In vitro antioxidant activity of Parnassia wightiana W. extracts

AIM: To investigate the total flavonoid contents and in vitro antioxidant activity of different extracts from Parnassia wightiana and their correlation. METHODS: 50% ethanol (in water, V/V) extract from Parnassia wightiana W. was successively extracted by using 3 kinds of different solvents to provide chloroform extract (CE), ethyl acetate extract (EAE), n-butanol extract (BE) and water extract (WE). The content of flavonoids in each extract was determined using the NaNO2-Al(NO3)3-NaOH method. Different antioxidant assays (OH, O2-, DPPHscavenging activity, reducing power and metal chelating activity) were employed to evaluate the antioxidant activities of four extracts, using butylated hydroxytoluene (BHT) as a reference. RESULTS: The total flavonoid content in EAE was the highest, followed BE, WE and CE. WE and BE showed better antioxidant activity than CE and EAE. Each extract showed concentration dependent antioxidant activity and a high correlation between content of flavonoids and antioxidant activity. CONCLUSION: The extrat of Parnassia wightiana W. may be used as natural antioxidant.