Anti-inflammatory Potential of Artemisia capillaris and Its Constituents in LPS-induced RAW264.7 Cells

Artemisia capillaris has been widely used as an alternative therapy for treating obesity and atopic dermatitis. It has been used as a hepatoprotactant. It is also used for ameliorating inflammatory reactions. Although there are several investigations on other Artemisia species, there is no systematic study describing the role of A. capillaris MeOH extract, its solvent soluble fractions, or derived anti-inflammatory principal components in regulating inflammatory conditions. Therefore, the objective of this study was to elucidate anti-inflammatory mechanisms of A. capillaris. Results revealed that MeOH extract of A. capillaris could decrease LPS-stimulated NO secretion. Of tested fractions, CH₂Cl₂, EtOAc, and n-BuOH strongly inhibited NO release from RAW264.7 cells. Bioactive mediators derived from CH₂Cl₂ and n-BuOH fractions elicited potent anti-inflammatory actions and strikingly abrogated LPS-triggered NO accumulation in RAW264.7 cells. Of particular interest, capillin and isoscopoletin possessed the most potent NO suppressive effects. Western blot analysis validated the molecular mechanism of NO inhibition and showed that capillin and isoscopoletin significantly down-regulated iNOS and COX-2 protein expression. Taken together, our results provide the first evidence that MeOH extract, CH₂Cl₂, EtOAc, and n-BuOH fractions from A. capillaris and its derived lead candidates can potently suppress inflammatory responses in macrophages by hampering NO release and down-regulating iNOS and COX-2 signaling.

Inhibition of advanced glycation endproducts formation by Korean thistle, Cirsium maackii

Objective: To evaluate inhibitory potential of seven Korean thistles against the advanced glycation endproducts (AGE) formation as well as to identify responsible compounds from the most active species. Methods: We used an in vitro AGE inhibition assay to evaluate the anti-diabetic complication potential of the methanol extracts of the selected Korean thistles. Results: Among the seven Korean thistles, the leaves of Cirsium maackii (C. maackii) exhibited the most significant inhibitory activity against AGE formation. By means of bioassay-directed fractionation, a lignan, chlorogenic acid and 14 flavonoids were isolated from the active ethyl acetate soluble fraction of a methanol extract from C. maackii leaves. Luteolin and its 5-O-glucoside have been previously isolated; however, a lignan and 13 known compounds were isolated for the first time from C. maackii leaves in this study. Most of the isolated compounds exhibited inhibitory activities against potential AGE formation. Among them, cernuoside was shown to be the most potent AGE inhibitor with an IC50 value of 21.21 μ mol/L. Most importantly, two major flavonoids, luteolin and its 5-O-glucoside, also significantly inhibited AGE formation, with IC50 values of 36.33 and 37.47 μ mol/L, respectively. Structure activity relationship revealed that the presence of free 3' and 4' dihydroxyl group in flavonoids skeleton played an important role in AGE inhibition. Conclusions: These results indicate that C. maackii and C. maackii-derived flavonoids might be explored further to develop therapeutic agents for the prevention of diabetic complications due to their significant inhibitory activity against AGE formation.

Inhibition of advanced glycation endproducts formation by Korean thistle, Cirsium maackii

OBJECTIVE@#To evaluate inhibitory potential of seven Korean thistles against the advanced glycation endproducts (AGE) formation as well as to identify responsible compounds from the most active species.@*METHODS@#We used an in vitro AGE inhibition assay to evaluate the anti-diabetic complication potential of the methanol extracts of the selected Korean thistles.@*RESULTS@#Among the seven Korean thistles, the leaves of Cirsium maackii (C. maackii) exhibited the most significant inhibitory activity against AGE formation. By means of bioassay-directed fractionation, a lignan, chlorogenic acid and 14 flavonoids were isolated from the active ethyl acetate soluble fraction of a methanol extract from C. maackii leaves. Luteolin and its 5-O-glucoside have been previously isolated; however, a lignan and 13 known compounds were isolated for the first time from C. maackii leaves in this study. Most of the isolated compounds exhibited inhibitory activities against potential AGE formation. Among them, cernuoside was shown to be the most potent AGE inhibitor with an IC50 value of 21.21 μ mol/L. Most importantly, two major flavonoids, luteolin and its 5-O-glucoside, also significantly inhibited AGE formation, with IC50 values of 36.33 and 37.47 μ mol/L, respectively. Structure activity relationship revealed that the presence of free 3' and 4' dihydroxyl group in flavonoids skeleton played an important role in AGE inhibition.@*CONCLUSIONS@#These results indicate that C. maackii and C. maackii-derived flavonoids might be explored further to develop therapeutic agents for the prevention of diabetic complications due to their significant inhibitory activity against AGE formation.