Extract of Ziziphus jujuba Fruit (Jujube) Stimulates Expression of Enzymes Responsible for Heme Recycle via Anti-oxidant Response Element in Cultured Murine Macrophages.

Jujube, the fruit of Ziziphus jujuba Mill., is a functional food and commonly used as a health supplement worldwide. To study the beneficial role of jujube in heme iron recycling during erythrophagocytosis, the expression of heme oxygenase-1 (HO-1), biliverdin reductase A and B, and ferroportin were determined in jujube-treated cultured RAW 264.7 macrophages. Application of a chemically standardized jujube water extract in cultured RAW 264.7 cells for 24 h stimulated the expressions of HO-1, biliverdin reductase A, biliverdin reductase B, and ferroportin in a concentration-dependent manner, having the maximal responses from twofolds to threefolds. A plasmid containing anti-oxidant response element, a regulator for HO-1 transcription, was transfected into RAW 264.7 cells. Application of jujube water extract onto the transfected macrophages stimulated the anti-oxidant response element-mediated transcriptional activity by twofolds. These results supported the potential capacity of jujube by regulating expressions of heme iron recycling genes in cultured macrophages.