Chul Young Kim

Effect of Pressurized Liquids on Extraction of Antioxidants from Chlorella vulgaris

Chlorella vulgaris is a green microalga that contains various antioxidants, such as carotenoids and chlorophylls. In this study, antioxidants from C. vulgaris were extracted using pressurized liquid extraction (PLE), which has been recently used for bioactive compound extraction. The antioxidant capacity of individual compounds in chlorella was determined by online HPLC ABTS(*+) analysis. According to the antioxidant analysis of total extracts, the extraction yield, radical scavenging activity, and phenolic compounds using PLE were relatively high compared to those obtained using maceration or ultrasound-assisted extraction. On the basis of online HPLC ABTS(*+) analysis, the 15 major antioxidants from chlorella extracts were identified as hydrophilic compounds, lutein and its isomers, chlorophylls, and chlorophyll derivatives. Using PLE at high temperature (85-160 degrees C) significantly increased antioxidant extraction from chlorella, improving the formation of hydrophilic compounds and yielding more antioxidative chlorophyll derivatives. Online HPLC ABTS(*+) analysis was a useful tool for the separation of main antioxidants from PLE extracts and allowed the simultaneous measurement of their antioxidant capacity, which clearly showed that PLE is an excellent method for extracting antioxidants from C. vulgaris.

Induction of the Phase II Detoxification Enzyme NQO1 in Hepatocarcinoma Cells by Lignans from the Fruit of Schisandra chinensis through Nuclear Accumulation of Nrf2

The upregulation of phase II detoxification genes is believed to play an important role in cancer prevention. The molecular mechanism underlying the changes in gene expression that accompany cancer prevention involves activation of the transcription factor, NF-E2-related factor 2 (Nrf2). In traditional medicine, the fruit of Schisandra chinensis Baill is used as a tonic, an anti-tussive and an anti-aging drug. In the current study, nine lignans were isolated from S. chinensis and tested for their ability to induce quinone reductase (QR) activity in Hepa1c1c7 mouse hepatocarcinoma cells. Tigloylgomisin H (TGH) and angeloylgomisin H (AGH) significantly induced QR activity and exhibited a relatively high chemoprevention index (CI) (10.80 and 4.59, respectively) as compared to control. TGH also induced QR activity in BPrc1 mouse hepatocarcinoma cells as well, which are defective in aryl hydrocarbon nuclear translocator (Arnt). In HepG2 human hepatocarcinoma cells, TGH significantly activated gene expression mediated by the antioxidant response element (ARE), a key regulatory region in the promoters of detoxification enzymes, through the nuclear accumulation of Nrf2. The results of the current study suggest that TGH functions as a novel monofunctional inducer that specifically upregulates phase II enzymes through the Nrf2-ARE pathway. TGH thus represents a potential liver cancer prevention agent.

Molecular characteristics and immunomodulatory activities of water-soluble sulfated polysaccharides from Ulva pertusa.

Sulfated polysaccharides isolated from Ulva pertusa and fractionated using anion-exchange chromatography were investigated to determine their molecular characteristics and bioactivities. The crude and fractionated polysaccharides (F(1), F(2), and F(3)) were mainly composed of carbohydrates (59.9-65.9%), sulfates (11.6-15.3%), and uronic acid (7.30-16.4%) with small amounts of proteins (1.40-4.80%). Rhamnose (62.5-80.7%) was the major monosaccharide unit of these polysaccharides, with different levels of glucose (13.5-27.4%) and xylose (2.74-11.5%). The polysaccharides contained one or two major subfractions with weight-average molecular mass ranging from 51.1×10(3) to 1,690×10(3) g/mol. The relatively low in vitro anticancer activity of the polysaccharides (22.3-42.4%) suggested that they had little cytotoxicity against the cancer cell line used (AGS). On the other hand, the polysaccharides significantly stimulated Raw 264.7 cells, inducing considerable amounts of nitric oxide and various cytokines production, which suggested that they could be strong immunostimulators.

Heme oxygenase 1-mediated novel anti-inflammatory activities of Salvia plebeia and its active components

ETHNOPHARMACOLOGICAL RELEVANCE Salvia plebeia R. Br. (SP) has been widely used as a traditional folk medicine for the treatment of infectious diseases and pain. An anti-inflammatory potential of SP has remains largely unknown. AIM OF THE STUDY We tried to elucidate the principle mechanism and the active ingredients underlying the anti-inflammatory activities of SP. MATERIALS AND METHODS We investigated the protective activities of SP methanolic extract (SPME) and seven representative ingredients against inflammation. Quantitative analysis using HPLC-DAD-ESI/MS was conducted to determine the relative amounts of these seven active ingredients in SPME. Both in vitro murine macrophages and in vivo mouse models were employed to elucidate SP- and active ingredient-mediated anti-inflammatory effects. RESULTS SPME significantly reduced inflammatory processes both in vivo in a TPA-induced ear edema model and in vitro in lipopolysaccharide (LPS)-activated macrophages. SPME decreased the release of nitric oxide (NO) and prostaglandin E2 (PGE2) and expression of inducible nitric oxide synthase (iNOS). Seven active components (luteoloside (C1), nepitrin (C2), homoplantagenin (C3), luteolin (C4), nepetin (C5), hispidulin (C6), and eupatorin (C7)) of SPME were analyzed and their relative concentrations were determined, demonstrating that C2, C3, C5 and C6 were present in higher amounts than were C1, C4, and C7. These major compounds inhibited NO and PGE2 production, and iNOS and COX-II protein expression through heme oxygenase-1 (HO-1) induction via activation of nuclear factor erythroid 2-related factor2 (Nrf2). CONCLUSION Our data demonstrate that SPME possesses potent in vitro and in vivo anti-inflammatory activities. Nepetin and hispidulin, and their glycosides are the major active compounds in SPME, and their effects are mediated by Nrf2/HO-1 signaling. Taken together, we propose that SPME and its active ingredients may serve as novel therapeutic candidates for diseases associated with excessive inflammation.

Anti-Allergic Prenylated Flavonoids from the Roots of Sophora flavescens

The bioassay-guided fractionation of the MeOH extract from the root of Sophora flavescens led to the isolation of eight known prenylated flavonoids ( 1 - 8) responsible for the IN VITRO anti-allergic activity. Among them, kushenol N ( 3), sophoraflavanone G ( 6), and leachianone A ( 7) demonstrated significant inhibition of the release of beta-hexosaminidase from cultured RBL-2H3 cells with IC (50) values ranging from 15 to 30 muM.

Youngia denticulata Protects Against Oxidative Damage Induced by tert-Butylhydroperoxide in HepG2 Cells

Improvement of liver function is one of the most popular commercial health claims of functional foods in Asian countries, including Korea. After examining the potential of several traditional Korean wild vegetables for enhancing liver function, we found that Youngia denticulata Kitam. has strong hepatoprotective effects against oxidative stress induced by tert-butylhydroperoxide (t-BHP). We are the first to report that the extract and ethyl acetate fractions of Y. denticulata have radical scavenging activities and inhibit oxidative stress-induced cell death and DNA damage in HepG2 cells. The extract and ethyl acetate fractions significantly decreased cellular reactive oxygen species production and apoptosis induced by t-BHP in HepG2 cells. In addition, they prevented the depletion of cellular glutathione, which is an important defense molecule against oxidizing xenobiotics. Chlorogenic acid and 3,5-dicaffeoylquinic acid were found to be major active components responsible for the activity of Y. denticulata and could serve as marker compounds for standardization. These data suggest that Y. denticulata could be promoted as a potential antioxidative functional food candidate, particularly for hepatoprotection against oxidative stress.

Bioavailability of hydroxycinnamic acids from Crepidiastrum denticulatum using simulated digestion and Caco-2 intestinal cells.

Hydroxycinnamic acids have antioxidant properties and potentially beneficial effects on human health. This study investigated the digestive stability, bioaccessibility, and permeability of hydroxycinnamic acids from Crepidiastrum denticulatum using simulated digestion and Caco-2 intestinal cells. The major compounds of C. denticulatum were determined to be four hydroxycinnamic acids [caftaric acid, chlorogenic acid, chicoric acid, and 3,5-di-O-caffeoylquinic acid (3,5-DCQA)] and one flavonoid (luteolin-7-O-glucuronide) by high-performance liquid chromatography and electrospray ionization mass spectrometry. Hydroxycinnamic acids from C. denticulatum were rapidly released in the stomach and duodenum phase, maximizing the possibility of absorption in the intestinal Caco-2 cells. The digestive stability and bioaccessibility of hydroxycinnamic acids from C. denticulatum were markedly low after simulated digestion and remained minimal in the soluble fraction of the ileum phase. Unlike the four hydroxycinnamic acids, luteolin-7-O-glucuronide was stable in terms of digestive stability and bioaccessibility during simulated digestion. The cell permeabilities (P(app A to B)/P(app B to A)) of caftaric acid (0.054) and chlorogenic acid (0.055) were higher than those of chicoric acid (0.011) and 3,5-DCQA (0.006) in general. That of luteolin-7-O-glucuronide was not detectable, showing its low absorption in Caco-2 cells. These results indicate that the rapid release of hydroxycinnamic acids in the stomach and duodenum phase may increase the potential for absorption in Caco-2 cells, and that luteolin-7-O-glucuronide, which was stable in terms of digestive stability and bioaccessibility, has relatively low absorption compared with hydroxycinnamic acids.

Anti-inflammatory properties of a triterpenoidal glycoside from Momordica cochinchinensis in LPS-stimulated macrophages.

Two triterpenoidal saponins were isolated from the seeds of Momordica cochinchinensis Sprenger (Cucurbitaceae). Identification of chemical structures has been performed by 1H- and 13C-NMR spectroscopy and gas chromatography (GC). One of the saponins is a new gypsogenin glycoside, named as gypsogenin 3-O-β-D-galactopyranosyl(1→2)-[α-L-rhamnopyranosyl(1→3)]-β-D-glucuronopyranoside (compound 1), which is reported for the first time from natural resources. The other saponin is a quillaic acid glycoside (compound 2), which showed anti-inflammatory activities in RAW 264.7 cells. The mechanistic understanding of anti-inflammatory activities demonstrates that compound 2 inhibits lipopolysaccharide-induced expression of nitric oxide and IL-6 via NF-κB pathway.

Potent Anti-inflammatory and Analgesic Actions of the Chloroform Extract of Dendropanax morbifera Mediated by the Nrf2/HO-1 Pathway

Dendropanax morbifera LEVEILLE (DP) has been used in traditional Korean medicines to treat a variety of inflammatory diseases. Although the in vitro anti-inflammatory potential of this plant is understood, its in vivo efficacy and underlying molecular mechanism of anti-inflammatory effects are largely unknown. We elucidated the anti-inflammatory and analgesic activities and the underlying molecular mechanisms of DP using in vitro and in vivo models. Lipopolysaccharide (LPS)-stimulated murine macrophages were used to analyze the in vitro anti-inflammatory potential of DP extract and to elucidate the underlying mechanisms. In vivo animal models of phorbol 12-myristate 13-acetate (TPA)-induced ear edema and acetic acid-induced writhing response tests were used to analyze the in vivo anti-inflammatory effects and anti-nociceptive effects of DP extract, respectively. Methanolic extract of DP (DPME) significantly inhibited the release of nitric oxide (NO) and prostaglandin E2 (PGE2) in LPS-activated macrophages. Among the five sub-fractions, the chloroform fraction (DP-C) showed the most potent suppressive effects against pro-inflammatory mediators and cytokines in LPS-stimulated macrophages. These effects were attributed to inhibition of nuclear factor-κB (NF-κB) nuclear translocation and c-Jun N terminal kinase (JNK) 1/2 phosphorylation and to activation of NF-E2-related factor 2/heme oxygenase-1 (Nrf2/HO-1) signaling. DP-C exhibited strong protective in vivo effects in TPA-induced ear edema mouse model and acetic acid-induced writhing response test. Our data suggest that DP-C has potent anti-inflammatory and analgesic activities and may be a promising treatment against a variety of inflammatory diseases.

Hydroxycinnamic Acids in Crepidiastrum denticulatum Protect Oxidative Stress-Induced Retinal Damage

We investigated the effects of an ethanol extract of C. denticulatum (EECD) in a mouse model of glaucoma established by optic nerve crush (ONC), and found that EECD significantly protected against retinal ganglion cell (RGC) death caused by ONC. Furthermore, EECD effectively protected against N-methyl-d-aspartate-induced damage to the rat retinas. In vitro, EECD attenuated transformed retinal ganglion cell (RGC-5) death and significantly blunted the up-regulation of apoptotic proteins and mRNA level induced by 1-buthionine-(S,R)-sulfoximine combined with glutamate, reduced reactive oxygen species production by radical species, and inhibited lipid peroxidation. The major EECD components were found to be chicoric acid and 3,5-dicaffeoylquinic acid (3,5-DCQA) that have shown beneficial effects on retinal degeneration both in vitro and in vivo studies. Thus, EECD could be used as a natural neuroprotective agent for glaucoma, and chicoric acid and 3,5-DCQA as mark compounds for the development of functional food.