Yeon-Kye Kim

Propolis induces cell cycle arrest and apoptosis in human leukemic U937 cells through Bcl-2/Bax regulation

We investigated mechanism(s) where propolis induces apoptosis in human leukemic U937 cells. Propolis inhibited the proliferation of U937 cells in a dose-dependent manner by inducing apoptosis and blocking cell cycle progression in the G2/M phase. Western blot analysis showed that propolis increases the expression of p21 and p27 proteins, and decreases the levels of cyclin B1, cyclin A, Cdk2 and Cdc2, thereby contributing to cell cycle arrest. DAPI staining assay revealed typical morphology features of apoptotic cells. Propolis-induced apoptosis was also confirmed by assays with annexin V-FITC, PI-labeling and DNA fragmentation assay. The increase in apoptosis level induced by propolis was associated with down-regulation of Bcl-2 and activation of caspase-3, but not with Bax. These results suggests that propolis-induced apoptosis is related to the selective activation of caspase-3 and induction of Bcl-2/Bax regulation.

A novel function of benzyl isothiocyanate in vascular smooth muscle cells: the role of ERK1/2, cell cycle regulation, and matrix metalloproteinase-9.

Dietary isothiocyanates (ITCs) have shown protective effects against certain chemically induced cancers in animal models. These inhibitory effects are associated with reduced levels of extracellular signal‐regulated kinase (ERK) 1/2 activity and the arrest of the G1 cell cycle. Benzyl isothiocyanate (BITC) treatment down‐regulates cyclins and CDKs and up‐regulates the expression of the CDK inhibitor p21, but up‐regulation of p27 or p53 was not detected. Since antiatherogenic effects are not needed for antiproliferation, we determined whether BITC exerted inhibitory effects on matrix metalloproteinase‐9 (MMP‐9) activity in TNF‐α‐induced vascular smooth muscle cells (VSMCs). BITC inhibited TNF‐α‐induced MMP‐9 secretion in VSMC in a dose dependent manner. This inhibition was characterized by the down‐regulation of MMP‐9, which is transcriptionally regulated at the NF‐κB site, and the activation protein‐1 (AP‐1) site in the MMP‐9 promoter. These findings indicate that BITC is an effective agent for inhibiting cell proliferation, the G1 to S phase cell cycle progress, and MMP‐9 expression through the transcription factors NF‐κB and AP‐1 in TNF‐α‐induced VSMC.

Comparison on proximate composition and nutritional profile of red and black sea cucumbers (Apostichopus japonicus) from Ulleungdo(Island) and Dokdo(Island), Korea

The proximate composition, fatty acid, and amino acid profile of the body wall and viscera of each red and black sea cucumber (Apostichopus japonicus) from Ulleungdo(Island) and Dokdo(Island) in Korea were compared. Moisture, ash, crude protein, and crude lipid contents ranged between 80.26–91.49, 2.57–6.85, 1.13–3.99, and 0.14–2.12%, respectively. The fatty acid values varied depending on the species and the regions of collection. The anteiso C17:0, C16:1Δ9, C17:1Δ7, C18:1Δ11, and C16:2Δ7 were only observed in the body wall. Among the tested fatty acids, the C18:1Δ11 was specific in red sea cucumber, and C20:4Δ6 (17.7%) and C20:5Δ3 (17.6%) were the predominant polyunsaturated fatty acids (PUFA) in all samples. The contents of the C18:0 dimethyl acetal (C18:0 DMA), C16:1Δ7, C16:1Δ5, and C18:1Δ5 were compared in details. Total amino acids (TAA) of body wall were 1.3–1.9 times higher than those of viscera. Glutamic acid and aspartic acid constituted the major TAA of sea cucumbers. The ratio of essential amino acids (EAA): nonessential amino acids (NEAA) on TAA ranged from 1.15 to 0.67 of sea cucumbers. Viscera of red sea cucumber from Dokdo(Island) were rich in free amino acids (FAA) and showed a high content in leucine.

Dipeptide (Tyr-Ile) Acting as an Inhibitor of Angiotensin -I-Converting Enzyme (ACE) from the Hydrolysate of Jellyfish Nemopilema nomurai

The jellyfish Nemopilema nomurai was hydrolyzed with papain and a novel dipeptide purified via ultrafiltration, gel filtration chro matography with Sephadex LH-20, and reverse phase chromatography using C 18 and C 12 columns. The IR, 1H NMR, 13C NMR, and MS spectrometer analyses showed that the dipeptide comprised tyrosine-isoleucine (Tyr-Ile). The IC 50 and K i values were 6.56

Purification and characterization of angiotensin-1 converting enzyme (ACE)-inhibitory peptide from the jellyfish, Nemopilema nomurai

The Nemopilema nomurai hydrolysate was produced by the reaction of papain, and an angiotensin-Ι converting enzyme (ACE)-inhibitory peptide was purified by using the molecular cut-offs membrane filter, the gel filtration chromatography with Sephadex LH-20 and the reverse phase chromatographic method using C 18 and C 12 columns. Purification yield of the active peptide was estimated to be 0.2 ± 0.1%, starting from the lyophilized jellyfish. The infrared (IR), proton nuclear magnetic resonance spectroscopy (1H NMR), carbon nuclear magnetic resonance (13C NMR) and mass spectrometry (MS) spectrometer analyses elucidated that the structure of the purified peptide is tyrosine-isoleucine (Tyr-Ile). The inhibitory concentration at 50% (IC50) and Ki values were calculated to be 2.0 ± 0.3 μg/ml and 3.3 ± 0.3 μM, respectively, which acts as a competitive inhibitor to ACE. Keywords : Angiotensin-Ι converting enzyme, Jellyfish, Nemopilema nomurai , Papain hydrolysate, Tyrosine-Isoleucine African Journal of Biotechnology Vol. 12(15), pp. 1888-1893

ACE-Inhibitory Properties of Proteolytic Hydrolysates from Giant Jellyfish Nemopilema nomurai

This study aimed to determine the degree of hydrolysis and angiotensin-I-converting enzyme (ACE)-inhibitory activity of Giant Jellyfish Nemopilema nomurai (jellyfish) hydrolysates. The degree of hydrolysis using six proteolytic enzymes (Alcalase, Flavo zyme, Neutrase, papain, Protamex, and trypsin) ranged from 13.1-36.8% and the inhibitory activities from 20.46-79.58%. Using papain hydrolysate, we newly isolated and characterized ACE-inhibitory peptides with a molecular weight of 3,000-5,000 Da that originated from jellyfish collagen. The purified peptide (FII-b) was predicted to be produced from an alpha-2 fragment of the type IV collagen of jellyfish. The N-terminal sequence of FII-b was Asp-Pro-Gly-Leu-Glu-Gly-Ala-His-Gly- and showed 87% identity to the collagen type IV alpha-2 fragment of Rattus norvegicus and a predicted protein from Nematostella vectensis, indicating that the ACE-inhibitory peptide originated from the collagen hydrolysate and had an IC 50 value of 3.8 μg/mL. The primary structure of the fragment is now being studied; this peptide represents an interesting new type of ACE inhibitor and will provide knowledge of the potential applications of jellyfish components as therapies for hypertension.

Angiotensin-I converting enzyme fatty acid inhibitory fractions from the Korean melania snail Semisulcospira coreana

The angiotensin-I converting enzyme (ACE) inhibitory activity of Semisulcospira coreana was investigated. Crude CH2Cl2 and MeOH extracts showed 59.3 and 25.6% ACE-inhibitory activities at 5 mg/mL, respectively. After 2 phase separations including n-hexane, 85% aqueous MeOH, n-BuOH, and H2O, the 85% aq. MeOH fraction exhibited the highest ACE-inhibitory activity of 62.1%. The inhibitory activity of 85% aq. EtOH subfraciton 5 (merf5) partially purified using C18 reversed-phase flash chromatography was increased up to 94.6% at 0.5 mg/mL. Typical fatty acids signals observed in 1H NMR and gas chromatography analysis of merf5 and n-BuOH subfractions 6 (burf6) indicated that components of merf5 and burf6 included fatty acids. The fatty acid fractions from S. coreana act as novel ACE inhibitors.

Study on UV Absorption Materials Derived from Red Algae Gloiopeltis fucatas and Mazzaella sp. in Russia

We investigated ultraviolet (UV) absorption materials from Russian seaweeds. First, the UV absorptivities of five seaweeds Gloiopeltis fucatas, Mazzaella sp., Mastocarpus pacificus, Laminaria cichorioides, Saccharina japonica were evaluated by a UV spectrometer. Of these seaweeds, Gloiopeltis fucatas and Mazzaella sp. showed high levels of UV absorption. Column chromatography of active 50% aqueous ethanol extracts from Gloiopeltis fucatas and Mazzaella sp. resulted in the purification of two known compounds. Spectroscopic techniques identified their structures as shinorine and palythine. These materials exhibited UV absorptive capabilities at wavelengths of 333 and 320 nm, respectively. These results suggest that Gloiopeltis fucatas and Mazzaella sp. may be useful as natural cosmeceutical sources.

Proximate and Fatty Acid Compositions of 14 Species of Coastal and Offshore Fishes in Korea

Proximate and fatty acid compositions in muscle tissue were studied in 14 species of coastal and offshore fishes in Korea. Lipid content ranged from 0.57 to 10.5% and was higher in migratory and reef dwelling fishes than in de-mersal fishes. Protein content ranged from 14.4 to 20.3% and moisture content ranged from 72.4 to 81.8% in all fish samples. There was a negative correlation between lipid and moisture content in all fish samples (r= -0.90, P<0.001). The prominent fatty acids were 16:0, 22:6n-3 (docosahexaenoic acid, DHA), 18:1n-9, 20:5n-3 (eicosapentaenoic acid, EPA), 16:1n-7, 18:0 and 18:1n-7. Most demersal fishes contained considerably higher amounts of 20:4n-6 and/or 22:5n-3 compared with migratory and reef dwelling fishes. The proportion of total polyunsaturated fatty acid (PUFA), including DHA and EPA, was higher in demersal fishes (38.6-54.0%) than in migratory and reef dwelling fishes (23.5-35.2%).Key words: Docosahexaenoic acid, Eicosapentaenoic acid, Fish, Lipid, PUFA

Antioxidant and Cholinesterase Inhibitory Activities of Aqueous Extract from Rainbow Trout Oncorhynchus mykiss

We investigated the antioxidant and cholinesterase inhibitory activities of the aqueous extract of rainbow trout Oncorhynchus mykiss. The antioxidant activity of O. mykiss aqueous extract was determined by in vitro peroxynitrite scavenging activity and reducing power assays. The aqueous extract of O. mykiss showed potent peroxynitrite radical scavenging activity (IC50=0.12 ± 0.001 mg/mL) and reducing power (absorbance=0.47 ± 0.001) at the concentration of 1 mg/mL. The in vitro cholinesterase inhibitory activity of O. mykiss aqueous extract was examined using spectrophotometric analyses of acetyl- and butyrylcholinesterase. The aqueous extract of O. mykiss showed acetylcholinesterase inhibitory activity (IC50=1.61 ± 0.13 mg/mL), but did not exhibit inhibitory activity against butyrylcholinesterase. These results suggest that O. mykiss possesses antioxidant and acetylcholinesterase inhibitory activities and provide scientific evidence for the health benefits of O. mykiss aqueous extract.