Effect of <Emphasis Type="Italic">Pinus radiate</Emphasis> bark extracts with different molecular weight distributions on cell growth of NIH/3T3 fibroblasts and dendrite retraction of B16 melanoma cells

Hot water extract (HWE) of Pinus radiata bark was separated into monomeric polyphenol (MPP), oligomeric proanthocyanidin (OPA), and polymeric proanthocyanidin (PPA) fractions by monitored chromatography using a Sephadex LH 20 column and an UV detector at 250 nm. The effects of these fractions on NIH/3T3 fibroblasts and B16 melanoma cells were examined by evaluating cell viability, melanogenesis (melanin content), morphological changes, and tyrosinase inhibitory activity. The polyphenolic fractions had a proliferation effect on fibroblasts, with cell growth increasing significantly (P < 0.01) even at the high concentration of 1250 μg/ml. At 125 μg/ml, HWE, MPP, and OPA had no effect on melanogenesis, whereas PPA significantly upregulated melanogenesis (P < 0.05). Melanogenesis was significantly upregulated in melanoma cells treated with these fractions at the high concentration of 600 μg/ml (P < 0.01). B16 melanoma cells cultured with the proanthocyanidin (PA)-rich fractions (HWE, OPA, and PPA) showed marked dendrite retraction, leading to significant morphological transformation. OPA in particular showed colored adhesion on the surface of melanoma cells. All four fractions significantly inhibited mushroom tyrosinase activity when compared to arbutin and ascorbic acid 2-glucoside (P < 0.05). The tyrosinase inhibitory activity of OPA and PPA did not differ significantly (P = 0.11), indicating that the inhibitory effects had a low correlation with molecular weight distribution. The inhibition kinetics of PPA determined using a Lineweaver-Burk plot indicated that PPA is a noncompetitive inhibitor of l-3,4-dihydroxyphenylalanine oxidation by mushroom tyrosinase.     

Electron spectroscopy of aqueous solution interfaces reveals surface enhancement of halides

It has been suggested that enhanced anion concentrations at the liquid/vapor interface of airborne saline droplets are important to aerosol reactions in the atmosphere. We report ionic concentrations in the surface of such solutions. Using x-ray photoelectron spectroscopy operating at near ambient pressure, we have measured the composition of the liquid/vapor interface for deliquesced samples of potassium bromide and potassium iodide. In both cases, the surface composition of the saturated solution is enhanced in the halide anion compared with the bulk of the solution. The enhancement of anion concentration is more dramatic for the larger, more polarizable iodide anion. By varying photoelectron kinetic energies, we have obtained depth profiles of the liquid/vapor interface. Our results are in good qualitative agreement with classical molecular dynamics simulations. Quantitative comparison between the experiments and the simulations indicates that the experimental results exhibit more interface enhancement than predicted theoretically.     

Bile tolerant <Emphasis Type="Italic">Lactobacillus reuteri</Emphasis> isolated from pig feces inhibits enteric bacterial pathogens and porcine rotavirus

Lactic acid producing bacterial strain Probio-16 was isolated from the swine excrements under anaerobic conditions and characterized by morphology and biochemical characteristics. The strain was further identified by 16S rRNA gene sequencing and phylogeneitc analysis. The antimicrobial activity of the strain was assayed by testing for growth inhibition of thirteen pathogenic microorganisms. The strain was tested for antiviral activity against porcine rotavirus in vitro in African green monkey epithelial cell line TF-104. Antibiotic susceptibility of the strain against 13 antibiotics was tested using disk diffusion method. Phenotypically and through 16S rRNA gene sequences, Probio-16 was identified and named as Lactobacillus reuteri Probio-16. This strain was resistant to pH 2.0, 5% porcine bile and exhibited antimicrobial activity against all the thirteen enteric bacterial pathogens tested. Probio-16 supernatant inhibited porcine rotavirus in vitro in TF-104 cell lines. Except for erythromycin and penicillin G at a concentration of 4 μg/ml, Probio-16 showed resistance to all other thirteen antibiotics tested. This study indicates L. reuteri Probio-16 as a novel strain with its tolerance to low pH and bile, antimicrobial activity, antibiotic resistance and antiviral activity against rotavirus, and an ideal probiotic candidate for animal and human application after the proper in vivo experiments.     

Molecular Markers Dispute the Existence of the Afro-Andean Group of the Bean Angular Leaf Spot Pathogen, Phaeoisariopsis griseola

ABSTRACT Coevolution of the angular leaf spot pathogen, Phaeoisariopsis griseola, with its common bean host has been demonstrated, and P. griseola isolates have been divided into Andean and Mesoamerican groups that correspond to defined bean gene pools. Recent characterization of P. griseola isolates from Africa has identified a group of isolates classified as Andean using random amplified polymorphic DNA (RAPD), but which are able to infect some Mesoamerican differential varieties. These isolates, designated Afro-Andean, have been identified only in Africa. Random amplified microsatellites, RAPD, and restriction digestion of amplified ribosomal intergenic spacer region were used to elucidate the relationships among the Afro-Andean, Andean, and Mesoamerican groups of P. griseola. Cluster and multiple correspondence analysis of molecular data separated isolates into Andean and Meso-american groups, and the Afro-Andean isolates clustered with Andean isolates. Analysis of molecular variance ascribed 2.8% of the total genetic variation to differences between Afro-Andean and Andean isolates from Africa. Gene diversity analysis revealed no genetic differentiation (G(ST) = 0.004) between Afro-Andean and Andean isolates from Africa. However, significant levels of genetic differentiation (G(ST) = 0.39) were observed between Afro-Andean or Andean isolates from Africa and Andean isolates from Latin America, revealing significant geographical differentiation within the Andean lineage. Results from this study showed that Afro-Andean isolates do not constitute a new P. griseola group and do not represent long-term evolution of the pathogen genome, but rather are likely the consequents of point mutations in genes for virulence. This finding has significant implications in the deployment of resistant bean genotypes.     

Antibacterial activity of hydroxyalkenyl salicylic acids from sarcotesta of Ginkgo biloba against vancomycin-resistant Enterococcus

A chloroform fraction prepared from the sarcotesta of Ginkgo biloba showed potent inhibitory activity against vancomycin-resistant Enterococcus (VRE). The active compounds were elucidated to be 2-hydroxy-6-(8-pentadecenyl) salicylic acid (1) and 2-hydroxy-6-(10-heptadecenyl) salicylic acid (2) based on their spectral analysis. Compounds 1 and 2 showed significant antibacterial activities against VRE.     

Preparation and characterization of water/oil and water/oil/water emulsions containing biopolymer-gelled water droplets

The purpose of this study was to create water-in-oil (W/O) and water-in-oil-in-water (W/O/W) emulsions containing gelled internal water droplets. Twenty weight percent W/O emulsions stabilized by a nonionic surfactant (6.4 wt % polyglycerol polyricinoleate, PGPR) were prepared that contained either 0 or 15 wt % whey protein isolate (WPI) in the aqueous phase, with the WPI-containing emulsions being either unheated or heated (80 degrees C for 20 min) to gel the protein. Optical microscopy and sedimentation tests did not indicate any significant changes in droplet characteristics of the W/O emulsions depending on WPI content (0 or 15%), shearing (0-7 min at constant shear), thermal processing (30-90 degrees C for 30 min), or storage at room temperature (up to 3 weeks). W/O/W emulsions were produced by homogenizing the W/O emulsions with an aqueous Tween 20 solution using either a membrane homogenizer (MH) or a high-pressure valve homogenizer (HPVH). For the MH the mean oil droplet size decreased with increasing number of passes, whereas for the HPVH it decreased with increasing number of passes and increasing homogenization pressure. The HPVH produced smaller droplets than the MH, but the MH produced a narrower particle size distribution. All W/O/W emulsions had a high retention of water droplets (>95%) within the larger oil droplets after homogenization. This study shows that W/O/W emulsions containing oil droplets with gelled water droplets inside can be produced by using MH or HPVH.     

A modeling study of soil temperature and moisture effects on population dynamics of Paronychiurus kimi (Collembola: Onychiuridae)

The effect of soil moisture on population dynamics of Paronychiurus kimi (Collembola) was examined by combining an empirical soil moisture model with a temperature-sensitive, stage-structured population model. Field observations of soil temperature were used to drive the population model, and simulations were compared to field observations of juvenile and adult densities. Simulations without soil moisture effects produced stable, interyear population dynamics and a significant correlation between simulations and observations (n=12, r ²=0.40, P<0.05) but overestimated densities during much of the year. Adding responses to soil moisture improved the fit between simulations and observations (n=13, r ²=0.40), suggesting that soil moisture is a major limiting factor on field populations of P. kimi. Moreover, an observed temporary decline in field populations during spring could be explained partly by the effects of an herbicide, paraquat (N,N′-dimethyl-gamma,gamma′-bipyridylium dichloride) (r ²=0.45), suggesting that paraquat imposes additional limits on collembolan populations.     

Variation in isoflavone of soybean cultivars with location and storage duration

Fifteen soybean [Glycine max (L.) Merrill] cultivars were grown in Seoul, Suwon, and Kyongsan, Korea, in 1998, 1999, and 2000, and their isoflavone contents were assessed. After harvest, the beans were stored for 3 years at room temperature. Soybean isoflavones were analyzed using high-performance liquid chromatography (HPLC) within each crop year and after storage. Total isoflavone contents ranged from 188.4 to 685.6 mg 100 g(-1) in 1998, from 218.8 to 948.9 mg 100 g(-1) in 1999, and from 293.1 to 483.0 mg 100 g(-1) in 2000. The year x variety, and year x location x variety interactions were significantly different in 1998, the year x location, year x variety, and year x location x variety interactions were significantly different in 1999, and the year x variety interaction was significantly different in 2000 for total and individual isoflavone contents. Total isoflavone contents of soybeans stored for 1 year were only slightly higher than those of soybeans stored for 2 or 3 years. However, the concentrations of individual isoflavones, especially 6' '-O-malonyldaidzin and 6' '-O-malonylgenistin, decreased markedly in soybeans stored for 2 or 3 years. These data suggest that it may be feasible to improve soybean cultivars with higher antioxidative substances.     

Exploitation of polyphenol-rich pine barks for potent antioxidant activity

The phenolic composition of pine bark from a variety of Pinus species was estimated by measuring Klason lignin, acid-soluble lignin, and a 1% NaOH extract. Polyphenol contents of hot water extracts from pine bark were determined by the Folin-Ciocalteu assay and the vanillin-H₂SO₄ assay. Among the pine bark varieties investigated, Pinus radiata bark showed the highest polyphenol content and potent antioxidant activity. Pinus rigida bark was also a usable polyphenol-rich source, whereas Pinus densiflora bark had a low yield (5.1%) of hot water extract, although it showed potent antioxidant activity. Correlations between proanthocyanidin content in pine bark and antioxidant activity were observed. The results suggested that proanthocyanidin was the crucial contributor to potent antioxidant activity in pine bark. The publication of this article was made possible by an Emachu Research Fund. The authors are grateful for the fund.