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| Author(s): |
Priscilla Maria Ponce Vareda
Total Authors: 1
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| Document type: | Doctoral Thesis |
| Press: | Botucatu. 2017-12-19. |
| Institution: | Universidade Estadual Paulista (Unesp). Instituto de Biociências. Botucatu |
| Defense date: | 2017-02-16 |
| Advisor: | José Roberto Bosqueiro |
| Abstract | |
Diabetes mellitus (DM) is a metabolic disease characterized by hyperglycemia resulting from defects in insulin secretion or action, which results in carbohydrates, proteins and lipids metabolism disturbances. DM incidence increases alarmingly worldwide and studies with plants, which exhibit anti-diabetic effects, arouse researcher’s interests. In previous results we observed that streptozotocin-induced diabetic mice showed an improvement in diabetic condition after the treatment with Myrcia bella leaves crude extract. In this work, we have decided to evaluate the molecular mechanisms involved in glucose uptake and storage process in peripheral tissues such as liver, gastrocnemius muscle and adipose tissue. Furthermore, to evaluate the extract in vivo and in vitro inhibitory activity of alpha glycosidase and alpha amylase enzymes and insulin content in pancreas. Diabetic mice (STZ SAL and STZ EXT) and normoglicemic control mice (CTL SAL and CTL EXT) were treated during 21 days with saline or M. bella crude extract at 600 mg/kg. Liver was collected to gene and protein expression involved in glycogenesis, glycogenolysis and gluconeogenesis process. Gastrocnemius muscle to gene and protein expression involved in insulin signaling pathway and glucose uptake and white adipose tissue to the expression of the mainly proteins involved in insulin signaling pathway. Pancreas was collected to evaluate the insulin content. The treatment with M. bella crude extract seems to modulate the process of glucose storage and release in liver of diabetic mice (STZ EXT) thought the increase of glycogen synthase expression and decrease of the of PEPCK and glucose – 6- phosphatase expression as well as the respectively genes involved in the translation of PEPCK and glucose – 6- phosphatase . The treatment with M. bella extract also increased the GLUT4 protein expression in adipose tissue of diabetic mice (STZ EXT). The in vitro and in vivo analysis showed the extract is efficient in alpha glycosidase and amylase enzymes inhibition as well as in decreasing the postprandial glycemia after starch and maltose ingestion. Finally, we conclude that, at least in part, the extract acts in glycemia reduction through modulation of processes that regulates glucose uptake, storage and release from liver. Moreover, the extract action may be associated with the glucose uptake in adipose tissue as well as through the inhibition of alpha glycosidase and alpha amylase enzymes. (AU) | |
| FAPESP's process: | 12/23605-2 - Investigation of mechanism involved in hypoglycemic action of crude extract of Myrcia bella in liver, skeletal muscle and adipose tissue in model type 1 diabetes by streptozotocin |
| Grantee: | Priscilla Maria Ponce Vareda |
| Support Opportunities: | Scholarships in Brazil - Doctorate |