Manh Heun Kim

The antioxidant and anti-inflammatory effects of phenolic compounds isolated from the root of Rhodiola sachalinensis A. BOR.

Isolation of compounds from the root of Rhodiola sachalinensis (RRS) yielded tyrosol (1), salidroside (2), multiflorin B (3), kaempferol-3,4′-di-O-β-D-glucopyranoside (4), afzelin (5), kaempferol (6), rhodionin (7), and rhodiosin (8). Quantification of these compounds was performed by high-performance liquid chromatography (HPLC). To investigate the antioxidant and anti-inflammatory effects of the compounds, DPPH radical scavenging, NBT superoxide scavenging and nitric oxide production inhibitory activities were examined in LPS-stimulated Raw 264.7 cells. We suggest that the major active components of RRS are herbacetin glycosides, exhibiting antioxidant activity, and kaempferol, exhibiting anti-inflammatory activity.

Two new hemiterpene glycosides from the leaves of Ilex rotunda. thunb

Chromatographic separation of the 80% MeOH extract of the leaves of Ilex rotunda (IR) led to isolation of two new hemiterpene glycosides, tentatively named as rotundarpenoside A (1) and rotundarpenoside B (2), along with five known caffeoyl derivatives (3–7). The chemical structures of these compounds were elucidated using 1D/2D NMR, HR-MS, and the absolute configuration was confirmed by Mosher’s method. In order to evaluate their anti-oxidative activities, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity and xanthine oxidase superoxide scavenging activities (NBT) were determined.

Rotundarpene inhibits Toll-like receptor 2 activation-induced production of inflammatory mediators in keratinocytes by suppressing the Akt and NF-κB pathways

Microbial components have been shown to be involved in the pathogenesis of inflammatory skin diseases. The extract of from the barks of Ilex rotunda Thunb has demonstrated anti-inflammatory and anti-oxidant effects. However, the effect of hemiterpene rotundarpene (4-caffeoyl-3-methyl-but-2-ene-1,4-diol) on the Toll-like receptor (TLR)-2 activation-induced production of inflammatory mediators in keratinocytes has not been studied. Using human keratinocytes, we investigated the effect of rotundarpene on the inflammatory mediator production in relation to the TLR-2-mediated-Akt and NF-κB pathways, which regulates the transcription genes involved in immune and inflammatory responses. Rotundarpene, Akt inhibitor, Bay 11-7085 and N-acetylcysteine each attenuated the lipoteichoic acid- or peptidoglycan-induced production of cytokines and chemokines, expression of TLR-2, activation of NF-κB and Akt, and formation of reactive oxygen species in keratinocytes. Cyclosporine A attenuated the bacterial component-induced production of inflammatory mediators but did not reduce the formation of reactive oxygen species. The results show that rotundarpene may attenuate the bacterial component-stimulated production of inflammatory mediators in keratinocytes by suppressing the TLR-2-mediated activation of the Akt and NF-κB pathways. The effect of rotundarpene may be attributed to its inhibitory effect on the formation of reactive oxygen species. Rotundarpene may exert a preventive effect against the bacterial component-mediated inflammatory skin diseases.

Anti-Oxidative and Anti-Proliferative Activity on Human Prostate Cancer Cells Lines of the Phenolic Compounds from Corylopsis coreana Uyeki

Fifteen phenolic compounds, including three caffeoyl derivatives, four gallotannins, three ellagitannins and five flavonoids, were isolated from an 80% MeOH extract of the leaves of Corylopsis coreana Uyeki (Korean winter hazel; CL). The anti-oxidative activities [1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity and xanthine oxidase superoxide scavenging activities (NBT)] and the anti-proliferative activity on human prostate cancer cell lines (DU145 and LNCaP) were also evaluated.

3,4,5-tricaffeoylquinic Acid inhibits the lipopolysaccharide-stimulated production of inflammatory mediators in keratinocytes.

Background and Purpose: Microbial product lipopolysaccharide (LPS) has been shown to be involved in the pathogenesis of inflammatory skin diseases. Caffeoyl derivatives have demonstrated anti-inflammatory and antioxidant effects. However, the effect of 3,4,5-tricaffeoylquinic acid (3,4,5-triCQA) on the production of microbial product-induced inflammatory mediators in keratinocytes has not yet been studied. Experimental Approach: Using human keratinocytes, we investigated the effect of 3,4,5-triCQA on the LPS-stimulated production of inflammatory mediators in relation to the nuclear factor (NF)-ĸB, Akt and ERK pathways. Results: 3,4,5-triCQA inhibited the LPS-induced expression of Toll-like receptor 4, and the production of cytokines and chemokines in keratinocytes. 3,4,5-triCQA, Bay 11-7085, Aĸt inhibitor and ERK inhibitor each attenuated the LPS-induced production of inflammatory mediators by inhibiting the NF-ĸB, Akt and ERK pathways. Conclusions and Implications: 3,4,5-triCQA may attenuate the LPS-stimulated production of inflammatory mediators in keratinocytes by suppressing the Toll-like receptor 4 expression-mediated activation of the Akt, ERK and NF-ĸB pathways. 3,4,5-triCQA may exert a preventive effect against microbial product-induced inflammatory skin diseases.

Two new phenolic compounds from the leaves of Alnus sibirica Fisch. ex Turcz.

Two new phenolic compounds, 4-O-glucopyranosyl-5-O-caffeoylshikimic acid (1) and 2,3-digalloyl oregonin (2), were isolated along with eight known phenolic compounds (3–10) from an 80% acetone extract of Alnus sibirica leaves. The chemical structures of these compounds were elucidated using 1D/2D nuclear magnetic resonance and high resolution-MS. The anti-oxidative activities of these compounds were determined by assaying their 1,1-diphenyl-2-picrylhydrazyl radical and nitroblue tetrazolium superoxide anion scavenging activity. All of the isolated phenolic compounds (1–10) exhibited potent anti-oxidative activities. In particular, 2 and 4, which are diarylheptanoids, and 10 which is ellagitannin exhibited excellent anti-oxidative activities with almost the same potency as that of the positive controls L-ascorbic acid and allopurinol.

The comparison of DPPH-scavenging capacity and anti-inflammatory effects of phenolic compounds isolated from the stems of Stewartia koreana Nakai

The Stewartia koreana Nakai (SK) had been used in oriental traditional medicine as a remedy for acute gastroenteritis, liver diseases, quadriplegia and pain. The antioxidant activity guided isolation 80% methyl extract from stems of SK yielded eight phenolic compounds. We evaluated the anti-oxidative and anti-inflammatory effects of these compounds via assays of 1,1-diphenyl-2-picrylhydazyl (DPPH) radicals and inhibition of nitric oxide (NO) production in lipopolysaccharide-stimulated RAW 264.7 macrophage cells. The results demonstrated that syringaresinol (6) exhibited significant DPPH radical-scavenging activity and inhibitory effects on NO production compared with its positive controls, ascorbic acid and l-NMMA, respectively.