Seul Lee

Purification, characterization and immunomodulating activity of a pectic polysaccharide isolated from Korean mulberry fruit Oddi (Morus alba L.).

A water-soluble polysaccharide (JS-MP-1) was isolated and purified from the Korean mulberry fruits Oddi (Morus alba L.) by crushing the fresh fruits then performing ethanol precipitation and DEAE-cellulose ion exchange chromatography. The neutral monosaccharide composition of the purified JS-MP-1 was determined to be composed mainly of galactose (37.6%, in mole percent), arabinose (36.3%), and rhamnose (18.4%), while other major sugars such as glucose, xylose, mannose, and fucose were present as minor components. HPLC analysis revealed that JS-MP-1 contains both galacturonic acid (GalA) and glucuronic acid (GlcA) at approximately 4:1 in mole percent. Monosaccharide composition, Fourier-transform infrared (FTIR) analysis, biochemical analysis, and elemental analysis suggested that JS-MP-1 is an acidic heteropolysaccharide, most likely a rhamnoarabinogalacturonan type plant pectic polysaccharide, with an apparent molecular mass of 1600 kDa containing no, or if any, negligible level of sulfate esters and proteins. Enzyme-Linked Immunosorbent Assay and RT-PCR analysis demonstrated that JS-MP-1 significantly stimulates murine RAW264.7 macrophage cells to release chemokines (RANTES and MIP-1α) and proinflammatory cytokines (TNF-α and IL-6) and to induce the expression of iNOS and COX-2, which are responsible for the production of NO and prostaglandin PGE2, respectively. These results suggest that the mulberry fruit-derived polysaccharide JS-MP-1 can act as a potent immunomodulator, and these observations may support the applicability of this polysaccharide as an immunotherapeutic adjuvant or the water extracts of the mulberry fruit as a beneficial health food.

Enzymatic Biosynthesis of Novel Resveratrol Glucoside and Glycoside Derivatives.

ABSTRACT A UDP glucosyltransferase from Bacillus licheniformis was overexpressed, purified, and incubated with nucleotide diphosphate (NDP) d- and l-sugars to produce glucose, galactose, 2-deoxyglucose, viosamine, rhamnose, and fucose sugar-conjugated resveratrol glycosides. Significantly higher (90%) bioconversion of resveratrol was achieved with α-d-glucose as the sugar donor to produce four different glucosides of resveratrol: resveratrol 3-O-β-d-glucoside, resveratrol 4′-O-β-d-glucoside, resveratrol 3,5-O-β-d-diglucoside, and resveratrol 3,5,4′-O-β-d-triglucoside. The conversion rates and numbers of products formed were found to vary with the other NDP sugar donors. Resveratrol 3-O-β-d-2-deoxyglucoside and resveratrol 3,5-O-β-d-di-2-deoxyglucoside were found to be produced using TDP-2-deoxyglucose as a donor; however, the monoglycosides resveratrol 4′-O-β-d-galactoside, resveratrol 4′-O-β-d-viosaminoside, resveratrol 3-O-β-l-rhamnoside, and resveratrol 3-O-β-l-fucoside were produced from the respective sugar donors. Altogether, 10 diverse glycoside derivatives of the medically important resveratrol were generated, demonstrating the capacity of YjiC to produce structurally diverse resveratrol glycosides.

Immunostimulating activity of maysin isolated from corn silk in murine RAW 264.7 macrophages

Corn silk (CS) has long been consumed as a traditional herb in Korea. Maysin is a major flavonoid of CS. The effects of maysin on macrophage activation were evaluated, using the murine macrophage RAW 264.7 cells. Maysin was isolated from CS by methanol extraction, and preparative C18 reverse phase column chromatography. Maysin was nontoxic up to 100 μg/ml, and dose-dependently increased TNF-α secretion and iNOS production by 11.2- and 4.2-fold, respectively, compared to untreated control. The activation and subsequent nuclear translocation of NF-κB was substantially enhanced upon treatment with maysin (1-100 μg/ml). Maysin also stimulated the phosphorylation of Akt and MAPKs (ERK, JNK). These results indicated that maysin activates macrophages to secrete TNF-α and induce iNOS expression, via the activation of the Akt, NF-κB and MAPKs signaling pathways. These results suggest for the first time that maysin can be a new immunomodulator, enhancing the early innate immunity. [BMB Reports 2014; 47(7): 382-387]

Corn silk maysin induces apoptotic cell death in PC-3 prostate cancer cells via mitochondria-dependent pathway

AIMS Despite recent advances in prostate cancer diagnostics and therapeutics, the overall survival rate still remains low. This study was aimed to assess potential anti-cancer activity of maysin, a major flavonoid of corn silk (CS, Zea mays L.), in androgen-independent human prostate cancer cells (PC-3). MAIN METHODS Maysin was isolated from CS of Kwangpyeongok, a Korean hybrid corn, via methanol extraction and preparative C18 reverse phase column chromatography. Maysin cytotoxicity was determined by either monitoring cell viability in various cancer cell lines by MTT assay or morphological changes. Apoptotic cell death was assessed by annexin V-FITC/PI double staining, depolarization of mitochondrial membrane potential (MMP), expression levels of Bcl-2 and pro-caspase-3 and by terminal transferase mediated dUTP-fluorescein nick end labeling (TUNEL) staining. Underlying mechanism in maysin-induced apoptosis of PC-3 cells was explored by evaluating its effects on Akt and ERK pathway. KEY FINDINGS Maysin dose-dependently reduced the PC-3 cell viability, with an 87% reduction at 200 μg/ml. Maysin treatment significantly induced apoptotic cell death, DNA fragmentation, depolarization of MMP, and reduction in Bcl-2 and pro-caspase-3 expression levels. Maysin also significantly attenuated phosphorylation of Akt and ERK. A combined treatment with maysin and other known anti-cancer agents, including 5-FU, etoposide, cisplatin, or camptothecin, synergistically enhanced PC-3 cell death. SIGNIFICANCE These results suggested for the first time that maysin inhibits the PC-3 cancer cell growth via stimulation of mitochondria-dependent apoptotic cell death and may have a strong therapeutic potential for the treatment of either chemo-resistant or androgen-independent human prostate cancer.

Combining non-contrast and dual-energy CT improves diagnosis of early gout

ObjectivesTo determine the incremental value of non-contrast CT (NCCT) on dual-energy CT (DECT) in symptomatic first metatarsophalangeal (MTP) joints in early gout.MethodsOne hundred and fifteen painful joints were consecutively enrolled and gout was diagnosed based on the 2015 EULAR/ACR criteria and/or arthrocentesis. Two readers independently evaluated DECT alone and combined NCCT and DECT (NCCT+DECT) based on four semiquantitative scales. Sensitivities and specificities were compared using McNemar’s test. AUC was compared.ResultsOf the 115 joints, 72 were defined as an early gout group and 43 as a gout-negative group after exclusion. The sensitivity and specificity for the early gout group on DECT alone were as followed: reader 1 – 52.8% and 100.0% and reader 2 – 51.4% and 100.0%. NCCT+DECT results were as follows: reader 1 – 79.2% and 93.0% and reader 2 – 79.2% and 95.3%. AUC was significantly higher in NCCT+DECT compared to that in DECT alone for the early gout group (0.888 vs. 0.774 for reader 1, p = 0.0004; 0.896 vs. 0.816 for reader 2, p = 0.0142). The false-negative cases on DECT occurred more frequently with the first-onset gout, and tended to be affected by a longer duration of symptoms in the post-hoc analysis.ConclusionThe combined analysis of NCCT and DECT improves diagnostic capabilities in symptomatic early gout involving the first MTP joint.Key Points• MSU crystal depositions in early gout may be seen on non-contrast CT, while still being undetectable by DECT.• Combining non-contrast CT and DECT improves detection of early gout.• False negatives of DECT are more common than previously reported in cases of first-onset gout.