Jong Seok Baik

Cytoprotective effect of phloroglucinol on oxidative stress induced cell damage via catalase activation

We investigated the cytoprotective effect of phloroglucinol, which was isolated from Ecklonia cava (brown alga), against oxidative stress induced cell damage in Chinese hamster lung fibroblast (V79‐4) cells. Phloroglucinol was found to scavenge 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH) radical, hydrogen peroxide (H2O2), hydroxy radical, intracellular reactive oxygen species (ROS), and thus prevented lipid peroxidation. As a result, phloroglucinol reduced H2O2 induced apoptotic cells formation in V79‐4 cells. In addition, phloroglucinol inhibited cell damage induced by serum starvation and radiation through scavenging ROS. Phloroglucinol increased the catalase activity and its protein expression. In addition, catalase inhibitor abolished the protective effect of phloroglucinol from H2O2 induced cell damage. Furthermore, phloroglucinol increased phosphorylation of extracellular signal regulated kinase (ERK). Taken together, the results suggest that phloroglucinol protects V79‐4 cells against oxidative damage by enhancing the cellular catalase activity and modulating ERK signal pathway.

Triphlorethol-A from Ecklonia cava protects V79-4 lung fibroblast against hydrogen peroxide induced cell damage

In the present study, triphlorethol-A, a phlorotannin, was isolated from Ecklonia cava and its antioxidant properties were investigated. Triphlorethol-A was found to scavenge intracellular reactive oxygen species (ROS) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical, and thus prevented lipid peroxidation. The radical scavenging activity of triphlorethol-A protected the Chinese hamster lung fibroblast (V79-4) cells exposed to hydrogen peroxide (H2O2) against cell death, via the activation of ERK protein. Furthermore, triphlorethol-A reduced the apoptotic cells formation induced by H2O2. Triphlorethol-A increased the activities of cellular antioxidant enzymes like, superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx). Hence, from the present study, it is suggestive that triphlorethol-A protects V79-4 cells against H2O2 damage by enhancing the cellular antioxidative activity.

Biological Activities of Korean Citrus obovoides and Citrus natsudaidai Essential Oils against Acne-Inducing Bacteria

This study was designed to analyze the chemical composition of Citrus obovoides (Geumgamja) and Citrus natsudaidai (Cheonyahagyul) oils and to test their biological activities. These citrus essential oils were obtained by steam distillation of fruits collected from Jeju Island, Korea, and were analyzed using gas chromatograph (GC)-flame ionization detectors (FID) and GC-MS. Limonene and γ-terpinene were the major components of the two citrus species. To evaluate in vitro anti-acne activity, they were tested against Propionibacterium acnes and Staphylococcus epidermidis, which are involved in acne. The Geumgamja and Cheonyahagyul oils exhibited antibacterial activity against both P. acnes and S. epidermidis. Their effects on DPPH radical scavenging, superoxide anion radical scavenging, and nitric oxide radical were also assessed. Cheonyahagyul and Geumgamja exhibited only superoxide anion radical-scavenging activity. To assess their potential usefulness in future cosmetic product applications, the cytotoxic effects of the two oils were determined by colorimetric MTT assays using two animal cell lines: normal human fibroblasts and HaCaT cells. They exhibited low cytotoxicity at 0.1 μl/ml in both cell lines. In addition, they reduced P. acnes-induced secretion of interleukin-8 (IL-8) and tumor necrosis factor alpha (TNF-α) in THP-1 cells, an indication of anti-inflammatory effects. Therefore, based on these results, we suggest that Geumgamja and Cheonyahagyul essential oils are attractive acne-mitigating candidates for topical application.

Chemical composition, antioxidant, anti-elastase, and anti-inflammatory activities of Illicium anisatum essential oil

Chemical composition, antioxidant, anti-elastase, and anti-inflammatory activities of Illicium anisatum essential oil The essential oil of air-dried Illicium anisatum (Illiciaceae), obtained by hydrodistillation was analyzed by gas chromatography-mass spectrometry (GC-MS). Fifty-two components were identified in the essential oil and the main component was eucalyptol (21.8 %). The antioxidant and anti-elastase activities of the essential oil were also investigated; the essential oil exhibited moderate DPPH scavenging and anti-elastase activities. To clarify the mechanism of the anti-inflammatory activities of I. anisatum essential oil (IAE), we evaluated whether it could modulate the production of nitric oxide (NO) and prostaglandin E2 (PGE2) by activated macrophages. The results indicate that IAE is an effective inhibitor of LPS-induced NO and PGE2 production in RAW 264.7 cells. These inhibitory activities were accompanied by dose-dependent decreases in the expression of iNOS and COX-2 proteins and iNOS and COX-2 mRNA. In order to determine whether IAE can be safely applied to human skin, the cytotoxic effects of IAE were determined by colorimetric MTT assays in human dermal fibroblast and keratinocyte HaCaT cells. IAE exhibited low cytotoxicity at 100 μg mL-1. Based on these results, we suggest that IAE may be considered an anti-aging and anti-inflammatory candidate for cosmetic materials, but additional in vitro and in vivo tests have to be performed to prove its safety and efficacy. Kemijski sastav, antioksidativno djelovanje, inhibicija elastaze i protuupalno djelovanje eteričnog ulja biljke Illicium anisatum Eterično ulje biljke Illicium anisatum dobiveno destilacijom vodenom parom analizirano je plinskom kromatografijom-spektrometrijom masa (GC-MS). Identificirane su pedeset i dvije komponente eteričnog ulja, a glavna komponenta je eukaliptol (21,8 %). Ispitivanje antioksidativnog djelovanja te djelovanja na elastazu ukazuju na umjerenu spo-sobnost hvatanja DPPH radikala i inhibicije elastaze. Kako bi se objasnio mehanizam protuupalnog djelovanja eteričnog ulja I. anisatum (IAE), ispitan je učinak na moduliranje produkcije dušikovog(II) oksida (NO) i prostaglandina E2 (PGE2) iz aktiviranih makrofaga. Rezultati ukazuju da je IAE učinkovit inhibitor LPS-inducirane produkcije NO i PGE2 u RAW 264.7 stanicama. Inhibitorno djelovanje popraćeno je smanjenjem ekspresije iNOS i COX-2 proteina i iNOS i COX-2 mRNA. Kako bi se odredilo može li se IAE sigurno primijeniti na ljudsku kožu, citotoksični učinci IAE određeni su kolorimetrijskim MTT testom u humanim dermalnim fibroblastima i keratinocitima HaCaT. IAE je pokazao nisku citotoksičnost pri koncentraciji 100 μg mL-1. Temeljem ovih rezultata IAE se može smatrati potencijalnim sredstvom protiv starenja i protuupalnim sredstvom u kozmetičkim pripravcima. Međutim, dodatni in vitro i in vivo testovi nužni su za potvrdu njegove sigurnosti i učinkovitosti.

Anti-inflammatory effects of isoketocharbroic acid from brown alga, Sargassum micracanthum

During our on-going screening program designed to isolate natural compounds from marine environments, we isolated isoketochabrolic acid (IKCA) from Sargassum micracanthum, an important brown algae distributed in Jeju Island, Korea. Furthermore, we evaluated the inhibitory effects of IKCA on nitric oxide (NO) production in lipopolysaccharide (LPS)-triggered macrophages. IKCA strongly inhibited NO production, with an IC50 value of 58.31 μM. Subsequent studies demonstrated that IKCA potently and concentration-dependently reduced prostaglandin E2 (PGE2), tumor necrosis factor-alpha (TNF-α), interleukin (IL)-1β, and IL-6 cytokine production. In conclusion, to the best of our knowledge, this is the first study to show that IKCA isolated from S. micracanthum has a potent anti-inflammatory activity. Therefore, IKCA might be useful as an anti-inflammatory health supplement or functional cosmetics.

Anti-inflammatory Constituents from Branches of Corylus hallaisanensis Nakai.

Development of bioactive ingredients from natural sources has long been the research project of our laboratory. In this study, the extract from Corylus hallaisanensis Nakai branches was investigated and their anti-inflammatory constituents were identified. The prepared ethanol extract was successively partitioned into n-hexane, ethyl acetate, n-butanol and aqueous layers. Upon anti-inflammatory screenings, ethyl acetate fraction exhibited good nitric oxide production inhibitory activity in lipopolysaccharide-induced RAW 264.7 cells. Further phytochemical studies for the ethyl acetate fractions led to isolation of four constituents such as β-sitosterol (1), 3,3’,4’-tri-O-methylellagic acid (2), carpinontriol A (3) and carpinontriol B (4). All of the compounds were isolated for the first time from this plant. The isolates 2, 3 and 4 showed considerable inhibition on the production of nitric oxide in the RAW 264.7 cell without causing cell toxicities. And compounds 3 and 4 reduced the production of interleukin-6, an inflammatory cytokine, in dose-dependent manner in RAW 264.7 cells. Based on these results, C. hallaisanensis extracts could be potentially applicable as anti-inflammatory agents in pharmaceutical or cosmetic industries.