Preliminary Study On The 5-lipoxidase Inhibitory Activities Of Chinese Yam (Dioscorea Opposita Thunb.)

5-lipoxidase (5-LOX) is one of the key enzymes in inflammation.Chinese yam(Dioscorea opposita Thunb.) as a medical and edible plant with various activities and functions. This study investigated the inhibitory activity of Chinese yam on 5-LOX1. Inhibition of yam extracts on the 5-LOXThe inhibitory activities of extracts from yam against 5-LOX was carried out by Fe2+ -xylenol orange method in vitro under the condition of 25 ℃ in Tris-HCl solution containing 230 U/mL enzyme and 7 μmol/L LA. The FOX reagent was added in the solution at the ratio of 1:1, and the reaction time is 10 min. The Ethyl acetate portion showed stronger inhibitory effect with ICso=25.00mg/L.2. Isolation and identification of Ethyl acetate portion of Chinese yam’extracts.Using Silica gel column chromatography, batatasin Ⅰ,β-sitosterol and6,7-dihydroxy-2,4-phenanthrene were isolated and identified from ethyl acetate portion of Chinese yam’ extracts.3. Inhibition of several compounds from yam on the 5-LOXThe inhibition of several compounds from yam including β-sitosterol, allantoin, batatasin Ⅰ, batatasin Ⅴ,batatasin Ⅳ, and two analogs of batatasin Ⅳ.6,7-dihydroxy-2,4-phenanthrene against 5-LOX were assayed. The results revealed that 6,7-dihydroxy-2,4-phenanthrene showed stronger inhibitory effect with IC50=0.30 mmol/L, however, the inhibition of batatasin Ⅳ, and two analogs of batatasin Ⅳ were all less than 35% at the concentration of 1 mmol/L.