, and Decoctions: Antioxidant Activities and Inhibition of Carbohydrate and Lipid Metabolic Enzymes.

Vahl., A. Gray, and L. decoctions were investigated for their health-benefit properties, in particular with respect to antioxidant activity and inhibitory ability towards key enzymes with impact in diabetes and obesity (α-glucosidase, α-amylase and pancreatic lipase). Additionally, the phenolic profiles of the three decoctions were determined and correlated with the beneficial properties. The decoction was the most promising in regard to the antioxidant effects, namely in the scavenging capacity of the free radicals DPPH, NO and O₂, and the ability to reduce Fe, as well as the most effective inhibitor of α-glucosidase (EC = 36.0 ± 2.7 μg/mL vs. EC = 345.3 ± 6.4 μg/mL and 71.2 ± 5.0 μg/mL for and respectively). This superior activity of the decoction over those of and was, overall, highly correlated with its richness in caffeic acid and derivatives. In turn, the decoction exhibited good inhibitory capacity against xanthine oxidase activity, a fact that could be associated with its high content of flavones, in particular the glycosidic forms of apigenin, scutellarein and luteolin.