Structural characteristics, antioxidant properties and antiaging activities of galactan produced by Mentha haplocalyx Briq
CARBOHYDRATE POLYMERS
Authors: Jiang, Peng; Meng, Wei; Shi, Fengxue; Chen, Chen; Sun, Yu; Jiao, Lili
Abstract
An antioxidant-active polysaccharide (WMP) with a molecular weight of 26.91 kDa was isolated from Mentha haplocalyx Briq by water extraction, ethanol precipitation and gel filtration. According to HPLC, methylation, GC-MS, and 1D/2D nuclear magnetic resonance spectroscopy, WMP is a heteropolysaccharide composed of Gal (84.2 %), Glc (9.8 %), Man (2.8 %) and Ara (3.2 %) with (1 -> 6)-alpha-D-Galp and (1 -> 4, 6)-alpha-D-Galp residues in the backbone and (1 -> 6)-alpha-D-Galp and (1 -> 6)-alpha-D-Glcp residues in the branch. The branch point was located at C-4 of (1 -> 4, 6)-alpha-D-Galp residue with a branching degree of 19.71 %. WMP showed remarkably high scavenging ability for 1, 1-diphenyl-2-picrylhydrazyl (DPPH) and hydroxyl radicals, ferrous ion chelating activity and ferric reducing powder in vitro. In vivo result showed that WMP oral administration substantially increased the activities of antioxidant enzymes, including SOD, GSH-Px and CAT, and decreased MDA levels in the serum and liver of D-Gal-induced aging mice. Therefore, WMP can be an effective natural antioxidant.
Cationic/Anionic Polyelectrolyte (PLL/PGA) Coated Vesicular Phospholipid Gels (VPGs) Loaded with Cytarabine for Sustained Release and Anti-glioma Effects
DRUG DESIGN DEVELOPMENT AND THERAPY
Authors: Qi, Na; Zhang, Yu; Tang, Xing; Li, Aimin
Abstract
Background: Cationic and anionic polymer-modified nanoparticles offer promising properties for the drug and gene delivery. Our study uses cationic/anionic polyelectrolyte coated vesicular phospholipid gels (VPGs) loaded with cytarabine (Ara-C) that enhance in vitro and in vivo anti-glioma effects. Methods: Sodium cholesteryl sulfate (SCS) or octadecylamine (ODA) incorporated in a phospholipids phase were used to prepare charged VPGs, and cationic E-polylysine (PLL) coated VPGs (PLL-SCS VPGs) and anionic gamma-polyglutamic acid (PGA) coated VPGs (PGA-ODA VPGs) were prepared via electrostatic interactions, respectively. The morphology, particle size, zeta potential, rheology properties, and in vitro release were then characterized. The in vitro cytotoxicity and cellular uptake were evaluated on U87-MG glioma cells. The in vivo antitumor effects were studied on BALB/c nude mice bearing a right flank U87-MG glioma model. Results: The TEM images and physicochemical properties of cationic/anionic polyelectrolyte coated VPGs exhibited that polymers covered on the vesicular surface. The results of rheologic property analysis showed that cationic/anionic polyelectrolyte coated VPGs enhanced the viscosity of uncoated VPGs. The in vitro release experiments revealed that cationic/anionic polyelectrolyte coated VPGs kept Ara-C sustained release up to 18 days. Specially, compared with PLL-SCS VPGs, PGA-ODA VPGs demonstrated higher in vitro cytotoxicity and cellular uptake efficiency in U87-MG glioma cells, and enhanced in vivo antitumor effects when subcutaneously injected around the tumor. No severe toxicity appeared in the right flank U87-MG glioma model of BALB/c nude mice. Conclusion: Anionic gamma-PGA coated VPGs were superior to cationic PLL coated VPGs in terms of improving the anti-glioma effect for local delivery.