Protective effects of leflunomide against ischemia-reperfusion injury of the rat liver

Hepatic ischemia-reperfusion (I/R) injury may be developed in some conditions, such as trauma, major hepatic resection, hemorrhagic shock or liver transplantation. I/R injury of the liver causes hepatocellular damage that may lead to hepatic failure. A considerable body of evidence indicates that reactive oxygen species (ROS) and inflammation may contribute to hepatocellular injury in liver I/R. Leflunomide is an isoxazole derivative, and a unique immunomodulatory agent. In the present study, we examined the effects of leflunomide on the neutrophil activation with oxidative stress and some antioxidant enzymes in the reperfusion following I/R in the rat liver. Thirty-two rats divided into four groups: group 1 (control); was given leflunomide 10 mg/kg, i.g.; group 2 (SHAM), animals were only laparotomized; group 3 (liver I/R), and group 4 (liver I/R + Leflunomide). In group 4, rats were pretreated with leflunomide (10 mg/kg, i.g.) two doses prior to experiment. In groups 3 and 4, occluding the hepatic pedicel for 60 min induced ischemia and reperfusion was allowed thereafter for 60 min. At the end of the reperfusion period, rats were sacrificed. superoxide dismutase, catalase, nitric oxide, xanthine oxidase, malondialdehyde, protein carbonyl and myeloperoxidase levels were determined in hepatic tissue as well as histological examination with H and E staining. Group 3 animals demonstrated severe deterioration of liver morphology and a significant liver oxidative stress. Pretreatment of animals with leflunomide markedly attenuated morphological alterations and neutrophil activation, reduced elevated oxidative stress products levels and restored the depleted hepatic antioxidant enzyme. The findings imply that ROS play a causal role in I/R-induced hepatic injury, and leflunomide exerts hepatoprotective effects probably by the anti-inflammatory effect with radical scavenging and antioxidant activities.     

川芎嗪对大鼠急性坏死性胰腺炎肺损伤的保护作用

目的探讨微循环障碍在急性坏死性胰腺炎肺损伤中的作用,同时观察川芎嗪对胰腺炎肺损伤的干预效应。方法SD大鼠192只,随机均分为对照组(C)、胰腺炎组(P)、川芎嗪治疗组(T)。大鼠胰腺被膜下均匀注射5%牛磺胆酸钠4ml·kg-1,制作急性坏死性胰腺炎模型,C组胰腺被膜下注射等量生理盐水,T组经股静脉注射0.6%川芎嗪10ml·kg-1。每组中8只SD大鼠采用放射性生物微球技术,在制模后0.5、2.0、6.0、12.0h分别测定肺的血流量,另8只用于胰腺、肺的病理评分,以肺组织的过氧化酶(MPO)活性、肺湿/干重比作为衡量肺损伤的指标。结果P、C组相比,各时相肺脏的血流量均明显降低(P<0.05);各时相病理改变明显加重,时间越长,损害越重,其程度与血流量相关;肺干/湿明显加重,组织MPO活性明显增加(P<0.05或P<0.01)。T、P组相比,各时相肺的血流量较P组均明显降低(P<0.01);各时相病理改变明显减轻,肺干/湿无明显变化(P>0.05),组织MPO活性明显下降(P<0.05)。急性坏死性胰腺炎(ANP)时,肺组织血流量与肺湿/干重比率、肺组织MPO活性、肺组织损伤程度呈显著负相关。结论微循环障碍在急性坏死性胰腺炎的肺组织损伤中起着重要的作用。川芎嗪可以改善微循环,减轻胰腺及肺损害。     

Gambogic acid alleviates inflammation and apoptosis and protects the blood-milk barrier in mastitis induced by LPS

Mastitis is one of the most common diseases among dairy cows. There is still much debate worldwide as to whether antibiotic therapy should be given to dairy cows, or if natural products should be taken as a substitute for antibacterial therapy. As the antibiotic treatment leads to the bacterial resistance and drug residue in milk, introducing natural products for mastitis is becoming a trend. This study investigates the mechanisms of the protective effects of the natural product gambogic acid (GA) in lipopolysaccharide (LPS)-induced mastitis. For in vitro treatments, it was found that GA reduced IL-6, TNF-α, and IL-1β levels by inhibiting the phosphorylation of proteins in the nuclear factor κB (NF-κB) and the mitogen-activated protein kinase (MAPK) pathway. GA also maintained a stable membrane mitochondrial potential and inhibited the overproduction of reactive oxygen species, which protected the cells from apoptosis. On the other hand, in vivo treatments with GA were found to reduce pathological symptoms markedly, and protected the blood-milk barrier from damage induced by LPS. The results demonstrate that GA plays a vital role in suppressing inflammation, alleviating the apoptosis effect, and protecting the blood-milk barrier in mastitis induced by LPS. Thus, these results suggest that the natural product GA plays a potential role in mastitis treatment.     

Expression of neutrophil elastase and myeloperoxidase mRNA in patients with newly diagnosed type 2 diabetes mellitus

Background and aimsNeutrophil elastase and myeloperoxidase enzymes protect us from infection by killing pathogens. However, exaggerated activities of these enzymes can induce tissue damage, inflammation and oxidative stress. The present study was aimed to explore the expressions of neutrophil elastase and myeloperoxidase mRNA in the peripheral blood leukocytes (PBL) in patients with newly diagnosed type 2 diabetes mellitus.MethodsIn this cross-sectional study, 104 participants including 65 normoglycemic control subjects and 39 newly diagnosed type 2 diabetes patients were recruited. Glycemic and metabolic markers were evaluated from fasting blood samples. The mRNA levels of neutrophil elastase and myeloperoxidase genes in the PBL were quantified by real-time quantitative PCR.ResultsCompared to control subjects, diabetes patients showed a significant down regulation of both neutrophil elastase (p = 0.039) and myeloperoxidase (p = 0.023) mRNA expressions in the PBL. The neutrophil elastase and myeloperoxidase mRNA levels showed a negative trend with fasting glucose levels but did not show any significant correlations with HbA1c, insulin level, insulin resistance or sensitivity status.ConclusionsIt was concluded that type 2 diabetes mellitus is associated with a decrease in neutrophil elastase and myeloperoxidase gene expression in the PBL.     

The composition of chlorinated or oxidized phosphatidylcholine products changes with hypochlorite concentration: Application to abscess lipid analysis

Hypochlorous acid, produced by myeloperoxidase upon neutrophil activation, can oxidize various compounds and exert antimicrobial activity in vivo. To elucidate the mechanisms underlying the reactions of the unsaturated phosphatidylcholines, which abound in cell membranes, with hypochlorous acid, we identified and examined phosphatidylcholine chlorination and oxidation products formed under various reaction conditions. We first investigated the products of unsaturated phosphatidylcholine and hypochlorous acid reaction with respect to hypochlorite concentration and reaction time. Next, we examined the lipids extracted postmortem from human abscesses. For all the analyses, we used liquid chromatography–quadrupole time-of-flight mass spectrometry. Various compounds, including phosphatidylcholine chlorohydrin and phosphatidylcholine hydroxide/epoxide, were detected. Oxidized phosphatidylcholines were mainly detectable upon reaction with low concentrations of sodium hypochlorite, whereas chlorinated phosphatidylcholines formed in the presence of higher concentrations. In human abscesses, oxidized phosphatidylcholines were detected in the cases with high procalcitonin concentration, whereas chlorinated phosphatidylcholines were undetected. The detections of oxidized phosphatidylcholines in human tissues might indicate previous exposure to hypochlorous acid in septic cases. Our results provide insight into the mechanisms underlying pathogen survival following inflammation associated with neutrophil activation and topical myeloperoxidase release and show postmortem biomarkers candidates for sepsis.     

Myeloperoxidase activity in skin lesions

The measurement of the myeloperoxidase activity was used to quantify the acute granulocyte reaction. A 35% loss of blood resulted in a clear decrease of the myeloperoxidase activity at the edges of experimental incision wounds in rat skin in the first day after inflicting the wounds. After 12 h only about one-third and after 24 h about half of the activity observed in the wounds without the loss of blood remained. After 3 days however the activity had returned to the same level as in the wounds without any loss of blood. In very deep excoriations of the rat skin where only a narrow zone of the dermis was left about double the activity increase was observed after 12 and 24 h when compared to values observed in very superficial or moderate excoriations. When the same type of excoriations were made in both thin inguinal skin and thick dorsal skin then a much higher peroxidase activity increase was observed over 4, 12 and 24 h in the thin inguinal skin than in the excoriations made in the thick dorsal skin. Received: 16 December 1996 / Received in revised form: 28 May 1997     

Potential Prophylactic Effect of Berberine against Rat Colon Carcinoma Induce by 1,2-Dimethyl Hydrazine

Introduction: Colon Cancer remains one of the major worldwide causes of cancer related morbidity and mortalityin both genders. Berberine (BBR), a major component of alkaloids that possess a variety of pharmacological properties.Objective: This study shows the ameliorating roles of berberine on 1,2 Di methyl hydrazine (DMH) induced coloncancer in male Swiss albino rats. Methods: The rats were segregated into four groups: group 1, control rats; group2, rats were orally received berberine (75 mg/kg b.wt./day) daily for ten weeks; group 3,rats were subcutaneouslyinjected with DMH (20 mg/kg b.wt) once a week for 8 weeks ,group 4, rats were treated firstly with berberine fortwo weeks before DMH intoxication and concurrently with DMH over 8 weeks. Result: DMH injection decreasedthe antioxidants levels (GSH and SOD) and increased inflammatory markers (MPO, MAPK and COX-2). Moreover,it downregulated apoptotic markers (Caspase-3 and P53) expression that confirmed by colon cell proliferation. Theprophylactic effect of berberine was noticed as its pre-and co-administration increased antioxidants status and apoptoticmarkers expression that associated with inflammatory markers down-regulation with absence of proliferated coloncells. Conclusion: Therefore, the overall findings proved that the anti-proliferative effect of berberine return to itsantioxidants and anti-inflammatory properties that activated the programmed cell death process.     

Hyperbaric oxygen and neutrophil accumulation/tissue damage during permanent focal cerebral ischaemia in rats

The use of hyperbaric oxygenation (HBO) for the treatment of severe brain ischaemia remains controversial. The HBO may interfere with destructive neutrophil (PMN) infiltration following ischaemia/reperfusion. The effects of HBO on PMN accumulation and the area of ischaemic tissue damage were investigated in rats having permanent focal ischaemia (4 h). The right middle cerebral arteries of a group of Wistar rats were permanently occluded. The rats were then randomly divided into those (n=7) to be treated with HBO at 2 atm for 230 min and those (n=8) to breathe air at atmospheric pressure for an equivalent period. The HBO had no effect on permanent ischaemia, as there was no significant difference in the area of ischaemic tissue damage between HBO-treated [mean (SD)] [331 (88) mm³] and non-treated animals [322 (111) mm³]. Moreover, the increase in myeloperoxidase [5.4 (4.1) compared to 2.4 (1.2) pg·g^–1 wet weight of brain] was not significantly different. The results indicate that HBO did not reduce tissue damage during 4 h of permanent focal ischaemia. Electronic Publication     

代谢基因MPOG-463A多态检测在大肠癌早期诊断中的研究

目的探讨MPOG-463A基因多态性与大肠癌易感性的关系。方法取103例大肠癌组织和143例癌旁正常大肠组织（对照组）的石蜡切片样本，应用聚合酶联反应（pcR）及限制性片断长度多态性（RFLP）进行检测。结果MPO基因型（GG，GA，AA）在大肠癌组的分布为47．57％、31．07％、21．35％，正常组为27．97％、37．06％、34．97％，两组间比较差异有统计学意义（P〈0．05）；含MPOG-463A等位片段的基因型在大肠癌组中的分布为38．3％，正常组为53．5％，两组间比较差异有统计学意义（P〈0．05）。结论MPOG-463A基因多态性可能是大肠癌发病的一个基因型危险因素，具有对肿瘤进行早期诊断和判断预后的潜在价值。