Inadequate dietary magnesium intake increases atherosclerotic plaque development in rabbits

Epidemiological studies have shown dietary magnesium (Mg) intake and serum Mg levels to be inversely correlated with the development of atherosclerosis. We hypothesized that low levels of Mg would promote atherosclerotic plaque development in rabbits. New Zealand white rabbits (4 months old, n = 22) were fed an atherogenic diet containing 0.12% (−Mg), 0.27% (control), or 0.43% (+Mg) Mg for 8 weeks. Blood samples were obtained at baseline, 2, 4, 6, and 8 weeks and were assayed for total cholesterol, high-density lipoprotein (HDL), non-HDL, triglycerides (TG), C-reactive protein, serum Mg, and erythrocyte Mg. Aortas from −Mg had significantly more plaque, with an intima thickness 42% greater than control and 36% greater than +Mg. Serum cholesterol levels rose over time, and at 8 weeks, −Mg had the highest and +Mg the lowest total and non-HDL cholesterol and TG levels, although these results did not reach significance. Over time, serum Mg levels increased, and erythrocyte Mg levels decreased. C-reactive protein significantly increased in all groups at 4 and 6 weeks but returned to baseline levels by 8 weeks. This study supports the hypothesis that inadequate intake of Mg results in an increase in atherosclerotic plaque development in rabbits.     

Administration of ciprofibrate to lactating mothers induces PPARα-signaling pathway in the liver and kidney of suckling rats

It is well known that the hypolipidemic drug ciprofibrate induces peroxisome proliferation in rodent liver, which in turn leads to the oxidative stress, and modifies some parameters related to cell proliferation and apoptosis. The administration of ciprofibrate to rats during the lactating period determined in their pups significant modifications in hepatic peroxisome enzyme activities, induction of the PPARalpha-target gene, Cyp4a10, and perturbation in cell proliferation and apoptosis, which affected the size of the liver. Moreover, this modification was associated to about two-fold induction of mRNA-PPARalpha. On the contrary, in the kidney, although a similar two-fold up-regulation of PPARalpha was detected, the induction of both peroxisomal enzyme activities and Cyp4a10 were weak, and no alterations were detected, neither in cell cycle nor in the size of the tissue. Our results indicate that the response to ciprofibrate is stronger in the liver than in the kidney of newborn rats.     

Human multiple myeloma cells express peroxisome proliferator-activated receptor gamma and undergo apoptosis upon exposure to PPARgamma ligands

Multiple myeloma is essentially an incurable malignancy and it is therefore of great interest to develop new therapeutic approaches. We previously reported that human B cell-lymphomas express the nuclear receptor peroxisome proliferator-activated receptor gamma (PPARgamma) and are killed by PPARgamma ligands. Herein, we investigate the therapeutic potential of PPARgamma ligands for multiple myeloma. The human multiple myeloma cell lines ANBL6 and 8226 express PPARgamma mRNA and protein. The PPARgamma ligands, 15-deoxy-Delta12,14-prostaglandin J2 (15d-PGJ2) and ciglitazone, induced multiple myeloma cell apoptosis as determined by terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) assay, loss of mitochondrial membrane potential, and caspase activation. Importantly, the ability of PPARgamma ligands to kill both multiple myeloma cell lines was not abrogated by Interleukin-6 (IL-6), a multiple myeloma growth survival factor. Finally, the RXR ligand 9-cis retinoic acid (9-cis RA) in combination with PPARgamma ligands greatly enhanced multiple myeloma cell killing. These new findings support that PPARgamma ligands may represent a novel therapy for multiple myeloma.     

Peroxisome proliferator-activated receptor-α and liver cancer: where do we stand?

The peroxisome proliferator-activated receptor- (PPAR), first identified in 1990 as a member of the nuclear receptor superfamily, has a central role in the regulation of numerous target genes encoding proteins that modulate fatty acid transport and catabolism. PPAR is the molecular target for the widely prescribed lipid-lowering fibrate drugs and the diverse class of chemicals collectively referred to as peroxisome proliferators. The lipid-lowering function of PPAR occurs across a number of mammalian species, thus demonstrating the essential role of this nuclear receptor in lipid homeostasis. In contrast, prolonged administration of PPAR agonists causes hepatocarcinogenesis, specifically in rats and mice, indicating that PPAR also mediates this effect. There is no strong evidence that the low-affinity fibrate ligands are associated with cancer in humans, but it still remains a possibility that chronic activation with high-affinity ligands could be carcinogenic in humans. It is now established that the species difference between rodents and humans in response to peroxisome proliferators is due in part to PPAR. The cascade of molecular events leading to liver cancer in rodents involves hepatocyte proliferation and oxidative stress, but the PPAR target genes that mediate this response are unknown. This review focuses on the current understanding of the role of PPAR in hepatocarcinogenesis and identifies future research directions that should be taken to delineate the mechanisms underlying PPAR agonist-induced hepatocarcinogenesis.     

尼美舒利对食管癌Eca-109细胞生长的影响及其可能机制

目的:探讨尼美舒利对人食管癌Eca-109细胞生长和凋亡的影响及其作用机制。方法:应用MTT比色法检测尼美舒利对Eca-109细胞体外生长的抑制作用;流式细胞仪测定细胞周期和凋亡,琼脂糖凝胶电泳法进一步观察细胞凋亡;RT-PCR法检测COX-2、PPARγmRNA表达变化,Western blot检测PPARγ蛋白表达变化。结果:尼美舒利(50~400μmol/L)对Eca-109细胞生长有抑制作用,随浓度升高、时间延长作用增强,呈剂量-时间效应关系;可使Eca-109细胞G0/G1期比例增高,S期细胞减少,凋亡细胞增多并出现典型的凋亡细胞DNA ladder。此外,尼美舒利可下调COX-2表达并上调PPARγ表达。结论:尼美舒利能抑制Eca-109细胞的生长,其机制可能是通过抑制Eca-109细胞增殖、诱导细胞周期G0/G1期阻滞、细胞凋亡、下调COX-2表达、上调PPARγ表达而实现的。     

过氧化物酶体增殖物激活受体-γ与胰腺疾病的关系

过氧化物酶体增殖物激活受体γ（peroxisome proliferator activated receptor γ,PPARγ）是一类依赖配体活化的转录因子,属于Ⅱ型核激素受体超家族成员。PPAR-γ是近年来国内外研究的一个热点,现已明确其在细胞增殖分化、炎症反应、糖代谢及脂类代谢具有重要的调节作用。本文就PPARγ与胰腺疾病的关系作一综述。     

Synthesis and anti-diabetic activity of （RS）-2-ethoxy-3-{4-[2-（4-trifluoro-methanesulfonyloxy-phenyl）-ethoxy]-phenyl}-propionic acid

AIM: To synthesize and study the anti-diabetic activity of (RS)-2-ethoxy-3-{4-[2-(4-trifluoromethanesulfonyloxy-phenyl)-ethoxy]-phenyl}-propionic acid (compound I). METHODS: Compound I was prepared in 6 steps, using 4-(2-hydroxy-ethyl)-phenol as the starting material. The in vitro selectivity and potency of target compound I, rosiglitazone and WY-14643 on human PPARalpha and PPARgamma were determined in reporter gene assays. In vivo, rosiglitazone and compound I were administered orally to KK(Ay) mice for 14 d. Insulin tolerance tests and oral glucose tolerance tests were performed on the 10th and 14th day of treatment, respectively. At the end of the treatment, sera were collected for biochemical analysis. RESULTS: In vitro, compound I significantly activated both PPARalpha and PPARgamma. In vivo, compound I corrected the impaired insulin and glucose tolerance of KK(Ay) mice, and produced a significant reduction in plasma triglyceride levels after 14 d of treatment. The effect produced was significant compared with the control group. CONCLUSION: Both in vitro and in vivo anti-diabetic activity studies for compound I were conducted and the data suggest that this compound is a potentially effective anti-diabetic agent.     

Herbal medicines for the prevention of alcoholic liver disease: A review

Ethnopharmacological relevance

Long-term excess alcohol exposure leads to alcoholic liver disease (ALD)—a global health problem without effective therapeutic approach. ALD is increasingly considered as a complex and multifaceted pathological process, involving oxidative stress, inflammation and excessive fatty acid synthesis. Over the past decade, herbal medicines have attracted much attention as potential therapeutic agents in the prevention and treatment of ALD, due to their multiple targets and less toxic side effects. Several herbs, such as Cnidium monnieri (L.) Cusson (Apiaceae), Curcuma longa L. (Zingiberaceae) and Pueraria lobata (Willd.) Ohwi (Leguminosae), etc., have been shown to be quite effective and are being widely used in China today for the treatment of ALD when used alone or in combination.

Aim of the review

To review current available knowledge on herbal medicines used to prevent or treat ALD and their underlying mechanisms.

Materials and methods

We used the pre-set searching syntax and inclusion criteria to retrieve available published literature from PUBMED and Web of Science databases, all herbal medicines and their active compounds tested on ALD induced by both acute and chronic alcohol ingestion were included.

Results

A total of 40 experimental studies involving 34 herbal medicines and (or) active compounds were retrieved and reviewed. We found that all reported extracts and individual compounds from herbal medicines/natural plants could be beneficial to ALD, which might be attributed to regulate multiple critical targets involved in the pathways of oxidation, inflammation and lipid metabolism.

Conclusions

Screening chemical candidate from herbal medicine might be a promising approach to drug discovery for the prevention or treatment of ALD. However, further studies remain to be done on the systematic assessment of herbal medicines against ALD and the underlying mechanisms, as well as their quality control studies.     

SIRT1、PGC-1α在原发性开角型青光眼患者小梁网组织中的表达及意义

目的　检测原发性开角型青光眼（primary open-angle glaucoma，POAG）患者小梁网组织中沉默信息调节因子2相关酶1（silent information regulator factor 2 related enzyme 1，SIRT1）和过氧化物酶体增殖物激活受体γ辅激活因子1α（peroxisome proliferator-activated receptor γ coactivator-1α，PGC-1α）表达水平，探讨其与POAG小梁网组织功能损伤的关系。方法　收集2017年1月至2018年4月在海南医学院第一附属医院手术切除确诊为POAG 40例（40眼）患者的小梁网组织为POAG组样本，另取30例眼球供体的小梁网组织为对照组样本，采用RT-PCR法检测2组小梁网组织中SIRT1、PGC-1α mRNA表达，免疫组织化学染色法检测SIRT1、PGC-1α蛋白表达，同时检测过氧化物酶（peroxidase dismutase，POD）和超氧化物歧化酶（superoxide dismutase，SOD）水平。结果　POAG组小梁网组织中SIRT1、PGC-1α mRNA表达水平（0.11±0.03、0.32±0.10）均低于对照组（0.24±0.07、0.67±0.21）（均为P＜0.05）；POAG组小梁组织中SIRT1表达与PGC-1α表达呈正相关关系（r=0.759，P＜0.05）；POAG组小梁网组织中POD水平［（102.59±22.37）×10³ U·L^-1］高于对照组［（73.46±15.81）×10³U·L^-1］（P＜0.05），SOD水平［（347.62±50.73）U·L^-1］低于对照组［（412.57±61.25）U·L^-1］（P＜0.05）；POAG组小梁网组织中SIRT1、PGC-1α表达与POD水平均呈负相关关系（r=-0.636、-0.737，均为P＜0.05），与SOD水平均呈正相关关系（r=0.662、0.614，均为P＜0.05）。结论　POAG患者小梁网组织中SIRT1和PGC-1α表达水平降低，可能在线粒体功能失调和氧化应激对小梁网的损伤中发挥重要调控作用。     

过氧化物酶体增殖体激活受体-γ2基因Pro12Ala多态性与肥胖的关系

目的 探讨过氧化物酶体增殖体激活受体-γ2(PPAR-γ2)基因外显子2的Pro12Ala多态性与肥胖的关系.方法 运用多聚酶链式反应.限制性片段长度基因多态性(PCR-RFLP法)分析方法,对116例超重或肥胖患者和89例正常对照者PPAR-γ2基因Pro12Ala多态性位点进行基因分型.结果 超重或肥胖组Ala等位基因频率(11.64%)显著高于正常对照组(5.06%),在所检测人群中,PA/AA基因型者具有更高的体质量指数和血浆甘油三酯水平(P＜0.05).结论 PPARγ2的Pro12Ala变异与肥胖的发生有关,12Ala更易发生肥胖.