Bracteanolide A abrogates oxidative stress-induced cellular damage and protects against hepatic ischemia and reperfusion injury in rats.

Liver diseases, including viral hepatitis, liver cirrhosis, and liver cancer, mostly remain silent until the late stages and pose a continuing threat to millions of people worldwide. Liver transplantation is the most appropriate solution in the case of liver failure, but it is associated with hepatic ischemia and reperfusion (I/R) injury which severely reduces the prognosis of the patients. In order to ameliorate I/R injury, we investigated the potential of bracteanolide A, from the herb Tradescantia albiflora Kunth in protecting the liver from I/R injury. We first determined the protective effect of bracteanolide A against oxidative stress and DNA damage using HepG2 hepatocyte cell line and then assessed the levels of inflammatory cytokines and antioxidant proteins in response to hepatic insult using an animal model of hepatic I/R injury. The results showed bracteanolide A greatly enhanced cell survival and decreased reactive oxygen species (ROS) production under H2O2 induction. It also upregulated the expression of nuclear factor (erythroid-derived 2)-like2 (Nrf2) and its downstream cytoprotective proteins NAD(P)H quinone oxidoreductase 1 (NQO1) and heme oxygenase-1 (HO-1). Bracteanolide A effectively reduced the severity of liver lesions in I/R-injured rats revealed by histological analysis and significantly decreased the levels of alanine transaminase (ALT), aspartate transaminase (AST), cyclooxygenase-2, and inflammatory cytokines interleukin (IL)-1ß and tumor necrosis factor (TNF)-α. Bracteanolide A preconditioning effectively protected the liver from I/R damage in the animal model, and this easily applied procedure may provide a new means to ameliorate hepatic I/R injury during liver surgeries.

Ergostatrien-3ß-ol (EK100) from Antrodia camphorata Attenuates Oxidative Stress, Inflammation, and Liver Injury In Vitro and In Vivo.

Hepatic ischemia/reperfusion (IR) injury is a complication that occurs during liver surgery, whereby hepatic tissue is injured by oxygen deficiency during ischemia, then further damaged by a cascade of inflammatory and oxidative insults when blood is resupplied during reperfusion. Antrodia camphorata is an indigenous fungus in Taiwan and an esteemed Chinese herbal medicine with various bioactivities. This study examined the effect of ergostatrien-3ß-ol (EK100), an active compound found in both the fruiting body and mycelia of A. camphorata, on IR injury pathologies in rats and cell models of oxidative and inflammatory stress. Male Sprague-Dawley rats were randomly assigned to receive a vehicle or 5 mg/kg EK100 prior to hepatic IR injury induced by 1 h ischemia followed by 24 h reperfusion, or a sham operation. RAW 264.7 murine macrophages and HepG2 hepatocytes were pretreated with EK100, then inflammation was induced with lipopolysaccharides in the former and oxidative stress was induced with hydrogen peroxide in the latter. EK100 decreased IR-induced elevation in serum levels of alanine aminotransferase and aspartate aminotransferase and lowered levels of the inflammatory cytokines tumor necrosis factor-α, interleukin (IL)-6, and IL-1ß. In addition, EK100 significantly reduced hepatic mRNA levels of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2, as well as nitrite production and iNOS gene expression in both hepatocyte and macrophage cell lines. We demonstrated that EK100 exhibits potent protec-tion against hepatic IR injury, which may be used to design strategies to ameliorate liver damage during liver surgery.

Construction of a Lactobacillus plantarum Strain Expressing the Capsid Protein of Porcine Circovirus Type 2d (PCV2d) as an Oral Vaccine.

Porcine circovirus type 2 (PCV2) is a pathogenic virus that causes high rates of porcine death, resulting in severe economic losses to the swine industry. In recent years, the prevalence of PCV2d genotype infection in pigs has increased, but most commercially available vaccines were developed against the PCV2a strain and do not ensure complete protection from PCV2d. Here, we first constructed an expression vector for the antigenic ORF2-encoded capsid protein of PCV2d (pLp3050-His6-tag-capsid). We then utilized Lactobacillus plantarum to express the protein at mucosal sites in orally vaccinated mice. After transducing L. plantarum with pLp3050-His6-tag-capsid, the expressed protein could be found in cell wall and cell-free supernatant fractions by Western blotting. Using flow cytometry, we found that L. plantarum cells with surface-displayed capsid protein increased with time after SppIP induction. Finally, mice that were orally immunized 18 times with capsid-expressing L. plantarum showed increased levels of capsid-specific sIgA and virus neutralizing activity at mucosal sites, suggesting mucosal immunity had been stimulated by the vaccine. Overall, our findings demonstrate the feasibility and utility of a PCV2d-based vaccine, which may be of great value in porcine agriculture.

Proteomic changes associated with metabolic syndrome in a fructose-fed rat model.

Metabolic syndrome (MetS), characterized by a constellation of disorders such as hyperglycemia, insulin resistance, and hypertension, is becoming a major global public health problem. Fructose consumption has increased dramatically over the past several decades and with it the incidence of MetS. However, its molecular mechanisms remain to be explored. In this study, we used male Sprague-Dawley (SD) rats to study the pathological mechanism of fructose induced MetS. The SD rats were fed a 60% high-fructose diet for 16 weeks to induce MetS. The induction of MetS was confirmed by blood biochemistry examination. Proteomics were used to investigate the differential hepatic protein expression patterns between the normal group and the MetS group. Proteomic results revealed that fructose-induced MetS induced changes in glucose and fatty acid metabolic pathways. In addition, oxidative stress and endoplasmic reticulum stress-related proteins were modulated by high-fructose feeding. In summary, our results identify many new targets for future investigation. Further characterization of these proteins and their involvement in the link between insulin resistance and metabolic dyslipidemia may bring new insights into MetS.

Protective Effects of N-acetylcysteine and a Prostaglandin E1 Analog, Alprostadil, Against Hepatic Ischemia: Reperfusion Injury in Rats.

Ischemia-reperfusion (I/R) injury has a complex pathophysiology resulting from a number of contributing factors. Therefore, it is difficult to achieve effective treatment or protection by individually targeting the mediators or mechanisms. Our aim was to analyze the individual and combined effects of N-acetylcysteine (NAC) and the prostaglandin E1 (PGE1) analog alprostadil on hepatic I/R injury in rats. Thirty male Sprague-Dawley rats were randomly divided into five groups (six rats per group) as follows: Control group, I/R group, I/R + NAC group, I/R + alprostadil group, and I/R + NAC + alprostadil group. The rats received injections of NAC (150 mg/kg) and/or alprostadil (0.05 µg/kg) over a period of 30 min prior to ischemia. These rats were then subjected to 60 min of hepatic ischemia followed by a 60-min reperfusion period. Hepatic superoxide dismutase (SOD), catalase, and glutathione levels were significantly decreased as a result of I/R injury, but they were increased in groups treated with NAC. Hepatic malondialdehyde (MDA), myeloperoxidase (MPO), and nitric oxide (NO) activities were significantly increased after I/R injury, but they were decreased in the groups with NAC treatment. Alprostadil decreased NO production, but had no effect on MDA and MPO. Histological results showed that both NAC and alprostadil were effective in improving liver tissue morphology during I/R injury. Although NAC and alprostadil did not have a synergistic effect, our findings suggest that treatment with either NAC or alprostadil has benefits for ameliorating hepatic I/R injury.

Preconditioning somatothermal stimulation on Qimen (LR14) reduces hepatic ischemia/reperfusion injury in rats.

BACKGROUND: In human beings or animals, ischemia/reperfusion (I/R) injury of the liver may occur in many clinical conditions, such as circulating shock, liver transplantation and surgery and several other pathological conditions. I/R injury has a complex pathophysiology resulting from a number of contributing factors. Therefore, it is difficult to achieve effective treatment or protection by individually targeting the mediators. This study aimed at studying the effects of local somatothermal stimulation preconditioning on the right Qimen (LR14) on hepatic I/R injury in rats. METHODS: Eighteen male Sprague-Dawley rats were randomly divided into three groups. The rats were preconditioned with thermal tolerance study, which included one dose of local somatothermal stimulation (LSTS) on right Qimen (LR14) at an interval of 12 h, followed by hepatic ischemia for 60 min and then reperfusion for 60 min. Serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) have been used to assess the liver functions, and liver tissues were taken for the measurements such as malondialdehyde (MDA), glutathione (GSH), catalase (CAT), superoxidase dismutase (SOD), and myeloperoxidase (MPO). RESULTS: The results show that the plasma ALT and AST activities were higher in the I/R group than in the control group. In addition, the plasma ALT and AST activities decreased in the groups that received LSTS. The hepatic SOD levels reduced significantly by I/R injury. Moreover, the hepatic MPO activity significantly increased by I/R injury while it decreased in the groups given LSTS. CONCLUSIONS: Our findings show that LSTS provides a protective effects on the liver from the I/R injury. Therefore, LSTS might offer an easy and inexpensive intervention for patients who have suffered from I/R of the liver especially in the process of hepatotomy and hepatic transplantation.

Preconditioned hyperbaric oxygenation protects the liver against ischemia-reperfusion injury in rats.

Hyperbaric oxygen (HBO) therapy is an effective adjunct in treating ischemia-reperfusion (I/R) injury of brain, small intestine, testis, and crushing extremities. This study was designed to test the hypotheses that preconditioning the rats with HBO could protect the liver against subsequent I/R injury. Daily treatment with one-dose HBO (90 min, 2.5 ATA) was brought about for male Sprague Dawley rats for 1 to 3 days before an I/R injury of liver. Hepatic expression of heat-shock protein 70 (Hsp70), total concentration of glutathione (GSH), activity of catalase, superoxide dismutase (SOD), and serum AST and ALT were estimated before and after HBO, as well as after I/R injury. The results showed that activity of hepatic catalase was decreased by one dose, but not three doses, of HBO as compared with baseline data. However, hepatic Hsp70 expression fluctuated insignificantly. AST and ALT increase less in rats preconditioned with one-dose HBO as compared with those without HBO or with three-dose HBO. Our results showed preconditioning by one-dose HBO protects rat liver against subsequent ischemia-reperfusion injury.

Salvianolic acid B enhances in vitro angiogenesis and improves skin flap survival in Sprague-Dawley rats.

Insufficient angiogenesis and microcirculatory intravascular clotting have been implicated in the pathophysiology of skin flap failure. Salvianolic acid B (Sal B), isolated from Salvia miltiorrhiza, has been reported to enhance angiogenesis in vitro. This study was aimed to determine the efficacy of Sal B on ischemia-reperfusion injury of the skin flap in Sprague-Dawley rats. Sal B was administered intraperitoneally 2 h before operation, and on the 2nd and 4th days after surgical elevation of an extended epigastric adipocutaneous flap (5 x 7 cm) in ketamine-anesthetized rats. Flap ischemia was achieved by ligating the right superficial epigastric artery and vein and clamping the left superficial epigastric artery and vein for 3 h and then released. Percentage of flap necrosis area (FNA) and plasma levels of aspartate aminotransferase, alanine aminotransferase, creatinine, and malondialdehyde were measured at 7 days after the operation. Animals were divided into six groups, including: vehicle, Sal B low dose (5 mg/kg), Sal B high dose (50 mg/kg) and each with [mesh(+)] or without mesh [mesh(-)] placement. In the three groups with mesh(+), FNA in control flaps was 53.7 +/- 6.9%, whereas low-dose and high-dose Sal B significantly improved flap survival with FNA 27.4 +/- 3.8% and 25.3 +/- 4.3%, respectively (P < 0.05, one-way ANOVA). In the three groups with mesh(-), control flaps were 35.9 +/- 4.5%, whereas high-dose Sal B also significantly improved flap survival with FNA 17.9 +/- 4.7% (P < 0.05, one-way ANOVA). There were no differences in aspartate aminotransferase, alanine aminotransferase, creatinine, or malondialdehyde between groups. We conclude that Sal B attenuates ischemia-reperfusion injury of skin flap, and provides therapeutic potential in reconstructive plastic surgery.