Toshitsugu Sato

Glycyrrhizin prevents of lipopolysaccharide/D-galactosamine-induced liver injury through down-regulation of matrix metalloproteinase-9 in mice

Glycyrrhizin, a biological active compound isolated from the liquorice root, has been used as a treatment for chronic hepatitis. We have examined the involvement of matrix metalloproteinase (MMP)‐9 in the development of lipopolysaccharide (LPS) and D‐galactosamine (GalN)‐induced liver injury in mice. We also investigated the effect of glycyrrhizin on expression of MMP‐9 in this model. Levels of serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) increased after LPS/GalN treatment. Expression of MMP‐9 mRNA and protein was markedly up‐regulated in liver tissues 6–8 h after LPS/GalN treatment. Pretreatment with glycyrrhizin (50 mg kg−1) and the MMP inhibitor (5 mg kg−1) suppressed increases in serum levels of ALT and AST in mice treated with LPS/GalN. Furthermore, glycyrrhizin inhibited levels of both mRNA and protein for MMP‐9. Immunohistochemical reaction for MMP‐9 was observed in macrophages/monocytes infiltrated in the inflammatory area of liver injury. Glycyrrhizin reduced the infiltration of inflammatory cells and immunoreactive MMP‐9 in liver injury. The results indicated that MMP‐9 played a role in the development of LPS/GalN‐induced mouse liver injury, and suggested that an inhibition by glycyrrhizin of the acute liver injury may have been due to a down‐regulation of MMP‐9.

Inhibition by licochalcone A, a novel flavonoid isolated from liquorice root, of IL‐1β‐induced PGE2 production in human skin fibroblasts

Licochalcone A, a novel flavonoid isolated from the root of Glycyrrhiza inflata, has been reported to exhibit anti‐inflammatory activity in animal models. In this study, we examined the effect of licochalcone A on the production of chemical mediators such as prostaglandin (PG)E2 and cytokines by interleukin (IL)‐1β in human skin fibroblasts. Licochalcone A (IC50 15.0 nm) inhibited PGE2 production, but not IL‐6 and IL‐8 production, in response to IL‐1β. NS‐398 (IC50 1.6 nm), a COX‐2 selective inhibitor, also suppressed the PGE2 production. Furthermore, licochalcone A and NS‐398 suppressed PGF2α production by IL‐1β. However, licochalcone A (1 μm) had no effect on increased levels of cyclooxygenase (COX)‐2 mRNA and protein in cells. Dexamethasone (100 nm) not only inhibited PGE2, PGF2α, IL‐6 and IL‐8 production but also strongly suppressed the expression of COX‐2 mRNA and protein. Licochalcone A had no effect on COX‐1‐dependent PGE2 production, whereas indometacin (100 nm), a dual inhibitor of COX‐1 and COX‐2, was very effective. These results suggest that licochalcone A induces an anti‐inflammatory effect through the inhibition of COX‐2‐dependent PGE2 production. Furthermore, it appears that the inhibitory effect of licochalcone A on PGE2 production in response to IL‐1β is quite different from that of the steroid.

Interanal stool bag for the bedridden elderly with pressure ulcer

Elderly bedridden patients with decubitus suffer from infection by decubitus contamination from stools. We developed a disposable interanal stool bag that collects stools without contamination. The interanal stool bag attaches perianally and detaches easily, similar to an artificial anal bag. Since the new bag keeps the perineum clean, it is accepted not only by patients with bed sores but also by caregivers.