Ji Ye Mok

Effect of Electrospun Non-Woven Mats of Dibutyryl Chitin/Poly(Lactic Acid) Blends on Wound Healing in Hairless Mice

The aim of this study was to examine the proliferative ability of dibutyryl chitin (DBC) on scratch wounds in HaCaT keratinocytes and to evaluate the effect of nanoporous non-woven mat (DBCNFM) on skin wound healing in hairless mice using the advantages of DBCNFM, such as high porosity and high surface area to volume. The cell spreading activity of DBC was verified through a cell spreading assay in scratched human HaCaT keratinocytes. Scratch wound experiments showed that DBC notably accelerates the spreading rate of HaCaT keratinocytes in a dose dependent manner. The molecular aspects of the healing process were also investigated by hematoxylin & eosin staining of the healed skin, displaying the degrees of reepithelialization and immunostaining on extracellular matrix synthesis and remodeling of the skin. Topical application of DBCNFM significantly reduced skin wound rank scores and increased the skin remodeling of the wounded hairless mice in a dose dependent way. Furthermore, DBCNFM notably increased the expression of the type 1 collagen and filaggrin. These results demonstrate that DBC efficiently accelerates the proliferation of HaCaT keratinocytes and DBCNFM notably increases extracellular matrix synthesis on remodeling of the skin, and these materials are a good candidate for further evaluation as an effective wound healing agent.

Inhibitory effect of dibutyryl chitin ester on nitric oxide and prostaglandin E2 production in LPS-stimulated RAW 264.7 cells

Inflammation is a highly complex process that protects against foreign challenge or tissue injury. The ester derivative dibutyryl chitin (DBC) reportedly accelerates wound healing and exerts an anti-inflammatory effect. However, little is known regarding the inhibitory effect of DBC in anti-inflammation. In this study, we investigated the effect of DBC on the inducible nitric oxide synthetase (iNOS) and cyclooxygenage-2 (COX-2) pathways and pro-inflammatory cytokine production in lipopolysaccharide (LPS)-treated RAW 264.7 macrophages. Our results demonstrate that DBC (MW 3,772) significantly inhibits overproduction of NO and PGE2 as well as pro-inflammatory cytokines, such as tumor necrosis factor-α and interleukin-1β, in LPS-stimulated RAW 264.7 macrophages. Inhibition of NO and PGE2 overproduction in LPSstimulated RAW 264.7 macrophages by DBC was mediated through the down-regulation of iNOS and COX-2 expression. These results demonstrate that DBC efficiently inhibits inflammation and has potential as an effective anti-inflammatory and wound healing agent.

Prenylated chalcone from Sophora flavescens suppresses Th2 chemokine expression induced by cytokines via heme oxygenase-1 in human keratinocytes.

We recently reported the inhibitory effect of an oral administration of a Sophora flavescens Aiton methanol extract on the development of atopic dermatitis in the NC/Nga model mice. Heme oxygenase (HO)-1 has recently emerged as an important cytoprotective enzyme against oxidative stress and inflammatory responses in many cell types. The aim of this study was to investigate the possible mechanism by which prenylated chalcone (PC, 7,9,2′,4′-tetrahydroxy-8-isopentenyl-5-methoxychalcone), a natural product isolated from S. flavescens, inhibited cytokine-induced Th2 chemokine expression in human keratinocytes, HaCaT cells. The level of chemokine expression was measured by reverse transcription-polymerase chain reaction and HO-1 study was performed by Western blot analysis. Interferon-γ (IFN-γ) and tumor necrosis factor-α (TNF-α)-induced thymus- and activation-regulated chemokine (TARC/CCL17), macrophage-derived chemokine (MDC/CCL22), cutaneous T-cell attracting chemokine (CTACK/CCL27) expression in a dose-dependent manner. Interestingly, PC significantly suppressed IFN-γ and TNF-α-induced TARC/CCL17, MDC/CCL22 and CTACK/CCL27 expression via the induction of heme oxygenase (HO)-1. This suppression was completely restored by HO-1 siRNA, suggesting a direct role of HO-1 for the suppressive effect. Furthermore, exogenous CO, but not other end products of HO-1 activity, also suppressed IFN-γ and TNF-α-induced TARC/CCL17, MDC/CCL22 and CTACK/CCL27 expression. These results demonstrate that prenylated chalcone induces HO-1 expression, which in turn HO-1 and/or CO suppresses Th2 chemokine expressions induced by cytokines in human HaCaT cells.

Antioxidant and Anti-inflammatory Effects of Ethanol Extracts from Perilla frutescens

Department of Food and Nutrition, Kunsan National UniversityAbstract We investigated the effects of an ethanol extract from Perilla frutescens sprouts (PFSE) as an antioxidant, andits effects on edema and inflammation in RAW 264.7 cells and HMC-1 cells. The antioxidant activities (DPPH and ABTSradical scavenging) of PFSE were similar to those of butylated hydroxytoluene (BHT) and (±)-6-hydroxy-2,5,7,8-tetramethylchromane-2-carboxylic acid (Trolox). We also investigated the anti-inflammatory effects of PFSE onlipopolysaccharide (LPS)-stimulated RAW 264.7 cells and HMC-1 cells stimulated with phorbol 12-myristate 13-acetate(PMA) with the calcium ionophore A23187. TNF-α and IL-1β production, which had been increased by treatment withLPS or PMA plus A23187, were significantly inhibited by PFSE in a dose-dependent manner. Furthermore, PFSEsignificantly reduced the xylene-induced ear edema and the carrageenan-induced paw edema of ICR mice in a dose-dependent manner. The effects of PFSE (200 mg/kg) in reducing ear and paw edema were similar to those of aspirin (50mg/kg). These results suggest that PFSE can be potentially used as a medicine for treating oxidative stress, an edematousand inflammatory disease.Keywords: Perilla frutescens sprouts, ethanol extract, antioxidant, edema, anti-inflammation

Effects of Antioxidant and Blood Flow Improvement of Grape Leaf Extract and Resveratrol from Vitis romaneti

The purpose of this study is to investigate the effects of 80% ethanol grape leaf extract (VGLE) and resveratrol (VGLR) from Vitis romaneti on antioxidant of red blood cells (RBC) of rat and efficacy of blood flow improvement in a rat model of topical ferric chloride ()-induced carotid artery damage. RBC oxidative hemolysis and plasma lipid peroxidation induced by the aqueous peroxyl radical generator 2,2`-azobis(2-amidinopropane) dihydrochloride were significantly suppressed by VGLE or VGLR in a dose-dependent manner. The treatment seriously damaged the carotid artery: the walls of the artery and blood flow. However, VGLE or VGLR administration has ameliorated the blood flow and suppressed thrombus in blood vessels. These results suggest that VGLE or VGLR ameliorates the oxidative stress of RBC and thrombosis against blood vessel damage.

Effect of Persimmon Leaf Extract on Phthalic Anhydride-induced Allergic Response in Mice.

The purpose of this study was to investigate the anti-allergy activities of persimmon leaf extract (PLE) on a phthalic anhydride (PA)-induced allergic mouse model. A human leukemic mast cell line (HMC-1) was used to examine the inhibitory activity of PLE on the histamine release by human leukemic mast cells. PLE inhibited histamine release from HMC-1 cells in response to cross-linkage of high-affinity IgE receptor-α (FcεRIα). Additionally, a PA-induced allergic mouse model was used to investigate the effects of PLE in vivo. Mice were orally administrated with or without PLE of single dose (250 mg/kg/day) for 31 days. Oral intake of PLE significantly inhibited passive cutaneous reactions. Oral administration of PLE to PA-induced allergic mice also led to a striking suppression of the development of contact dermatitis, ear swelling and lymph node weight. In addition, PA-specific IL-4 production of draining lymph node cells was markedly diminished by PLE oral administration, but not IFN-γ. Furthermore, PLE treatment suppressed PA-induced thymus and activation-regulated chemokine (CCL17) and cutaneous T cell-attracting chemokine (CCL27) expressions in ear tissues. Based on these results, we suggest that PLE may have therapeutic potential as an effective material for management of irritant contact dermatitis or related inflammatory diseases.

Protective effect of astragalin and quercetin on ultraviolet (UV)-irradiated damage in HaCaT cells and Balb/c mice

Co-treatment of astragalin and quercetin (AGQC) significantly suppressed the ultraviolet (UV)-induced keratinocyte damage. Administration of AGQC in UV-irradiated mice reduced the histological skin alterations and the levels of chemokine (C-X-C motif) ligand 1 (CXCL1) and CXCL2. These results suggest that AGQC has a potential use as a compound for protection against UV-irradiated skin damage.