiple sclerotic patients. In cell culture, human serum (HS) is one of the promising substitutions for fetal calf serum (FCS) that can induce different autoreactivity of T cells and fluctuation of autoantibody production from B cells. Because of immunomodulatory function of vitamin A, we examined the effect of HS and FCS on CD4(+) T cells proliferation in response to MOG in correlation with serum retinol-binding protein (RBP)/transthyretin (TTR) ratio, as an indirect way to assess vitamin A status in multiple sclerotic patients. Patients' peripheral blood mononuclear cells were isolated and cultured in the presence of MOG as well as FCS and HS both separately and together. Cell proliferation was evaluated using BrdU kit. Serum RBP and TTR levels were measured by ELISA kit. FCS and HS increase CD4(+) T cell proliferation. RBP/TTR ratio has significant negative correlation with cell proliferation in the presence of MOG, HS, and FCS. HS with FCS provides an appropriate medium for autoreactivity and proliferation of CD4(+) T cells. Vitamin A has a crucial role in regulation of this pathway.

The effect of vitamin A supplementation on stimulated T-cell proliferation with myelin oligodendrocyte glycoprotein in patients with multiple sclerosis.

BACKGROUND: Multiple sclerosis (MS) is an autoimmune disease whereby myelin sheath of the central nervous system is destroyed. Vitamin A is known to play a role in the immune system. It has been recognized that some metabolites of vitamin A can be used effectively to treat experimental autoimmune encephalomyelitis (EAE). AIMS: The effect of vitamin A as retinyl palmitate on T-cell proliferation in MS patients. SETTING AND DESIGN: This study is a double blind clinical trial of two test groups over a period of 6 months. MATERIALS AND METHODS: Thirty five multiple sclerosis (MS) patients were divided into two groups. One group received 25,000 IU/day vitamin A (as retinyl palmitate) and the other group were administered a placebo. The peripheral blood mononuclear cells (PBMCs) were separated and stimulated with myelin oligodendrocyte glycoprotein (MOG) and phytohemagglutinin (PHA) before and after the trial period. BrdU calorimetric assay was performed to measure cell proliferation. STATISTICAL ANALYSIS: Analysis of covariance (ANCOVA) and paired t-test were used to analyze the data. RESULTS: Observations showed statistical significant differences in the reduction of cell proliferation in the presence of MOG and fetal calf serum (FCS) in the culture medium, between patients receiving vitamin A and the placebo (P = 0.046). Although, this difference was not significant between the two vitamin A and placebo groups in MOG treatment with human serum, a decrease was observed in the group of patients taking vitamin A supplements (P = 0.019). Phytohemagglutinin did not cause any change in cell proliferation between the two groups. CONCLUSION: The results suggest supplementation with retinyl palmitate in patients with MS reduce MOG stimulatory effects on T-cells.

Lymphocyte cytotoxicity of oxLDL in patients with atherosclerosis.

BACKGROUND: Atherosclerosis, a chronic inflammatory disease of the vessel wall, is characterized by local and systemic immune responses to a variety of antigens. Oxidized low-density lipoprotein (oxLDL) is considered as an important determining factor in the pathogenesis of atherosclerosis. OBJECTIVE: The purpose of this study was to investigate the degree of peripheral blood mononuclear cells (PBMC) vulnerability to in vitro oxLDL-induced cytotoxicity from atherosclerotic patients in comparison to healthy individuals. METHODS: Thirty patients with atherosclerotic lesions, confirmed by angiography, and 30 matched healthy individuals were investigated. PBMC was prepared from individuals' blood samples which were further stimulated with low dose (1 µg/mL) and high dose (50 µg/mL) of extensively oxidized LDL. MTT assay was utilized to measure cell viability and proliferation. Stimulation index (SI) was calculated as mean ratio of optical density (OD) of the stimulated cells divided by OD of untreated cells. RESULTS: Low dose oxLDL treatment caused no significant proliferative or cytotoxic effect in the control group; however, similar treatment caused significant cytotoxic effect in the patients compared to the controls (p=0.026). High dose oxLDL treatment induced more significant cytotoxicity in the patients compared to the controls (p=0.006). Comparison of the SI between the two groups of patients and controls showed significantly lower index by either the low (p=0.03) or the high dose (p<0.001) oxLDL in the patients compared to the controls. CONCLUSIONS: PBMC from patients with atherosclerosis showed increased susceptibility to oxLDL-induced cytotoxicity. Our results imply that prolonged exposure to elevated levels of circulating oxLDL could weaken the cellular defense mechanisms by progressive depletion of the pool of antiapoptotic proteins, rendering the cells more vulnerable to oxLDL-induced cell death.

Defective T-cell Proliferation and IL-2 Production in a Subgroup of Patients with Coronary Artery Disease.

Atherosclerosis is a chronic inflammatory disease of the arterial wall characterized by innate and adaptive immune responses to a variety of microbial and self-antigens. Given the crucial role of adaptive immunity in the pathogenesis of atherosclerosis, this study was performed to investigate the proliferative response of peripheral blood mononuclear cells (PBMC) and interleukin (IL)-2 production in patients with coronary artery disease (CAD). In this study, 25 patients with chronic stable CAD and 25 healthy individuals were investigated. The PBMCs were separated and stimulated with phytohaemagglutinin (PHA). MTT assay was performed to measure cell viability and proliferation. IL-2 concentrations in cell culture supernatants were determined by Enzyme-Linked Immunosorbent Assay. PHA-stimulated cells revealed a significantly increased optical density (OD) in both groups of patients (p=0.004) and controls (p<0.001). However, the patient group showed a significantly lower Stimulation index (SI) (p=0.001). Upon in vitro stimulation with PHA, IL-2 levels were significantly increased in both groups of patients and controls (p<0.001). However, IL-2 concentrations were significantly lower in the patient group (p=0.018). Six patients showed defective IL-2 production, whereas similar finding was not observed in the normal control subjects (p=0.022). PBMCs from patients with coronary artery disease showed defective PHA-induced mitogenesis and IL-2 production. Considering the autoimmune nature of atherosclerosis, decreased IL-2 production may potentially enhance the atherogenic process, leading to spontaneous activation of autoreactive T lymphocytes.