The MRI technique has been used in diagnosis of manganism in humans and non-human primates. This cross-sectional study was designed to explore whether the pallidal signal intensity in T1-weighted MRI correlated with Mn levels in the blood compartment among Mn-exposed workers and to understand to what extent the MRI signal could reflect Mn exposure. A group of 18 randomly selected male Mn-exposed workers of which 13 were smelting workers with high exposure (mean of airborne Mn in work place: 1.26 mg/m3; range: 0.31–2.93 mg/m3), and 5 power distribution control workers with low exposure (0.66 mg/m3 and 0.23–0.77 mg/m3) from a ferroalloy factory, and another group of 9 male subjects as controls from a non-smelting factory who were office or cafeteria workers (0.01 mg/m3 and 0–0.03 mg/m3) were recruited for neurological tests, MRI examination, and analysis of Mn in whole blood (MnB), plasma (MnP) or red blood cells (MnRBC). No clinical symptoms and signs of manganism were observed among these workers. MRI data showed average increases of 7.4% (p < 0.05) and 16.1% (p < 0.01) in pallidal index (PI) among low- and high-exposed workers, respectively, as compared to controls. Fourteen out of 18 Mn-exposed workers (78%) had intensified PI values, while this proportion was even higher (85%) among the high Mn-exposed workers. Among exposed workers, the PI values were significantly associated with MnRBC (r = 0.55, p = 0.02). Our data suggest that the workers exposed to airborne Mn, but without clinical symptoms, display an exposure-related, intensified MRI signal. The MRI, as well as MnRBC, may be useful in early diagnosis of Mn exposure.
Manganese; MRI; Red blood cells; Trace element; Smelting workers; Biomarker
Manganese (Mn)-induced Parkinsonism has been well documented; however, little attention has been devoted to Mn-induced cardiovascular dysfunction. This review summarizes literature data from both animal and human studies on Mn’s effect on cardiovascular function. Clinical and epidemiological evidence suggests that the incidence of abnormal electrocardiogram (ECG) is significantly higher in Mn-exposed workers than that in the control subjects. The main types of abnormal ECG include sinus tachycardia, sinus bradycardia, sinus arrhythmia, sinister megacardia, and ST-T changes. The accelerated heartbeat and shortened P-R interval appear to be more prominent in female exposed workers than in their male counterparts. Mn-exposed workers display a mean diastolic blood pressure that is significantly lower than that of the control subjects, especially in the young and female exposed workers. Animal studies indicate that Mn is capable of quickly accumulating in heart tissue, resulting in acute or sub-acute cardiovascular disorders, such as acute cardiodepression and hypotension. These toxic outcomes appear to be associated with Mn-induced mitochondrial damage and interaction with the calcium channel in the cardiovascular system.
Manganese; occupational exposure; cardiovascular toxicity; ECG; hypotension; vasodilatation
Minimally processed water bamboo shoot (WBS) lignifies and deteriorates rapidly at room temperature, which limits greatly its marketability. This study was to investigate the effect of modified atmosphere packaging (MAP) on the sensory quality index, lignin formation, production of radical oxygen species (ROS) and activities of scavenging enzymes, membrane integrity and energy status of minimally processed WBS when packaged with or without the sealed low-density polyethylene (LDPE) bags, and then stored at 20°C for 9 days or 2°C for 60 days.
The sensory quality of minimally processed WBS decreased quickly after 6 days of storage at 20°C. Low temperature storage maintained a higher sensory quality index within the first 30 days, but exhibited higher contents of lignin and hydrogen peroxide (H2O2) as compared with non-MAP shoots at 20°C. Combined MAP and low temperature storage not only maintained good sensory quality after 30 days, but also reduced significantly the increases in lignin content, superoxide anion (O2.-) production rate, H2O2 content and membrane permeability, maintained high activities of superoxide dismutase (SOD), catalase (CAT) and ascorbate peroxidase (APX), and reduced the increase in activities of lipase, phospholipase D (PLD) and lipoxygenase (LOX). Furthermore, the minimally processed WBS under MAP condition exhibited higher energy charge (EC) and lower adenosine monophosphate (AMP) content by the end of storage (60 days) at 2°C than those without MAP or stored for 9 days at 20°C.
These results indicated that MAP in combination with low temperature storage reduced lignification of minimally processed WBS, which was closely associated with maintenance of energy status and enhanced activities of antioxidant enzymes, as well as reduced alleviation of membrane damage caused by ROS.
Water bamboo shoot; Modified atmosphere packaging; Lignification; Antioxidant enzyme; Membrane integrity; Energy
In the title compound, C16H18N4O2, known also as peribedil, the dihedral angle between the mean planes of the pyrimidine and benzene rings is 56.5 (8)°. The 1,3-dioxole fragment adopts an envelope conformation with the methylene C atom forming the flap; this atom deviates by 0.232 (3) Å from the plane defined by the remaining atoms of the 1,3-benzodioxole unit. In the crystal, C—H⋯π interactions between c-glide-related molecules arrange them into columns extending along the c-axis direction. The columns related by a unit translation along the b axis are packed into (100) layers via another C—H⋯π interaction involving the pyrimidine ring as an acceptor.
Hepatitis B virus (HBV) is an important infectious agent that causes widespread concern because billions of people are infected by at least 8 different HBV genotypes worldwide. However, reconstruction of the phylogenetic relationship between HBV genotypes is difficult. Specifically, the phylogenetic relationships among genotypes A, B, and C are not clear from previous studies because of the confounding effects of genotype recombination. In order to clarify the evolutionary relationships, a rigorous approach is required that can effectively explore genetic sequences with recombination.
In the present study, phylogenetic relationship of the HBV genotypes was reconstructed using a consensus phylogeny of phylogenetic trees of HBV genome segments. Reliability of the reconstructed phylogeny was extensively evaluated in agreements of local phylogenies of genome segments.
The reconstructed phylogenetic tree revealed that HBV genotypes B and C had a closer phylogenetic relationship than genotypes A and B or A and C. Evaluations showed the consensus method was capable to reconstruct reliable phylogenetic relationship in the presence of recombinants.
The consensus method implemented in this study provides an alternative approach for reconstructing reliable phylogenetic relationships for viruses with possible genetic recombination. Our approach revealed the phylogenetic relationships of genotypes A, B, and C of HBV.
Phylogeny; Hepatitis B virus; Recombination; Consensus tree
Recent studies have demonstrated that cellular energy is a key factor switching on ripening and senescence of fruit. However, the factors that influence fruit energy status remain largely unknown.
HPLC profiling showed that ATP abundance increased significantly in developing preharvest litchi fruit and was strongly correlated with fruit fresh weight. In contrast, ATP levels declined significantly during postharvest fruit senescence and were correlated with the decrease in the proportion of edible fruit. The five gene transcripts isolated from the litchi fruit pericarp were highly expressed in vegetative tissues and peaked at 70 days after flowering (DAF) consistent with fruit ADP concentrations, except for uncoupling mitochondrial protein 1 (UCP1), which was predominantly expressed in the root, and ATP synthase beta subunit (AtpB), which was up-regulated significantly before harvest and peaked 2 days after storage. These results indicated that the color-breaker stage at 70 DAF and 2 days after storage may be key turning points in fruit energy metabolism. Transcript abundance of alternative oxidase 1 (AOX1) increased after 2 days of storage to significantly higher levels than those of LcAtpB, and was down-regulated significantly by exogenous ATP. ATP supplementation had no significant effect on transcript abundance of ADP/ATP carrier 1 (AAC1) and slowed the changes in sucrose non-fermenting-1-related kinase 2 (SnRK2) expression, but maintained ATP and energy charge levels, which were correlated with delayed senescence.
Our results suggest that senescence of litchi fruit is closely related with energy. A surge of LcAtpB expression marked the beginning of fruit senescence. The findings may provide a new strategy to extend fruit shelf life by regulating its energy level.
Litchi (Litchi chinensis Sonn.) fruit are highly perishable and have a very short shelf life, easily turning brown and decaying. This study investigated the efficiency of pyrogallol, a catechin on the physiology and biochemistry in relation to storage life of litchi fruit.
Fruit were treated with pyrogallol at 1 mM and then stored at ambient temperature (25°C) or low temperature (4°C). Compared with control, pyrogallol significantly reduced pericarp browning and delayed the rotting of fruit day 4 at 25°C, and on day 30 at 4°C. The chemical treatment reduced respiration rate and the activities of peroxidase (POD) and polyphenol oxidase (PPO), and delayed the loss of membrane permeability. Pyrogallol increased the activity of phenylalanine ammonia-lyase (PAL), delayed the loss of anthocyanin and phenolics, and maintained high 2,2-diphenyl-1-picrlhydrazyl (DPPH) radical scavenging activity and reducing power. High performance liquid chromatograph (HPLC) analysis clearly indicated that treated fruit contained higher concentration of the four phenolic compounds procyanidin B1, (+)-catechin, (−)-epicatechin and (−)-epicatechin-3-gallate.
The application of pyrogallol partially reducing pericarp browning and changed quality-related physiological activities and, thus, pyrogallol could have beneficial effects on pericarp browning and fruit decay control, and could be helpful for litchi fruit postharvest storage.
Litchi fruit; Pyrogallol; Physiology; Postharvest; Quality; Storage
The Chinese bayberry (Myrica rubra Sieb. and Zucc.) is a subtropical fruit native to China, with unique flavor, sweet and sour taste, and high nutrition and health values. The fruit is highly perishable and susceptible to mechanical injury, physiological deterioration and fungal decay once harvested. This study was to investigate the effect of hypobaric storage on the quality of Chinese bayberry fruit and then develop storage technology to prolong the supply of the fruit.
The fruit stored under hypobaric conditions exhibited lower decay, higher titratable acidity and total phenolics compared with those stored under normal atmospheric conditions. Hypobaric storage significantly reduced malonaldehyde accumulation, respiratory rate and maintained high catalase and peroxidase activities of Chinese bayberry fruit. Ferric reducing antioxidant power was also higher in the fruit stored under hypobaric condition than those under normal atmospheric conditions.
Hypobaric storage improved the metabolism, antioxidant system and postharvest quality of Chinese bayberry fruit and provided an effective alternative method to prolong the storage life of this fruit.
Chinese bayberries; Hypobaric storage; Quality; Antioxidant enzymes; Antioxidant capacity
This study was conducted to increase the bioactivity of litchi pericarp polysaccharides (LPPs) biotransformed by Aspergillus awamori. Compared to the non-A. awamori-fermented LPP, the growth effects of A. awamori-fermented LPP on Lactobacillus bulgaricus and Streptococcus thermophilus were four and two times higher after 3 days of fermentation, respectively. Increased 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity and DNA protection activity of litchi pericarp polysaccharides were also achieved after A. awamori fermentation. Moreover, the relative content of glucose and arabinose in LPP after fermentation decreased from 58.82% to 22.60% and from 18.82% to 10.09%, respectively, with a concomitant increase in the relative contents of galactose, rhamnose, xylose, and mannose. Furthermore, lower molecular weight polysaccharides were obtained after A. awamori fermentation. It can be concluded that A. awamori was effective in biotransforming LPP into a bioactive mixture with lower molecular weight polysaccharides and higher antioxidant activity and relative galactose content.
Litchi (Litchi chinensis Sonn.) pericarp is a major byproduct which contains a significant amount of polyphenol. This study was designed to biotransformation litchi pericarp extract (LPE) by Aspergillus awamori to produce more bioactive compounds with stronger antioxidant activities.
The study exhibited that the 2,2-diphenyl-1-picrylhydrazyl radical scavenging activities significantly (p < 0.05) increased from 15.53% to 18.23% in the water-extracted fraction and from 25.41% to 36.82% in the ethyl acetate-extracted fraction. Application of DNA cleavage assay further demonstrated the enhanced protection effect of the fermented phenolics on DNA damage. It is also noted that the water-extracted fraction of the fermented LPE possessed a much stronger capacity than the ethyl acetate-extracted fraction to prevent from damage of supercoiled DNA. Interestingly, it was found that some new compounds such as catechin and quercetin appeared after of A. awamori fermentation of LPE, which could account for the enhanced antioxidant activity.
The DPPH radical scavenging activity and DNA protection effect of LPE were increased by Aspergillus awamori bioconversion while some compounds responsible for the enhanced antioxidant activity were identified. This study provided an effective way of utilizing fruit pericarp as a readily accessible source of the natural antioxidants in food industry and, thus, extended the application area such as fruit by-products.
Litchi pericarp; Phenolics; Aspergillus awamori; DPPH radical scavenging activity; DNA protection; HPLC
The biopreservation of foods using bacteriocinogenic lactic acid bacteria (LAB) isolated directly from foods is an innovative approach. The objectives of this study were to isolate and identify bacteriocinogenic LAB from various cheeses and yogurts and evaluate their antimicrobial effects on selected spoilage and pathogenic microorganisms in vitro as well as on a food commodity.
LAB were isolated using MRS and M17 media. The agar diffusion bioassay was used to screen for bacteriocin or bacteriocin-like substances (BLS) producing LAB using Lactobacillus sakei and Listeria innocua as indicator organisms. Out of 138 LAB isolates, 28 were found to inhibit these bacteria and were identified as strains of Enterococcus faecium, Streptococcus thermophilus, Lactobacillus casei and Lactobacillus sakei subsp. sakei using 16S rRNA gene sequencing. Eight isolates were tested for antimicrobial activity at 5°C and 20°C against L. innocua, Escherichia coli, Bacillus cereus, Pseudomonas fluorescens, Erwinia carotovora, and Leuconostoc mesenteroides subsp. mesenteroides using the agar diffusion bioassay, and also against Penicillium expansum, Botrytis cinerea and Monilinia frucitcola using the microdilution plate method. The effect of selected LAB strains on L. innocua inoculated onto fresh-cut onions was also investigated.
Twenty percent of our isolates produced BLS inhibiting the growth of L. innocua and/or Lact. sakei. Organic acids and/or H2O2 produced by LAB and not the BLS had strong antimicrobial effects on all microorganisms tested with the exception of E. coli. Ent. faecium, Strep. thermophilus and Lact. casei effectively inhibited the growth of natural microflora and L. innocua inoculated onto fresh-cut onions. Bacteriocinogenic LAB present in cheeses and yogurts may have potential to be used as biopreservatives in foods.
Lactic acid bacteria; Bacteriocins; Bacteriocin-like substance (BLS); Antimicrobials; Fresh-cut onions
Antioxidant activities of wampee peel extracts using five different solvents (ethanol, hexane, ethyl acetate, butanol and water) were determined by using in-vitro antioxidant models including total antioxidant capability, 1,1-diphenyl-2-picryl hydrazyl (DPPH) radical scavenging activity, reducing power, and superoxide scavenging activity. Ethyl acetate fraction (EAF) exhibited the highest antioxidant activity compared to other fractions, even higher than synthetic antioxidant butylated hydroxyl toluene (BHT). In addition, the EAF exhibited strong anticancer activities against human gastric carcinoma (SGC-7901), human hepatocellular liver carcinoma (HepG-2) and human lung adenocarcinoma (A-549) cancer cell lines, higher than cisplatin, a conventional anticancer drug. The total phenolic content of wampee fraction was positively correlated with the antioxidant activity. This is the first report on the antioxidant and anticancer activities of the wampee peel extract. Thus, wampee peel can be used potentially as a readily accessible source of natural antioxidants and a possible pharmaceutical supplement.
Litchi fruit pericarp tissue is considered an important source of dietary phenolics. This study consisted of two experiments. The first was conducted to examine the effects of various extraction temperatures (30, 40, 50, 60, 70 and 80 °C) and pH values (2, 3, 4, 5 and 6) on the extraction yield of phenolics from litchi fruit pericarp. Extraction was most efficient at pH 4.0, while an extraction temperature of 60 °C was the best in terms of the combined extraction yield of phenolics and the stability of the extracted litchi anthocyanins. The second experiment was carried out to further evaluate the effects of various temperatures (25, 35, 45, 55 and 65 °C) and pH values (1, 3, 5 and 7) on the total antioxidant ability and scavenging activities of DPPH radicals, hydroxyl radical and superoxide anion of the extracted anthocyanins. The results indicated that use of 45–60 °C or pH 3–4 exhibited a relatively high antioxidant activity. The study will help improve extraction yield of phenolics from litchi fruit pericarp and promote better utilization of the extracted litchi anthocyanins as antioxidants.
Litchi; extraction; temperature; pH; phenolics; anthocyanin; antioxidant activity
The phenolic profile and antioxidant activities of oolong tea extract were investigated after tea was steeped in 90 or 100 °C water for 3 or 10 min. The extraction yield increased with increasing temperature and extended steeping time. However, higher temperature and longer time (100 °C water for 10 min) led to loss of phenolics. The aqueous extract of oolong tea (AEOT) at 100 °C for 3 min exhibited the strongest antioxidant activity. The major polyphenolic components of the AEOT were identified as (−)-epigallocatechin (EGC), (−)-epigallocatechin gallate (EGCG) and (−)-epicatechin-3-gallate (ECG). The two major catechins (EGC and EGCG) in the tea infusion contributed significantly to the investigated antioxidant activities [i.e., the 2,2-diphenyl-2-picrylhydrazyl hydrate (DPPH) radical scavenging and superoxide radical scavenging activities] with high correlation values in r = 0.9486 and 0.9327 for the EGC and r = 0.9592 and 0.8718 for the EGCG, respectively.
Oolong tea; Infusion; Antioxidant activity; Phenolics