1.Effect and mechanism of Vaspin on insulin resistance of 3T3-L1 adipocytes induced by palmitic acid
Shiwei LIU ; Ruixue DUAN ; Jiaxin ZHANG ; Yaru WU ; Xin LI ; Shenghui GUO ; Meimei WANG ; Tao YUAN ; Zhufang SHEN ; Kui FU
Chinese Journal of Clinical Nutrition 2018;26(4):235-240
Objective To investigate the effects of vaspin on insulin resistants of 3T3-L1 adipocyte through the insulin receptor substrates (IRS) /phosphatidylinositol 3-kinase (PI3K) /protein kinase B (Akt) /glucose transporter (Glut) signaling pathway.Methods 3T3-L1 cells cultured by palmitic acid (PA) were used to establish insulin resistance models,which were divided into PA group,PA + 100 ng/ml vaspin group,PA+200 ng/ml vaspin group,PA+400 ng/ml vaspin group and PA+400 ng/ml vaspin+wortmannin (PI3K inhibitor) group.Glucose uptake and consumption were assessed by 2-deoxy H3-D-glucose incorporation and glucose oxidase-peroxidase respectively.IRS/PI3K/Akt/Glut signaling pathway was evaluated using reverse transcription polymerase chain reaction and Western blot analysis.Results Compared with PA group,glucose uptake and consumption increased gradually with the increasing of vaspin concentration in other groups (P < 0.05).mRNA levels of IRS-1,Akt and Glut 4 increased gradually as vaspin concentration increasing (P<0.05),and the ratios of p-IRS-1 to IRS-1,p-Akt to Akt and Glut 4 protein level also showed the same trends (P<0.05).However,glucose uptake and consumption in PA+400 ng/ml vaspin+wortmannin group were less than that of PA +400 ng/ml vaspin group (P<0.05).PA+400 ng/ml vaspin+wortmannin group showed lower mRNA and protein phosphorylation levels of IRS-1,Akt and Glut 4 (P<0.05),and that the ratios of p-IRS-1 to IRS-1,p-Akt to Akt and Glut 4 protein levels decreased (P<0.05).Conclusions Vaspin can improve the insulin sensitivity of 3T3-L1 adipocyte by activating IRS/PI3K/Akt/Glut signaling pathway.
2.Anti-diabetic effects and mechanisms of action of a Chinese herbal medicine preparation JQ-Rand in diabetic KKmice.
Quan LIU ; Shuainan LIU ; Lihui GAO ; Sujuan SUN ; Yi HUAN ; Caina LI ; Yue WANG ; Nan GUO ; Zhufang SHEN
Acta Pharmaceutica Sinica B 2017;7(4):461-469
Refined-JQ (JQ-R) is a mixture of refined extracts from(Ranunculaceae),(Leguminosae) and(Caprifoliaceae), the three major herbs of JinQi-JiangTang tablet, a traditional Chinese medicine (TCM) formula. The mechanisms by which JQ-R regulates glucose metabolism and improves insulin sensitivity were studied in type 2 diabetic KKmice and insulin-resistant L6 myotubes. To investigate the mechanisms by which JQ-R improves insulin sensitivity, a model of insulin-resistant cells induced with palmitic acid (PA) was established in L6 myotubes. Glucose uptake and expression of factors involved in insulin signaling, stress, and inflammatory pathways were detected by immunoblotting. JQ-R showed beneficial effects on glucose homeostasis and insulin resistance in a euglycemic clamp experiment and decreased fasting insulin levels in diabetic KKmice. JQ-R also improved the plasma lipid profiles. JQ-R directly increased the activity of superoxide dismutase (SOD) and decreased malondialdehyde (MDA) as well as inducible nitric oxide synthase (iNOS) levels in insulin-resistant L6 cells, and elevated the insulin-stimulated glucose uptake with upregulated phosphorylation of AKT. The phosphorylation levels of nuclear factor kappa B (NF-B p65), inhibitor of NF-B (IB), c-Jun N-terminal kinase (JNK1/2) and extracellular-signal-regulated kinases (ERK1/2) were also changed after JQ-R treatment compared with the control group. Together these findings suggest that JQ-R improved glucose and lipid metabolism in diabetic KKmice. JQ-R directly enhanced insulin-stimulated glucose uptake in insulin-resistant myotubes with improved insulin signalling and inflammatory response and oxidative stress. JQ-R could be a candidate to achieve improved glucose metabolism and insulin sensitivity in type 2 diabetes mellitus.
3.Flavanols from thevar.and their hypoglycemic and hypolipidemic activities.
Xin WANG ; Quan LIU ; Hongbo ZHU ; Hongqing WANG ; Jie KANG ; Zhufang SHEN ; Ruoyun CHEN
Acta Pharmaceutica Sinica B 2017;7(3):342-346
-Glucosidase and lipase inhibitors play important roles in the treatment of hyperglycaemia and dyslipidemia. To identify novel naturally occurring inhibitors, a bioactivity-guided phytochemical research was performed on the pu-erh tea. One new flavanol, named (-)-epicatechin-3---coumarate (), andknown analogs (-) were isolated from the aqueous extract of the pu-erh tea. Their structures were determined by spectroscopic and chemical methods. Furthermore, the water extract of pu-erh tea and its fractions exhibited inhibitory activities against-glucosidases and lipases; compoundshowed moderate inhibitory effect against sucrase with an ICvalue of 32.5 μmol/L and significant inhibitory effect against maltase with an ICvalue of 1.3 μmol/L. Compounds,,anddisplayed moderate activity against a lipase with ICvalues of 16.0, 13.6, 19.8, and 13.3 μmol/L, respectively.
4.Farnesoid X receptor regulates glucose and lipid metabolisms.
Qian JIANG ; Jun PENG ; Shuainan LIU ; Zhufang SHEN
Acta Pharmaceutica Sinica 2015;50(3):245-51
As a member of nuclear receptor superfamily, farnesoid X receptor (FXR) has been shown to regulate numerous metabolic pathways, which include playing an important role in bile acid metabolism, maintaining lipid and glucose homeostasis when FXR is activated. With the prevalence of the glucose and lipids disorder, FXR attracts increasing attention. It may be a potential target for the treatment of type 2 diabetes mellitus and lipid disorders.
5.Chemical constituents of the roots of Macleaya microcarpa and activation efficacy of benzophenanthridine alkaloids for the transcription of xbp1 gene.
Yang LIU ; Anjun DENG ; Lin MA ; Haijing ZHANG ; Zhihui ZHANG ; Lianqiu WU ; Zhufang SHEN ; Wenjie WANG ; Hailin QIN
Acta Pharmaceutica Sinica 2015;50(2):207-10
Ongoing study on the chemical constituents of the roots of Macleaya microcarpa led to the isolation of eight compounds of derivatives of triterpenes and organic acids in addition to some previously identified benzophenanthridines. The eight compounds were identified by spectroscopic methods as well as comparison with literature values as 1-oxo-2, 22 (30)-hopandien-29-oic acid (1), 3-oxo-12-oleanen-30-oic acid (2), 3α-hydroxy-12-oleanen-30-oic acid (3), 3β-hydroxy-12-oleanen-30-oic acid (4), ferulic acid (5), ferulic acid 4-O-β-D-glucoside (6), 3-O-feruloylquinic acid (7), and methyl 3-O-feruloylquinate (8). Of which, 1 is a new triterpenoid of hopanes and 2-8 are isolated from M microcarpa for the first time. In order to discover natural active compounds as potential agents of anti-ulcerative colitis (UC), an in vitro drug high-throughput screening model targeted x-box-binding protein 1 (xbp1) was employed to evaluate the activity of the major chemical constituents of M microcarpa. The result confirmed that two dihydrobenzophenanthridines, dihydrosanguinarine (9) and dihydrochelerythrine (10), showed a certain activity on activating the transcription of xbpl, a transcription factor (TF) associated with the occurrence, development, and potential treatment of UC, with their relative activating ratios being 1.76 and 1.77 times, respectively, as compared with control group.
6.Determination of serum acetaminophen based on the diazo reaction and its application in the evaluation of gastric emptying.
Caina LI ; Sujuan SUN ; Zhufang SHEN
Acta Pharmaceutica Sinica 2015;50(5):560-4
This study aims to establish a method to determine the serum acetaminophen concentration based on diazo reaction, and apply it in the gastric emptying evaluation. Theoretically, acetaminophen could take hydrolysis reaction in hydrochloric acid solution to produce p-aminophenol, which could then take diazo reaction resulting in a product with special absorption peak at 312 nm. Then the serum acetaminophen concentration and recovery rate were calculated according to the standard curve drawn with absorbance at 312 nm. ICR mice were given a dose of acetaminophen (500 mg x kg(-1)) by gavage and the serum acetaminophen was dynamically measured through the diazo reaction. Besides, ICR mice were subcutaneously injected with the long-acting GLP-1 analog GW002 before the gavage of acetaminophen, and serum acetaminophen concentration was measured as above to study how GW002 could influence the gastric emptying. The data showed acetaminophen ranging from 0 to 160 μg x mL(-1) could take diazo reaction with excellent linear relationship, and the regression equation was y = 0.0181 x +0.0104, R2 = 0.9997. The serum acetaminophen was also measured with good linear relationship (y = 0.0045 x + 0.0462, R = 0.9982) and the recovery rate was 97.4%-116.7%. The serum concentration of acetaminophen reached peak at about 0.5 h after gavage, and then gradually decreased. GW002 could significantly lower the serum acetaminophen concentration and make the area under the concentration-time curve (AUC) decrease by 28.4%. In conclusion, a method for the determination of serum acetaminophen based on the diazo reaction was established with good accuracy and could be used in the evaluation of gastric emptying.
7.Advances in diabetic animal models and its application in the traditional Chinese medicine research.
Long CHENG ; Zhufang SHEN ; Guibo SUN ; Xiaobo SUN
Acta Pharmaceutica Sinica 2015;50(8):951-8
The high and continuing soaring incidence of diabetes may become a huge obstacle to China's development. The antidiabetic drug development is one way to solve the problem. Animal model is a powerful tool for drug development. This paper compares and analyzes the three kinds of animal models for antidiabetic drug development in replicating principle, methods and characteristic, then summarized the application in the research of traditional Chinese medicine. At the same time, the analysis of the market, application and clinical advantages of hypoglycemic medicine from traditional Chinese medicine, is given in this paper, based on the literature analysis. From the point of the clinic advantage embodiment and new drug development, this paper will provide advisory and assistance support for the anti-diabetic fighting with traditional Chinese medicine.
8.Metformin ameliorates β-cell dysfunction by regulating inflammation production, ion and hormone homeostasis of pancreas in diabetic KKAy mice.
Shuainan LIU ; Quan LIU ; Sujuan SUN ; Shaocong HOU ; Yue WANG ; Zhufang SHEN
Acta Pharmaceutica Sinica 2014;49(11):1554-62
This study is to evaluate the effects of the metformin (Met) on β cell function of diabetic KKAy mice. Female diabetic KKAy mice selected by insulin tolerance test (ITT) were divided randomly into two groups. Con group was orally administered by gavage with water, Met group with metformin hydrochloride at a dose of 0.2 g x kg(-1) for about 12 weeks. ITT and glucose tolerance tests (OGTT) were determined. Beta cell function was assessed by hyperglycemic clamp. Pancreatic biochemical indicators were tested. The changes of gene and protein expression in the pancreas and islets were also analyzed by Real-Time-PCR and immunostaining. Met significantly improved glucose intolerance and insulin resistance in KKAy mice. Fasting plasma glucose and insulin levels were also decreased. In addition, Met markedly increased glucose infusion rate (GIR) and elevated the Ist phase and maximum insulin secretion during clamp. It showed that Met decreased TG content and iNOS activities and increased Ca(2+) -Mg(2+)-ATPase activity in pancreas. Islets periphery was improved, and down-regulation of glucagon and up-regulated insulin protein expressions were found after Met treatment. Pancreatic mRNA expressions of inflammation factors including TLR4, NF-κB, JNK, IL-6 and TNF-α were down-regulated, p-NF-κB p65 protein levels also down-regulated by Met. And mRNA expressions of ion homeostasis involved in insulin secretion including SERCA2 and Kir6.2 were up-regulated by Met. Met increased SIRT5 expression level in pancreas of KKAy mice under the hyperglycemic clamp. These results indicated that chronic administration of Met regulated pancreatic inflammation generation, ion and hormone homeostasis and improved β cell function of diabetic KKAy mice.
9.Establishment and application of screening methods for non-agonist PPARγ ligand.
Yi HUAN ; Jun PENG ; Yue WANG ; Chunming JIA ; Ke WANG ; Kehua WANG ; Zhiqiang FENG ; Zhufang SHEN
Acta Pharmaceutica Sinica 2014;49(12):1658-64
In-vitro assay methods were established to evaluate transactivation and binding activity of compounds on peroxisome proliferator-activated receptor y (PPARγ). Firstly, plasmids were constructed for transactivation assay of PPARγ response element (PPRE) triggered reporter gene expression, and for cell-based binding activity assay of the chimeric receptor, which was fused with PPARγ ligand binding domain (LBD) and yeast transcriptional activator Gal4. Secondly, by using PPARy competitive binding assay based on time resolved-fluorescence resonance energy transfer (TR-FRET), affinities of compounds and drugs to PPARγ were evaluated. In application of these above methods, the PPARγ activating potency and characteristics of different compounds were evaluated, and a novel benzeneselfonamide derivative, ZLJ01, was found to have comparable binding activity and affinity with the well-known PPARy agonist, but lack of PPRE mediated transactivation activity. In preliminary study on in-vitro hypoglycemic activity, ZLJ1 was found to promote insulin-stimulated glucose uptake by liver cells. Therefore, we believe that combining transactivation and binding activity as well as affinity evaluation, the system could be used to screen non-agonist PPARγ ligand as anovel PPARγ modulator
10.Establishment of a selective evaluation method for DPP4 inhibitors based on recombinant human DPP8 and DPP9 proteins.
Jinglong LIU ; Yi HUAN ; Caina LI ; Minzhi LIU ; Zhufang SHEN
Acta Pharmaceutica Sinica B 2014;4(2):135-140
Dipeptidyl peptidase 4 (DPP4) is recognised as an attractive anti-diabetic drug target, and several DPP4 inhibitors are already on the market. As members of the same gene family, dipeptidyl peptidase 8 (DPP8) and dipeptidyl peptidase 9 (DPP9) share high sequence and structural homology as well as functional activity with DPP4. However, the inhibition of their activities was reported to cause severe toxicities. Thus, the development of DPP4 inhibitors that do not have DPP8 and DPP9 inhibitory activity is critical for safe anti-diabetic therapy. To achieve this goal, we established a selective evaluation method for DPP4 inhibitors based on recombinant human DPP8 and DPP9 proteins expressed by Rosetta cells. In this method, we used purified recombinant 120 kDa DPP8 or DPP9 protein from the Rosetta expression system. The optimum concentrations of the recombinant DPP8 and DPP9 proteins were 30 ng/mL and 20 ng/mL, respectively, and the corresponding concentrations of their substrates were both 0.2 mmol/L. This method was highly reproducible and reliable for the evaluation of the DPP8 and DPP9 selectivity for DPP4 inhibitor candidates, which would provide valuable guidance in the development of safe DPP4 inhibitors.


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