[Vitamins and Immune System Health].

Keeping the immune system healthy forms an effective way to fight infections. Past experience has shown that, in addition to effective interventions including vaccination, drug therapy, and non-pharmaceutical intervention (NPI), dietary nutrition and mental health are also key factors in maintaining immune system health and combating emerging and sudden outbreaks of infections. As the main dietary nutrients, vitamins are active regulators of the immune response and exert a critical impact on the immunity of the human body. Vitamin deficiency causes increased levels of inflammation and decreased immunity, which usually starts in the oral tissues. Appropriate vitamin supplementation can help the body optimize immune function, enhance oral immunity, and reduce the negative impact of pathogen infection on the human body, which makes it a feasible, effective, and universally applicable anti-infection solution. This review focuses on the immunomodulatory effects of vitamin A, B, C, D, and E and proposes that an omics-based new systemic approach will lead to a breakthrough of the limitations in traditional single-factor single-pathway research and provide the direction for the basic and applied research of vitamin immune regulation and anti-infection in all aspects.

Analysis of trans-resveratrol and trans-piceid in vegetable foods using high-performance liquid chromatography.

Trans-resveratrol and resveratrol glucoside are natural phenolic compounds existed in a wide variety of plant species, which are extensively consumed in many countries. The existing studies excessively focused on grapes and their products, and little about daily vegetable foods. Actually, in much more countries, vegetable foods are residents' principal food and nutrient origins. This study was to investigate the levels of trans-resveratrol and trans-piceid in daily vegetable foods of China using high-performance liquid chromatography (HPLC) method with fluorescence detection (FLD). Trans-piceid was the major form existing in most vegetable foods, and most of the samples contained higher trans-piceid than trans-resveratrol. The contents of trans-resveratrol and trans-piceid in different varieties and regions were different. Moreover, peculiar vegetable foods to some region were also one of the most important sources of trans-resveratrol and trans-piceid. Therefore, vegetable foods were other significant sources of trans-resveratrol and trans-piceid except the foods published.

Ameliorative effects of lutein on non-alcoholic fatty liver disease in rats.

AIM: To investigate the therapeutic effects of lutein against non-alcoholic fatty liver disease (NAFLD) and the related underlying mechanism. METHODS: After 9 d of acclimation to a constant temperature-controlled room (20 °C-22 °C) under 12 h light/dark cycles, male Sprague-Darley rats were randomly divided into two groups and fed a standard commercial diet (n = 8) or a high-fat diet (HFD) (n = 32) for 10 d. Animals receiving HFD were then randomly divided into 4 groups and administered with 0, 12.5, 25, or 50 mg/kg (body weight) per day of lutein for the next 45 d. At the end of the experiment, the perinephric and abdominal adipose tissues of the rats were isolated and weighed. Additionally, serum and liver lipid metabolic condition parameters were measured, and liver function and insulin resistance state indexes were assessed. Liver samples were collected and stained with hematoxylin eosin and Oil Red O, and the expression of the key factors related to insulin signaling and lipid metabolism in the liver were detected using Western blot and real-time polymerase chain reaction analyses. RESULTS: Our data showed that after being fed a high-fat diet for 10 d, the rats showed a significant gain in body weight, energy efficiency, and serum total cholesterol (TC) and triglyceride (TG) levels. Lutein supplementation induced fat loss in rats fed a high-fat diet, without influencing body weight or energy efficiency, and decreased serum TC and hepatic TC and TG levels. Moreover, lutein supplementation decreased hepatic levels of lipid accumulation and glutamic pyruvic transaminase content, and also improved insulin sensitivity. Lutein administration also increased the expression of key factors in hepatic insulin signaling, such as insulin receptor substrate-2, phosphatidylinositol 3-kinase, and glucose transporter-2 at the gene and protein levels. Furthermore, high-dose lutein increased the expression of peroxisome proliferators activated receptor-α and sirtuin 1, which are associated with lipid metabolism and insulin signaling. CONCLUSION: These results demonstrate that lutein has positive effects on NAFLD via the modulation of hepatic lipid accumulation and insulin resistance.

Resveratrol ameliorates high glucose and high-fat/sucrose diet-induced vascular hyperpermeability involving Cav-1/eNOS regulation.

Vascular endothelial hyperpermeability is one of the manifestations of endothelial dysfunction. Resveratrol (Res) is considered to be beneficial in protecting endothelial function. However, currently, the exact protective effect and involved mechanisms of Res on endothelial dysfunction-hyperpermeability have not been completely clarified. The aim of present study is to investigate the effects of Res on amelioration of endothelial hyperpermeability and the role of caveolin-1 (Cav-1)/endothelial nitric oxide synthase (eNOS) pathway. Adult male Wistar rats were treated with a normal or high-fat/sucrose diet (HFS) with or without Res for 13 weeks. HFS and in vitro treatment with high glucose increased hyperpermeability in rat aorta, heart, liver and kidney and cultured bovine aortic endothelial cells (BAECs), respectively, which was attenuated by Res treatment. Application of Res reversed the changes in eNOS and Cav-1 expressions in aorta and heart of rats fed HFS and in BAECs incubated with high glucose. Res stimulated the formation of NO inhibited by high glucose in BAECs. Beta-Cyclodextrin (ß-CD), caveolae inhibitor, showed the better beneficial effect than Res alone to up-regulate eNOS phosphorylative levels, while NG-Nitro-77 L-arginine methyl ester (L-NAME), eNOS inhibitor, had no effect on Cav-1 expression. Our studies suggested that HFS and in vitro treatment with high glucose caused endothelial hyperpermeability, which were ameliorated by Res at least involving Cav-1/eNOS regulation.

Alteration of lipid profile in subclinical hypothyroidism: a meta-analysis.

BACKGROUND: Previous studies yielded controversial results about the alteration of lipid profiles in patients with subclinical hypothyroidism. We performed a meta-analysis to investigate the association between subclinical hypothyroidism and lipid profiles. MATERIAL AND METHODS: We searched PubMed, Cochrane Library, and China National Knowledge Infrastructure articles published January 1990 through January 2014. Dissertation databases (PQDT and CDMD) were searched for additional unpublished articles. We included articles reporting the relationship between subclinical hypothyroidism and at least 1 parameter of lipid profiles, and calculated the overall weighted mean difference (WMD) with a random effects model. Meta-regression was used to explore the source of heterogeneity among studies, and the Egger test, Begg test, and the trim and fill method were used to assess potential publication bias. RESULTS: Sixteen observational studies were included in our analysis. Meta-analysis suggested that the serum total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and total triglyceride levels were significantly increased in patients with subclinical hypothyroidism compared with euthyroidism individuals; the WMD were 12.17 mg/dl, 7.01 mg/dl, and 13.19 mg/dl, respectively (P<0.001 for all). No significant difference was observed for serum high-density lipoprotein cholesterol (HDL-C). Match strategy was the main source of heterogeneity among studies in TC and LDL-C analysis. Potential publication bias was found in TC and LDL-C analysis by the Egger test or Begg test and was not confirmed by the trim and fill method. CONCLUSIONS: Subclinical hypothyroidism may correlate with altered lipid profile. Previous studies had limitations in the control of potential confounding factors and further studies should consider those factors.

Iodine excess induces hepatic steatosis through disturbance of thyroid hormone metabolism involving oxidative stress in BALB/c mice.

Iodine excess is emerging as a new focus. A better understanding of its hazardous effects on the liver will be of great benefit to health. The aim of this study is to illustrate the effects of iodine excess on hepatic lipid homeostasis and explore its possible mechanisms. One hundred twenty BaLB/c mice were given iodine at different levels (0, 0.3, 0.6, 1.2, 2.4, and 4.8 mg I/L) in drinking water for 1 or 3 months. Lipid parameters and serum thyroid hormones were measured. Hepatic type 1 deiodinase activity and oxidative stress parameters were evaluated. The mRNA expression of sterol regulatory element-binding protein-1c (SREBP-1c) and fatty acid synthase (FAS) was detected by real-time polymerase chain reaction. Dose-dependent increase of hepatic triglyceride content was detected (r = 0.680, P < 0.01) in iodine-loaded groups. Evident hepatic steatosis was observed in 2.4 and 4.8 mg I/L iodine-loaded groups. The activities of antioxidant enzymes (glutathione peroxidase and superoxide dismutase) were decreased, and the malondialdehyde level was increased by excessive iodine in both serum and liver in a dose-dependent manner, accompanying the decrease of hepatic D1 activity. That resulted in the increase of serum total thyroxine and the decrease of serum total triiodothyronine in iodine-loaded groups. The mRNA expression of SREBP-1c and FAS was increased in iodine-loaded groups in response to the change of serum triiodothyronine. Present findings demonstrated that iodine excess could dose dependently induce hepatic steatosis. Furthermore, our data suggested that the disturbance of thyroid hormone metabolism involving oxidative stress may play a critical role in iodine excess-induced hepatic steatosis.

Supplemental selenium alleviates the toxic effects of excessive iodine on thyroid.

As excessive iodine intake is associated with a decrease of the activities of selenocysteine-containing enzymes, supplemental selenium was hypothesized to alleviate the toxic effects of excessive iodine. In order to verify this hypothesis, Balb/C mice were tested by giving tap water with or without potassium iodate and/or sodium selenite for 16 weeks, and the levels of iodine in urine and thyroid, the hepatic selenium level, the activities of glutathione peroxidase (GSHPx), type 1 deiodinase (D1), and thyroid peroxidase (TPO) were assayed. It had been observed in excessive iodine group that hepatic selenium, the activities of GSHPx, D1, and TPO decreased, while in the groups of 0.2 mg/L, 0.3 mg/L and 0.4 mg/L supplemental selenium, the urinary iodine increased significantly. Compared with the group of excessive iodine intake alone, supplemental selenium groups had higher activities of GSHPx, D1, and TPO. We could draw the conclusion that supplemental selenium could alleviate toxic effect of excessive iodine on thyroid. The optimal dosage of selenium ranges from 0.2 to 0.3 mg/L which can protect against thyroid hormone dysfunction induced by excessive iodine intake.

Dose and time-dependent hypercholesterolemic effects of iodine excess via TRbeta1-mediated down regulation of hepatic LDLr gene expression.

BACKGROUND: With the global improvement of iodine nutrition, iodine excess is emerging as a new concern. AIM OF STUDY: The aim of this study is to illustrate the physiological effects and potential molecular mechanisms of excessive iodine intake on lipid metabolism. METHODS: Balb/c mice were given drinking water containing different levels of iodine for 1 month and treated with 1.2 microg/mL iodine for different periods of time, respectively. Plasma lipid parameters and serum thyroid hormones were measured. Expressions of hepatic genes were detected by real-time polymerase chain reactions and Western blot. RESULTS: Dose-dependent hypercholesterolemic effects were detected in mice (TC, r = 0.615; p < 0.01). Drinking 1.2 microg/mL iodine water for 1 month had no significant effect on serum lipid metabolism, while prolonged exposure induced an increase of serum cholesterol. Serum thyroid hormones were not affected by iodine throughout the study. At the molecular level, we detected a dose-dependent attenuation of hepatic low density lipoprotein receptor (LDLr) and thyroid hormone receptor beta1 (TRbeta1) expression in parallel to the change of serum cholesterol. Treatment with 1.2 microg/mL iodine water for 1 month did not affect LDLr and TRbeta1 expression, while 3 or 6 months exposure resulted in a decrease of their expression. CONCLUSION: Present findings demonstrated dose- and time-dependent hypercholesterolemic effects of iodine excess. Furthermore, our data suggests that TRbeta1-mediated down regulation of hepatic LDLr gene may play a critical role in iodine excess-induced hypercholesterolemic effects.

The diabetogenic effects of excessive ethanol: reducing beta-cell mass, decreasing phosphatidylinositol 3-kinase activity and GLUT-4 expression in rats.

The diabetogenic impact of ethanol remains as a focal point of basic and clinical investigations. In this study, Wistar rats were subjected to daily intragastric ethanol administration (10 ml/kg body weight injection with 0 (control), 10, 20 and 33 % (v/v) ethanol in the injections, respectively) for 19 weeks. At the end of the administration, we found that the fasting plasma glucose level of the 33 % (v/v) ethanol-loaded group was 18 % higher than the control. Insulin sensitivity was decreased in a dose-dependent manner in all the ethanol-loaded groups (r - 0.842, P < 0.001) during intraperitoneal insulin tolerance test. Necrotic/haemorrhagic injury was detected in the pancreas and islet beta-cell mass was significantly reduced in the 33 % (v/v) ethanol-loaded rats by immunohistochemical and morphometric analysis. At the molecular level, we detected a dose-dependent attenuation of phosphatidylinositol 3-kinase activity (r - 0.956, P < 0.001) and GLUT-4 expression (GLUT-4 mRNA, r - 0.899, P < 0.001; GLUT-4 protein, r - 0.964, P < 0.001) in skeletal muscle. These results demonstrated that drinking is a conditional aetiological factor for diabetes and excessive ethanol intake is negatively associated with both insulin sensitivity and beta-cell mass. The whole-body insulin resistance might result from the ethanol-induced insulin signalling defects in muscle.

[Intervention of selenium on neurogranin expression in filial cerebrum of mice with excess iodine].

OBJECTIVE: To study the effects of excess iodine intake on neurogranin expression in cerebrum of filial mice and the intervention of selenium. METHODS: Sixty BALB/c mice were divided randomly into four groups with different drinking water: control group (tap water, NC), excess iodine group (3000 microg/L I, EL +), supplementing selenium group (200 microg/L Se, Se +) and the excess iodine plus selenium (3000 microg/L + I 200 microg/L Se, EI + Se +) group. The mice were mated at the end of the fourth month. Serum T4 and T3 were determined on postnatal day 14 and 28. The expression level of neurogranin in filial cerebrum was measured by immunohistochemistry and Western blot. RESULTS: Serum T4 level in EI (68.78 +/- 11.10 nmol/ L) + was lower significantly than that in NC (100.85 +/- 11.47 nmol/ L) and EI + Se + (93.15 +/- 12.10 nmol/ L) on postnatal day 14. Western blot analysis showed that the relative level of neurogranin in EI + (0.621 +/- 0.041) was lower than that in NC (0.841 +/- 0.039) and EI + Se + (0.781 +/- 0.029) on postnatal day 14 (P < 0.05). No significant difference in serum T4 and neurogranin level between four groups on postnatal day 28. CONCLUSION: Excess iodine intake might change the expression of neurogranin in filial cerebrum and the selenium supplementation might alleviate it.

Effect of selenium supplementation on activity and mRNA expression of type 1 deiodinase in mice with excessive iodine intake.

OBJECTIVE: To investigate the effect of selenium supplementation on the selenium status and selenoenzyme, especially the activity and mRNA expression of type 1 deiodinase (D1) in mice with excessive iodine (EI) intake and to explore the mechanism of selenium intervention on iodine-induced abnormities. METHODS: Weanling female BALB/c mice were given tap water or 3 mg/L of iodine or supplemented with 0.5 mg/L or 1.0 mg/L of selenium in the presence of excessive iodine for 5 months. Selenium status, thyroid hormone level, hepatic and renal D1 activity and mRNA expression were examined. RESULTS: Excessive iodine intake significantly decreased the selenium concentration in urine and liver, and the activity of glutathione peroxidase (GSH-Px) in liver. Meanwhile, serum total T4 (TT4) increased while serum total T3 (TT3) decreased. Hepatic D1 enzyme activity and mRNA expression were reduced by 33% and 86%, respectively. Renal D1 enzyme activity and mRNA were reduced by 30% and 55%, respectively. Selenium supplementation obviously increased selenium concentration, activity of GSH-Px and Dl as well as mRNA expression of D1. However, increasing the supplementation of Se from 0.5 to 1.0 mg/L did not further increase selenoenzyme activity and expression. CONCLUSION: Relative selenium deficiency caused by excessive iodine plays an essential role in the mechanism of iodine-induced abnormalities. An appropriate dose of selenium supplementation exercises a beneficial intervention.

Selenium supplement alleviated the toxic effects of excessive iodine in mice.

The relationship between the iodine intake level of a population and the occurrence of thyroid diseases is U-shaped. When excessive iodine is ingested, hypothyroidism or hyperthyroidism associated with goiter might develop. The aim of the study was to evaluate the effect of Se supplementation on the depression of type 1 deiodinase (D1) and glutathione peroxidase (GSHPx) activities caused by excessive iodine. D1 activity was assayed by the method with 125I-rT3 as a substrate. Compared to the effect of iodine alone, iodine in combination with selenium increased the activities of D1 and GSHPx. The addition of selenium alleviated the toxic effects of iodine excess on the activities of D1 and GSHPx.

[Effect of high-iodine intake on MBP mRNA expression in cerebrum of filial mice and selenium intervention].

OBJECTIVE: To study the effect of selenium supplementation on myelin basic protein (MBP) mRNA expression in cerebrum of high-iodine intake filial mice. METHODS: 135 weanling female Balb/C mice were assigned into 3 groups and given drinking water including different doses of iodine and selenium. Normal control (NC, tap water), high iodine intake group (HI, 3.0 mg/L I of drinking water), high iodine intake and selenium supplementation group I (HI + Se, 3.0 mg/L I + 0.5 mg/L Se of drinking water). All the male and female mice were mated after 4 months later, related indicators of filial mice on 14 day were determined. RESULTS: In filial mice, compared with NC group, serum TT4 decreased significantly in HI groups, TT3 also decreased, and mRNA expression of MBP in cerebrum was down-regulated 27%. The selenium suppleme ntation groups inhibited the decrease of TT4 and TT3, up regulated the m RNA expression of MBP in cerebrum. CONCLUSION: High-iodine Intake can decrease thyroxine of filial mice, which maybe is the reason for down-regulated m RNA expression of MBP in cerebrum, and selenium can exert some intervention by thyroxine, but need to verify more.

[Oxidative damage and apoptosis in NIT-1 cells induced by ethanol].

OBJECTIVE: To decide whether ethanol induce apoptosis in mouse insulinoma cells (NIT-1) and the potential mechanism involved. METHODS: After NIT-1 cells were exposed to various concentrations of ethanol, agarose gel electrophoresis was used to detected DNA fragmentation. malondialdehyde (MDA) content, glutathione (GSH) level, superoxide dismutase(SOD) and glutathione peroxidase (GSH-Px) were measured in NIT-1 cells to evaluate the oxidative damage degree. Caspase-3 relative activity was determined by colorimetric assay. RESULTS: The results showed a "DNA ladder" pattern after treated with ethanol in NIT-1 cells. The MDA content was higher, the SOD activity, GSH-Px activity and GSH content were lower in ethanol group than those of control group. Ethanol increased the caspase-3 activity by a dose and time dependent manner. CONCLUSION: Higher concentration of ethanol induces imbalance of oxidation and antioxidative ability in NIT-1 cells, and oxidative stress further leads to apoptosis which may be related to the increased caspase-3 activity.

CYP2E1-dependent hepatotoxicity and oxidative damage after ethanol administration in human primary hepatocytes.

AIM: To observe the relationship between ethanol-induced oxidative damage in human primary cultured hepatocytes and cytochrome P450 2E1 (CYP2E1) activity, in order to address if inhibition of CYP2E1 could attenuate ethanol-induced cellular damage. METHODS: The dose-dependent (25-100 mmol/L) and time-dependent (0-24 h) exposures of primary human cultured hepatocytes to ethanol were carried out. CYP2E1 activity and protein expression were detected by spectrophotometer and Western blot analysis respectively. Hepatotoxicity was investigated by determination of lactate dehydrogenase (LDH) and aspartate transaminase (AST) level in hepatocyte culture supernatants, as well as the intracellular formation of malondialdehyde (MDA). RESULTS: A dose-and time-dependent response between ethanol exposure and CYP2E1 activity in human hepatocytes was demonstrated. Moreover, there was a time-dependent increase of CYP2E1 protein after 100 mmol/L ethanol exposure. Meanwhile, ethanol exposure of hepatocytes caused a time-dependent increase of cellular MDA level, LDH, and AST activities in supernatants. Furthermore, the inhibitor of CYP2E1, diallyl sulfide (DAS) could partly attenuate the increases of MDA, LDH, and AST in human hepatocytes. CONCLUSION: A positive relationship between ethanol-induced oxidative damage in human primary cultured hepatocytes and CYP2E1 activity was exhibited, and the inhibition of CYP2E1 could partly attenuate ethanol-induced oxidative damage.

Induction of heme oxygenase-1 in human hepatocytes to protect them from ethanol-induced cytotoxicity.

UNLABELLED: We investigated the relationship between ethanol exposure and heme oxygenase (HO-1) in human hepatocytes in order to ascertain if induction of HO-1 can prevent ethanol induced cellular damage. METHODS: Dose-dependent (25-100 mmol/L) and time-dependent (0-24 h) ethanol exposure were used in the present study. HO-1 mRNA and protein expression were detected by PT-PCR and Western blot respectively. HO-1 activity was indicated by bilirubin and Fe2+ formation. Cytotoxicity was investigated by means of lactate dehydrogenate (LDH) and aspartate transaminase (AST) level in culture supernatants, as well as the intracellular formation of malondialdehyde (MDA), cellular glutathione (GSH) status and CYP 2E1 activity. RESULTS: We first demonstrated a dose-dependent response between ethanol exposure and HO-1 mRNA and protein expression in human hepatocytes. We further observed a time-dependent increase of HO-1 mRNA expression using 100 mmol/L ethanol starting 30 minutes after ethanol exposure, reaching its maximum between 3 h and 9 h. Being similar increased protein expression started to what had been demonstrated with the mRNA level, at 6 h after ethanol exposure, and kept continuous elevated over 18 h. In addition, we found that ethanol exposure to hepatocytes markedly increased HO-1 enzyme activity in a time-dependent manner measured as bilirubin and Fe2+ formation in human hepatocytes. Our results clearly showed that ethanol exposure caused a significant increase of LDH, AST, and MDA levels, while the antioxidant GSH was time-dependently reduced. Furthermore, we demonstrated that pre-administration of cobalt protoporphyrin (CoPP) induced HO-1 in human hepatocytes, and prevented an increase of MDA and a decrease of GSH. These effects could be partially reversed by zinc protoporphyrin (ZnPP), an antagonist of HO-1 induction. CONCLUSION: HO-1 expression in cells or organs could lead to new strategies for better prevention and treatment of ethanol-induced oxidative damage in human liver.

[Influence of alcohol on insulin sensitivity and insulin receptor substrate-1 mRNA expression in rat skeletal muscle].

OBJECTIVE: To investigate the molecular mechanism of the effect of alcohol on insulin sensitivity. METHODS: Four groups of Wistar rats were used, i.e. control (C) group, and low (L), moderate (M) and high (H) alcohol group. Alcohol doses of each group were 0, 0.6, 1.8 and 3.0 ml.(kg.bw)(-1).day(-1). Each group was comprised of 10 male and 10 female rats. Alcohol was given to rats by gastric intubation. Thirteen weeks later, serum was collected for testing of fasting plasma glucose and insulin. HOMA-IR index of each group were calculated. Total muscle RNA was extracted using Trizol Reagent (Promega). The expression level of IRS-1 mRNA in muscle was detected by RT-PCR. RESULTS: In female rats, the fasting plasma glucose of group (8.36 +/- 0.57) mmol/L was higher and the fasting plasma insulin (15.25 +/- 3.32) was lower than those of group C (7.56 +/- 0.85, 20.80 +/- 3.25). The HOMA-IR of group L (1.775 3 +/- 0.138 1) was lower than that of group C (1.982 6 +/- 0.124 6) (P < 0.05), while IRS-1 mRNA (0.766 1 +/- 0.076 9) was up-regulated (P < 0.05); HOMA-IR of group M (2.202 2 +/- 0.271 0) was higher than that of group C (P < 0.01), while IRS-1 mRNA (0.501 8 +/- 0.049 2) was suppressed (P < 0.01); HOMA-IR of group H (1.850 1 +/- 0.162 8) was not significantly changed as compared with that of group C (1.982 6 +/- 0.124 6) (P > 0.05), while IRS-1 mRNA (0.418 1 +/- 0.049 1) was significantly suppressed (P < 0.01). In male rats, the fasting plasma glucose and insulin had the similar change as those of female rats. The HOMA-IR of group M (1.878 5 +/- 0.250 2) was lower than that of C group (2.147 3 +/- 0.330 8) (P < 0.05), IRS-1 mRNA was up-regulated (0.824 9 +/- 0.064 7) (P < 0.05). CONCLUSIONS: The present study showed that low-to-moderate dose of alcohol could increase insulin sensitivity; while alcohol abuse could decrease insulin sensitivity. Sex difference in this effect was found. Changes of IRS-1 mRNA expression may be involved in the molecular mechanism of the effects of alcohol on insulin sensitivity.

ROS-related enzyme expressions in endothelial cells regulated by tea polyphenols.

OBJECTIVE: Elevation of reactive oxygen species (ROS), especially the level of superoxide is a key event in many forms of cardiovascular diseases. To study the mechanism of tea polyphenols against cardiovascular diseases, we observed the expressions of ROS-related enzymes in endothelial cells. METHODS: Tea polyphenols were co-incubated with bovine carotid artery endothelial cells (BCAECs) in vitro and intracellular NADPH oxidase subunits p22phox and p67phox, SOD-1, and catalase protein were detected using Western blot method. RESULTS: Tea polyphenols of 0.4 microg/mL and 4.0 microg/mL (from either green tea or black tea) down-regulated NADPH oxidase p22phox and p67phox expressions in a dose-negative manner (P < 0.05), and up-regulated the expressions of catalase (P < 0.05). CONCLUSIONS: Tea polyphenols regulate the enzymes involved in ROS production and elimination in endothelial cells, and may be beneficial to the prevention of endothelial cell dysfunction and the development of cardiovascular diseases.