Guangyu Xu

Effects of compound K on hyperglycemia and insulin resistance in rats with type 2 diabetes mellitus.

Compound K (CK) is a final metabolite of panaxadiol ginsenosides from Panax ginseng. Although anti-diabetic activity of CK has been reported in recent years, the molecular mechanism of CK in the treatment of diabetes mellitus remains unclear. In the present investigation, we established a rat model of type 2 diabetes mellitus (T2DM) with insulin resistance using high-fat diet (HFD) and streptozotocin (STZ), and attempted to verify more details and exact mechanisms in the treatment of T2DM. CK was administered orally at three doses [300, 100 and 30 mg/kg bodyweight (b.w.)] to the diabetic rats. Bodyweight, food-intake, fasting blood glucose (FBG), fasting serum insulin (FINS), insulin sensitivity (ISI), total glycerin (TG), total cholesterol (TC), as well as oral glucose tolerance test (OGTT) were evaluated in normal and diabetic rats. According to our results, CK could improve bodyweight and food-intake of diabetic rats. CK exhibited dose-dependent reduction of FBG, TG and TC of diabetic rats. CK treatment also enhanced FINS and ISI. Meanwhile, the glucose tolerance observed in the present study was improved significantly by CK. It is concluded from the results that CK may have improving effects on hyperglycemia and insulin resistance of diabetic rats. Furthermore, research showed that CK could promote the expression of InsR, IRS1, PI3Kp85, pAkt and Glut4 in skeletal muscle tissue of diabetic rats. These results indicate that the hypoglycemic activity of CK is mediated by improvement of insulin sensitivity, which is closely related to PI3K/Akt signaling pathway.

In Vitro Antioxidant activities and anti-diabetic effect of a polysaccharide from Schisandra sphenanthera in rats with type 2 diabetes

A water soluble polysaccharide (SSPW1), with an average molecular weight of 191.18KD, was isolated and purified from the water extract of Schisandra sphenanthera by DEAE-52 and Sephadex G-100 column chromatography. SSPW1 contained 48.92% neutral sugar, 5.56% proteins and 42.83% uronic acid, and were composed of rhamnose, arabinose, mannose, galactose, glucose at a molar ratio of 13.52, 5.69, 3.92, 41.28 and 35.59. In vitro experiment showed that SSPW1 have a satisfactory scavenging effect on superoxide anion free radical, hydroxyl radical and DPPH free radical. In vivo experiment showed that SSPW1 could increase the body weight, improve the glucose tolerance, reduce FBG, and elevate the levels of FINS and the value of ISI in the diabetic rats. In addition, SSPW1 could reduce the MDA content, and increase GSH-PX, CAT and SOD activities. These results suggest that SSPW1 has both in vitro and in vivo antioxidant effect, which may be closely related to its antidiabetic effect.

Identification of velvet antler by random amplified polymorphism DNA combined with non-gel sieving capillary electrophoresis

Abstract Mitochondrial DNA of velvet antler was amplified with random amplified polymorphic DNA (RAPD) technique and the PCR products were detected with non-gel sieving capillary electrophoresis to establish a RAPD-HPCE method used for identifying the authenticity of velvet antler or it counterfeits. Factors that could affect the PCR amplification and capillary electrophoresis were optimized. Under the optimized conditions, namely, 20 mmol L−1 NaH2PO4–Na2HPO4–2 mmolL−1 EDTA buffer solution [0.8% (W/V) HPMC, 15 mmol L−1 TBAP and pH 7.3], −10 kV injection voltage and −8 kV separation voltage, Cervus nippon Temminck antler, Cervus elaphus Linnaeus antler, Rangifer tarandus antler, Cervus canadensis antler and Elaphurus davidianus antler were analyzed. The analysis on the similarity of obtained elctrophoretograms showed that there were significant differences in similarities of different velvet antlers, which could be used for the quick identification of the authenticity of velvet antler samples. It can be found that the technique of RAPD combined with HPCE is advantageous in rich polymorphism, high detection rate, simple and convenient performance, high efficiency, rapidness and sensitivity, indicating that it should be suitable for the quick identification of the authenticity of velvet antler samples.

mRNA chip-based analysis on transcription factor regulatory network central nodes of protection targets of Deproteinized Extract of Calf Blood on acute liver injury in mice

&NA; Our previous study found that Deproteinized Extract of Calf Blood (DECB) could protect the acute liver injury induced by carbon tetrachloride in mice, but the target‐related transcription factors and their regulatory networks were not comprehensively studied. Based on the mRNA expression microarray data obtained in the previous study, the mRNA transcription factor regulatory networks were constructed by screening the transcription factors of differentially expressed genes and their corresponding target proteins, and the analysis on the functions and pathways of the regulatory network central nodes was performed. Eight genes Ltf, Tnf, Il6, Jun, Il12b, Stat3, Rel and Crem could regulate the inflammatory factors, and TNF signaling pathway and Jak‐STAT signaling pathway might play an important role in the mechanism through which DECB protected the liver of mice. DECB can not only inhibit the apoptosis of hepatocytes, but also inhibit the inflammatory cytokines.

Combined antitumor effects of P‑5m octapeptide and 5‑fluorouracil on a murine model of H22 hepatoma ascites

The present study has demonstrated that P-5m octapeptide (P-5m) has therapeutic potential in metastatic human hepatocarcinoma, possibly through the modulation of matrix metalloproteinase-2 expression. The purpose of the present study was to evaluate the antitumor effect of P-5m combined with 5-fluorouracil (5-Fu) on the treatment of hepatoma 22 (H22) hepatocarcinoma malignant ascites in a mouse model. The inhibitory effect on the growth of mouse ascites tumors was monitored by measuring body weight gain, survival time, ascites volume, numbers of tumor cells, DNA synthesis and peritoneal capillary permeability analysis. The present data revealed a significant reduction in ascites volume and cell count in mice that were treated with P-5m plus 5-Fu. Furthermore, the median survival time in mice in the combination group was prolonged compared with the disease control group. Moreover, a significant reduction in the total H22 ascites cell count in mice from the combination group was observed when compared with the disease control group. P-5m plus 5-Fu was able to induce the cell cycle arrest and inhibit the peritoneal capillary permeability of the mice. To conclude, the present study indicated that P-5m may have therapeutic potential in ascites caused by hepatocellular carcinoma.

Improvement of Learning and Memory Induced by Cordyceps Polypeptide Treatment and the Underlying Mechanism

Our previous research revealed that Cordyceps militaris can improve the learning and memory, and although the main active ingredient should be its polypeptide complexes, the underlying mechanism of its activity remains poorly understood. In this study, we explored the mechanisms by which Cordyceps militaris improves learning and memory in a mouse model. Mice were given scopolamine hydrobromide intraperitoneally to establish a mouse model of learning and memory impairment. The effects of Cordyceps polypeptide in this model were tested using the Morris water maze test; serum superoxide dismutase activity; serum malondialdehyde levels; activities of acetyl cholinesterase, Na+-k+-ATPase, and nitric oxide synthase; and gamma aminobutyric acid and glutamate contents in brain tissue. Moreover, differentially expressed genes and the related cellular signaling pathways were screened using an mRNA expression profile chip. The results showed that the genes Pik3r5, Il-1β, and Slc18a2 were involved in the effects of Cordyceps polypeptide on the nervous system of these mice. Our findings suggest that Cordyceps polypeptide may improve learning and memory in the scopolamine-induced mouse model of learning and memory impairment by scavenging oxygen free radicals, preventing oxidative damage, and protecting the nervous system.