In vitro anti-oxidant and hypoglycemic activity of acetonitrile-water extract of Origanum vulgare leaves harvested in different times / 中草药

ABSTRACT

Objective: By investigating the material composition, anti-oxidant and hypoglycemic activity of acetonitrile-water extracts of Origanum vulgare leaf (OL) in different harvest time, to acquire the scientific data for the utilization of OL. Methods: OL was extracted with acetonitrile and water (1 1). The contents of total phenols and total flavonoid were measured by Foline-Phenol reagent method and AlCl3 colorimetry. The main compositional analysis was performed using LC-QTOF-MS technology. Meanwhile, the anti-oxidation of OL extracts in different harvest time was evaluated by total anti-oxidant capacity assay kit with ABTS method and ferric reducing anti-oxidant potential assay (FRAP). The methods of 2-NBDG glucose uptake and α-glycosides inhibition were applied to evaluate hypoglycemic activity of OL extracts. Results: The six main components in OL extract were identified to be origanoside I, luteolin 7-O-glucuronide, apigenin 7-O-glucuronide, rosmarinic acid, lithospermic acid and origanoside I derivative. The contents of total phenols and the total flavonoids were the highest in OL extracts harvested in July and September, respectively. There was good in vitro anti-oxidant and hypoglycemic activity for OL extracts harvested in different times. Among them, the best anti-oxidant activity was observed in OL extracts harvested in July, while the best hypoglycemic activity was observed in OL extracts harvested in October. Conclusion: OL has potential anti-oxidant and hypoglycemic activity, which is affected by the harvest time.