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1.
Heliyon ; 10(11): e32322, 2024 Jun 15.
Article in English | MEDLINE | ID: mdl-38912491

ABSTRACT

Specific anthocyanins and phenolic compounds exhibit acetylcholinesterase inhibitory (AChEi) activity. In this study, the AChEi activity of jaboticaba peel extracts were investigated based on their high phenol contents. Jaboticaba peel ethanolic extract (PEX) and aqueous extract (PAX) were prepared by extracting jaboticaba peel with 95% ethanol and boiling water, respectively. Through HPLC-MS/MS and HPLC-PDA analysis, gallic acid was identified in PAX with a concentration of 598.13 ± 42.43 mg/100 g extract, and ellagic acid in PEX with a concentration of 350.47 ± 8.53 mg/100 g extract. Both PEX and PAX showed dose-dependent inhibition against AChE activity, with IC50 values of 3.54 and 4.07 mg/mL, respectively. The mechanism of inhibition of PEX was determined to be non-competitive inhibition based on the decreasing V max and relatively constant K m with increasing PEX concentration, as determined using a Lineweaver-Burk plot.

2.
Biomedicines ; 12(3)2024 Feb 28.
Article in English | MEDLINE | ID: mdl-38540152

ABSTRACT

This study compared gut (fecal) microbiota profiles between pre-term and full-term infants, assuming that pre-term infants without feeding intolerance would have gut microbiota similar to those of full-term infants. A total of 13 pre-term infants (gestational age < 37 weeks, birthweight ≤ 2500 g) and 10 full-term infants were included. The pre-term infants were assigned to the feeding tolerance (FT) group (n = 7) if their daily intake exceeded 100 mL/kg/day at two weeks after birth, or the feeding intolerance (FI) group (n = 6). Microbial DNA from weekly fecal samples was analyzed. The microbiota profiles of the pre-term infants and full-term infants were significantly different (p = 0.0001), as well as the FT and FI groups (p = 0.0009). The full-term group had more diversity, with higher concentrations of facultative anaerobes such as Bifidobacteriaceae and Lactobacteriaceae. The FT group's gut microbiota matured over four weeks, with higher levels of digestion-related bacteria, while the FI group had more pathogens. In the FI group, a significant difference was observed between the first and second weeks, with no significant differences noted between the first week and the third or fourth weeks. The delay in the development of the pre-term infants' gut microbiota may be associated with the FI.

3.
Plant Foods Hum Nutr ; 78(2): 286-291, 2023 Jun.
Article in English | MEDLINE | ID: mdl-36820999

ABSTRACT

Early intervention can significantly improve the colorectal cancer survival rate. Foods rich in phenolic compounds, such as jaboticaba (Myrciaria cauliflora), may prevent tumorigenesis. We investigated the effectivity of jaboticaba whole fruit ethanolic extract (FEX) in suppressing aberrant crypt foci (ACF), the earliest lesion of colorectal cancer (CRC), in 1,2-dimethylhydrazine (DMH)-induced rats and the underlying mechanisms related to the gut microbiota composition and short chain fatty acid (SCFA). This study was approved by the Institutional Animal Care and Use Committee (IACUC) of Providence University (Trial Registration Number 20180419A01, registration date: 22 December 2018). The FEX contains gallic acid and an especially high ellagic acid concentration of 54.41 ± 1.80 and 209.79 ± 2.49 mg/100 g FEX. The highest total ACF number (150.00 ± 43.86) was recorded in the DMH control (D) group. After 56 days of oral FEX treatment, the total ACF number in the low FEX dosage (DL) group was significantly lower compared to the D group (p < 0.05). The large-sized ACF (> 5 foci), which has a higher probability of progressing to later stage, was significantly decreased in the high FEX dosage (DH) group. The 16s rDNA metagenomic sequencing of the cecal material revealed that the CRC biomarker Lachnoclostridium was significantly suppressed in the DH group (p < 0.05), whereas some SCFA-producing taxa and the cecal butyrate concentration were significantly elevated in the DL and DH groups (p < 0.05). This study demonstrated the potential of jaboticaba whole fruit in CRC prevention, especially in the initial stage, by shifting gut microbiota composition and improving cecal butyrate level.


Subject(s)
Aberrant Crypt Foci , Colonic Neoplasms , Colorectal Neoplasms , Rats , Animals , Fruit , Gallic Acid , Colorectal Neoplasms/prevention & control , Butyrates , 1,2-Dimethylhydrazine/toxicity
4.
Microorganisms ; 10(5)2022 Apr 20.
Article in English | MEDLINE | ID: mdl-35630298

ABSTRACT

Furfural and hydroxy-methyl-furfural (HMF) are produced by lignocellulosic biomass during heat or acid pretreatment and are toxic to yeast. Aldehyde reductase is the main enzyme to reduce furfural and HMF. To improve the conversion efficiency of lignocellulosic biomass into ethanol, we constructed Saccharomyces cerevisiae with overexpression of aldehyde reductase (encoded by ari1). The gene of aldehyde reductase (encoded by ari1) was cloned via polymerase chain reaction (PCR) and ligated with the expression vector pGAPZαC. Western blot coupled with anti-His tag confirmed overexpression of the ari1 gene. The growth curves of the wild and ari1-overexpressed strain in the YPD medium were found to be almost identical. Compare to the ari1-overexpressed strain, the wild strain showed a longer doubling time and lag phase in the presence of 20 mM furfural and 60 mM HMF, respectively. The real-time PCR results showed that furfural was much more potent than HMF in stimulating ari1 expression, but the cell growth patterns showed that 60 mM HMF was more toxic to yeast than 20 mM furfural. S. cerevisiae with ari1 overexpression appeared to confer higher tolerance to aldehyde inhibitors, thereby increasing the growth rate and ethanol production capacity of S. cerevisiae in an aldehyde-containing environment.

5.
Food Nutr Res ; 642020.
Article in English | MEDLINE | ID: mdl-33447179

ABSTRACT

BACKGROUND: The antioxidant effects of Bacillus subtilis-fermented red bean (natto-red bean) extract (NRBE) in young (6 weeks old) Sprague-Dawley rats and aged (12 months old) mice had been reported previously. OBJECTIVE: To evaluate the antioxidant and anti-inflammatory effects of NRBE in the kidneys of streptozocin-induced diabetic rats. DESIGN: Normal control rats and diabetic rats were orally gavaged with saline and low-dose NRBE (100 mg/kg body weight [BW]), medium-dose NRBE (200 mg/kg BW), and high-dose NRBE (500 mg/kg BW), for 12 weeks and then sacrificed. Concentration of fasting glucose, adiponectin, renal function markers, antioxidative markers, and pro-inflammatory markers were measured. RESULTS: Oral administration of 50% ethanolic extract of NRBE with a dosage of 100 mg/kg BW, 200 mg/kg BW, or 500 mg/kg BW could improve the symptoms of kidney enlargement and renal function. Supplementation of NRBE can effectively inhibit the formation of renal reactive oxygen species and advanced-glycation end-products and increase renal glutathione content and serum adiponectin. A low dose of NRBE (100 mg/kg BW) decreased fasting blood sugar and renal interleukin (IL)-6 expression. Serum C-reactive protein, renal tumor necrosis factor-α, and monocyte chemoattractant protein-1 concentrations were decreased, and renal superoxide dismutase activity was increased in the medium-dose NRBE group. Twenty-four hour creatinine clearance and urinary albumin excretion also improved by medium-dose NRBE supplementation. In NRBE, total phenols and flavonoids were 6.3 mg gallic acid equivalent/g and 12.02 mg rutin equivalent/g, respectively, and kampherol was the major active antioxidant compound. CONCLUSION: This study demonstrated that appropriate amount of NRBE, 200 mg/kg BW in rats, could prevent diabetic nephropathy by improving antioxidant status and inhibiting inflammation in renal tissue.

6.
Int J Immunopathol Pharmacol ; 30(1): 105-112, 2017 Mar.
Article in English | MEDLINE | ID: mdl-28281874

ABSTRACT

Xylaria nigripes ( XN) is a medicinal fungus that was used traditionally as a diuretic, nerve tonic, and for treating insomnia and trauma. In this study, we elucidated possible mechanisms of neuroprotective effects of XN mycelia extracts. XN mycelia were produced by fermentation. Hot water extract and 70% ethanol extract of XN mycelia were evaluated on hydrogen peroxide (H2O2)-induced apoptosis in PC12, a rat pheochromocytoma cell line. Both XN extracts effectively protected PC12 cells against H2O2-induced cell damage by inhibiting release of lactate dehydrogenase, decreasing DNA damage, restoring mitochondrial membrane potential, and arresting abnormal apoptosis through upregulation of Bcl-2 and downregulation of Bax and caspase 3. Compared to water extract, ethanol extract showed not only greater neuroprotective effects but also a higher antioxidant activity by scavenging DPPH radicals, inhibiting lipid peroxidation, and reducing power. High phenolic content and antioxidant activity may provide the neuroprotective properties of XN ethanol extract.


Subject(s)
Biological Products/pharmacology , Neuroprotective Agents/pharmacology , Xylariales , Animals , Apoptosis/drug effects , Biological Products/chemistry , Caspase 3/metabolism , Flavonoids/analysis , Hydrogen Peroxide , L-Lactate Dehydrogenase/metabolism , Lipid Peroxidation/drug effects , Membrane Potential, Mitochondrial/drug effects , Mycelium/chemistry , Neuroprotective Agents/chemistry , PC12 Cells , Phenols/analysis , Polysaccharides/analysis , Proto-Oncogene Proteins c-bcl-2/metabolism , Rats
7.
Bioengineered ; 8(5): 524-535, 2017 Sep 03.
Article in English | MEDLINE | ID: mdl-27937123

ABSTRACT

Lignocellulosic biomass is an attractive low-cost feedstock for bioethanol production. During bioethanol production, Saccharomyces cerevisiae, the common used starter, faces several environmental stresses such as aldehydes, glucose, ethanol, high temperature, acid, alkaline and osmotic pressure. The aim of this study was to construct a genetic recombinant S. cerevisiae starter with high tolerance against various environmental stresses. Trehalose-6-phosphate synthase gene (tps1) and aldehyde reductase gene (ari1) were co-overexpressed in nth1 (coded for neutral trehalase gene, trehalose degrading enzyme) deleted S. cerevisiae. The engineered strain exhibited ethanol tolerance up to 14% of ethanol, while the growth of wild strain was inhibited by 6% of ethanol. Compared with the wild strain, the engineered strain showed greater ethanol yield under high stress condition induced by combining 30% glucose, 30 mM furfural and 30 mM 5-hydroxymethylfurfural (HMF).


Subject(s)
Ethanol/metabolism , Genetic Enhancement/methods , Glucose/metabolism , Metabolic Engineering/methods , Multienzyme Complexes/genetics , Saccharomyces cerevisiae/physiology , Stress, Physiological/genetics , Ethanol/isolation & purification , Up-Regulation/genetics
8.
Bioengineered ; 7(6): 445-458, 2016 Nov.
Article in English | MEDLINE | ID: mdl-27484300

ABSTRACT

A genetic recombinant Saccharomyces cerevisiae starter with high ethanol tolerance capacities was constructed. In this study, the gene of trehalose-6-phosphate synthase (encoded by tps1), which catalyzes the first step in trehalose synthesis, was cloned and overexpressed in S. cerevisiae. Moreover, the gene of neutral trehalase (encoded by nth1, trehalose degrading enzyme) was deleted by using a disruption cassette, which contained long flanking homology regions of nth1 gene (the upstream 0.26 kb and downstream 0.4 kb). The engineered strain increased its tolerance against ethanol and glucose stress. The growth of the wild strain was inhibited when the medium contained 6 % or more ethanol, whereas growth of the engineered strain was affected when the medium contained 10 % or more ethanol. There was no significant difference in the ethanol yield between the wild strain and the engineered strain when the fermentation broth contained 10 % glucose (p > 0.05). The engineered strain showed greater ethanol yield than the wild type strain when the medium contained more than 15 % glucose (p < 0.05). Higher intracellular trehalose accumulation by overexpression of tps1 and deletion of nth1 might provide the ability for yeast to protect against environmental stress.


Subject(s)
Ethanol/chemistry , Genetic Engineering , Glucosyltransferases/genetics , Saccharomyces cerevisiae Proteins/genetics , Saccharomyces cerevisiae/genetics , Trehalase/genetics , Trehalose/metabolism , Fermentation , Gene Deletion , Glucose/metabolism , Glucosyltransferases/metabolism , Industrial Microbiology , Saccharomyces cerevisiae/enzymology , Saccharomyces cerevisiae Proteins/metabolism , Stress, Physiological , Trehalase/metabolism
9.
J Fluoresc ; 26(5): 1699-708, 2016 Sep.
Article in English | MEDLINE | ID: mdl-27349802

ABSTRACT

A new efficient chemosensor 1 was prepared, for the detection of Fe(3+) in solutions as a colorimetric and fluorescent sensor. The visual and fluorescent behaviors of the receptor toward various metal ions were also explored. The receptor shows exclusive response toward Fe(3+) ions and also distinguishes Fe(3+) from other cations by color change and fluorescence enhancement in hydroalcoholic solution (MeOH/H2O = 9/1, v/v). Thus, the receptor can be used as a colorometric and fluorescent sensor for the determination of Fe(3+) ion. The fluorescence microscopy experiments showed that the chemosensor is efficient for detection of Fe(3+) in vitro, developing a good image of the biological organelles. Graphical Abstract ᅟ.

10.
PLoS One ; 11(3): e0150490, 2016.
Article in English | MEDLINE | ID: mdl-26938062

ABSTRACT

A chitosanase was purified from jelly fig latex by ammonium sulfate fractionation (50-80% saturation) and three successive column chromatography steps. The purified enzyme was almost homogeneous, as determined by SDS-polyacrylamide gel electrophoresis (SDS-PAGE) and gel activity staining. The molecular mass of the enzyme was 20.5 kDa. The isoelectric point (pI) was <3.5, as estimated by isoelectric focusing electrophoresis on PhastGel IEF 3-9. Using chitosan as the substrate, the optimal pH for the enzyme reaction was 4.5; the kinetic parameters Km and Vmax were 0.089 mg mL-1 and 0.69 µmol min-1 mg-1, respectively. The enzyme showed activity toward chitosan polymers which exhibited various degrees of deacetylation (21-94%). The enzyme hydrolyzed 70-84% deacetylated chitosan polymers most effectively. Substrate specificity analysis indicated that the enzyme catalyzed the hydrolysis of chitin and chitosan polymers and their derivatives. The products of the hydrolysis of chitosan polymer derivatives, ethylene glycol (EG) chitosan, carboxymethyl (CM) chitosan and aminoethyl (AE) chitosan, were low molecular weight chitosans (LMWCs); these products were referred to as EG-LMWC, CM-LMWC and AE-LMWC, respectively. The average molecular weights of EG-LMWC, CM-LMWC and AE-LMWC were 11.2, 11.2 and 8.89 kDa, respectively. All of the LMWC products exhibited free radical scavenging activities toward ABTS•+, superoxide and peroxyl radicals.


Subject(s)
Chitosan/chemical synthesis , Ficus/chemistry , Glycoside Hydrolases/chemistry , Latex/chemistry , Plant Proteins/chemistry , Ammonium Sulfate/chemistry , Benzothiazoles/antagonists & inhibitors , Chitin/chemistry , Chitosan/analogs & derivatives , Chitosan/chemistry , Free Radical Scavengers/chemistry , Glycoside Hydrolases/isolation & purification , Hydrogen-Ion Concentration , Hydrolysis , Isoelectric Point , Kinetics , Molecular Weight , Peroxides/antagonists & inhibitors , Plant Proteins/isolation & purification , Solubility , Substrate Specificity , Sulfonic Acids/antagonists & inhibitors , Superoxides/antagonists & inhibitors , Water
11.
J Fluoresc ; 25(5): 1331-7, 2015 Sep.
Article in English | MEDLINE | ID: mdl-26215081

ABSTRACT

A new and efficient chemodosimeter for ferric ions has been developed. The visual and fluorescent behaviors of the compound toward various metal ions were investigated: ferric ions are distinguished from other cations by selective color change and unusual fluorescence enhancement in mixed aqueous solution. Fluorescence microscopy experiments showed that this receptor is effective for detection of Fe(3+) in vitro, developing a good image of the biological organelles. The sensing mechanism is shown to involve a hydrolysis process.


Subject(s)
Fluorescent Dyes/chemistry , Iron/analysis , Iron/chemistry , Microscopy, Fluorescence/methods , Aldehydes/chemistry , Animals , Cell Survival , Mice , Pyrenes/chemistry , Quinolines/chemistry , RAW 264.7 Cells , Schiff Bases/chemistry
12.
J Med Food ; 18(7): 724-30, 2015 Jul.
Article in English | MEDLINE | ID: mdl-25871313

ABSTRACT

Red bean (Phaseolus radiatus L. var. Aurea) is a leguminous seed and mainly used as one of the popular ingredients in oriental desserts. The objective of this study was to evaluate the anti-inflammatory activity of 50 g/kg ethanolic extract of red bean (RBE) by measuring lipopolysaccharide (LPS)-induced expressions of nitric oxide (NO), inducible nitric oxide synthase (iNOS), cyclooxygenase 2 (COX-2), tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6) in RAW 264.7 macrophages. On the other hand, the antioxidant activity of RBE was determined by thiobarbituric acid reactive substances method and comet assay using H2O2-induced macrophages. The results showed that RBE at the concentrations of 50-200 µg/mL can significantly suppress the inflammatory responses in LPS-stimulated macrophages through the reduction of cellular NO and downregulation of the gene expressions of iNOS, COX-2, TNF-α, and IL-6 in a dose-dependent manner. Furthermore, RBE can diminish H2O2-induced oxidative damage in RAW 264.7 macrophage. Phenolic compounds and cyanidin-3-O-glucoside from BRE may have efficacy as overall in vitro anti-inflammatory and antioxidant agents. Red bean exerts an anti-inflammatory response and has potential as a health-promoting ingredient.


Subject(s)
Anti-Inflammatory Agents/pharmacology , Antioxidants/pharmacology , Macrophages/drug effects , Oxidative Stress/drug effects , Phaseolus/chemistry , Plant Extracts/pharmacology , Animals , Anthocyanins/analysis , Cyclooxygenase 2/genetics , Down-Regulation/drug effects , Ethanol , Hydrogen Peroxide/pharmacology , Inflammation/chemically induced , Inflammation/prevention & control , Interleukin-6/genetics , Lipopolysaccharides/pharmacology , Macrophages/immunology , Macrophages/metabolism , Mice , Nitric Oxide/analysis , Nitric Oxide Synthase Type II/genetics , Phytotherapy , RAW 264.7 Cells , Seeds/chemistry , Tumor Necrosis Factor-alpha/genetics
13.
PLoS One ; 9(12): e113596, 2014.
Article in English | MEDLINE | ID: mdl-25437446

ABSTRACT

Using 4-methylumbelliferyl-ß-D-N,N',N″-triacetylchitotrioside (4-MU-GlcNAc3) as a substrate, an acidic chitinase was purified from seeds of black soybean (Glycine max Tainan no. 3) by ammonium sulfate fractionation and three successive steps of column chromatography. The purified chitinase was a monomeric enzyme with molecular mass of 20.1 kDa and isoelectric point of 4.34. The enzyme catalyzed the hydrolysis of synthetic substrates p-nitrophenyl N-acetyl chitooligosaccharides with chain length from 3 to 5 (GlcNAcn, n = 3-5), and pNp-GlcNAc4 was the most degradable substrate. Using pNp-GlcNAc4 as a substrate, the optimal pH for the enzyme reaction was 4.0; kinetic parameters Km and kcat were 245 µM and 10.31 min-1, respectively. This enzyme also showed activity toward CM-chitin-RBV, a polymer form of chitin, and N-acetyl chitooligosaccharides, an oligomer form of chitin. The smallest oligomer substrate was an N-acetylglucosamine tetramer. These results suggested that this enzyme was an endo-splitting chitinase with short substrate cleavage activity and useful for biotechnological applications, in particular for the production of N-acetyl chitooligosaccharides.


Subject(s)
Chitinases/metabolism , Glycine max/enzymology , Seeds/enzymology , Acetylglucosamine/analogs & derivatives , Acetylglucosamine/metabolism , Chitin/chemistry , Chitin/metabolism , Chitinases/antagonists & inhibitors , Chitinases/chemistry , Chitinases/isolation & purification , Enzyme Inhibitors/pharmacology , Hydrogen-Ion Concentration , Hydrolysis , Hymecromone/analogs & derivatives , Hymecromone/metabolism , Molecular Weight , Oligosaccharides/metabolism , Temperature
14.
Food Chem Toxicol ; 71: 10-6, 2014 Sep.
Article in English | MEDLINE | ID: mdl-24880013

ABSTRACT

Our previous study demonstrated that the oral administration of low molecular weight chitosans (LMWC), prepared by hydrolyzing crab shell chitosans with bamboo shoots chitosanase in an appropriate dose, reduced aristolochic acid-induced renal lesions in mice. The objectives of this study were to evaluate the safety of LMWC using genetic and animal toxicity assays. Two assays for genotoxicity were performed: the chromosomal aberration of Chinese hamster ovary cells (CHO-K1 cells) (in vitro) and micronucleus assays in mice (in vivo). Acute oral toxicity and 28-day repeated feeding toxicity tests were performed via the oral gavage method in Sprague-Dawley (SD) rats. LMWC did not induce an increase in micronucleus ratios in vivo, and the chromosome aberration assay indicated that the LMWC was safe in terms of clastogenicity in doses up to 5.0 mg/ml. No acute lethal effect at a maximum tested dose of 5.0 g LMWC/kg body weight (bw) was observed in rats. The results of the 28-day study revealed no adverse effects on the body weight, feed consumption, hematology, blood biochemical parameters, organ weights or pathology. The no observed adverse effect level (NOAEL) of LMWC in rats was 1.0 g/kg bw for the subacute toxicity study.


Subject(s)
Bambusa/enzymology , Chitosan/pharmacology , Glycoside Hydrolases/metabolism , Plant Shoots/enzymology , Animals , Crustacea , Hydrolysis , In Vitro Techniques , Male , Mice , Mice, Inbred ICR , Molecular Weight
15.
J Sci Food Agric ; 93(10): 2562-7, 2013 Aug 15.
Article in English | MEDLINE | ID: mdl-23440932

ABSTRACT

BACKGROUND: The purpose of this study was to investigate the effects of 50% ethanol extracts from red bean non-fermented (RBE) and fermented by Bacillus subtilis (RBNE) on the antioxidant status of aged ICR mouse. RESULTS: Compared to 2-month-old ICR mouse, the plasma total antioxidant status (TAS) in 12-month-old ICR mouse decreased about 57%, while malondialdehyde (MDA) levels in the liver and brain of 12-month-old ICR mouse increased 56% and 30%, respectively. Orally administration of RBE or RBNE could completely recover the changes of MDA and plasma TAS levels due to the aging process. Vitamin E contents declined 88% in the liver and 74% in the brain of aged ICR mouse. At a level of 0.3 or 0.6 g kg(-1) body weight, RBNE raised vitamin E content in the liver and brain; however, RBE showed no significant influence. All antioxidant enzymes activities in the liver and brain of aged ICR mouse decreased compared to those activities in 2-month-old ICR mouse. RBNE could significantly enhance the superoxide dismutase activity in the brain of aged ICR mouse. CONCLUSION: Oral administration of RBE or RBNE could improve antioxidant status in aged ICR mouse. Fermentation by Bacillus subtilis could enhance the antioxidant properties of red bean.


Subject(s)
Antioxidants/pharmacology , Bacillus subtilis , Brain/metabolism , Fabaceae/microbiology , Liver/metabolism , Superoxide Dismutase/metabolism , Vitamin E/metabolism , Aging , Animals , Antioxidants/metabolism , Brain/enzymology , Fermentation , Food Microbiology , Liver/enzymology , Male , Malondialdehyde/metabolism , Mice , Mice, Inbred ICR , Plant Preparations/pharmacology , Seeds/microbiology
16.
Food Chem ; 135(4): 2529-35, 2012 Dec 15.
Article in English | MEDLINE | ID: mdl-22980838

ABSTRACT

An acidic peroxidase isoform, POD-A, with a molecular mass of 69.4 kDa and an isoelectric point of 3.5 was purified from papaya latex. Using o-phenylenediamine (OPD) as a hydrogen donor (citrate-phosphate as pH buffer), the optimum pH for the function of POD-A was 4.6, and the optimum temperature was 50°C. The peroxidase activity of POD-A toward hydrogen donors was both pH- and concentration-dependent. Under optimal conditions, POD-A catalysed the oxidation of OPD at higher rates than pyrogallol, catechol, quercetin and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS). The chemical modification reagents N-bromosuccinimide and sodium azide significantly inhibited POD-A activity. The results of kinetic studies indicated that POD-A followed a ping-pong mechanism and had a K(m) value of 2.8mM for OPD. Using CPC silica-immobilised POD-A for the determination of micromolar H(2)O(2) in milk, the lower limit of determination was 0.1 µM, and the recoveries of added H(2)O(2) were 96-109%.


Subject(s)
Carica/enzymology , Hydrogen Peroxide/analysis , Milk/chemistry , Peroxidase/chemistry , Plant Proteins/chemistry , Animals , Cattle , Enzyme Stability , Food Contamination/analysis , Kinetics , Peroxidase/isolation & purification , Plant Proteins/isolation & purification
17.
J Ethnopharmacol ; 140(1): 91-7, 2012 Mar 06.
Article in English | MEDLINE | ID: mdl-22240512

ABSTRACT

ETHNOPHARMACOLOGICAL RELEVANCE: Graptopetalum paraguayense E. Walther, a widely consumed vegetable in Taiwan, has many biological effects and has been used in folk medicine to alleviate hepatic disorders, exert diuretic effects, and relieve pain and infections. However, little data exist regarding its safety. MATERIALS AND METHODS: Two genotoxicity assays were performed: chromosomal aberration of Chinese hamster ovary (CHO-K1 cells) (in vitro) and micronucleus assay in mice (in vivo). Acute oral toxicity and 28-day repeated feeding toxicity tests were performed by oral gavage in Sprague-Dawley (SD) rats. RESULTS: GWE did not increase micronucleus ratios in vivo, and by chromosome aberration assay, GWE was safe up to 1.2mg/ml with regard to clastogenicity. Chromatid breakage was observed at high concentrations (2.5 and 5.0mg/ml) of GWE. GWE had no acute lethal effect at the maximum dose (5g/kg bw) in rats. In the 28-day study, there were no adverse effects on body weight, feed consumption, hematology, blood biochemical parameters, organ weight, or pathology. CONCLUSION: The acute toxicity study showed that the LD(50) of GWE was greater than the tested dose (up to 1g/kg bw) in SD rats. In the subacute toxicity study, the no observed adverse effect level (NOAEL) of GWE in rats was 1g/kg bw. The in vivo study of mammalian erythrocyte micronuclei confirmed the Ames test results, demonstrating that GWE has no mutagenicity. High doses of GWE require further examination due to its clastogenic potential.


Subject(s)
Crassulaceae , Erythrocytes/drug effects , Ovary/drug effects , Plant Extracts/pharmacology , Animals , Cell Line , Chromatids/drug effects , Consumer Product Safety , Crassulaceae/adverse effects , Cricetinae , Female , Lethal Dose 50 , Male , Medicine, Traditional , Mice , Mice, Inbred ICR , Micronuclei, Chromosome-Defective , No-Observed-Adverse-Effect Level , Plant Extracts/adverse effects , Plant Leaves , Rats, Sprague-Dawley , Taiwan , Toxicity Tests
18.
J Agric Food Chem ; 60(2): 649-57, 2012 Jan 18.
Article in English | MEDLINE | ID: mdl-22166086

ABSTRACT

Two thermally stable chitosanase isoforms were purified from the sheaths of chitosan-treated bamboo shoots. Isoforms A and B had molecular masses of 24.5 and 16.4 kDa and isoelectric points of 4.30 and 9.22, respectively. Using chitosan as the substrate, both isoforms functioned optimally between pH 3 and 4, and the optimum temperatures for the activities of isoforms A and B were 70 and 60 °C, respectively. The kinetic parameters K(m) and V(max) for isoform A were 0.539 mg/mL and 0.262 µmol/min/mg, respectively, and for isoform B were 0.183 mg/mL and 0.092 µmol/min/mg, respectively. Chitosans were susceptible to degradation by both enzymes and could be converted to low molecular weight chitosans between 28.2 and 11.7 kDa. Furthermore, the most susceptible chitosan substrates were 50-70 and 40-80% deacetylated for isoforms A and B, respectively. Both enzymes could also degrade chitin substrates with lower efficacy. N-Bromosuccinimide and Woodward's reagent K strongly inhibited both enzymes.


Subject(s)
Bambusa/enzymology , Glycoside Hydrolases/isolation & purification , Glycoside Hydrolases/metabolism , Bromosuccinimide/pharmacology , Chitin/metabolism , Chitosan/chemistry , Chitosan/metabolism , Edetic Acid/pharmacology , Electrophoresis, Polyacrylamide Gel , Enzyme Inhibitors/pharmacology , Enzyme Stability , Glycoside Hydrolases/antagonists & inhibitors , Glycoside Hydrolases/chemistry , Hydrogen-Ion Concentration , Isoelectric Point , Isoenzymes , Kinetics , Metals/pharmacology , Molecular Weight , Plant Shoots/enzymology , Substrate Specificity , Temperature
19.
J Gen Appl Microbiol ; 55(5): 395-401, 2009 Oct.
Article in English | MEDLINE | ID: mdl-19940385

ABSTRACT

Human alpha-defensin 5 (HD5), a small cationic peptide, is expressed in Paneth cell granules of small intestinal crypts. HD5 exhibits high antimicrobial activity against a broad spectrum of pathogenic agents, including bacteria, fungi, and viruses. In this study, the constitutive expression of HD5 antimicrobial peptide was achieved using the methylotrophic yeast, Pichia pastoris (P. pastoris). HD5 cDNA was amplified by polymerase chain reaction (PCR) using human lung cell cDNA as template. The 96-bp DNA fragment encoding mature HD5 peptide (amino acid 63-94) was subcloned into the yeast expression vector and transfected into P. pastoris X-33 expression host by electroporation. The recombinant HD5 (rHD5) was detected in the supernatant of transfected yeast by western blot analysis. The recombinant HD5 crude extract from transfected P. pastoris showed antimicrobial activities against Salmonella typhimurium, Staphylococcus aureus and pathogenic E. coli. However, rHD5 did not inhibit the growth of lactic acid bacteria such as Lactobacillus bulgaricus, Bifidobacterium bifidum, or B. longum. These results indicated that the rHD5 expressed in P. pastoris selectively inhibited the growth of specific bacteria.


Subject(s)
DNA, Complementary/genetics , Pichia/metabolism , alpha-Defensins/metabolism , Animals , Anti-Infective Agents/metabolism , Anti-Infective Agents/pharmacology , Antimicrobial Cationic Peptides/genetics , Antimicrobial Cationic Peptides/metabolism , Antimicrobial Cationic Peptides/pharmacology , Cloning, Molecular , Fungi/genetics , Humans , Microbial Sensitivity Tests , Paneth Cells , Pichia/genetics , Recombinant Fusion Proteins/genetics , alpha-Defensins/genetics
20.
Am J Chin Med ; 36(2): 369-83, 2008.
Article in English | MEDLINE | ID: mdl-18457367

ABSTRACT

This study was aimed to evaluate the antioxidant abilities of water (SGWE), 50% ethanolic (SGE50) and 95% ethanolic (SGE95) extracts from the stem of Graptopetalum paraguayense, and the extract with the highest antioxidant activity was assayed for its inhibitory effect on proliferation of human hepatoma (Hep G2) cell line. Antioxidant abilities of extracts were assessed their radical-scavenging abilities and effects on Fe/ascorbate-induced lipid peroxidation in a liposome model system. The results of this study showed that antioxidant activities were increased with the increase of the extracts concentrations, and the activities correlated with both the total phenol and anthocyanin contents. A comparison of the 50% inhibition concentration (IC(50)) values of different antioxidant reactions revealed that SGWE was the more effective at scavenging superoxide anion radical and preventing lipid peroxidation than SGE50 and SGE95 (p<0.05). The flow cytometry results indicated that SGWE lowered cell viability, and induced G1 phase arrest and apoptosis in Hep G2 cells. These results demonstrated the antioxidant and anti-hepatoma potential of stem of Graptopetalum paraguayense.


Subject(s)
Antioxidants , Carcinoma, Hepatocellular/pathology , Cell Proliferation/drug effects , Crassulaceae/chemistry , Free Radical Scavengers , Plant Extracts/pharmacology , Plant Stems/chemistry , Anthocyanins/analysis , Apoptosis/drug effects , Cell Line, Tumor , Cell Survival/drug effects , Dose-Response Relationship, Drug , Ethanol , Humans , Lipid Peroxidation/drug effects , Phenol/analysis , Plant Extracts/chemistry , Water
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