Hui Guo

Xi'an Jiaotong University, Ch’ang-an, Shaanxi, China

Are you Hui Guo?

Claim your profile

Publications (3)8.57 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Chitosan, a naturally occurring biopolymer, has received considerable attention for pharmaceutical applications due to its biocompatible, biodegradable and less toxic properties. In this study, sulfated chitooligosaccharides (COS-S) with different degrees of substitution (DS) were prepared to improve both its water-solubility and bioactivity. Additionally, the protective effects of COS-S on hydrogen peroxide (H(2)O(2))-induced dysfunction in MIN6 cells were investigated. COS-SI (DS, 0.8) and COS-SII (DS, 1.9) significantly increased the cell viability in a dose-dependent manner. COS-S also significantly suppressed NO production, the activity and mRNA expression of iNOS, and the protein level of NF-κB protein p65, which were activated by H(2)O(2). Furthermore, we demonstrated that COS-S led to an increase in the Bcl-2/Bax mRNA expression ratio and the inhibition of Caspase-3 mRNA expression in H(2)O(2)-stimulated MIN6 cells. Additionally, COS-SII (DS, 1.9) exhibited a superior protective effect on H(2)O(2)-induced apoptosis compared to COS-SI (DS, 0.8). These results indicated the good anti-oxidative capacity of COS-S and the possible mechanism via the blockade of the NF-κB signaling pathway. The protective effects of COS-S against oxidative injuries in MIN6 cells were depended on both DS and concentration.
    No preview · Article · Oct 2012 · International journal of biological macromolecules
  • Xiaoyun Lu · Xiaoyan Mo · Hui Guo · Yali Zhang
    [Show abstract] [Hide abstract]
    ABSTRACT: The optimal conditions for sulfation of polysaccharides from persimmon fruits (PFP) with chlorosulfonic acid-pyridine (CSA-Pyr) method were determined by response surface methodology. Box-Behnken design was applied to evaluate the effects of three independent variables (volume ratio of Pyr to CSA, volume ratio of PFP to SO(3)Pyr and reaction time) on the degree of substitution (DS), molecular weight (MW) and activated partial thromboplastin time (APTT) of sulfated polysaccharides (PFP-S). The APTT activity of PFP-S could be improved by application of various volume ratio of Pyr to CSA, volume ratio of PFP to SO(3)Pyr and reaction time, which was possible due to the degradation of polysaccharides to different extent and increasing of DS. The optimal conditions to obtain the strongest APTT of PFP-S were the volume ratio of CSA to Pyr of 1:8, the volume ratio of SO(3)Pyr to PFP of 1:3.6 and the reaction time of 3h, respectively.
    No preview · Article · Aug 2012 · International journal of biological macromolecules
  • Xiaoyun Lu · Hui Guo · Yali Zhang
    [Show abstract] [Hide abstract]
    ABSTRACT: Sulfated chitooligosaccharides (COS-S) with different degrees of substitution (DS) were obtained by the chlorosulfuric acid/pyridine method. Protective effects of COS-S against hydrogen peroxide (H(2)O(2))-induced damage were investigated in pancreatic β-cells MIN6 cell line. The cell viability, morphology, insulin contents, malondialdehyde (MDA) inhibition, lactate dehydrogenase (LDH) release and the levels of antioxidant enzymes including catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidise (GPx) were evaluated under oxidative damage by 150 μM H(2)O(2) for 6h. COS-S did not show any harmful or inhibitory effect on cell growth at concentrations ranging from 0.1 to 0.5 mg/ml. While COS-S could enhance the cell viability, decrease the production of ROS, and reduce the MDA level as well as LDH level in oxidative damaged β-cells by being an antioxidant. The underlining mechanisms of protective effects of COS-S are partly due to the enhancement of antioxidant enzyme activity and inhibition of intracellular ROS production, along with suppressing MIN6 cell apoptosis subsequent to the amelioration of ROS. Moreover, increased DS might contribute to the defense mechanisms against H(2)O(2)-induced oxidative damage in MIN6 cells. These results indicated that the antioxidant properties of COS-S hold great potential for the oxidative diseases treatment, and the sulfate content of polysaccharides made great role in regulating antioxidant activities.
    No preview · Article · Jan 2012 · International journal of biological macromolecules