No abstract

Although Aster glehni has been reported to prevent diabetes mellitus, hypercholesterolemia, insomnia, and cardiovascular disease, the anti-inflammatory effect of Aster glehni in colonic tissue remains unclear. In this study, we investigated the anti-inflammatory effects and the underlying molecular mechanism of an ethanol extract of Aster glehni (AG) in mice with dextran sulfate sodium (DSS)-induced colitis. AG significantly attenuated DSS-induced DAI scores, which implied that it suppressed diarrhea, gross bleeding, and the infiltration of immune cells. AG administration also effectively prevented shortening of the colon length and enlargement of the spleen size. Histological examinations indicated that AG suppressed colonic damage and the thickness of the muscle layer induced by DSS. In addition, AG inhibited the production of pro-inflammatory cytokines, such as TNF-α, IL-1β, and IL-6, and the protein expression of COX-2 and iNOS in mice with DSS-induced colitis. Administration with AG suppressed the activation of nuclear factor-κB (NF-κB) including the nuclear translocation of the p65 NF-κB subunit, phosphorylation and degradation of IκB-α. Taken together, these findings suggest that the anti-inflammatory effects of AG are mainly related to the inhibition of the expressions of inflammatory mediators via NF-κB inactivation, and support its possible therapeutic application in colitis.

Phytochemical studies on the constituents of the rhizomes of Imperata cylindrica (Gramineae) were performed using high-performance liquid chromatography (HPLC). We also aimed to search for any biologically active substance capable of inhibiting nitric oxide (NO) formation in lipopolysaccharide (LPS)-activated macrophage 264.7 cells, by testing four compounds isolated from this plant. Four compounds, including a new chromone, isoeugenin, along with ferulic acid, p-coumaric acid, and caffeic acid were isolated and identified by NMR spectroscopy. The structure of isoeugenin was determined as 7-hydroxy-5-methoxy-2-methylchromone by the 2D-NMR technique. Among the four compounds, isoeugenin has the lowest IC 50 value on the inhibition of NO production in LPS-activated macrophage RAW264.7 cells (IC 50 , 9.33 µg/mL). In addition, isoeugenin significantly suppressed the LPS-induced expressions of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), and proinflammatory cytokines mRNA levels. Taken together, these results suggest that the anti-inflammatory activity of isoeugenin is associated with the down-regulation of iNOS, COX-2, and pro-inflammatory cytokines in RAW264.7 cells. Accordingly, our results suggest that the new chromone isoegenin should be considered a potential treatment for inflammatory disease.

Animal experiments were performed to develop Salvia plebeia (Labiatae) as a medicinal herb with sedative and gastroprotective activities; the former activity was measured using a pentobarbital-induced assay and the latter activity was measured in two gastric lesion-induced assays (HCl/EtOH-induced and indomethacin/bethanechol-induced assays) in mice. The MeOH extract and its EtOAc fraction were effective, although the former was less active than the latter. Rosmarinic acid (RA) isolated from S. plebeia was active in the same method at 10 and 20 mg/kg (p.o.). HPLC quantification demonstrated that RA comprised the largest proportion (28.5% of the MeOH extract, 33.0% of EtOAc extract; 4.46% of dry weight) of S. plebeia. The contents of five other compounds were much less than that of RA, although the contents of the three glycosides, 6-hydroxyluteolin 7-O-glucoside (0.28% of dry weight), cynaroside (0.35%) and nepitrin (0.43%) were higher than those of the two aglycones, quercetin (0.024%) and eupatilin (0.058%). The HPLC method was validated in terms of linearity, precision, accuracy and reproducibility. These results suggest that the main polyphenol, RA, plays a major role in the sedative and gastroprotective effects of S. plebeia.