Correlation Analysis between the Active Ingredients and the Antioxidant or Cholate-binding Ability of Ethanol Extracts from Psoralea corylifolia L.

Objective: The contents of main active ingredients, antioxidant and cholate binding ability of different ethanol extracts from Psoralea corylifolia L. were explored based on the mode of correlation of “components-efficacy”. Methods: Psoralea corylifolia L. was extracted with anhydrous ethanol, 75% ethanol, 50% ethanol and water. The contents of total flavonoids and total polyphenols in Psoralea corylifolia L. were determined. The antioxidant and lipid-lowering activities in vitro of Psoralea corylifolia L. were evaluated by three antioxidant systems and the binding ability of cholate salts, respectively, and the correlation analysis was conducted. Results: The contents of total flavonoids and total polyphenols in anhydrous ethanol extract were the highest, (50.317±0.018) mg/g and (3.860±0.045) mg/g, respectively. The 50% ethanol extract showed the best ability to scavenge ABTS^＋· and DPPH·, the IC₅₀ values were 0.76 and 1.63 mg/mL, respectively. The anhydrous ethanol extract showed the strongest reducing ability, the A_0.5 value was 2.63 mg/mL. The water extract showed the strongest binding capacity to sodium cholate, the IC₅₀ value was 0.67 mg/mL. The 50% ethanol extract showed the strongest binding capacity to sodium taurocholate and sodium glycinate, the IC₅₀ values were 1.26 and 0.41 mg/mL, respectively. The correlation results showed that the content of total flavonoids of different ethanol extracts from Psoralea corylifolia L. had a significant positive correlation with DPPH· clearance rate and sodium taurocholate binding rate (P<0.05). And the content of total flavonoids and total polyphenols had a very significant positive correlation with reduction ability (P<0.01). While the content of total polyphenols had a significant negative correlation with sodium cholate binding rate (P<0.05). Conclusion : The 50% ethanol extract of Psoralea corylifolia L. has high content of active ingredients and the strongest antioxidant and cholate binding ability. It can be used as a potential important source of natural antioxidant and lipid-lowering active substances.