Anti-inflammatory effects of enzyme-treated asparagus extract and its constituents in hepatocytes

摘要

Background: Asparagus ( Asparagus officinalis L.) is one of the most ancient vegetables, and it is rich in asparagine. Enzyme-treated asparagus extract (ETAS?; Amino Up Chemical Co., Ltd., Sapporo, Japan) is the final product of enzyme-treatment of asparagus stems and subsequent extraction. Two constituents were purified from ETAS and identified: 5-hydroxymethyl-2-furfural (HMF), an abundant constituent, and ( S )-asfural, a novel constituent, which is a derivative of HMF. ETAS has been reported to increase the expression of heat shock proteins (HSPs), which are essential for the repair or removal of defective proteins. The expression of Hsp family genes is regulated by the transcription factor heat shock factor 1 (HSF1). It is unknown whether ETAS and its constituents elicit anti-inflammatory effects, such as the suppression of nitric oxide (NO), an inflammatory mediator synthesized by inducible nitric oxide synthase (iNOS) in interleukin (IL)-1β-treated hepatocytes.