Antioxidant Activity andα-Amylase Inhibitory Effect of Polyphenolic-Rich Extract fromOriganum GlandulosumDesf

Abstract

The polyphenolic-rich extract of Tunisian Origanum glandulosum Desf. was investigated for its phenolic composition, antioxidant activity and potential to contribute to the dietary management of type II diabetes. By mean of an ultra-performance liquid chromatography-electrospray ionization- mass spectrometry (UPLC-PDA-ESI-MS) 16 phenolics were characterized. The major detected compounds are caffeic acid, luteloin glucoside, xanthomicrol and carvacrol. The polyphenolic-rich extract presented a notable antioxidant activity similar to that of the synthetic antioxidant Trolox. It was found to inhibit, in a concentration dependent manner, the α-amylase activity with an IC50 value (8.22 mg/mL) comparable to that of Acarbose (6.12 mg/mL). Overall, our findings suggest that O. glandulosum could be considered as a valuable source of high-value phytochemicals with pharmaceutical and functional food additive applications. Practical Applications Origanum glandulosum Desf., a North African endemic species, is one of the most used plants in folk medicine against whooping cough, fever, bronchitis and diabetes. In the present work, the ability of O. glandulosum to inhibit pancreatic α-amylase in vitro as well as to act as antioxidant food was investigated. The results suggest that O. glandulosum could be considered as a valuable source of phytochemicals with a potent α-amylase inhibition property and antioxidant capacity. Further animal and clinical studies were needed to confirm the potential use of O. glandulosum for the management of type II diabetes.