Increase in anti-inflammatory activities of radical-degraded porphyrans isolated from discolored nori (Pyropia yezoensis).

The anti-inflammatory properties of porphyrans (D1-D4) obtained from four discolored nori (Pyropia yezoensis) with different growth backgrounds were studied to examine possible variations in their bioactivities. Elution profiles of the porphyrans on Sepharose 4B indicated that D2-porphyran had relatively lower-molecular-size porphyrans than the other porphyrans. Inhibitory activities of the four porphyrans against nitric oxide (NO) and tumor necrosis factor-α (TNF-α) secretion by lipopolysaccharide (LPS)-stimulated RAW264.7 cells were different, whereas no significant differences were observed in the sulfate and anhydrogalactose levels. D2-porphyran showed the highest inhibitory activity against NO and TNF-α secretion by LPS-stimulated RAW264.7 cells, whereas D3- and D4-porphyrans had almost no activity. All porphyrans were efficiently degraded by free radical generated with ascorbate and hydrogen peroxide. The free-radical degradation resulted in a significant increase in the inhibitory activities of the four porphyrans against NO and TNF-α secretion, with varying rates depending on the porphyrans. The ability of D2-porphyran to suppress the receptor activator of nuclear factor κB ligand (RANKL)-induced osteoclastogenesis in RAW264.7 cells was also significantly enhanced after degradation. Our results suggest that molecular size is an important factor affecting the anti-inflammatory activity of porphyrans, and radical degradation might be a promising procedure to obtain active low-molecular-size porphyrans.

Inhibitory effect of sulphated polysaccharide porphyran (isolated from Porphyra yezoensis) on RANKL-induced differentiation of RAW264.7 cells into osteoclasts.

Safe and efficient therapeutic agents for bone diseases are required in natural sources. We previously found that edible seaweed-derived polysaccharide porphyran exhibited anti-inflammatory effects through the down regulation of nuclear factor-κB. The aim of this study was to investigate the availability of porphyran as a therapeutic agent for bone diseases. The effects of porphyran on receptor activator of nuclear factor κB ligand (RANKL)-induced osteoclastogenesis in RAW264.7 cells were examined. Porphyran suppressed RANKL-induced osteoclast formation in a concentration-dependent manner (6.25-50 µg/ml) without any cytotoxic effects. Furthermore, real-time polymerase chain reaction analyses indicated that porphyran at 50 µg/ml significantly attenuated the RANKL-induced increase in the mRNA levels of osteoclastogenesis-related marker genes such as nuclear factor of activated T cells, tartrate-resistant acid phosphatase, cathepsin K, and matrix metalloproteinase-9 in RAW264.7 cells. To our knowledge, this is the first report showing that edible-seaweed-derived polysaccharide porphyran can suppress RANKL-induced osteoclastogenesis. Our results suggest that porphyran can be used as a safe therapeutic agent to improve osteoclast-related pathological conditions.

Evaluation on antioxidant properties of sixteen plant species from Jeju Island in Korea.

In this study, the antioxidant properties of 80 % ethanol extracts of 16 species of plants from Jeju Island in Korea were evaluated using various antioxidant assays, including the DPPH (1,1-Diphenyl-2-pricrylhydrazyl) radical scavenging, superoxide scavenging, xanthine oxidase inhibition and hydrogen peroxide scavenging activities. Among the 16 plant extracts tested, CN-13 showed strong antioxidant properties in the DPPH radical scavenging and hydrogen peroxide scavenging tests. The CN-13 ethanol extract was thus selected to be used for further experiments, and was separated into various fractions using four different organic solvents (n-hexane, methylene chloride, ethyl acetate and butanol). The ethyl acetate fraction of CN-13 extract evidenced strong DPPH radical scavenging properties as compared to the other fractions. The ethyl acetate fraction also strongly inhibited DNA-damage induced by hydrogen peroxide-oxidative damage in a mouse lymphoma (L5178Y-R) cell line. Moreover, a correlation between the total phenolic content of the extract, and its antioxidant property was reported.

Antioxidant and anti-inflammatory activities of porphyran isolated from discolored nori (Porphyra yezoensis).

We found that discolored waste nori with no commercial value, contains much higher level of porphyran than normal nori that is a sheeted food stuff prepared from P. yezoensis used in sushi. Chemical analyses revealed that mean molecular mass of the porphyran prepared from discolored nori (dc-porphyran) was much lower than that of the porphyran from normal nori (n-porphyran). Dc-porphyran showed slightly greater scavenging activity toward superoxide anion and hydroxyl radical than n-porphyran. Dc-porphyran inhibited nitric oxide (NO) production in LPS-stimulated RAW264.7 cells through preventing the expression of inducible NO synthase, whereas no such activity was observed in n-porphyran. Since acid-hydrolyzed n-porphyran showed the inhibitory activity on NO production from LPS-stimulated RAW264.7 cells, the molecular size of porphyran was suggested to be a critical factor for the activity. Dc-porphyran was separated into 4 fractions (F1-F4) on DEAE-chromatography, and F1 showed the highest inhibitory effect on NO production from LPS-stimulated RAW264.7 cells. Our results indicate that discolored waste nori is useful as a source of porphyran with even better bioactivities than porphyran from normal nori.

Anti-inflammatory effect of essential oil and its constituents from fingered citron (Citrus medica L. var. sarcodactylis) through blocking JNK, ERK and NF-κB signaling pathways in LPS-activated RAW 264.7 cells.

We investigated the composition of essential oil from fingered citron (Citrus medica L. var. sarcodactylis) (FCEO) peels by GC-MS and its anti-inflammatory effects on lipopolysaccharide (LPS) - stimulated mouse macrophage (RAW 264.7) cells. Fifteen compounds, representing 98.97% of the essential oil, were tentatively identified; the main constituents were limonene (52.44%) and γ-terpinene (28.41%). FCEO significantly inhibited nitric oxide (NO) and prostaglandin E2 (PGE2) by suppressing the protein expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX)-2, respectively. Additionally, FCEO suppressed the production of tumor necrosis factor-α (TNF-α), interleukin (IL)-1ß, and IL-6. FCEO attenuated LPS-induced nuclear factor-κB (NF-κB) activation via inhibition of inhibitor κB-α phosphorylation. Furthermore, FCEO blocked activation of c-Jun N-terminal kinase (JNK) and extracellular signal-regulated kinase (ERK) but not that of p38 mitogen-activated protein kinase. These results indicate that FCEO inhibits LPS-stimulated inflammation by blocking the NF-κB, JNK, and ERK pathways in macrophages, and demonstrate that FCEO possesses anti-inflammatory properties.

Acanthoic acid induces cell apoptosis through activation of the p38 MAPK pathway in HL-60 human promyelocytic leukaemia.

The present study was designed to evaluate the molecular mechanisms of the action of acanthoic acid (ACAN) from Acanthopanax koreanum (Araliaceae) against HL-60 human promyelocytic leukaemia cells. ACAN reduced the proliferation of HL-60 cells in a dose- and time-dependent manner accompanied by the induction of apoptosis. Possible mechanisms of ACAN-induced apoptosis were also examined. The results showed that ACAN-induced the phosphorylation of members of the mitogen-activated protein kinase (MAPK) family, c-Jun N-terminal kinase (JNK), p38 MAPK (p38), and extracellular signal-regulated kinase (ERK). A specific p38 MAPK inhibitor (SB203580) significantly blocked ACAN-induced apoptosis and cell viability, whereas an ERK inhibitor (PD98059) and JNK inhibitor (SP600125) had no effect. Moreover, ACAN induced the cleavage of caspase-3 and poly-ADP-ribose polymerase (PARP), and decreased the level of Bcl-xL, but these effects were inhibited by SB203580 pre-treatment. These results strongly suggest that ACAN may have cancer chemopreventive and therapeutic potential, due to its ability to activate the p38 MAPK-mediated signalling pathways.

Investigation of the component of Lycopodium serratum extract that inhibits proliferation and mediates apoptosis of human HL-60 leukemia cells.

In this study, we investigate a plant commonly used in herbal medicines, Lycopodium serratum, which is believed to have anti-cancer properties. An alcoholic extract of L. serratum (LSE) was investigated for its ability to induce apoptosis in cultured human promyelocytic leukemia HL-60 cells. Treatment of HL-60 cells with various concentrations of LSE (6-100 µg/mL) resulted in a sequence of events characteristic of apoptosis, including loss of cell viability, morphological changes, and increased sub-G(1) DNA content. Serratenediol (SE), a known biologically active agent, was isolated from MC fraction of LSE and was able to demonstrate significant and dose-dependent growth inhibitory effects on HL-60 cells. Similar to the effects observed with the crude LSE, the SE-related effects included the formation of apoptotic bodies and fragmented DNA, as well as the accumulation of DNA in the sub-G(1) phase of the cell cycle. Analysis of the mechanism of these events indicated that SE treated cells had an increased ratio of Bax/Bcl-xL, released the cytochrome c, activated caspase-9, -3, and cleaved poly-ADP-ribose polymerase (PARP); these observations are hallmarks of apoptotic events. Thus, the results suggest that SE can induce apoptosis via regulating the ratio of Bax/Bcl-xL in HL-60 cell lines.

Antioxidant peptides from protein hydrolysate of microalgae Navicula incerta and their protective effects in HepG2/CYP2E1 cells induced by ethanol.

Marine microalgae have been reported as valuable new sources of pharmacologically active compounds and there are now numerous commercial applications of microalgae. Hence, in this study we evaluated the protective effects of peptides purified from marine microalgae, Navicula incerta, against alcohol-induced damage in HepG2/CYP2E1 cells. To obtain bioactive peptides from microalgae, N. incerta was hydrolysed using various enzymes (alcalase, α-chymotrypsin, neutrase, papain, pepsin, pronase-E and trypsin), and the hydrolysates were evaluated for cytoprotective activity. Among them, papain-derived hydrolysate exhibited higher antioxidant activities than those of other enzymes. Therefore, papain hydrolysate was purified in order to obtain potent antihepatotoxic and antioxidative peptides. The amino acid sequences of the purified peptides were analysed as; NIPP-1 (Pro-Gly-Trp-Asn-Gln-Trp-Phe-Leu) with molecular mass 1 171 Da, and NIPP-2 (Val-Glu-Val-Leu-Pro-Pro-Ala-Glu-Leu) with molecular mass 1108 Da. Furthermore, this study demonstrated that NIPP-1 and NIPP-2 peptides inhibited ethanol-induced cytotoxicity in HepG2/CYP2E1 cells.

Neuroprotective effect of phlorotannin isolated from Ishige okamurae against H2O2 -induced oxidative stress in murine hippocampal neuronal cells, HT22.

The present study is designed to investigate the neuroprotective effect of a kind of phlorotannins, diphlorethohydroxycarmalol (DPHC) isolated from Ishige okamurae against hydrogen peroxide (H(2)O(2))-induced oxidative stress in murine hippocampal neuronal cells, HT22. H(2)O(2) treatment induced neurotoxicity, whereas DPHC prevented cells from H(2)O(2)-induced damage then restoring cell viability was significantly increased. DPHC slightly reduced the expression of Bax induced by H(2)O(2) but recovered the expression of Bcl-xL as well as caspase-9 and -3 mediated PARP cleavage by H(2)O(2). Intracellular reactive oxygen species (ROS) and lipid peroxidation was overproduced as the result of the addition of H(2)O(2); however, these ROS generations and lipid peroxidation were effectively inhibited by addition of DPHC in a dose-dependent manner. Moreover, DPHC suppressed the elevation of H(2)O(2)-induced Ca(2+) release. These findings indicate that DPHC has neuroprotective effects against H(2)O(2)-induced damage in neuronal cells, and that an inhibitory effect on ROS production may contribute to the underlying mechanisms.

Polyopes affinis alleviates airway inflammation in a murine model of allergic asthma.

Marine algae have been utilized in food as well as medicine products for a variety of purposes. The purpose of this study was to determine whether an ethanol extract of Polyopes affinis (P.affinis) can inhibit the pathogenesis of T helper 2 (Th2)-mediated allergen-induced airway inflammation in a murine model of asthma. Mice that were sensitized and challenged with ovalbumin (OVA) evidenced typical asthmatic reactions such as the following: an increase in the number of eosinophils in the bronchoalveolar lavage (BAL) fluid; a marked influx of inflammatory cells into the lung around blood vessels and airways as well as the narrowing of the airway luminal; the development of airway hyperresponsiveness (AHR); the presence of pulmonary Th2 cytokines; and the presence of allergenspecific immunoglobulin E (IgE) in the serum. The successive intraperitoneal administration of P. affinis ethanolic extracts before the last airway OVA-challenge resulted in a significant inhibition of all asthmatic reactions. These data suggest that P. affinis ethanolic extracts possess therapeutic potential for the treatment of pulmonary allergic disorders such as allergic asthma.

Screening of marine algae for potential tyrosinase inhibitor: those inhibitors reduced tyrosinase activity and melanin synthesis in zebrafish.

In order to find new anti-browning and whitening agents in this study, we investigated 43 indigenous marine algae for tyrosinase inhibitory activity. The extracts from Endarachne binghamiae, Schizymenia dubyi, Ecklonia cava (EC) and Sargassum silquastrum (SS) evidenced potent tyrosinase inhibitory activity similar to that of positive control, kojic acid. Among those marine algae, EC and SS are distributed abundantly on Jeju Island. Therefore, we selected those two species for further studies. Our results evidenced that both species reduced cellular melanin synthesis and tyrosinase activity. On the other hand, we utilized zebrafish as an alternative in vivo model. All the tested samples evidenced excellent inhibitory effects on the pigmentation of zebrafish, most likely due to their potential tyrosinase inhibitory activity. In simultaneous in vivo toxicity tests, no toxicity was observed in either algal species, on the other hand, toxicity was observed in positive controls. These results provided that EC and SS extract could be used as an ingredient for whiting cosmetics and that zebrafish is an alternative in vivo model.

Antioxidant properties of aqueous extracts from red tide plankton cultures.

The antioxidant properties of aqueous extracts from the dinophycean flagellates Gymnodinium impudicum and Alexandrium affine and the raphidophycean flagellate Chattonella ovata were examined. An electron spin resonance (ESR)-spin trapping method coupled with steady state kinetic analysis showed that all of the extracts directly scavenge superoxide, and that the superoxide scavenging potential of any of the extracts was comparable to that of L-ascorbic acid. As for hydroxyl radical scavenging, the Fenton reaction and the method of ultraviolet radiation to hydrogen peroxide were used as hydroxyl radical generation systems. All of extracts reduced the level of hydroxyl radicals in both of the systems, indicating that the extracts also directly scavenge hydroxyl radicals. Since the levels of phenolic compounds did not correlate with the antioxidant activities of the extracts, substances other than phenolic compounds also appeared to be attributable to the activities. It is of our interest that the scavenging activities of extract from G. impudicum against superoxide and hydroxyl radicals were increased by heat exposure at 100 degrees C and 200 degrees C respectively. Although the reason for the increased activities of the aqueous extract from G. impudicum is not clear, the heat-resistance of the extract from G. impudicum might make it a desirable antioxidant.