Broccoli (Brassica oleracea var. italia) florets were extracted with 80% methanol and the extract was sequentially fractionated with n-hexane, ethyl acetate, n-butanol, and distilled water. The extract and the fractions were evaluated for total phenolic content, sulforaphane content, antioxidant activity, and anti-inflammatory activity in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. The total phenolic content and sulforaphane content of the ethyl acetate fraction (EF) were 35.5 mg gallic acid equivalents/g and 620.2 μg/g, respectively. These values were higher than those of the 80% methanol extract and organic solvent fractions. The oxygen radical absorbance capacity of the EF [1,588.7 μM Trolox equivalents (TE)/mg] was 11-fold higher than that of the distilled water fraction (143.7 μM TE/mg). The EF inhibited nitric oxide release from LPS-stimulated RAW 264.7 cells in a dose-dependent manner and inhibited IκB-α degradation and nuclear factor-κB activation in LPS-stimulated RAW 264.7 cells. In conclusion, the EF of broccoli florets exerted potent antioxidant and anti-inflammatory effects.
Keywords: anti-inflammatory activity; antioxidant activity; broccoli florets; sulforaphane; total phenolics.