Previous studies have shown that sericin extracted from silk cocoon significantly reduces blood glucose levels and protects the nervous system against diabetes mellitus. In this study, a rat type 2 diabetes mellitus m...Previous studies have shown that sericin extracted from silk cocoon significantly reduces blood glucose levels and protects the nervous system against diabetes mellitus. In this study, a rat type 2 diabetes mellitus model was established by intraperitoneal injection of 25 mg/kg streptozotocin for 3 successive days, following which the rats were treated with sericin for 35 days. After treatment, the blood glucose levels of the diabetic rats decreased significantly, the growth hormone level in serum and its expression in the hippocampus decreased significantly, while the insulin-like growth factor-1 level in serum and insulin-like growth factor-1 and growth hormone receptor expression in the hippocampus increased significantly. The experimental findings indicate that sericin improves disorders of the growth hormone/insulin-like growth factor 1 axis to alleviate hippocampal damage in diabetic rats.展开更多
Background To better understand the possibilities of antiangiogenic tumor therapy and to assess possible side effects, we investigated the effect of tumour necrosis factor （TNF）-α and curcumin on the expression of ...Background To better understand the possibilities of antiangiogenic tumor therapy and to assess possible side effects, we investigated the effect of tumour necrosis factor （TNF）-α and curcumin on the expression of vascular endothelial growth factor （VEGF） in U937 and Raji cell lines and their effect on angiogenesis in a human umbilical vein endothelial cell （HUVECs）-derived cell line （ECV304）, and also the relationship between Notchl and VEGF. The aim of this study was to elucidate potential mechanisms controlling tumor neovascularization. Methods VEGF secreted by U937 and Raji cell lines was determined by ELISA. Angiogenesis was tested by network formation of endothelial cells on Matrigel. Levels of VEGF mRNA in U937 and Raji cells and Notchl mRNA levels in EV304 cells were determined by RT-PCR. Results Secretion of VEGF by U937 and Raji cells was increased by TNF-α treatment and suppressed by curcumin （P 〈 0. 01 ）. The mRNA expression of VEGF165 and VEGF121 （containing 165 and 121 amino acid residues, respectively） were detected in any fractions. TNF-α augmented the expression of VEGF165 and VEGF121 mRNA and curcumin reduced the expression （P 〈0. 01 ）. No networks or cords formed in control and curcumin groups. There was tube formation on matrigel in the supernatants of the Raji culture group and the supernatants groups treated by VEGF group and TNF-α in Raji cell. Notch1 mRNA was detected but there was no significant change in the VEGF group compared with control （P 〉 0. 05）. Conclusions Expressions of VEGF mRNA in U937 and Raji cells were increased by TNF-α and suppressed by curcumin. VEGF and TNF-α can induce angiogenesis, and curcumin can inhibit angiogenesis in ECV304 cells.展开更多
基金sponsored by the Natural Science Foundation of Hebei Province,H2012406018,H2013406096a grant from Hebei Province Department of Education,No.2006301
文摘Previous studies have shown that sericin extracted from silk cocoon significantly reduces blood glucose levels and protects the nervous system against diabetes mellitus. In this study, a rat type 2 diabetes mellitus model was established by intraperitoneal injection of 25 mg/kg streptozotocin for 3 successive days, following which the rats were treated with sericin for 35 days. After treatment, the blood glucose levels of the diabetic rats decreased significantly, the growth hormone level in serum and its expression in the hippocampus decreased significantly, while the insulin-like growth factor-1 level in serum and insulin-like growth factor-1 and growth hormone receptor expression in the hippocampus increased significantly. The experimental findings indicate that sericin improves disorders of the growth hormone/insulin-like growth factor 1 axis to alleviate hippocampal damage in diabetic rats.
基金This study was supported by a grant from the National NaturalScience Foundation of China (No.30472267)
文摘Background To better understand the possibilities of antiangiogenic tumor therapy and to assess possible side effects, we investigated the effect of tumour necrosis factor （TNF）-α and curcumin on the expression of vascular endothelial growth factor （VEGF） in U937 and Raji cell lines and their effect on angiogenesis in a human umbilical vein endothelial cell （HUVECs）-derived cell line （ECV304）, and also the relationship between Notchl and VEGF. The aim of this study was to elucidate potential mechanisms controlling tumor neovascularization. Methods VEGF secreted by U937 and Raji cell lines was determined by ELISA. Angiogenesis was tested by network formation of endothelial cells on Matrigel. Levels of VEGF mRNA in U937 and Raji cells and Notchl mRNA levels in EV304 cells were determined by RT-PCR. Results Secretion of VEGF by U937 and Raji cells was increased by TNF-α treatment and suppressed by curcumin （P 〈 0. 01 ）. The mRNA expression of VEGF165 and VEGF121 （containing 165 and 121 amino acid residues, respectively） were detected in any fractions. TNF-α augmented the expression of VEGF165 and VEGF121 mRNA and curcumin reduced the expression （P 〈0. 01 ）. No networks or cords formed in control and curcumin groups. There was tube formation on matrigel in the supernatants of the Raji culture group and the supernatants groups treated by VEGF group and TNF-α in Raji cell. Notch1 mRNA was detected but there was no significant change in the VEGF group compared with control （P 〉 0. 05）. Conclusions Expressions of VEGF mRNA in U937 and Raji cells were increased by TNF-α and suppressed by curcumin. VEGF and TNF-α can induce angiogenesis, and curcumin can inhibit angiogenesis in ECV304 cells.
