Biomedical subjects

Xiao-Ping Wang

Publications and source records attributed to Xiao-Ping Wang.

At least 19 recordsLinked to original sources

PubMed2007

Enhanced cytotoxicity of RIPTK gene therapy of pancreatic cancer via PDX-1 co-delivery.

BACKGROUND: Using in vivo mouse models, we have demonstrated that the insulin promoter-driven suicidal gene therapy (RIPTK) could be used in the treatment of mouse insulinoma and human pancreatic cancer cells. However, limitations of this therapy include tumor cells lack of sufficient PDX-1 protein and low levels of transgene expression mediated by liposome delivery system. The purpose of this study was to determine 1) whether transient transfection of PDX-1 into selected pancreatic cancer cells would lead to increased RIPTK cytotoxicity, and 2) whether an adenoviral delivery system would increase the overall RIPTK gene expression in vitro. MATERIAL AND METHODS: RIPlacZ and RSVlacZ plasmid DNA as well as AdCMVlacZ and AdRIPlacZ were used in transfection assays in human pancreatic cancer cell lines PANC-1 and MIA PaCa2 (n = 8). An expression plasmid DNA containing the mouse PDX-1 cDNA was also used. LacZ reporter assays were performed. RIPTK genes constructed either in plasmid or in adenoviral vectors were used in cytotoxic assays. RT-PCR assays were used to determine PDX-1 expression levels. RESULTS: PDX-1 protein was detected in the human pancreatic ductal carcinoma cell line PANC-1, a little in MIA PaCa2 cells. Liposome mediated (L) RSVlacZ and RIPlacZ transfection in PANC-1 cells resulted in 10.1% and 9.3% transgene expression, respectively. Co-delivery of PDX-1 had no significant effect on RSVlacZ expression (9.3%, P = NS) but significantly increased RIPlacZ gene expression (14.9% P < 0.05). Adenoviral mediated (Ad) RIPlacZ transgene was highly expressed in PANC-1 cells (66.1%) and the reporter activity was further enhanced when PDX-1 was co-delivered (70.2%, P < 0.05). Liposomal transfection of MIA PaCa2 cells using RSVlacZ and RIPlacZ reporter genes resulted in 9.3% and 1.0% gene expression, respectively. Co-transfection of PDX-1 in these cells resulted in a significant activation of RIPlacZ gene expression (14.5%, P < 0.05) with no effects on RSVlacZ treated cells (9.8%). AdCMVlacZ and AdRIPlacZ significantly increased reporter activities in MIA PaCa2 cells (63.0% and 9.8%, respectively). Transfection of PDX-1 also significantly enhanced the AdRIPlacZ activities (46.0%, P < 0.05), with no significant effect in AdCMVlacZ treated cells (68.2%). The cytotoxic effect of liposome-RIPTK/ganciclovir (GCV) in PANC-1 cells was 18.6% and increased to 22.8% when PDX-1 was co-transfected into the cells (P = NS). MIA PaCa2 cells treated with RIPTK alone resulted in 4.9% cell death and increased to 18.2% when exogenous PDX-1 was co-delivered (P < 0.05). The AdRIPTK gene delivery with GCV treatment caused significant cytotoxic effect in PANC-1 (29.3%) and MIA PaCa2 (12.4%) compared with untreated cells. The cytotoxic effects were further increased to 43.4% and 29.4% in PANC-1 and MIA PaCa2 cells, respectively, when PDX-1 was co-transfected (P < 0.05 for both). CONCLUSIONS: These data demonstrated that adenoviral mediated gene delivery resulted in a significant increase of transgene expression compared with liposomal delivery systems. RIPTK mediated cytotoxicity was also significantly enhanced via co-delivery of exogenous PDX-1 in these cells. Thus, these results also indicated that PDX-1 plays critical roles in insulin promoter activation and demonstrated that PDX-1 production is essential for insulin promoter-directed gene therapy.

Adenoviridae↗

PubMed2006

Gradient distribution of persistent organic contaminants along northern slope of central-Himalayas, China.

High mountains may serve as condenser for persistent organic pollutants (POPs) and the vegetation in remote areas has been used as a means to characterized atmospheric concentrations of air pollutants. In this study, organochlorine pesticides (OCPs) and polycyclic aromatic hydrocarbons (PAHs) in Himalayan spruce needle samples from Zhangmu-Nyalam region (central-Himalayas) were analyzed and the altitudinal gradient of these pollutants was investigated. Total HCHs and DDTs concentration in needles were in the range of 1.3-2.9 ng g(-1) dry weight and 1.7-11 ng g(-1) dry weight, which were lower than concentrations reported in spruce needles from Alps, however higher than concentrations in conifer needles from mountain areas of Alberta. Total Himalayan spruce needle PAHs was below 600 ng g(-1) and fluorene, phenanthrene and acenaphthene were abundant individual compounds measured. The ratios of alpha-HCH/gamma-HCH in pine needles were similar with the usual values for technical HCH, implying technical HCHs might be used in this region. The high ratios of o-p'-DDT/p-p'-DDT and no p-p'-DDE measured in this study led to the suspicion that a new source of o-p'-DDT and/or p-p'-DDT existed in this region. In addition, higher ratios of low molecular weight-/high molecular weight-PAHs in this region indicated that petroleum combustion, vehicle emission and low-temperature combustion might be the major contributions of PAH source. To examine the POPs distillation, the analyte concentrations were correlated with altitude. The more volatile OCPs, alpha-HCH, gamma-HCH, aldrin and alpha-endosulfan positively correlated with altitude, however, less volatile OCPs (DDT and DDD) inversely related with elevation. Almost all PAHs detected in this area showed positive correlations with altitude. It is worthy to note that heavy PAHs (Benzo[k] fluoranthene and Benzo[a]anthracene) displayed positive correlation, which implied the sources of PAHs were near the sampling sites. The distillation of POPs was strongly affected by the proximity between sampling sites and contaminant sources. If the contaminant sources are close to the mountains, it may be the dominant factor that controls the concentration gradient.

Air Pollutants↗

PubMed2006

Cytotoxic gene therapy for human breast cancer in vitro.

BACKGROUND: Transcription factor PDX-1 is expressed by human pancreatic and breast cancers. Although cytotoxicity of PDX-1-directed RIP-TK/GCV gene therapy to pancreatic cancer cells has been demonstrated, the efficacy of this treatment in breast cancer cells is unknown. The purpose of this study was to determine the expression of PDX-1 and its effect on RIP activation in two human breast cancer cell lines, AU565 and T47D. We also investigated the efficacy of RIP-TK/GCV gene therapy and examined whether exogenous PDX-1 to would enhance its cytotoxic effect. MATERIALS AND METHODS: RT-PCR was used to determine PDX-1 expression. Gene constructs RSVLacZ and RIPLacZ were used for transient transfection and LacZ expression was determined using reporter assays. T47D cells were also transfected with adenoviral vectors. Cells were transfected with RIP-TK and the suboptimal level of GCV was determined for each cell line. Following GCV treatment, cytotoxicity was measured using MTS assays. The effect of exogenous PDX-1 on LacZ expression and RIP-TK cytotoxicity was determined. RESULTS: PDX-1 mRNA was expressed in human breast cancer cells and activated the RIP. Exogenous PDX-1 enhanced LacZ expression in AU565 cells but not in T47D cells. Adenoviral transfection was more efficient in T47D cells than non-viral transfection. RIP-TK treatment was cytotoxic to AU565 and T47D cells and this effect was enhanced by exogenous PDX-1 with both transfection methods. CONCLUSIONS: RIP-TK/GCV therapy is cytotoxic to human breast cancer cells and exogenous PDX-1 enhances cytotoxicity. In vivo studies are necessary to determine the tumor specificity and efficacy of this treatment.

Adenoviridae↗

PubMed2006

The genomic analysis of the impact of steroid receptor coactivators ablation on hepatic metabolism.

Members of the steroid receptor coactivator (SRC) family, which include SRC-1 (NcoA-1/p160), SRC-2(TIF2/GRIP1/NcoA-2) and SRC-3(pCIP/RAC3/ACTR/pCIP/ AIB1/TRAM1), are critical mediators of steroid receptor action. Gene ablation studies previously identified SRC-1 and SRC-2 as being involved in the control of energy homeostasis. A more precise identification of the molecular pathways regulated by these coactivators is crucial for understanding the role of steroid receptor coactivators in the control of energy homeostasis and obesity. A genomic approach using microarray analysis was employed to identify the subsets of genes that are altered in the livers of SRC-1-/-, SRC-2-/-, and SRC-3-/- mice. Microarray analysis demonstrates that gene expression changes are specific and nonoverlapping for each SRC member in the liver. The overall pattern of altered gene expressions in the SRC-1-/- mice was up-regulation, whereas SRC-2-/- mice showed an overall down-regulation. Several key regulatory enzymes of energy metabolism were significantly altered in the liver of SRC-2-/- mice, which are consistent with the prior observation that SRC-2-/- mice have increased energy expenditure. This study demonstrates that the molecular targets of SRC-2 regulation in the murine liver stimulate fatty acid degradation and glycolytic pathway, whereas fatty acid, cholesterol, and steroid biosynthetic pathways are down-regulated.

Animals↗

PubMed2006

Study on homoeologous chromosome pairing and translocation induced by 5A/5R X 6A/6R wheat-rye substitution lines.

This article aims to study the homoeologous chromosome pairing and translocation induced by 5A/5R x 6A/6R wheat-rye substitution lines. To clarify the mechanism of homoeologous chromosome pairing and create wheat-rye translocation lines, two wheat-rye substitution lines, 5A/5R and 6A/6R were crossed. The chromosome behavior of pollen mother cells (PMCs) in meiosis was investigated in hybrid F1. Homoeologous chromosome pairing between wheat and rye occurred in 22.91% of PMC. Wheat-rye translocation lines were identified via C-banding and in situ hybridization (GISH) in hybrid F2 and later generations. In F2 generation, translocations happened in 9 of 45 plants, reached to 20%. These translocation lines were generated from homoeologous chromosome pairing, or mis-division and reconstruction of univalent chromosomes.

Chromosome Banding↗

PubMed2006

Somatostatin and its receptors in the development of the endocrine pancreas.

The development of the endocrine pancreas is regulated by numerous transcription and growth factors. Somatostatin (SST) is present in many tissues and acts as a neurotransmitter and autocrine/paracrine/endocrine regulator in response to ions, nutrients, peptides, and hormones as well as neurotransmitters. In the pancreas, there is evidence that SST acts an inhibitory paracrine regulator of hormone secretion. Somatostatin receptors (SSTRs) are a family of 5 transmembrane G protein-coupled receptors, which are widely expressed in mammals including humans. SSTRs regulate multiple downstream signal transduction pathways that mediate inhibitory effects. These receptors also exhibit age- and tissue-specific expression patterns. Interactions of SST and SSTRs are not only important during normal pancreas development, but have also been implicated in many pancreatic diseases such as diabetes mellitus and pancreatic cancer. In this review article, we use evidence from recently published animal studies to present the critical roles of SST and SSTRs proteins in the development of the endocrine pancreas.

Animals↗

PubMed2006

[Plasmid elimination effect of usnic acid on antibiotic-resistant Staphylococcus aureus].

OBJECTIVE: To observe the influence of Usnic acid on the antibiotic-resistant plasmid in Staphylococcus aureus (Sa). METHODS: The antibiotic-resistant plasmid was abstracted from the clinical divided strain of Sa and plasmid elimination test was performed in vitro. RESULTS: Plasmid elimination test showed that Usnic acid could eliminate the resistant plasmid in Sa effectively. At 24th and 48th hour after the treatment of Usnic acid, the elimination rate of resistant plasmid was 5.2% and 16.4% respectively. CONCLUSION: Usnic acid can eliminate the antibiotic-resistant plasmid in Sa. It is possible to use Usnic acid to treat the infection of antibiotic-resistant Sa in clinic.

Anti-Bacterial Agents↗

PubMed2006

[Study on the characteristics and compositions of fine particles left in the solution after decomposition of plant samples].

After decomposition of plant standard reference materials bush twigs and leaves (GBW07602, GBW07603), poplar leaves (GBW07604) and tea (GBW07605) with either dry ashing method or wet digestion method, all kinds of fine particles left in the solution were collected and examined carefully by a scanning electron microscope (SEM), and their chemical composition were investigated by a SEM-affiliated energy-dispersive X-ray spectrometer at the same time. Moreover, the concentrations of some metal elements distributed among four different tea SRM-originated particle fractions extracted following the BCR sequential extraction procedure were determined by AAS and ICP-AES. It was found that decomposition methods have a great influence on the structure of fine particles. When dry ashing method is used, grey-colored, fluffy and porous partices can be produced, whereas fewer white-colored, compact particles can be produced when another method is used. As for chemical composition, all kinds of fine particles are almost the same, with silicon and aluminium as their main constituents, and calcium, iron, potassium, titanium and so on as their minor ones. The elementaI distribution percentages in four different particle fractions in two kinds of plant-originated particles differ from element to element, which can result in severe negative errors when plant samples are decomposed and determined for elemental concentrations.

Camellia sinensis↗

PubMed2005

Heat shock protein 70 chaperoned alpha-fetoprotein in human hepatocellular carcinoma cell line BEL-7402.

AIM: To investigate the interaction between heat shock protein 70 (HSP70) and ?-fetoprotein (AFP) in human hepatocellular carcinoma (HCC) cell line BEL-7402. METHODS: The expression and localization of HSP70 and AFP in human HCC cell line BEL-7402 were determined by immunocytochemistry and indirect immunofluorescence cytochemical staining. The interaction between HSP70 and AFP in HCC cells was analyzed by immunoprecipitation and Western blot. RESULTS: Immunocytochemical staining detection showed that HCC cell BEL-7402 expressed a high level of HSP70 and AFP synchronously. Both were stained in cell plasma. AFP existed in the immunoprecipitate of anti-HSP70 mAb, while there was HSP70 in the immunoprecipitate of anti-AFP mAb. CONCLUSION: HSP70 chaperones AFP in human HCC cell BEL-7402. The interaction between HSP70 and AFP in human HCC cell can be a new route to study the pathogenesis and immunotherapy of HCC.

Carcinoma, Hepatocellular↗

PubMed2005

Hydrodynamic slip boundary condition at chemically patterned surfaces: a continuum deduction from molecular dynamics.

We investigate the slip boundary condition for flows past a chemically patterned surface. Molecular dynamics simulations show that fluid forces and stresses vary laterally along the patterned surface. A subtraction scheme is developed to verify the validity of the Navier slip boundary condition, locally, for the patterned surface. A continuum hydrodynamic model is formulated using the Navier-Stokes equation and the Navier boundary condition, with a slip length varying along the patterned surface. Steady-state velocity fields from continuum calculations are in quantitative agreement with those from molecular simulations.

Journal Article↗

PubMed2005

Co-expression of heat shock protein 70 and glucose-regulated protein 94 in human gastric carcinoma cell line BGC-823.

AIM: To investigate the co-expression and significance of heat shock protein 70 (HSP70) and glucose-regulated protein 94 (grp94) in human gastric carcinoma cell line BGC-823. METHODS: The expression and localization of HSP70 and grp94 in human gastric carcinoma cell line BGC-823 were determined by immunocytochemistry and indirect immunofluorescence cytochemical staining. Flow cytometry was used to analyze the correlation between expression of HSP70, grp94 and cell cycle in BGC-823 cell line. RESULTS: Gastric cancer cell line BGC-823 expressed high level of HSP70 and grp94. The positive rate of HSP70 and grp94 was 84.9+/-4.94% and 79.6+/-5.16%, respectively. Both of them were stained in cell plasma. There was a significant difference compared with control group (1.9+/-0.94%, P<0.01). During the cell cycle, HSP70 and grp94 were continuously expressed in BGC-823. CONCLUSION: HSP70 and grp94 are highly expressed in human gastric carcinoma BGC-823 cells through the whole cell cycle. There is no relationship between expression of HSP70, grp94 and cell cycle.

Cell Cycle↗

PubMed2005

Protective effect of Radix Acanthopanacis Senticosi capsule on colon of rat depression model.

AIM: To investigate the abnormity of rat colon caused by depression and the ameliorative effects of Radix Acanthopanacis Senticosi (RAS) capsule on colon and their mechanisms in rat depression model. METHODS: Chronic stress-induced model of depression of Wistar rats was produced. The experimental animals were randomly divided into model control, 5-aminosalicylic acid (5-ASA) therapy group and three RAS capsule therapy groups. These five groups were intracolonically treated daily (8:00 a.m.) for 2 wk with normal saline, 5-ASA (100 mg/kg) and RAS capsule at the doses of 300, 600 and 900 mg/kg, respectively. A normal control group of rats was also included in the study. Colonic activities of nitric oxide (NO) and superoxide dismutase (SOD), levels of malondialdehyde (MDA) and inducible nitric oxide synthase (iNOS) were determined by ultraviolet spectrophotometry. The expression of cyclooxygenase-2 (COX-2) in colonic tissue was detected by immunohistochemistry. RESULTS: Enhanced colon inflammatory response and oxidative stress were observed in the chronic stress-induced rat depression model, which manifested as the significant increase of MDA, iNOS and NO levels, as well as the expressions of COX-2 in the colon tissue, but the colonic SOD activity was significantly decreased compared with the normal control (MDA: 10.34+/-2.77 vs 2.55+/-0.70; iNOS: 1.11+/-0.44 vs 0.25+/-0.16; COX-2: 53.26+/-8.16 vs 4.87+/-1.65; NO: 11.28+/-5.66 vs 4.76+/-1.55; SOD: 53.39+/-11.15 vs 84.45+/-22.31; P < 0.01). However, these parameters were significantly ameliorated in rats treated locally with RAS capsule at the doses of 300, 600 and 900 mg/kg (iNOS: 0.65+/-0.31, 0.58+/-0.22 and 0.64+/-0.33; NO: 5.99+/-2.73, 6.87+/-1.96 and 6.50+/-1.58; MDA: 2.92+/-0.75, 3.19+/-1.08 and 3.26+/-1.24; SOD: 70.81+/-12.36, 73.30+/-15.30 and 69.09+/-11.03, respectively). The expressions of COX-2 in the colon were significantly ameliorated (28.83+/-9.48 and 27.04+/-9.56, respectively) when RAS capsule was administered at the doses of 600 and 900 mg/kg. CONCLUSION: Administration of RAS capsule intracolonically may have significant therapeutic effects on the colon of rat depression model, which are probably due to its antioxidative action and inhibition of arachidonic acid metabolism.

Animals↗

PubMed2005

Correlation between clinicopathology and expression of heat shock protein 70 and glucose-regulated protein 94 in human colonic adenocarcinoma.

AIM: To investigate the correlation between clinicopathology and expression of heat shock protein 70 (HSP70) and glucose-regulated protein 94 (grp94) in human colonic carcinoma. METHODS: The expression of HSP70 and grp94 was studied in 80 human colonic cancers with or without metastasis as well as in their adjacent mucous membrane by way of immunohistochemistry and pathology photograph analysis. RESULTS: The expression of HSP70 and grp94 was significantly higher in cancer than that in adjacent mucous membrane (92.5%, 85.0% vs 56.3%, 42.5%, P<0.01). HSP70 and grp94 expressed higher in moderately- and poorly-differentiated colonic cancers than that in their adjacent tissues (93.7%, 87.5%; 100%, 90% vs 56.3%, 42.5%; P<0.01). Dukes C and D stages of colonic cancers showed higher positive rates than Dukes A and B stage groups (97.1%, 91.2%; 100%, 90.9%; vs 80%, 70%; 78.6%, 71.4%; P<0.05). There were definite differences in HSP70 and grp94 expression between metastasis groups and non-metastasis groups (100% vs 75%, 100% vs 50%, P<0.05). CONCLUSION: The HSP70 and grp94 expression rates in colonic cancer groups are significantly higher than that in their adjacent mucous membrane. The HSP70 and grp94 expression in poorly-differentiated colonic cancers with metastasis is significantly higher than well-differentiated cancers without metastasis. The overexpression of HSP70 and grp94 can be used as diagnostic or prognostic markers for colonic cancer.

Adult↗

PubMed2005

Expression and significance of heat shock protein 70 and glucose-regulated protein 94 in human esophageal carcinoma.

AIM: To investigate the expression and significance of heat shock protein 70 (HSP70) and glucose-regulated protein 94 (grp94) in human esophageal carcinoma and adjacent normal tissues. METHODS: The expression of HSP70 and grp94 in 78 human esophageal cancer and adjacent normal tissues was studied by immunohistochemistry and pathology photograph analysis. RESULTS: Both esophageal cancer and adjacent normal tissues could express HSP70 and grp94. Of the 78 cases of esophageal carcinoma, 95.0%(72/78) showed positive HSP70, mainly stained in nuclei, while grp94 was mainly stained in cell plasma, and the positive rate was 71.8%(56/78). There was a significant difference in the expression of HSP70 and grp94 between esophageal cancer and adjacent normal tissues (P<0.01). Compared with adjacent normal tissues, there was a significant difference between differential types and HSP70 expression (P<0.01). CONCLUSION: HSP70 and grp94 express differently in cell plasma and nuclei. The expression intensity of HSP70 is related to the differentiation of esophageal carcinoma.

Aged↗

PubMed2005

Molecular targeting of pancreatic disorders.

During the last decade significant advances in gene therapy have made it possible to treat various pancreatic disorders in both animal models and in humans. For example, insulin gene delivery to non-beta-cell tissues has been shown to reverse hyperglycemia in diabetic mice, and islet transplantation, based on in vitro differentiation of beta cells and concomitant gene targeting to prevent host autoimmune responses, has become more feasible. Additionally, introduction of the glucokinase regulatory protein and protein kinase C-zeta have been shown to improve glucose tolerance in non-insulin-dependent diabetes mellitus animal models. Pancreatic cancer studies utilize several DNA-based strategies for tumor treatment including introduction of tumor suppressor genes, suppression of oncogenes, suicide gene/prodrug therapy, and restricted replication-competent virus therapy. Tumor-specific targeting is an important part of suicide gene therapy, and tumor-specific promoters are used for cell-specific targeting. Tumor-specific suicide gene therapy directed by the rat insulin promoter has been used to eliminate insulinoma tumors in a mouse model. This review compiles a compendium of information related to the treatment of pancreatic disorders using gene therapy.

Animals↗

PubMed2005

Tissue MicroArray analyses of pancreatic duodenal homeobox-1 in human cancers.

In previous studies, we demonstrated that rat insulin promoter (RIP)-driven gene therapy successfully targeted human pancreatic tumor PANC-1 cells and mouse insulinoma NIT-1 cells, which are both pancreatic duodenal homeobox-1 (PDX-1)-positive. The purpose of this study was to perform a human tissue array analysis to determine potential targets for RIP-driven gene therapy. A custom-designed tissue MicroArray analysis of various human cancer specimens was performed using a PDX-1 polyclonal antibody generated in our laboratory. The custom-designed Tissue MicroArray of human tumor specimens consists of human cancer specimens from different origins, such as the pancreas, breast, colon, prostate, kidney, liver, lung, and ovary. A panel of normal human specimens from 20 organs or tissues was used as a control. All tissues were fixed in formalin and embedded in paraffin. The immunohistochemistry studies of the cytoplasm and the nuclear expression levels were compared using the Loda method and blind reviews. Data are presented as the mean +/- SEM (p < 0.05 was considered significant by the unpaired student t-test). PDX-1 expression intensity was elevated in both benign and malignant tissues from the same patient with pancreas, breast, colon, prostate, and kidney cancers, whereas normal human tissues from control subjects without cancer did not express PDX-1. These results suggest that PDX-1 is an early marker for these cancers and could be potentially used as a diagnostic parameter and perhaps could be targeted by PDX-1-activated gene therapies, such as RIP-TK.

Adenocarcinoma↗

PubMed2005

Pancreatic polypeptide administration reduces insulin requirements of artificial pancreas in pancreatectomized dogs.

An artificial endocrine pancreas is a mechanical device that frequently measures blood glucose and adjusts the rate of insulin infusion to maintain normoglycemia. In this study, we evaluated the effect of pancreatic polypeptide (PP) on insulin requirements after total pancreatectomy. However, other endocrine hormones are needed not only to facilitate the effect of insulin, but also to regulate insulin functions in vivo. In this study, the effect of PP infusion on insulin requirements after total pancreatectomy in dogs is examined. After total pancreatectomy, five dogs were supported by artificial endocrine pancreas model STG-22 for 72 h. In a second group of five dogs, both insulin and PP were infused. Mean blood glucose levels and insulin requirements were compared between the two groups. There was no difference in mean plasma glucose levels between the two groups. In all 10 dogs, the mean blood glucose level for 72 h was 110 +/- 4 mg/dL and was tightly controlled between 65 and 190 mg/dL. However, the insulin requirement for the first and second postoperative days in the group treated with PP was significantly less than that of the control group (90.0 +/- 20.8 mU/kg vs. 445.0 +/- 151.9 mU/kg; P < 0.05, and 562.7 +/- 126.5 mU/kg vs. 1007.7 +/- 144.9 mU/kg; P < 0.05, respectively). We conclude that infusion of PP reduces the insulin requirement for the initial 48 h in pancreatectomized dogs treated with an artificial endocrine pancreas.

Animals↗

PubMed2005

Swietenia mahagony extract shows agonistic activity to PPAR(gamma) and gives ameliorative effects on diabetic db/db mice.

AIM: To search the peroxisome proliferator-activated receptor g (PPAR(gamma)) agonists from Swietenia mahagony extract (SmE) and observe the possible ameliorative effects of SmE on diabetic db/db mice. METHODS: The PPAR(gamma) agonistic activity of SmE was screened by yeast-two hybrid system. The blood glucose levels of diabetic db/db mice were measured using a blood glucose level monitor and the data were statistically analyzed by NDST8.8W software. RESULTS: By using the clinical drug rosiglitazone as a positive control, it was found that the PPARg agonistic activity of SmE at a concentration of 50 microg/L was approximately half that of 35.7 microg/L (0.1 micromol/L) of rosiglitazone. At the dose of 1000 mg/kg, SmE remarkably decreased the blood glucose concentration of db/db mice from (15.26+/-2.98) to (7.58+/-2.20) mmol/L, and reduced the blood glucose levels by 55.49% compared with the control group (P<0.01). CONCLUSION: SmE shows agonistic activity to PPARg and can ameliorate the blood glucose levels of diabetic db/db mice. SmE may be thus used as a potential agent for diabetes therapy.

Animals↗