Risk assessment of carcinogens in food

Risk Assessment and Risk Reduction of Ptaquiloside in Bracken Fern

This study was conducted to determine the optimal boiling time to reduce ptaquiloside (PTA) and to carry out a risk assessment for PTA, a representative toxic substance found in bracken fern (BF; Pteridium aquilinum), which is frequently consumed as food in East Asian countries. High-performance liquid chromatography showed that the concentration of PTA in BF was reduced by up to 99% after boiling for 20 min. Risk assessment results showed that the cancer margin of exposure (MOE; ≥ 25,000 = safe) to PTA for an average daily exposure scenario after boiling BF for 20 min was considered safe. In addition, the non-cancer MOE (≥ 300 = safe) to PTA under an average daily exposure scenario after BF boiling for 20 min was considered safe. However, human exposure to PTA was considered unsafe under the non-boiled BF exposure and maximum daily exposure scenarios. Therefore, boiling BF for at least 20 min is recommended before consumption, to reduce exposure to PTA as much as possible.

Estimasi Risiko Okratoksin A dari Konsumsi Kopi Bubuk di Indonesia

Ochratoxin A (OTA) is a nephrotoxic and carcinogenic mycotoxin that can be found in coffee. This study aimed to obtain the processing steps commonly applied by coffee shops in Indonesia, calculate the level of OTA in coffee bean and ground coffee, and the risk estimate of OTA exposure from ground coffee in Indonesia. The processing steps were determined through an online survey while the level of OTA in coffee was calculated from available references. The consumption level of ground coffee was determined from the Indonesia total diet study report and the exposure assessment was carried out by deterministic approach. The risk estimates were expressed as % risk towards provisional tolerable weekly intake (PTWI) and margin of exposure (MOE). Based on the survey of coffee shops (n=20), ground coffee is commonly processed using dry method consisting of cherries sorting, sun drying, roasting and grinding. Ground coffee was the most common coffee consumed by adults. Based on references from countries with climate similar to Indonesia, the level of OTA in coffee bean ranged from 0.033 to 168 μg/kg with an average of 12.25 μg/kg and 0.018-55 μg/kg in ground coffee averaging at 5.60 μg/kg. The individual exposure to OTA from drinking coffee is 0.014-0.744 ng/kg bw/day. The risk estimates shows that risk of ochratoxin A from ground coffee consumption is low, with risk percentage of <100 % provisional tolerable weekly intake (PTWI) and a MOE of higher than 10000 for all age groups. The study suggested that adults (19-55 years) have higher exposure and risk than the other age groups.

Thymol screening, phenolic contents, antioxidant and antibacterial activities of Iranian populations of Trachyspermum ammi (L.) Sprague (Apiaceae)

The seeds of Trachyspermum ammi were gathered at the ripening stage from different regions of Iran and grouped into 14 populations (P1-P14) accordingly. The essential oil (EO) extraction yielded in the 3.16–5% range. EOs were analyzed by gas chromatography-flame ionization detection (GC-FID) and gas chromatography-mass spectrometry (GC–MS) and 11 constituents were identified. Thymol (59.92–96.4%), p-cymene (0.55–21.15%), γ-terpinene (0.23–17.78%), and carvacrol (0.41–2.77%) were the major constituents. The highest contents of thymol and carvacrol were found in the Ghayen population (P2). Also, P2 and P8 (Estahban) had the highest value of total phenol (TPC) 43.2 mg gallic acid equivalent (GAE)/g DW, and total flavonoids (TFC) 8.03 mg quercetin equivalent (QE)/g DW, respectively. P1 (Kalat) had the highest total coumarin (TCC) value (0.26 mg coumarin equivalent CE/g DW). Based on EO constituents, principal component analysis (PCA) and cluster analysis classified populations into two chemotypes of thymol/p-cymene/γ-terpinene and thymol/carvacrol. The highest positive correlation coefficient was between α-terpinene and limonene (0.96), while the highest negative correlation was between thymol and p-cymene (–0.984). The antioxidant activities of extracts and EOs were evaluated by phosphomolybdenum (total antioxidant capacity; TAC), diphenylpicrylhydrazyl (DPPH IC₅₀), and ferric ion reducing antioxidant power (FRAP) assays. Also, the antimicrobial activity of EOs was studied against Escherichia coli and Staphylococcus aureus. P8 with high thymol, EO content (%v/w), TFC, and antibacterial and antioxidant activities is recommended but further studies are needed to confirm the chemotype introduction.

Food-Borne Chemical Carcinogens and the Evidence for Human Cancer Risk

Commonly consumed foods and beverages can contain chemicals with reported carcinogenic activity in rodent models. Moreover, exposures to some of these substances have been associated with increased cancer risks in humans. Food-borne carcinogens span a range of chemical classes and can arise from natural or anthropogenic sources, as well as form endogenously. Important considerations include the mechanism(s) of action (MoA), their relevance to human biology, and the level of exposure in diet. The MoAs of carcinogens have been classified as either DNA-reactive (genotoxic), involving covalent reaction with nuclear DNA, or epigenetic, involving molecular and cellular effects other than DNA reactivity. Carcinogens are generally present in food at low levels, resulting in low daily intakes, although there are some exceptions. Carcinogens of the DNA-reactive type produce effects at lower dosages than epigenetic carcinogens. Several food-related DNA-reactive carcinogens, including aflatoxins, aristolochic acid, benzene, benzo[a]pyrene and ethylene oxide, are recognized by the International Agency for Research on Cancer (IARC) as causes of human cancer. Of the epigenetic type, the only carcinogen considered to be associated with increased cancer in humans, although not from low-level food exposure, is dioxin (TCDD). Thus, DNA-reactive carcinogens in food represent a much greater risk than epigenetic carcinogens.

Risk Assessment of Polycyclic Aromatic Hydrocarbons (PAHs) in Smoked Sardinella sp. in Ghana: Impact of an Improved Oven on Public Health Protection

An improved fish smoking oven called FAO-Thiaroye Technique (FTT) has been introduced in Ghana and other countries in the Global South as a technical intervention for the high levels of polycyclic aromatic hydrocarbons (PAHs) in traditionally smoked fish produced in those regions. This study evaluated the extent to which the intervention reduces consumer exposure to PAHs (considering benzo(a)pyrene [BaP] as a marker) in smoked fish, using Ghana as a case. Smoked Sardinella sp. were sampled from two traditional ovens (Chorkor smoker and metal drum oven) and the FTT and their PAH levels were determined by gas chromatography-mass spectrometry. Samples of the product were also purchased from informal markets in three selected regions of Ghana and analyzed for their PAH levels. Cross-sectional consumer surveys were conducted in the selected regions to determine intakes of the commodity. A probabilistic risk assessment of PAH was then done by the margin of exposure (MoE) approach. BaP MoE as low as 1,060 and 752 were obtained for products from the traditional ovens and the informal markets, respectively, whereas the lowest value for FTT products was approximately 161,000. MoE values less than 10,000 were considered to denote a serious public health concern requiring risk management action. Therefore, the findings suggest that there is a potential health concern of high consumer exposure to PAHs in traditionally smoked fish in Ghana, and that the FTT is a technically viable intervention for the problem.

Uptake and translocation of UV-filters and synthetic musk compounds into edible parts of tomato grown in amended soils

In the last years, the number of wastewater treatment plants (WWTPs) has increased and consequently, sewage sludge production. This residue is very rich in crop nutrients, which makes it prone to be used as organic fertilizer or soil conditioner for agriculture. However, the presence of emerging pollutants in these fertilizers has raised concern, namely their potential accumulation in soil and, eventually their uptake by crops. Therefore, the main goal of this work was to study the potential plant uptake and translocation of ultraviolet-filters (UVFs) and synthetic musk compounds (SMCs). A total of 6 UVFs and 11 SMCs were analysed in Micro-Tom tomatoes grown in soil amended with a commercial sewage sludge-based organic fertilizer. Most of the studied compounds were detected in the tomato fruit, in concentrations ranging from 5 to 147 ng g^-1 dw for UVFs and from 1.3 to 68 ng g^-1 dw for SMCs. This indicates a potential uptake of these emerging pollutants and a subsequent translocation to the fruits. Besides that, UVFs show bioconcentration factors (BCFs) from 3 (DTS) to 33 (BZ) and SMCs from 0.2 (AHTN) to 23 (HHCB). Nevertheless, no risk by ingestion was observed based on estimation of the weekly exposure dose through hazard quotients (HQ < 0.02). SMCs galaxolide and tonalide seem to pose risk to the amended soils.

Antioxidant and functional properties of cowhide collagen peptides

In the present study, antioxidant activities and functional properties of cowhide collagen antioxidant peptides (CCAPs) with different molecular weight (MW) were investigated. The optimum preparation conditions of CCAPs were hydrolysis time of 1.53 hr, temperature of 54.9 °C, pH 7.38, and neutral enzyme to trypsin ratio of 0.048 g: 0.016 g according to single factor test and response surface methodology (RSM). Three fractions (CCAP-I, CCAP-II, and CCAP-III) were obtained by ultrafiltration and lyophilization. Antioxidant activities revealed that CCAP-III had high reducing power activity (0.323 ± 0.035) and scavenging effect on 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals (64.30 ± 5.99%), 2,2-azino-bis-(3-ethylbenzothiazoline)-6-sulfonic acid (ABTS) radicals (75.25 ± 3.14%), and hydroxyl radicals (68.26 ± 6.74%) compared to the other fractions. In addition, LC-MS/MS analysis showed that Ala-Gly-Glu-Arg, Gly-Ile-Ala-Gly-Glu-Arg, Gly-Pro-Ala-Gly-Pro-Ala-Gly-Pro-Arg, Gly-Val-Val-Gly-Pro-Glu-Gly-Ala-Arg and Gly-Phe-Ser-Gly-Leu-Asp-Gly-Ala-Lys were the major peptides of CCAP-III. CCAP-III showed good hygroscopicity (HYG), water holding capacity (WHC), and oil holding capacity (OHC) when compared with CCAP-I and CCAP-II. However, CCAP-II has great emulsifying properties, and CCAP-I has excellent foaming properties. Therefore, CCAPs can be used as a promising source of functional peptides with antioxidant properties. PRACTICAL APPLICATION: This study demonstrated the peptides of cowhide collagen has superior antioxidant and functional properties. This study provided a scientific basis for the preparation of antioxidant peptides from cowhide collagen.

Extraction of Bioactive Proteins from Seeds (Corn, Sorghum, and Sunflower) and Sunflower Byproduct: Enzymatic Hydrolysis and Antioxidant Properties

Background:

Food proteins have benefits for human health, which justifies their production and use. In this context, the use of seeds and byproducts that would be otherwise discarded is highlighted in the present work, to produce protein extracts and hydrolyzed proteins, generating opportunities to reduce environmental impacts.

Objective:

This work aimed to use different extraction methods to obtain protein extracts from seeds (corn, sorghum, and sunflower) and sunflower byproduct to determine their antioxidant activity, and apply different proteolytic enzymes in the hydrolysis of sunflower byproduct.

Methods:

The seeds of corn, sorghum, and sunflower, and sunflower byproduct were ground to produce flour and the protein extracts were prepared using five different methods. The bioactivity of fractions was analyzed by different methods (ABTS, DPPH, and FRAP) to evaluate the antioxidant activity.

Results:

The most effective methods, which resulted in higher protein extraction and antioxidant activity, were those in which NH4HCO3 (5 mM, pH 8.0) and H2O/C2H6O (2:3) were used. The highest protein contents were 797.9, 303.8, and 11296.5 μg/g, and the highest antioxidant activity was 34417.5, 9732.6, and 47473.1 μg TE/g from Soxhlet and Bligh and Dyer defatted extractions for sunflower seed, and sunflower byproduct, respectively. Regarding enzymatic hydrolysis, sunflower byproduct was the substrate that presented the highest degree of hydrolysis (11.06%) when Neutrase ® enzyme was used. Enzymatic hydrolysis increased antioxidant activity in the hydrolyzed proteins, approximately by 20.0%, using Neutrase® and 22.3% using Flavourzyme® treatments.

Conclusion:

The protein extracts and the hydrolyzed proteins exhibited high antioxidant activity, demonstrating great potential for use as natural antioxidants in food systems.

The safety evaluation of food flavoring substances: the role of genotoxicity studies

The Flavor and Extract Manufacturers Association (FEMA) Expert Panel relies on the weight of evidence from all available data in the safety evaluation of flavoring substances. This process includes data from genotoxicity studies designed to assess the potential of a chemical agent to react with DNA or otherwise cause changes to DNA, either in vitro or in vivo. The Panel has reviewed a large number of in vitro and in vivo genotoxicity studies during the course of its ongoing safety evaluations of flavorings. The adherence of genotoxicity studies to standardized protocols and guidelines, the biological relevance of the results from those studies, and the human relevance of these studies are all important considerations in assessing whether the results raise specific concerns for genotoxic potential. The Panel evaluates genotoxicity studies not only for evidence of genotoxicity hazard, but also for the probability of risk to the consumer in the context of exposure from their use as flavoring substances. The majority of flavoring substances have given no indication of genotoxic potential in studies evaluated by the FEMA Expert Panel. Examples illustrating the assessment of genotoxicity data for flavoring substances and the consideration of the factors noted above are provided. The weight of evidence approach adopted by the FEMA Expert Panel leads to a rational assessment of risk associated with consumer intake of flavoring substances under the conditions of use.

Analytical methodology to screen UV-filters and synthetic musk compounds in market tomatoes

A Quick, Easy, Cheap, Effective, Rugged and Safe (QuEChERS) methodology followed by gas chromatography-tandem mass spectrometry (GC-MS/MS) analysis was developed to extract thirteen synthetic musk compounds (SMCs: cashmeran, celestolide, phantolide, traseolide, galaxolide, tonalide, musk ambrette, musk xylene, musk ketone, musk tibetene, musk moskene, ethylene brassylate and exaltolide) and six ultraviolet-filters (UVFs: 2-ethylhexyl 4-dimethylaminobenzoate, 3-(4'-methylbenzylidene) camphor, 2-ethylhexyl 4-methoxycinnamate, 2-ethylhexyl 2-cyano-3,3-diphenylacrylate, benzophenone and drometrizole trisiloxane) from tomatoes. The proposed methodology was optimized: 2 g of freeze-dried tomato was extracted with 4 mL of water and 10 mL of ethyl acetate, adding 6 g of MgSO₄ and 1.5 g of NaCl, then a dispersive solid-phase extraction was performed using 3 g of MgSO₄, 300 mg of primary-secondary amino adsorbent (PSA) and 300 mg of octadecyl-silica (C18). Validation delivered recoveries between 81 (celestolide) and 119% (musk tibetene), with relative standard deviations <10%. The instrumental limit of detection varied from 0.02 (2-ethylhexyl 4-methoxycinnamate) to 3.00 pg (exaltolide and musk xylene). Regarding the method quantification limits, it ranged between 0.4 (celestolide) and 47.9 ng g^-1 dw (exaltolide). The method was applied to different varieties of tomatoes (Solanum lycopersicum), revealing UVFs and SMCs between 1 and 210 ng g^-1 dw. Higher concentrations were found for benzophenone (29-210 ng g^-1 dw) and galaxolide (9-53 ng g^-1 dw). The risk associated to the ingestion of contaminated tomatoes has also been estimated, showing that a potential health risk is unlikely.

Glyphosate toxicity and carcinogenicity: a review of the scientific basis of the European Union assessment and its differences with IARC

Glyphosate is the most widely used herbicide worldwide. It is a broad spectrum herbicide and its agricultural uses increased considerably after the development of glyphosate-resistant genetically modified (GM) varieties. Since glyphosate was introduced in 1974, all regulatory assessments have established that glyphosate has low hazard potential to mammals, however, the International Agency for Research on Cancer (IARC) concluded in March 2015 that it is probably carcinogenic. The IARC conclusion was not confirmed by the EU assessment or the recent joint WHO/FAO evaluation, both using additional evidence. Glyphosate is not the first topic of disagreement between IARC and regulatory evaluations, but has received greater attention. This review presents the scientific basis of the glyphosate health assessment conducted within the European Union (EU) renewal process, and explains the differences in the carcinogenicity assessment with IARC. Use of different data sets, particularly on long-term toxicity/carcinogenicity in rodents, could partially explain the divergent views; but methodological differences in the evaluation of the available evidence have been identified. The EU assessment did not identify a carcinogenicity hazard, revised the toxicological profile proposing new toxicological reference values, and conducted a risk assessment for some representatives uses. Two complementary exposure assessments, human-biomonitoring and food-residues-monitoring, suggests that actual exposure levels are below these reference values and do not represent a public concern.

Comprehensive estimate of the theoretical maximum daily intake of pesticide residues for chronic dietary risk assessment in Argentina

A chronic dietary risk assessment for pesticide residues was conducted for four age groups of the Argentinian population following the procedure recommended by the WHO. The National Theoretical Maximum Daily Intake (NTMDI) for 308 pesticides was calculated for the first time, using the Maximum Residue Limits (MRLs) from several Argentinean regulations and food consumption data from a comprehensive National Nutrition and Health Survey. The risk was estimated by comparing the TMDI with the Acceptable Daily Intakes (ADI) identified by various sources. Furthermore, for each of the compounds with a TMDI >65% of the ADI, a probabilistic analysis was conducted to quantify the probability of exceeding the ADI. In this study 27, 22, 10, and 6 active ingredients (a.i.) were estimated to exceed the 100% of the ADI for the different population groups: 6-23 month-old children, 2-5 year-old children, pregnant women, and 10-49 year-old women, respectively. Some of these ADI-exceeding compounds (carbofuran, diazinon, dichlorvos, dimethoate, oxydemeton-methyl and methyl bromide) were found in all four of these groups. Milk, apples, potatoes, and tomatoes were the foods that contributed most to the intake of these pesticides. The study is of primary importance for the improvement of risk assessment, regulations, and monitoring activities.

Simultaneous production of proteases and antioxidant compounds from agro-industrial by-products

The use of processes for simultaneous production of bioproducts as enzymes and bioactive compounds is an interesting alternative to reduce environmental impacts. Thus, the aim of this study was to produce simultaneously, using the biorefinery concept, both proteases and bioactive compounds with antioxidant activity from Bacillus sp. P45 cultivation by using different by-products. The integrated process developed in this study enabled to obtain enzymes with proteolytic and keratinolytic properties in a process with alternate substrates from agro-industrial by-products (feather meal, residual feather meal and biomass), thus, creating an interesting alternative to managing them. The residual biomass provided the highest protease activity (1306.6U/mL) and the reused feather meal reached the highest keratinolytic activity (89U/mL), both at 32h of cultivation. Moreover, hydrolysates produced in cultivation using feather meal and residual biomass had high antioxidant activity, they have great potential as natural antioxidants.

Potential for MERLIN-Expo, an advanced tool for higher tier exposure assessment, within the EU chemical legislative frameworks

MERLIN-Expo merges and integrates advanced exposure assessment methodologies, allowing the building of complex scenarios involving several pollution sources and targets. The assessment of exposure and risks to human health from chemicals is of major concern for policy and ultimately benefits all citizens. The development and operational fusion of the advanced exposure assessment methodologies envisaged in the MERLIN-Expo tool will have a significant impact in the long term on several policies dealing with chemical safety management. There are more than 30 agencies in Europe related to exposure and risk evaluation of chemicals, which have an important role in implementing EU policies, having especially tasks of technical, scientific, operational and/or regulatory nature. The main purpose of the present paper is to introduce MERLIN-Expo and to highlight its potential for being effectively integrated within the group of tools available to assess the risk and exposure of chemicals for EU policy. The main results show that the tool is highly suitable for use in site-specific or local impact assessment, with minor modifications it can also be used for Plant Protection Products (PPPs), biocides and REACH, while major additions would be required for a comprehensive application in the field of consumer and worker exposure assessment.

Fermented papaya preparation modulates the progression of N-methyl-N-nitrosourea induced hepatocellular carcinoma in Balb/c mice

AIM AND MAIN METHOD

The medicinal properties of fermented papaya preparation (FPP) derived from Carica papaya fruit was investigated in order to determine its ability to modulate the progression of N-methyl-N-nitrosourea induced hepatocellular carcinoma in Balb/c mice.

KEY FINDINGS

As well as reducing the physical symptoms associated with N-methyl-N-nitrosourea (MNU)-induced hepatocellular carcinoma, supplementation of Balb/c mice with 500mg FPP/kg BW for 92days normalized the blood cell count, led to an increased activity of several key antioxidant enzymes (SOD: +20%, CAT: +81%, GPx: +66.1%, GR: +54.4%; P<0.001 vs. MNU control), increased the ferrous reducing antioxidant potential (+36.7%, P<0.001 vs. MNU control) and reduced the extent of lipid peroxidation in the liver by 44.3% (P<0.001 vs. MNU control).

SIGNIFICANCE

Results demonstrated the ability of FPP to preserve the integrity of liver against oxidative damage and protect hepatocytes against irreversible DNA structural modifications induced by MNU, highlighting its potential role as an immune-defense modulator during hepatocarcinoma.

Purification and characterization of a ∼43 kDa antioxidant protein with antitumor activity from Pholiota nameko

BACKGROUND

Pholiota nameko water-soluble protein (PNWSP), isolated from the dried fruiting bodies of Pholiota nameko, was purified by a successive chromatographic process using Q anion exchange column, SP cation exchange column and Superdex 200 gel filtration column. PNWSP was assessed for antioxidant activities in different assay systems, and the effect on cell proliferation of human breast cancer MCF7 cells was investigated.

RESULTS

Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and analytical ultracentrifugation analysis revealed the homogeneity of PNWSP with apparent molecular weight of ∼43 kDa, and the identification was confirmed by peptide mass fingerprint analysis. It showed potential antioxidant activities in scavenging free radicals, reducing power and chelating effect on Fe(2+), and had a protective effect against DNA amage. Moreover, it inhibited the proliferation of MCF7 cells by inducing apoptosis, in which the change in cell cycle distribution and the loss of mitochondrial transmembrane potential were observed by flow cytometry.

CONCLUSIONS

The results showed that PNWSP could be a natural antioxidant and developed as a potential chemotherapeutic agent candidate against human breast cancer.

Effect of extraction solvents/techniques on polyphenolic contents and antioxidant potential of the aerial parts of Nepeta leucophylla and the analysis of their phytoconstituents using RP-HPLC-DAD and GC-MS

In the present study, evaluation of antioxidant potential, percentage yield, phytochemical and polyphenolic composition of different extracts obtained from the aerial parts ofNepeta leucophyllausing different extraction techniques/solvents was carried out.

Single-dose Intramuscular Injection Toxicology of Danggui Pharmacopuncture (DGP) in Sprague-Dawley Rats

Objectives:

The purpose of the study is to assess both the approximate lethal dose and the single dose intramuscular injection toxicity of Danggui (Angelica gigantis radix) pharmacopuncture (DGP) in Sprague-Dawley (SD) rats.

Methods:

The experiments were conducted at the good laboratory practice (GLP) laboratory, Biotoxtech Co., which is a laboratory approved by the ministry of food and drug safety (MFDS). The study was performed according to the GLP regulation and the toxicity test guidelines of the MFDS (2009) after approval of the institutional animal care and use committee of Biotoxtech. Single doses of DGP were injected intramuscularly into the rats in three test groups of 6 week old SD rats (5 male and 5 female rats per groups) in the amounts of 0.1, 0.5, and 1.0 mL/animal for groups 2, 3, and 4, respectively, and normal saline solution in the amount of 1.0 mL/animal was injected intramuscularly into the rats (5 male and 5 female rats) in the control group. Observations of the general symptoms and weight measurements were performed during the 14 day observation period after the injection. Hematologic and serum biochemical examination, necropsy, and a local tolerance test at the injection site were done after the observation period.

Results:

No death was observed in three test groups (0.1, 0.5 and 1.0 mL/animal group). In addition, the injection of DGP had no effect on general symptoms, weights, hematologic and serum biochemical examination, and necropsy. The results from the local tolerance tests at injection site showed no treatment related effects in the SD rats.

Conclusion:

The results of single dose intramuscular injection of DGP suggest that the approximate lethal dose is above 1.0 mL/animal for both male and female SD rats and that intramuscular injection of DGP may be safe.

Antioxidant and antiproliferative activities of methanolic extract from a neglected agricultural product: corn cobs

Neglected agricultural products (NAPs) are defined as discarded material in agricultural production. Corn cobs are a major waste of agriculture maize. Here, a methanolic extract from corn cobs (MEC) was obtained. MEC contains phenolic compounds, protein, carbohydrates (1.4:0.001:0.001). We evaluated the in vitro and in vivo antioxidant potential of MEC. Furthermore, its antiproliferative property against tumor cells was assessed through MTT assays and proteins related to apoptosis in tumor cells were examined by western blot. MEC showed no hydroxyl radical scavenger capacity, but it showed antioxidant activity in Total Antioxidant Capacity and DPPH scavenger ability assays. MEC showed higher Reducing Power than ascorbic acid and exhibited high Superoxide Scavenging activity. In tumor cell culture, MEC increased catalase, metallothionein and superoxide dismutase expression in accordance with the antioxidant tests. In vivo antioxidant test, MEC restored SOD and CAT, decreased malondialdehyde activities and showed high Trolox Equivalent Antioxidant Capacity in animals treated with CCl4. Furthermore, MEC decreased HeLa cells viability by apoptosis due an increase of Bax/Bcl-2 ratio, caspase 3 active. Protein kinase C expression increased was also detected in treated tumor cells. Thus, our findings pointed out the biotechnological potential of corn cobs as a source of molecules with pharmacological activity.

Cyclodextrin-promoted energy transfer for broadly applicable small-molecule detection

Reported herein is the development of non-covalent, proximity-induced energy transfer from small-molecule toxicants to organic fluorophores bound in the cavity of γ-cyclodextrin. This energy transfer occurs with exceptional efficiency for a broad range of toxicants in complex biological media, and is largely independent of the spectral overlap between the donor and acceptor. This generally applicable phenomenon has significant potential in the development of new turn-on detection schemes.

Free radical scavenging activity of peptide fractions from defatted soybean meal hydrolysates evaluated by electron spin resonance

Defatted soybean meal, a by-product of soybean oil extraction, was pretreated by ultrasonic and hydrolyzed with neutrase. The DSMH pretreated at 400 W of ultrasonic power, identified to possess the strongest antioxidant activity, was fractionated according to molecular weight into three fractions of DSMH-I (>10 kDa), DSMH-II (5-10 kDa), and DSMH-III (<5 kDa) using ultrafiltration. The fraction, DSMH-III (<5 kDa), exhibited the highest antioxidative activity and was further purified using ion-exchange chromatography. The DSMH-III was separated into five fractions (A, B, C, D, and E). Fraction C with molecular weight of 2434 Da exhibited the strongest free radical scavenging, which was evidenced by the electron spin resonance of 1,1-diphenyl-2-pycryl hydrazyl and hydroxyl radicals. Fraction C was subjected to reverse-phase high performance liquid chromatography and the sequences of the highest activity peptide were determined by liquid chromatography tandem mass spectrometry. The strongest antioxidant activity peptide had the amino acid sequence of Glu-Glu-Gln-Glu-Trp-Pro-Arg-Lys-Glu-Glu-Lys. In conclusion, ultrasonic treatment and ultrafiltration could enhanced antioxidant activity of DSMH.

A review on ochratoxin A transcriptomic studies

The mycotoxin Ochratoxin A (OTA) is a potent renal carcinogen in male rats. Transcriptomic studies on OTA (4 in vitro, 6 in vivo, 2 in vitro/in vivo) have been reviewed. The aim of 6 of them was mainly mechanistic whereas the rest had mostly predictive (1) or evaluation (5) purposes. An overall tendency towards gene expression downregulation was observed, probably as a result of protein synthesis inhibition. DNA damage response genes were not deregulated in most of the studies. Genes involved in acute renal injury, cell survival and cell proliferation were upregulated in several in vivo studies. Apoptosis genes were deregulated in vitro but less affected in vivo; activation of several MAPKs has been observed. Many genes related to oxidative stress or involved in cell-to-cell interaction pathways (Wnt) or cytoskeleton structure appeared to be deregulated either in vitro or in vivo. Regucalcin was highly downregulated in vivo and other calcium homeostasis genes were significantly deregulated in vitro. Genes related to OTA transport (OATs) and metabolism (CYPs) appeared downregulated in vivo. Overall, the mechanism of action of OTA remains unclear, however transcriptomic data have contributed to new mechanistic hypothesis generation and to in vitro-in vivo comparison.

Antioxidant potentials and anticholinesterase activities of methanolic and aqueous extracts of three endemic Centaurea L. species

The methanol and aqueous extracts of three endemic Centaurea species (C. polypodiifolia var. pseudobehen, C. pyrrhoblephara and C. antalyense) were investigated for their antioxidant and cholinesterase inhibitory activities. The antioxidant activities of these extracts were evaluated by in vitro models including, phosphomolybdenum assay, free radical scavenging assays (DPPH and ABTS), β-carotene/linoleic acid test system, metal chelating assay, FRAP assay, ferric and cupric reducing power. Cholinesterase inhibitory activities were examined using Ellman's colorimetric method. Total phenol, flavonoid, and saponin contents were also measured. Among the six Centaurea extracts evaluated, the highest antioxidant abilities were obtained from C. polypodiifolia var. pseudobehen. Methanolic extracts from C. polypodiifolia var. pseudobehen and C. antalyense had a noticeable inhibition towards AChE and BChE. These findings suggest that Centaurea species could be an anticholinesterase agent and antioxidant resource in some industries, such as food, pharmacology, and cosmetics.

Purification and characterization of a novel ~18 kDa antioxidant protein from Ginkgo biloba seeds

Ginkgo biloba seeds are widely used as a food and traditional medicine in China. In the present study, a novel antioxidant protein named GBSP was purified from Ginkgo biloba seeds. The protein (GBSP) was purified by homogenization of Ginkgo biloba seed powder in saline solution, 70% ammonium sulphate precipitation, filtration on a DEAE-Cellulose52 anion exchange column, gel filtration on a Sephadex G-50 column, and preparative chromatography on a C₁₈ column using RP-HPLC. GBSP showed an apparent molecular weight of 18 kDa by SDS-PAGE and MALDI-TOF/MS analyses. The amino acid sequence obtained by MALDI-TOF/TOF MS analysis showed GBSP was a novel protein, as no matching protein in was found the database. The protein exhibited significant antioxidant activities against free radicals such as DPPH, ABTS and superoxide anion and showed higher activity than α-tocopherol in a linoleic acid emulsion assay system. Furthermore, GBSP exhibited notable reducing power and a strong chelating effect on Cu²⁺ and Fe²⁺. Therefore, the present study demonstrates, for the first time, that this novel protein from Ginkgo biloba seeds is an excellent antioxidant.

Purification and characterization of novel antioxidant peptides from enzymatic hydrolysates of tilapia (Oreochromis niloticus) skin gelatin

To obtain hydrolysates with high degree of hydrolysis (DH) and scavenging radical activity, tilapia skin gelatin (TSG) was hydrolyzed by properase E and multifect neutral. The optimum hydrolysis condition of each enzyme was determined using the orthogonal experiment, and double-enzyme hydrolysis was further applied. The results showed the tilapia skin gelatin hydrolysate (TSGH) obtained by progressive hydrolysis using multifect neutral and properase E had the highest DH and hydroxyl radical scavenging activity. The IC(50) values of TSGH on scavenging 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical, superoxide anion radical (·O(2)) and hydroxyl radical (·OH) activities were also determined. TSGH was further purified using gel filtration chromatography, ion exchange chromatography, and RP-HPLC. The peptides were identified using nano-LC-ESI mass spectrometry. Finally, two antioxidant peptides were identified and the amino acid sequences were Glu-Gly-Leu (317.33 Da) and Tyr-Gly-Asp-Glu-Tyr (645.21 Da), respectively. The IC(50) values of two peptides on hydroxyl radical scavenging activities were 4.61 μg mL(-1)and 6.45 μg mL(-1), respectively. Therefore, the results demonstrated that the hydrolysates of TSG prepared by multifect neutral and properase E could serve as a source of peptides with high antioxidant activity. It provided a scientific basis for the preparation of antioxidant peptides.

Antioxidant activity, acetylcholinesterase inhibition, iridoid content and mutagenic evaluation of Leucosidea sericea

Leucosidea sericea is an important medicinal plant widely used in traditional medicine in southern Africa. Leaf and stem petroleum ether (PE), dichloromethane (DCM) and 50% aqueous methanol (MeOH) extracts were investigated for antioxidant and acetylcholinesterase inhibitory activities. The safety of the extracts was evaluated using the Ames test. In addition, the iridoid content of L. sericea stems and leaves were quantified. For DPPH radical-scavenging activity, the stem MeOH extract (EC(50) value: 1.6 μg/ml) was more potent than ascorbic acid (EC(50) value: 1.7 μg/ml). In the β-carotene-linoleic acid model system, antioxidant activity of the leaf DCM extract (89.8%) was not significantly different to that of butylated hydroxytoluene (BHT) (98.9%). All extracts showed a dose-dependent acetylcholinesterase inhibition; in terms of the IC(50) value, the leaf DCM extract (0.14 mg/ml) was the most potent sample. Total iridoid content was 35% higher in the stem extract than in the leaf extract. Based on the Ames test, L. sericea extracts were not mutagenic, either with or without S9 metabolic activation. These findings suggest the safety as well as the potential of L. sericea as a possible source of novel/alternative antioxidant and acetylcholinesterase inhibitory compounds.

Antioxidant properties of peptide fractions from silver carp (Hypophthalmichthys molitrix) processing by-product protein hydrolysates evaluated by electron spin resonance spectrometry

Silver carp processing by-product protein is usually discarded as an industrial solid waste. In this study the protein was recovered using a pH-shift method, after which seven commercial proteases were separately employed to prepare antioxidative hydrolysates. Among the hydrolysates, pepsin hydrolysates, which had the highest free radical-scavenging activity, were further separated into five peptide fractions, SCPH-I (>10kDa), SCPH-II (5-10kDa), SCPH-III (3-5kDa), SCPH-IV (1-3kDa), and SCPH-V (<1kDa), by using ultrafiltration. The antioxidative properties of the peptide fractions were investigated, using a free radical-scavenging assay, by electron spin resonance. The results show that SCPH-V had the highest scavenging effects on DPPH (1,1-diphenyl-2-picrylhydrazyl), hydroxyl and superoxide anion radicals. SCPH-V had potent antioxidant activity in the prevention of the peroxidation of linoleic acid and alleviation of H2O2-induced oxidative stress in human intestinal epithelial caco-2 cells. The results indicated that the antioxidant capacity of silver carp by-product hydrolysates could be enhanced by ultrafiltration.