[Study on effect of gypenosides on insulin sensitivity of rats with diabetes mellitus via regulating NF-κB signaling pathway].

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-1ß(IL-1ß), 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 ß(p-IKKß), 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-1ß and CRP, significantly increased expression levels of p-IRS-1(Tyr), p-Akt and GLUT4, and markedly inhibited p-IRS-1(Ser), p-IKKß, p-IκBα, p-p65 and NF-κB. The concentration of CRP and the expression levels of p-IRS-1(Ser), p-IKKß, 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.

Reverse tracing anti-thrombotic active ingredients from dried Rehmannia Radix based on multidimensional spectrum-effect relationship analysis of steaming and drying for nine cycles.

ETHNOPHARMACOLOGICAL RELEVANCE: In traditional Chinese medicine (TCM) and modern pharmacodynamics, dried Rehmannia Radix (DRR) possesses prominent anti-thrombotic activity that decreases after processing by nine steaming and drying cycles to develop processed Rehmannia Radix (PRR). Due to the complexity of the DRR components, the chemical mechanism leading to efficacy changes of DRR caused by processing is still unclear. AIM OF STUDY: This study aimed to trace the anti-thrombotic active compounds of DRR and different degrees of processed RR (PRR) and to evaluate the synergistic effects among different active components. MATERIALS AND METHODS: The anti-thrombotic active chemical fraction of DRR extracts was evaluated. Targeted fractions of the processed products of RR were prepared at different processing stages. The changes in monosaccharides, oligosaccharides and secondary metabolites during processing were characterized by multidimensional high-performance liquid chromatography (HPLC). The anti-thrombotic effects of targeted fractions of different RR samples were evaluated by analyzing the length of tail thrombus (LT) and serum biochemical indicators in carrageenan-induced tail-thrombus mice. The spectrum-effect relationships were investigated by partial least squares regression (PLSR) analysis and gray correlation analysis (GRA). Finally, the active compounds were screened by spectrum-effect relationship analysis and validated in vivo, and their synergistic effects were determined by Webb's fraction multiplication method. RESULTS: Six ingredients highly associated with anti-thrombotic activities were screened out by the spectrum-effect relationship analysis, of which oligosaccharides (stachyose, sucrose and raffinose) and iridoid glycosides (catalpol, leonuride and melitoside) possessed a synergistic effect on tumor necrosis factors (TNF-α), interleukin 1ß (IL-1ß) and plasminogen activator inhibitor 1 (PAI-1)/tissue-type plasminogen activator (t-PA) ratio in vivo with synergistic coefficient (SC) > 1. CONCLUSION: The main material basis of the anti-thrombotic activities of DRR is oligosaccharide components of stachyose, raffinose and sucrose, iridoid glycosides components of catalpol, leonuride and melittoside. The two kinds of components exert synergistic anti-thrombotic effects by inhibiting the expression of inflammatory factors and regulating the balance of the fibrinolysis system.

Zengye Decoction Ameliorates Insulin Resistance by Promoting Glucose Uptake.

The incidence of type 2 diabetes mellitus (T2DM) has been increasing in recent years and has become a serious threat to human health. Zengye Decoction (ZYD), a well-known traditional Chinese medicinal formula, has been used in the treatment of T2DM with yin asthenia and extreme heat since Qing Dynasty. However, the characteristics of antidiabetic activities of ZYD have not been fully elucidated. In our study, high-fat diet and streptozotocin were used to establish the T2DM rat model. After 3 weeks of treatment with ZYD, the fasting blood glucose (FBG), oral glucose tolerance, the fasting serum insulin concentration, insulin sensitivity index (ISI), serum lipid profiles, and pancreas histopathology were measured. Then, under circumstance of insulin-resistant glucose consumption, 2-(N-(7-nitrobenz-2-oxa-l,3-diazol-4-yl) amino)-2-deoxyglucose (2-NBDG) uptake and glycogen content in C2C12 myotubes, 3T3-L1 adipocytes, and HepG2 cells were determined, respectively. Finally, the expressions of key targets in the insulin signaling pathway were measured to explain the potential mechanism underlying these activities. After administration with ZYD, a notable reduction in FBG levels, oral glucose tolerance test-area under the curve, blood lipid metabolism, and ISI values were observed compared with the diabetic control group. Moreover, ZYD restored the damaged islet cells in T2DM rats. Significant increases in glucose consumption, glucose uptake, glycogen content, expression of glucose transporter type 4, and the ratio of p-Akt/Akt were observed in the ZYD groups. According to the above results, ZYD exhibited glucose disposal, including glucose consumption, glucose uptake, and glycogen content and promoted the Akt signal pathway, which indicates that ZYD exerts significant hypoglycemic effect in T2DM.

Comparisons of antithrombosis, hematopoietic effects and chemical profiles of dried and rice wine-processed Rehmanniae Radix extracts.

ETHNOPHARMACOLOGICAL RELEVANCE: In traditional Chinese medicine (TCM), Rehmanniae Radix (RR, derived from the root of Rehmannia glutinosa (Gaertn.) DC.) is commonly used as natural medicine for thousands of years, two types including the dried and rice-wine processed RR were used for different clinical purposes respectively, which were the typical case that pharmaceutical effect changed by processing in TCM. AIM OF STUDY: The goal of this study was to investigate the differences in the antithrombosis and hematopoietic effects of extracts of dried and processed RR (DRR and PRR) in vivo, and to explore the chemical basis underlying changes of medicinal properties caused by processing. MATERIALS AND METHODS: The aqueous extracts of DRR and PRR were prepared. Protective effect of varying doses of different extracts were investigated in type-I carrageenan induced mice tail thrombosis and cyclophosphamide induced myelosuppression model. The chemical composition of DRR and PRR extracts were determined by High Performance Liquid Chromatography coupled with tandem quadrupole time-of-flight Mass Spectrometry (HPLC/Q-TOF-MS). RESULTS: In antithrombosis activity tests, PRR possessed less ameliorated effects than DRR in the model mouse on body temperature, tail thrombus length and blood flow. Both DRR and PRR had no significant influence on prothrombin time (PT) and activated partial thromboplastin time (APTT), only high dose DRR could decrease the content of fibrinogen (FIB) in plasma. Histological examination of lung tissue suggested that thrombosis was significantly improved in DRR-H group. For myelosuppression model, only PRR could improve peripheral hemogram, both DRR and PRR had hematopoietic effects as demonstrated by their abilities to ameliorate the bone marrow nucleated cells (BMNC) and pathology of bone marrow tissue. The hematopoietic effects of PRR were significantly more potent than that of DRR at the concentration of 9 g/kg. By comparing the chemical composition, we found that iridoid glycosides were decreased and furfural derivatives increased in DRR after processing which may be the chemical mechanism contribute to the differences in efficacy. CONCLUSIONS: According to the results of this research, processing with rice wine for nine cycles significantly reduced antithrombotic effects and enhanced the hematopoietic effects of DRR as demonstrated in model mice. It can scientifically explain the different effect among two types of RR in clinical through the diverse method of processing and usage. Meanwhile, the predicted activity compounds from two types of RR can be potential candidates for the treatment of thrombosis and anemia.

Screening and identification of potential hypoglycemic components in Zeng Ye Tang by high-performance liquid chromatography coupled with tandem quadrupole time-of-flight mass spectrometry.

Zeng Ye Tang, a famous prescription consisting of Xuanshen, Maidong, and Shengdi (5:4:4), has been used in China for a long time to treat diabetes caused by excessive heat with yin deficiency. Although many studies have investigated the pharmacological effects of Zeng Ye Tang, the compounds responsible for its hypoglycemic effect have not been identified. In this study, 50 compounds in Zeng Ye Tang were identified by high-performance liquid chromatography coupled with tandem quadrupole time-of-flight mass spectrometry. From these 50 compounds, nine cell-interacted compounds were identified by biospecific cell extraction using 3T3-L1 adipocytes. Moreover, nine potential active compounds that could be released into the blood were also acquired through serum pharmacochemical analysis in normal and diabetic rats after administration with Zeng Ye Tang. According to the established quantitative analytical method of nine constituents by high-performance liquid chromatography, six shared prototype constituents (catalpol/harpagide/p-coumaric acid/harpagoside/angoroside C/cinnamic acid (75.56:19.74:1.00:15.11:20.36:7.65), were screened and verified to exert remarkable hypoglycemic activity on type 2 diabetic mice. In conclusion, the six shared constituents may be responsible for the hypoglycemic activity of Zeng Ye Tang.