Loading...
2 results
Search Results
Now showing 1 - 2 of 2
- Phenolic composition and antioxidant activity of Rocha pear and other pear cultivars: a comparative studyPublication . Salta, J.; Martins, A.; Santos, R. G.; Neng, N. R.; Nogueira, J. M.; Justino, Jorge; Rauter, A. P.The phenolic profile and the antioxidant activity of Rocha pear, a Portuguese pear cultivar, were determined and compared with the commercially available pear varieties Cornice, Abate, General Leclerc and Passe Crassane. Phenolic composition of the methanolic extracts of these pears was determined by high performance liquid chromatography with diode array detection (HPLC-DAD), while antioxidant activities were evaluated using three complementary test systems: DPPH radical scavenging activity, ferric reducing power capacity and beta-carotene/linoleic acid bleaching assay. When compared to the studied varieties, Rocha pear (peel and flesh) presented the highest content of total phenolics. Among them, chlorogenic, syringic, ferulic and coumaric acids, arbutin and (-)-epicatechin were detected as major components. In addition, among the tested varieties, Rocha pear presented the best antioxidant activities in the DPPH and ferric reducing power assays.
- New In Vitro studies on the bioprofile of Genista tenera antihyperglycemic extractPublication . Batista, D.; Falé, P.L.; Serralheiro, M.L.; Araújo, M.E.; Madeira, P.J.A.; Borges, C.; Torgal, Isabel; Goulart, Margarida; Justino, Jorge; Martins, A.; Rauter, A.P.The inhibition of a-glucosidase and glucose-6-phosphatase, two enzymes involved in the carbohydrate metabolism, is an important target to control glycaemia on individuals with type 2 diabetes. In this work we report for the first time the inhibition of both enzymes by the antihyperglycemic n-butanol extract from Genista tenera (Fabaceae). This extract decreased a-glucosidase and glucose-6-phosphatase activities to 0.97 and 80.25 %, respectively, being more effective than acarbose, and phlorizin, the positive controls, which reduced enzymes activities only to 17.39 and 96.06 %. Once inflammation and oxidative stress are related to diabetic impairments, the anti-inflammatory activity of the extract was also evaluated, through its inhibitory activity over COX-1 enzyme (47.5 % inhibition). Moreover, after induction of oxidative stress by UV radiation, the viability of irradiated rat liver hepatoma cells exposed to the extract was significantly higher (67.82 %) than that promoted by ascorbic acid, the positive control (45.05 %). In addition, the stability of the extract under gastrointestinal conditions was evaluated by HPLC–DAD-ESI–MS/MS. Flavonoid diglycosides were identified as the main constituents of the extract, and no alterations in the chemical composition nor in the antioxidant activity were observed after in vitro digestion with artificial gastric and pancreatic juices.