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Background: Field cricket (Gryllus bimaculatus) is newly emerged as an edible insect in several countries. Anti-inflammatory effect of glycosaminoglycan derived from this cricket on chronic disease animal model such as diabetic mouse has not been fully investigated yet. Thus, the objective of this study was to determine the anti-oxidative effect of such glycosaminoglycan on diabetic mouse., Methods: To discover potential therapeutic agents, field cricket glycosaminoglycan (GbG) was tested in the present study. Its anti-oxidative activities in diabetic mice were determined based on its abilities to reduce glucose, ALT, AST, ALP, LDL-cholesterol and BUN levels. Dung beetle (C. molossus) glycosaminoglycan (CaG) was used as a positive control. Db mice were intraperitoneally administered for 1 month according to their group assignments: 1) normal (DB-Hetero); 2) control (DB-Homo); 3) 5 mg/kg treatment of CaG (CaG5); 4) 5 mg/kg treatment of GbG (GbG5); and 5) 10 mg/kg treatment of metformin (Metformin 10)., Results: Blood glucose level decreased after 1st week of treatment with GbG. LDL-cholesterol and alkaline phosphatase levels were also inhibited by GbG. Markers of oxidative damage, such as protein carbonyl content and levels of hepatocellular biomarkers, were reduced in db mice treated with GbG. Especially anti-oxidative activities of catalase, superoxide dismutase and glutathione peroxidase were significantly increased in GbG treated group compared to those in the control (Db Homo). GbG was composed of heparin disaccharides. Its main N-glycan was identified as Hex 9 GlcNAc 2 (m/z 1905.7) with neutral mono-sugar mainly comprising of hexose and L (+) rhamnose by mass spectroscopy., Conclusions: Sero-biochemical and hepatocellular anti-oxidant assay results in db mice suggest that cricket (G. bimaculatus) glycosaminoglycan might possess anti-oxidative effect in diabetic state.

Background: Dung beetle glycosaminoglycan is known to possess anti-aging activities. However, its anti-cancer mechanisms are not fully elucidated yet. The objective of this study was to evaluate the anti-cancer effect of insect-derived polymer dung beetle glycosaminoglycan (GAG) after intraperitoneally injecting it to melanoma mice induced by B16F10 cells., Methods: To determine molecular mechanism involved in the anti-cancer effect of dung beetle GAG, its origin N-glycan under 3KD Dalton was assayed for melanoma cell cytotoxicity. Quantitative comparisons of adhesive molecule on extracellular matrix and activities of tissue inhibitor of metalloprotease 2 (TIMP-2) were also investigated. In vivo anti-cancer effect of dung beetle GAG on solid tumor size, survival time and gene-expression profiles was also assayed using B10F10 melanoma mice model. Mice with induced melanoma were then treated with Catharsius molossus (dung beetle) GAG (CaG) at 5 mg/kg for 8 weeks to investigate its anti-cancer effects compared to bumblebee (Bombus ignitus) queen glycosaminoglycan (IQG) and Huechys sanguinea glycosaminoglycan (HEG)., Results: These N-glycans derived from these GAG were composed of many linear heparinoid polysaccharides, polymers with hexose and N-acetylhexose. Adminstration with these GAGs increased survival time and decreased melanoma sizes in mice, in accordance with their inhibitory effects on cell growth ratio of melanoma B16F10. In addition, treatment with N-glycans derived from theses glycosaminoglycan increased activities of TIMP-2 in HMVEC cells pretreated with TNF-alpha and in melanoma cells, suggesting that they had anti-inflammatory and anticancer activities. In DNA microarray results, compared to control, CaG treated mouse group showed upregulation of 192 genes including collagen,typeI,alpha1 (Col1a1), consistent with the highly increased in vitro extracellular matrix (ECM) adhesion on collagen 1 and up-regulation of heparanase (Hpse). After treatment with CaG, a total of 152 genes were down-regulated, including nuclear RNA export factor (Nxf3) and hyaluronan proteoglycan link protein1 (Hapln1)., Conclusions: Glycosaminoglycan, CaG can strengthen ECM by increasing activity of TIMP-2 and adhesion activity on collagen known to inhibit changes of ECM, leading to tumor cell invasion and progression.