New In Vitro Studies on the Bioprofile of Genista tenera Antihyperglycemic Extract.
The inhibition of α-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 α-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.
Centro de Química e Bioquímica, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016, Lisbon, Portugal.
Daniela
D
Batista
Centro de Química e Bioquímica, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016, Lisbon, Portugal.|Institute of Pharmaceutical Science, King's College London, 150 Stamford Street, London, SE1 9NH, UK.
Pedro L
PL
Falé
Centro de Química e Bioquímica, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016, Lisbon, Portugal.
Maria L
ML
Serralheiro
Centro de Química e Bioquímica, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016, Lisbon, Portugal.
Maria E
ME
Araújo
Centro de Química e Bioquímica, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016, Lisbon, Portugal.
Paulo J A
PJ
Madeira
Centro de Química e Bioquímica, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016, Lisbon, Portugal.
Carlos
C
Borges
Escola Superior Agrária de Santarém, Quinta do Galinheiro, 2001-904, Santarém, Portugal.
Isabel
I
Torgal
Escola Superior Agrária de Santarém, Quinta do Galinheiro, 2001-904, Santarém, Portugal.
Margarida
M
Goulart
Escola Superior Agrária de Santarém, Quinta do Galinheiro, 2001-904, Santarém, Portugal.
Jorge
J
Justino
Centro de Química e Bioquímica, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016, Lisbon, Portugal. aimartins@fc.ul.pt.
Alice
A
Martins
Centro de Química e Bioquímica, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016, Lisbon, Portugal.
Amélia P
AP
Rauter
Antioxidant activity; Flavonoid glycosides; HPLC–DAD-ESI–MS/MS; In vitro digestion; α-Glucosidase inhibition