Protective role of curcumin in ameliorating AFB1-induced apoptosis via mitochondrial pathway in liver cells.

It is well documented that liver is the primary target organ of aflatoxin B1 (AFB1) and curcumin proved to be effective against AFB1-induced liver injury. In the present study, we investigated the preventive effects of curcumin against AFB1-induced apoptosis through the molecular regulation of p53, caspase-3, Bax, caspase-9, Bcl-2 and cytochrome-C associated with mitochondrial pathway. Liver antioxidant levels were measured. The hallmarks of apoptosis were analysed by methyl green-pyronin-Y staining, transmission electron microscopy, RT-PCR and western blot. Results revealed that dietary curcumin ameliorated AFB1-induced oxidative stress in a dose-dependent manner. Methyl green-pyronin-Y staining and transmission electron microscopy showed that AFB1 induced apoptosis and caused abnormal changes in liver cells morphology such as condensation of chromatin material, reduces cell volume and damaged mitochondria. Moreover, mRNA and protein expression results manifested that apoptosis associated genes showed up-regulation in AFB1 fed group. However, the supplementation of dietary curcumin (dose-dependently) alleviated the increased expression of the apoptosis associated genes at mRNA and protein level, and restored the hepatocytes normal morphology. The study provides an insight and a better understanding of the preventive mechanism of curcumin against AFB1-induced apoptosis in hepatocytes and provide scientific basis for the therapeutic uses of curcumin.

Effect of Curcumin as Feed Supplement on Immune Response and Pathological Changes of Broilers Exposed to Aflatoxin B1.

In this study, we examined the protective effects of curcumin against the AFB1-induced immune response of and pathological changes in broilers. Histopathology examinations showed that at day 28, AFB1 (5 mg/kg) exposure leads to severe histological changes in the spleen, thymus and bursa of Fabricius with a decrease in the number and karyoplasmic area ratio of plasma cells. Curcumin alleviated the AFB1-induced immune organs' damage as well as the changes in plasma cells in a dose-dependent manner. RT-PCR data showed that AFB1 significantly downregulated the IL-2 and IFN-γ mRNA expression levels in the thymus, spleen and bursa of Fabricius. However, curcumin supplementation improved the AFB1-induced immune organs' damage via upregulated cytokines' expression. Intriguingly, similar trends were noticed in abnormal morphological changes and the immune response at day 35 after the withdrawal of AFB1 and curcumin from the diet, suggesting the protective effects and immunomodulatory function against AFB1 in broilers. The current study provides a scientific experimental basis for the application of curcumin as a therapeutic drug or additive in animal husbandry productive practice.

Rutaecarpine may improve neuronal injury, inhibits apoptosis, inflammation and oxidative stress by regulating the expression of ERK1/2 and Nrf2/HO-1 pathway in rats with cerebral ischemia-reperfusion injury.

BACKGROUND: Cerebral ischemia-reperfusion (CI/R) injury is a more serious brain injury caused by the recovery of blood supply after cerebral ischemia for a certain period of time. Rutaecarpine (Rut) is an alkaloid isolated from Evodia officinalis with various biological activities. Previous studies have shown that Rut has a certain protective effect on ischemic brain injury, but the specific molecular mechanism is still unknown. METHODS: In this study, a rat model of CI/R was established to explore the effects and potential molecular mechanisms of Rut on CI/R injury in rats. RESULTS: The results showed that Rut alleviated neuronal injury induced by CI/R in a dose-dependent manner. Besides, Rut inhibited neuronal apoptosis by inhibiting the activation of caspase 3 and the expression of Bax. In addition, Rut alleviated the inflammatory response and oxidative stress caused by CI/R through inhibiting the production of pro-inflammatory factors (IL-6 and IL-1ß), lactate dehydrogenase (LDH), malondialdehyde (MDA) and ROS, and increased the levels of anti-inflammatory factors (IL-4 and IL-10) and superoxide dismutase (SOD). Biochemically, Western blot analyses showed that Rut inhibited the phosphorylation of ERK1/2 and promoted the expression of nuclear factor-erythroid 2 related factor 2 (Nrf2) pathway-related proteins (Nrf2, heme oxygenase 1 (HO-1) and NAD (P) H-quinone oxidoreductase 1) in a dose-dependent manner. These results show that Rut may alleviate brain injury induced by CI/R by regulating the expression of ERK1/2 and the activation of Nrf2/HO-1 pathway. CONCLUSION: In conclusion, these results suggest that Rut may be used as an effective therapeutic agent for damage caused by CI/R.

Water-soluble substances of wheat: a potential preventer of aflatoxin B1-induced liver damage in broilers.

Aflatoxin B1 (AFB1) is very harmful for broiler production and public health. The water-soluble castoff in gluten production, i.e., the water-soluble substances of wheat (WSW) that contains 14% pentosan has positive effect on animal nutrient absorption, immunity, and antioxidation. Our study aims to investigate the preventive effects of WSW against AFB1-induced broiler liver injury. One day-old Arbor Acres broilers were randomly separated to 4 groups and were, respectively, fed with control diet, diet with 5 mg/kg AFB1 standard, diet with 5 mg/kg AFB1 standard and 214 ml/kg WSW, and diet with 214 ml/kg WSW continuously for 28 d. The histopathological, ultra-structural, and serological changes were tested to evaluate liver damage. The hallmarks of hepatocellular autophagy, apoptosis, and inflammation were measured by Western Blot and real-time polymerase chain reaction. The content of AFB1 in chicken liver was detected with an ultra-high performance liquid chromatography linked with the fluorescence detection method. The results showed that (i) WSW restored AFB1-induced changes in serum biochemical parameters, and ameliorated histomorphological changes in hepatocytes, (ii) WSW reduced the content of AFB1 in chicken liver, (iii) WSW alleviated AFB1-induced autophagy inhibition by up-regulating hepatic LC3, beclin-1, and down-regulating hepatic mTOR and cytoplasmic P53 expressions, (iv) WSW alleviated AFB1-induced hepatocellular apoptosis via inhibiting pro-apoptotic gene expression (nuclear P53, Caspase3, Bax), and promoting anti-apoptotic gene expression (bcl-2), (v) WSW feeding ameliorated AFB1-induced liver inflammation via impeding TLR4/NF-${{\bf \kappa }}$B and IL-1/NF-${{\bf \kappa }}$B signaling pathways, down-regulating pro-inflammatory cytokines (IL-1${{\bf \beta }}$, IL-6, and IL-8), and markedly up-regulating anti-inflammatory genes (IL-10 and HO-1). Conclusively, WSW is a potential preventer of AFB1-induced broiler liver damage by reducing the AFB1 content in liver, accelerating hepatocellular autophagy and inhibiting hepatocytes apoptosis and liver inflammation.

Dual Role of Dietary Curcumin Through Attenuating AFB1-Induced Oxidative Stress and Liver Injury via Modulating Liver Phase-I and Phase-II Enzymes Involved in AFB1 Bioactivation and Detoxification.

It is well understood that liver cytochrome p450 enzymes are responsible for AFB1 bioactivation, while phase-II enzymes regulated by the transcription factor nuclear factor-erythroid-2-related factor 2 (Nrf2) are involved in detoxification of AFB1. In this study, we explored the potential of curcumin to prevent AFB1-induced liver injury by modulating liver phase-I and phase-II enzymes along with Nrf2 involved in AFB1 bioactivation and detoxification. Arbor Acres broiler were divided into four groups including control group (G1; fed only basal feed), curcumin alone-treated group (G2; 450 mg/kg feed), AFB1-fed group (G3; 5 mg/kg feed), and curcumin plus AFB1 group (G4; 5 mg AFB1+450 mg curcumin/kg feed). After 28 days, liver and blood samples were collected for different analyses. Histological and phenotypic results revealed that AFB1-induced liver injury was partially ameliorated by curcumin supplementation. Compared to AFB1 alone-treated group, serum biochemical parameters and liver antioxidant status showed that curcumin supplementation significantly prevented AFB1-induced liver injury. RT-PCR and western blot results revealed that curcumin inhibited CYP enzymes-mediated bioactivation of AFB1 at mRNA and protein level. Transcription factor Nrf2, its downstream genes such as GSTA3, and GSTM2 mRNA, and protein expression level significantly upregulated via dietary curcumin. In addition, GSTs enzyme activity was enhanced with dietary curcumin which plays a crucial role in AFB1-detoxification. Conclusively, the study provided a scientific basis for the use of curcumin in broiler's diet and contributed to explore the multi-target preventive actions of curcumin against AFB1-induced liver injury through the modulation of phase-I and phase-II enzymes, and its potent anti-oxidative effects.

High Fat Diet-Induced Hepatic 18-Carbon Fatty Acids Accumulation Up-Regulates CYP2A5/CYP2A6 via NF-E2-Related Factor 2.

To investigate the role of hepatic 18-carbon fatty acids (FA) accumulation in regulating CYP2A5/2A6 and the significance of Nrf2 in the process during hepatocytes steatosis, Nrf2-null, and wild type mice fed with high-fat diet (HFD), and Nrf2 silenced or over expressed HepG2 cells administered with 18-carbon FA were used. HE and Oil Red O staining were used for mice hepatic pathological examination. The mRNA and protein expressions were measured with real-time PCR and Western blot. The results showed that hepatic CYP2A5 and Nrf2 expression levels were increased in HFD fed mice accompanied with hepatic 18-carbon FA accumulation. The Nrf2 expression was increased dose-dependently in cells administered with increasing concentrations of stearic acid, oleic acid, and alpha-linolenic acid. The Nrf2 expression was dose-dependently decreased in cells treated with increasing concentrations of linoleic acid, but the Nrf2 expression level was still found higher than the control cells. The CYP2A6 expression was increased dose-dependently in increasing 18-carbon FA treated cells. The HFD-induced up-regulation of hepatic CYP2A5 in vivo and the 18-carbon FA treatment induced up-regulation of CYP2A6 in HepG2 cells were, respectively, inhibited by Nrf2 deficiency and Nrf2 silencing. While the basal expression of mouse hepatic CYP2A5 was not impeded by Nrf2 deletion. Nrf2 over expression improved the up-regulation of CYP2A6 induced by 18-carbon FA. As the classical target gene of Nrf2, GSTA1 mRNA relative expression was increased in Nrf2 over expressed cells and was decreased in Nrf2 silenced cells. In presence or absence of 18-carbon FA treatment, the change of CYP2A6 expression level was similar to GSTA1 in Nrf2 silenced or over expressed HepG2 cells. It was concluded that HFD-induced hepatic 18-carbon FA accumulation contributes to the up-regulation of CYP2A5/2A6 via activating Nrf2. However, the CYP2A5/2A6 expression does not only depend on Nrf2.

Prevalence of human parvovirus B19 DNA in cardiac tissues of patients with congenital heart diseases indicated by nested PCR and in situ hybridization.

BACKGROUND: Infection with parvovirus B19 (B19) was reported to be correlated with myocarditis, cardiomyopathy, and kawasaki disease. But no information is available about the relationship between inutero B19 infection and congenital heart disease (CHD). OBJECTIVE: To explore whether there is relationship between B19 infection and CHD. STUDY DESIGN: Retrospective investigation of biopsy samples from CHD patients from January 1996 to December 1998. METHODS: Parvovirus B19 was detected in biopsy samples from 42 cases of CHD patients and 38 cases of biopsy or autopsy samples from patients with other diseases (controls) by nested polymerase chain reaction (PCR) and in situ hybridization (ISH) technique. HE staining was also performed to observe the morphology of these cardiac tissue samples. RESULTS: Nested PCR assay indicated that seven of 42 (16.7%) CHD cardiac tissue were B19 DNA positive, while all the 38 controls were B19 DNA negative, the difference is significant (P = 0.012). ISH assay indicated that five of 42 (11.7%) CHD cardiac tissues were positive for B19 DNA and none of the control cardiac tissue were positive, all B19 DNA positive signals were located in the nucleuses of cardiac cells. HE staining showed that there was no inflammatory change in B19 DNA positive cardiac tissue. CONCLUSIONS: Parvovirus B19 DNA was presented in part of CHD cardiac tissues and located in nucleus, which suggested that inutero B19 infection might be correlated with CHD.

Toxoplasma gondii infection of decidual CD1c(+) dendritic cells enhances cytotoxicity of decidual natural killer cells.

There is crosstalk between decidual natural killer (dNK) cells and decidual dendritic cells (dDCs) that promotes tolerance of trophoblast cells carrying paternally derived antigens. In the present study, we report that infection of CD1c(+) dDCs with Toxoplasma gondii enhanced gamma interferon (IFN-γ) production by dNK cells in co-culture. The enhancement of IFN-γ production was induced by cytokine IL-12 which increased obviously in co-culture of dDCs with dNK cells following T. gondii infection, and this enhancement largely abrogated when cells were cultured in the presence of an anti-IL-12 antibody. The expression of KIR2DL4 and NKG2D on dNK cells was increased after T. gondii infection, and higher expression of NKG2D was induced by co-cultured dDCs. Neutralization of IL-12 decreased NKG2D expression on dNK cells. Furthermore, dDCs with T. gondii infection increased the cytotoxicity of co-cultured dNK cells against K562 target cells, which was mediated by activating receptor of NKG2D. Thus, T. gondii infection of dDCs enhanced dNK cell IFN-γ production and NKG2D expression, and then led to increased cytotoxicity of dNK cells. The up-regulated dNK cell cytotoxicity at the maternal-fetal interface may contribute to abnormal pregnancy outcomes caused by T. gondii infection in early pregnancy.

sHLA-G involved in the apoptosis of decidual natural killer cells following Toxoplasma gondii infection.

This study aims to assess whether soluble HLA-G (sHLA-G) is involved in apoptosis of decidual natural killer (dNK) cells following Toxoplasma gondii infection. dNK cells or NK-92 cells were infected with T. gondii and co-cultured with trophoblast cells or BeWo cells. Infected co-cultured cells were treated without or with sHLA-G neutralizing antibody. Uninfected co-cultured cells were used as controls. Apoptosis of dNK cells were analyzed by flow cytometry and confocal microscope. Real-time PCR and Western blot were used to determine caspase 3 and caspase 8 expression. sHLA-G in supernatant were measured by enzyme-linked immunosorbent assay (ELISA). In infection groups, sHLA-G was increased, while dNK apoptosis proteins caspase 3 and caspase 8 were up-regulated, but significantly decreased in the presence of sHLA-G neutralizing antibody compared to controls. Under the situation of T. gondii-infected dNK cells co-cultured with trophoblast cells, the up-regulation of sHLA-G could induce dNK cells apoptosis which ultimately may contribute to the abnormal pregnancy outcomes with T. gondii infection.