Antioxidative capacity of rosehip polyphenols and their potential role in type 2 diabetes mellitus prevention and management
Examensarbete för masterexamen
The health benefits derived from a diet rich in phenolic compounds have been suggested to be partly through effects generated in the gastrointestinal (GI) tract. Elevated blood glucose level plays an important role in the development of type 2 diabetes mellitus. The inhibition of digestive enzymes in the GT tract involved in starch degradation may lead to beneficial effects on blood glucose control after the intake of starch containing foods. The aim of this master thesis was to investigate the ability of rosehip extracts to inhibit α-amylase and α-glucosidase activity during in vitro digestion. Aqueous and methanol extracts of rosehip powder were analyzed for total phenolic content and antioxidant capacity. Folin-Ciocalteau method (FC) and oxygen-radical absorbance capacity (ORAC) assays were optimized for respective purposes. Porcine pancreas α-amylase (EC 126.96.36.199) and α-glucosidase (EC 188.8.131.52) were used in enzyme inhibition assays. Acarbose, a commercial pharmaceutical α-amylase inhibitor used as a therapeutic approach to control blood glucose levels, was used as a positive control. Rosehip extracts were found to have a high content of phenolic compounds and high antioxidant capacity. The extracts were able to exert a weak inhibitory effect on α-amylase and a strong inhibitory effect on α-glucosidase. Acarbose displayed an opposite pattern to these inhibition assays, which was consistent with its reported side effects. The results from this study show that rosehip extracts had high ability in inhibiting starch hydrolyzing enzymes and thereby decreasing potential blood glucose responses in vivo.
Kemi , Livsmedelsvetenskap , Livsvetenskaper , Chemical Sciences , Food Science , Life Science