Bioconversion enhances anti-oxidant and anti-inflammation activities of different parts of the Mulberry Tree (Morus alba L.), especially the leaf (Mori Folium)

The mulberry tree (Morus alba L.) has been traditionally used in Chinese medicine to treat inflammatory diseases. We investigated the effects of bioconversion on different components of the mulberry tree, and determined changes in the physiological activities. Ethyl acetate-soluble fractions of five different segments (fruit, Mori Fructus; leaf, Mori Folium; twig, Mori Ramulus; root, Mori Cortex; and mistletoe, Loranthi Ramulus) of the mulberry tree show enhanced anti-oxidant effects in the 2,2-diphenyl-1-picrylhydrazyl, and 2,2'-azinobis-(3-ethylvenzothiazoline-6-sulfonic acid) assays, and enhanced anti-inflammatory effects of lipopolysaccharide (LPS)-stimulated nitric oxide (NO) production in RAW 264.7 macrophages, after being treated with a crude enzyme extract from Aspergillus kawachii, in the following order of activity: Mori Folium>Mori Cortex>Mori Ramulus>Mori Fructus> Loranthi Ramulus. Ethyl acetatesoluble fraction of mulberry leaves (Mori Folium) that underwent bioconversion was most effective, and was devoid of any cytotoxicity. The fraction was also effective against mRNA expression of LPS-induced proinflammatory cytokines, such as inducible nitric oxide synthase, cyclooxygenase-2, tumor necrosis factor-α, interleukin-1β, and interleukin-6. In addition, the fraction was effective in LPSinduced phosphorylation of mitogen-activated protein kinases and IKK, and IκB degradation, followed by translocation of the nuclear factor-κB from the cytoplasm to the nucleus. Thus, bioconversion increased the anti-oxidative and anti-inflammatory activities of the mulberry leaf.