Study on effect of gypenosides on insulin sensitivity of rats with diabetes mellitus via regulating NF-κB signaling pathway / 中国中药杂志

This study focused on the ameliorative effects of gypenosides(GPS) on insulin sensitivity and inflammatory factors in rats with type 2 diabetes mellitus(T2 DM) and explored their possible molecular mechanisms. After the successful establishment of T2 DM model, diabetic rats were randomly divided into four groups, including model group, GPS groups(200, 100 mg·kg~(-1)) and metformin group(100 mg·kg~(-1)), with healthy rats serving as the control. After 6-week intragastric administration, fasting blood glucose(FBG) and oral glucose tolerance were examined. The levels of insulin, C-peptide, tumor necrosis factor-α(TNF-α), interleukin-1β(IL-1β), interleukin-6(IL-6) and C-reactive protein(CRP) in serum were examined. Then the homeostasis model assessment of insulin resistance(HOMA-IR) and insulin sensitivity index(ISI) were calculated. The protein expression levels of phosphorylated insulin receptor substrate-1(p-IRS-1) and phosphorylated protein kinase B(p-Akt) in skeletal muscle were measured by Western blot, as well as those of phosphorylated inhibitor of nuclear factor-κB(NF-κB) kinase β(p-IKKβ), phosphorylated alpha inhibitor of NF-κB(p-IκBα) and phosphorylated p65 subunit of NF-κB(p-p65) in adipose tissue. The relative expression levels of glucose transporter 4(GLUT4) mRNA in skeletal muscle and NF-κB mRNA in adipose tissue were measured by qRT-PCR, and the morphological changes of pancreatic tissue were observed. Compared with the model group, the GPS groups witnessed significant decrease in FBG, marked amelioration of impaired oral glucose tolerance and significant increase in ISI. Further, the high-dose GPS group saw significantly reduced HOMA-IR, TNF-α, IL-1β and CRP, significantly increased expression levels of p-IRS-1(Tyr), p-Akt and GLUT4, and markedly inhibited p-IRS-1(Ser), p-IKKβ, p-IκBα, p-p65 and NF-κB. The concentration of CRP and the expression levels of p-IRS-1(Ser), p-IKKβ, p-IκBα and NF-κB were remarkably reduced in the low-dose GPS group. However, GPS was found less effective in the regulation of serum insulin, C-peptide and IL-6 levels and the alleviation of pancreatic islet injury. The results indicated that GPS can reduce FBG and improve insulin sensitivity in diabetic rats possibly by regulating the NF-κB signaling pathway, inhibiting inflammation, and thereby regulating the expression of key proteins in the insulin signaling pathway.

Allele-selective lowering of mutant HTT protein by HTT-LC3 linker compounds.

Accumulation of mutant proteins is a major cause of many diseases (collectively called proteopathies), and lowering the level of these proteins can be useful for treatment of these diseases. We hypothesized that compounds that interact with both the autophagosome protein microtubule-associated protein 1A/1B light chain 3 (LC3)1 and the disease-causing protein may target the latter for autophagic clearance. Mutant huntingtin protein (mHTT) contains an expanded polyglutamine (polyQ) tract and causes Huntington's disease, an incurable neurodegenerative disorder2. Here, using small-molecule-microarray-based screening, we identified four compounds that interact with both LC3 and mHTT, but not with the wild-type HTT protein. Some of these compounds targeted mHTT to autophagosomes, reduced mHTT levels in an allele-selective manner, and rescued disease-relevant phenotypes in cells and in vivo in fly and mouse models of Huntington's disease. We further show that these compounds interact with the expanded polyQ stretch and could lower the level of mutant ataxin-3 (ATXN3), another disease-causing protein with an expanded polyQ tract3. This study presents candidate compounds for lowering mHTT and potentially other disease-causing proteins with polyQ expansions, demonstrating the concept of lowering levels of disease-causing proteins using autophagosome-tethering compounds.

Effects of various doses of Liushen Pill on microvessel density in models of esophageal cancer xenografts / 中国组织工程研究

BACKGROUND:Liushen Pil is a traditional Chinese herbal formula, has the effects of heat-clearing and detoxicating, eliminating stagnation, detumescence and al eviating pain. Modern pharmacology verifies that Liushen Pil has anti-inflammatory, analgesic, cardiac, anti-viral, anti-tumor effects, and has been extensively used in the treatment of various infectious diseases and malignant cancer. OBJECTIVE:To investigate the inhibitory effects of Liushen Pil on esophageal cancer xenografts, and effects on microvessel density and vascular endothelial growth factor expression. METHODS:After reproducing nude mouse models of human esophageal cancer, 48 nude mice were randomly divided into high-dose Liushen Pil group, moderate-dose Liushen Pil group, low-dose Liushen Pil group, cisplatin group, model group and blank group. According to medication regimen, drugs were given. The growth of transplanted tumor of nude mice was dynamical y observed in each group. The nude mice were sacrificed after 20 days of treatment. Neoplasm weight was taken and the tumor-suppressing rate was calculated. Immunohistochemistry was used to detect microvessel density and the expression of vascular endothelial growth factor. RESULTS AND CONCLUSION:The weight of transplanted tumor was significantly lower in the high-dose Liushen Pil group, moderate-dose Liushen Pil group, low-dose Liushen Pil group, and cisplatin group than in the model group (P<0.05). Microvessel density and the expression of vascular endothelial growth factor were obviously lower in the each Liushen Pil group than in the model group, but not as apparent as that in the cisplatin group. Results suggested that Liushen Pil can inhibit the growth of the esophageal cancer xenografts. Liushen Pil can down-regulate the expression of vascular endothelial growth factor and reduce microvessel density, which is one of the tumor-inhibiting mechanism of Liushen Pil .

Screening and analysis of Chinese herbs with liver channel tropism acting on human liver cancer cell differential expressed protein tyrosine kinase / 中国中西医结合急救杂志

Objective To screen the Chinese drugs with liver channel tropism acting on the characteristic differential expressed protein of human liver cancer cell protein tyrosine kinase (PTKs) system by protein chip technology, and to analyze the difference in different Chinese drugs with liver channel tropism in relation to PTKs regulation. Methods Forty BALB/C nude mice were chosen; a piece of subcutaneous tumor mass was implanted into the left lobe of liver parenchyma to reduplicate the orthotopically implanted tumor models. After modeling for 10 days, the tumorigenicity was confirmed, and all the nude mice models were divided into four groups; different Chinese medicine extracts were injected intra-peritoneally into corresponding treatment groups respectively, and the methods of treatment in the 4 groups were as follows: In liver channel tropism drug pair of Huayu Xiaozhen group, rhizoma sparganii and curcuma zedoary with dosage containing crude drug 4.5 g·kg-1·d-1 was given, in liver channel tropism drug pair of Gongdu Sanjie group, the extract of centipede and scorpion with dosage containing crude drug 0.3 g·kg-1·d-1 was intra-peritoneally injected, in spleen channel tropism drug pair control group, astragalus and rhizoma atractylodis macrocephalae with dosage containing crude drug 6.3 g·kg-1·d-1 was given, and in the model group, equal amount of 0.9% normal saline was intra-peritoneally injected. After the drug treatment for 3 weeks, the mice were sacrificed and the liver cancer tissue was obtained; after its total protein was extracted, protein chip technology was applied to screen the Chinese drug pair with liver channel tropism acting on differential expressed PTKs of human liver cancer cells, and the results were analyzed by cluster analysis.Results After the end of the experiment, there were 6 animals in Huayu Xiaozhen drug pair group, 5 in Gongdu Sanjie drug pair group, 5 in control drug pair group and 7 in model group. The protein chip screening results showed that the adjusting fold greater > 1.50 or < 0.67 was defined as the difference with statistical significance. Compared with model group, there were 42 up-regulated expressions of PTKs in Huayu Xiaozhen drug pair group, including 29 receptor tyrosine kinases (RTKs) and 13 non-receptor protein tyrosine kinases (nrPTKs) of which the erythropoietin having adjusting fold over 5.0 produced liver cell receptor B1 (EphB1), epidermal growth factor receptor (ErbB2, ErbB4) etc. 3 RTKs; there were 7 RTKs with adjusting fold 3.0 - 5.0 including EphA1, EphA3, EphA7, fibroblast growth factor receptor 2-α (FGFR2-α), hepatocyte growth factor receptor (HGFR), macrophage colony-stimulating factor receptor (M-CSFR) and vascular endothelial growth factor receptor 2 (VEGFR2), and 2 nrPTKs with adjusting fold 3.0 - 5.0 were non-receptor tyrosine kinase BMX (BMX) and Janus kinase 1 (JAK1). In the Gongdu sanjie drug pair group, there were 23 up-regulated expressions: 15 RTKs and 8 nrPTKs, and 6 down-regulated expressions; the RTKs with adjusting fold 3.0 - 5.0 were ErbB4, M-CSFR and 1 nrPTKs that was megakaryocyte-associated tyrosine kinase (MATK). In the control drug pair group, there were 28 up-regulated and 8 down-regulated expressions. The results of cluster analysis showed that in Huayu Xiaozhen drug pair group, there were 17 differential expressed PTKs in accord with the screen criteria of which 9 were RTKs [receptor tyrosine kinase-like orphan receptor 2 (ROR2), stem cell factor receptor (SCFR), anaplasia lymphoma kinase (ALK), platelet-derived growth factor receptor β (PDGFR-β), insulin-like growth factor-IR receptor (IGF-IR), ErbB2, ErbB3, EphB1 and EphA2], 1 nrPTKs [fps/fes related tyrosine kinase (FER)] and 7 PTKs 3 RTKs (M-CSFR, FGFR2-α, EphA3) and 4 nrPTKs [acetate kinase 1 (ACK1), bruton tyrosine kinase (Btk), non-receptor tyrosine kinase ABL1 (ABL1) and BMX]. In Gongdu Sanjie drug pair group, there were 7 differential expressed PTKs in accord with the screen criteria 5 RTKs (M-CSFR, FGFR1, ROR2, EphB1, ErbB2) and 2 nrPTKs [src-related kinase lacking C-terminal regulation and N-terminal myristylation sites (SRMS), FER]. Conclusions The drug pair of centipede and scorpion with Gongdu Sanjie action possesses a more effective anti-HCC role than the drug pair of rhizoma sparganii and curcuma zedoary with Huayu Xiaozhen action, the mechanism is possibly via the regulation of PTKs signal pathway. The liver channel tropism drug pair of rhizoma sparganii and curcuma with action of promoting blood circulation and removing blood stasis possibly has an independent anti-HCC effective pathway outside the PTKs signal system.