Lactoferrin Alleviated AFM1-Induced Apoptosis in Intestinal NCM 460 Cells through the Autophagy Pathway

Aflatoxin M1 (AFM1) is the only mycotoxin with maximum residue limit in milk, which may result in serious human diseases. On the contrary, lactoferrin (Lf) is an active protein with multiple functions. Studies have confirmed that Lf has a powerful potential to protect the intestines, but the influence of Lf on mycotoxins is not clear. This study aims to explore whether Lf can protect the cytotoxicity induced by AFM1, and determine the underlying mechanisms in human normal colonic epithelial NCM460 cells. The results indicated that AFM1 decreased the cell viability, and increased the levels of apoptosis and autophagy of NCM460 cells. Lf can alleviate the cytotoxicity induced by AFM1 through enhancing cell viability, significantly down-regulated the expression of apoptotic genes and proteins (BAX, caspase3, caspase9, caspase3, and caspase9), and regulated the gene and protein expression of autophagy factors (Atg5, Atg7, Atg12, Beclin1, ULK1, ULK2, LC3, and p62). Furthermore, interference of the key gene Atg5 of autophagy can reduce AFM1-induced apoptosis, which is consistent with the role of Lf, implying that Lf may protect AFM1-induced intestinal injury by inhibiting excessive autophagy-mediated apoptosis. Taken together, our data indicated that Lf has a mitigating effect on apoptosis induced by AFM1 through the autophagy pathway.

Effect of Cooking and Freezing on Levels of pesticides residues in Local Fresh Fish

Pesticides are an important part of pests controlling strategies. Misuse of such chemicals has been linked to pollution of various environments and toxicities that lead to various health conditions and diseases. Importance of healthy and non-contaminated fish for human diet is essentially required. Samples of 14 local fresh fish (tilapia, grey mullet, and cat fish) were analyzed for seven pesticides (endosulfan, heptachlor, malathion, chlorpyrifos, bifenthrin, deltamethrin, and fenoxycarb) using liquid chromatography with tandem mass spectrometry (LC-MS/MS). Heat processing applied for positive samples by two different cooking method (roasting at 79 °C for 10 min and frying at 210 °C for 40 min) have influenced the levels of studied pesticides and significantly reduced their levels by 53-95%. Freezing preservation of contaminated fish at -70 °C for one month only reduced the level of the pesticides by 6-30%, however, final reduced levels were not below recommended maximum residue limit values.

Assessment for the passage of tylosin into the milk of Anatolian buffaloes

Tylosin is a broad-spectrum macrolide antibiotic commonly employed in veterinary medicine to treat bacterial infections. The present study assessed the milk-passage patterns of tylosin up to the 16th milking after a single intramuscular injection at the dose of 10 mg/kg/b.w. to Anatolian buffaloes. The residue levels of tylosin in milk samples of each animal were analysed by LC-MS/MS. The detection and determination limits of the employed method were 0.19 μg/kg and 0.64 μg/kg, respectively. The highest level of tylosin was found to be at the second milking. At the ninth milking, tylosin residue level decreased under the maximum residue limit of 50 μg/kg. Additionally, the employed LC-MS/MS method is used to assess tylosin residue in 40 milk samples and all of the samples were found to be tylosin free. In conclusion, this study determined the milk passaged levels of tylosin into milk of Anatolian buffaloes using an LC-MS/MS method.

Evaluation of the Relationship among Biogenic Amines, Nitrite and Microbial Diversity in Fermented Mustard

Biogenic amines (BAs) and nitrites are both considered harmful compounds for customer health, and are closely correlated with the microorganisms in fermented mustard (FM). In this study, BAs and nitrite contents in fifteen FM samples from different brands were analyzed. The concentrations of cadaverine in one sample and of histamine in one sample were above the toxic level. Moreover, five FM samples contained a high level of nitrite, exceeding the maximum residue limit (20 mg/kg) suggested by the National Food Safety Standard. Then, this study investigated bacterial and fungal communities by high-throughput sequencing analysis. Firmicutes and Basidiomycota were identified as the major bacteria and fungi phylum, respectively. The correlations among microorganisms, BAs and nitrite were analyzed. Typtamine showed a positive correlation with Lactobacillus and Pseudomonas. Cadaverine and nitrite is positively correlated with Leuconostoc. Furthermore, thirteen strains were selected from the samples to evaluate the accumulation and degradation properties of their BAs and nitrite. The results indicated that the Lactobacillus isolates, including L. plantarum GZ-2 and L. brevis SC-2, can significantly reduce BAs and nitrite in FM model experiments. This study not only assessed the contents of BAs and nitrite in FM samples, but also provided potential starter cultures for BAs and nitrite control in the FM products industry.

Dissipation and Distribution of Picarbutrazox Residue Following Spraying with an Unmanned Aerial Vehicle on Chinese Cabbage (Brassica campestris var. pekinensis)

We assessed the residual distribution and temporal trend of picarbutrazox sprayed by agricultural multicopters on Chinese cabbage and considered fortification levels and flying speeds. In plot 2, 14 days after the last spraying, the residues decreased by ~91.3% compared with those in the samples on day 0. The residues in the crops decreased by ~40.8% of the initial concentration owing to growth (dilution effect) and by ~50.6% after excluding the dilution effect. As the flight speed increased, picarbutrazox residues decreased (p < 0.05, least significant deviation [LSD]). At 2 m s−1 flight speed, the residual distribution differed from the dilution rate of the spraying solution. The average range of picarbutrazox residues at all sampling points was 0.007 to 0.486, below the limit of quantitation −0.395, 0.005–0.316, and 0.005–0.289 mg kg−1 in plots 1, 2, 3, and 4, respectively, showing significant differences (p < 0.05, LSD). These results indicated that the residual distribution of picarbutrazox sprayed by using a multicopter on the Chinese cabbages was not uniform. However, the residues were less than the maximum residue limit in all plots. Accordingly, picarbutrazox was considered to have a low risk to human health if it was sprayed on cabbage according to the recommended spraying conditions.

Estimation of residue degradation of cypermethrin and chlorpyrifos in brinjal, tomato and cauliflower under supervised field trial

A study was carried out to detect and estimate the residue of cypermethrin and chlorpyrifos in brinjal, tomato and cauliflower using Gas Chromatography (GC) coupled with Electron Capture Detector (ECD) and Flame Thermionic Detector (FTD). Three supervised field trials were conducted and sprayed with the recommended dose of cypermethrin (1 ml/L of water) and chlorpyrifos (3 ml/L of water) in three vegetables by knapsack sprayer. Samples were collected at 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, and 11 days after spray (DAS). The quantity of cypermethrin residue was above EU-MRLs (Maximum Residue Limit set by European Union) up to 4 DAS with 0.538 mg/kg in cauliflower; 3 DAS with 0.508 mg/kg in brinjal and 0.695 mg/kg in tomato. The quantity decreased down 0.328-0.019 mg/kg in cauliflower (4-9 DAS); 0.098-0.012 mg/kg (4-7 DAS) in brinjal and 0.458-0.022 mg/kg (4-7 DAS) in tomato which were below EU-MRLs (0.5 mg/kg). The quantity of chlorpyrifos residue was above EU-MRLs up to 9 DAS with 0.012 mg/kg in cauliflower but in brinjal and tomato, the detected quantities were above EU-MRLs up to 7 DAS with 0.029 mg/kg and 0.017 mg/kg residue. No residue was detected from brinjal and tomato samples collected at 8 DAS. But in cauliflower, no residue was detected at 10 days after spray. So, brinjal, tomato and cauliflower can be harvested safely at 4 DAS and 5 DAS for cypermethrin and in case of chlorpyrifos it was 8 DAS in brinjal and tomato and 10 DAS in cauliflower. Asian Australas. J. Biosci. Biotechnol. 2021, 6 (2), 60-67

Comparative Studies on Grain Quality and Pesticide Residues in Maize Stored in Hermetic and Polypropylene Storage Bags

The conventional method of grain storage involving the use of polypropylene bags in conjunction with pesticides and hermetic bags are paramount in developing countries. However, there is limited information on grain quality and pesticide residue concentration of maize stored in such bags. This work determined grain quality and pesticide residue concentrations of maize stored in polypropylene and hermetic storage bags. Maize samples stored for a period of one year in polypropylene and hermetic bags were obtained from three major maize growing communities in the Ashanti region of Ghana and were analyzed for grain quality, aflatoxin content and pesticide residue concentration using standard methods. The amount of diseased, discolored, broken, insect-damaged, stained, germinated, shriveled, total defective, inorganic and organic matter of maize stored in hermetic bags was significantly lower than that of polypropylene. Levels of aflatoxin in maize stored in the polypropylene bags were significantly higher (13.9 ppb–20 ppb) than in maize stored in the hermetic bags (0.90 ppb–2.6 ppb). Out of 35 pesticides screened, only lambda-cyhalothrin was detected in polypropylene bags and deltamethrin in hermetic bags. The presence of these pesticide residues may be due to their long-lasting abilities. Levels of lambda-cyhalothrin residues were above the maximum residue limit (MRL) of 0.02 mg/kg, but have no significant effect on health. Deltamethrin residue concentrations in hermetically stored maize samples were below the MRL. In conclusion, maize grains stored in hermetic bags have higher grain quality and lower aflatoxin and pesticide residue concentrations than polypropylene bags. Education and promotion on the utilization of hermetic bags should be a priority in storing and supplying safe maize grains to consumers.

Development of a Nonenzymatic Electrochemical Sensor for Organophosphate Pesticide Detection Using Copper (II) Oxide Nanorod Electrodes

Inorganic electrode materials of low cost, lower complexity, and high stability have become the more preferred choice over enzyme usage in electrochemical sensors. In this work, copper oxide (CuO) nanorods (NRs) were synthesized on copper foil as electrodes through anodization and annealing processes. The synthesized electrodes were used to analyse the organophosphate pesticides (OPPs) and interference molecules by cyclic voltammetry. The CuO NR sensor was able to identify and quantify different kinds of OPPs with an elevated sensitivity of 1.269, 1.425, 1.657, and 2.833 μA/ng mL-1 for chlorpyrifos, parathion, paraoxon, and pirimiphos and explicitly separate them from interference molecules (i.e., carbaryl, paraquat, sodium nitrate, sodium sulphate, and toluene). Moreover, this electrochemical pesticide sensor achieved a very low limit of detection (LOD) in the 10-7 molar level with a high selectivity among all tested analytes. The LOD for each pesticide ranged from 0.29 to 0.61 μM, revealing the ability to define the maximum residue limit in food. In short, our enzyme-free CuO NR sensor is a promising platform to deliver a fast, low-cost, and reliable pesticide detection unit.

Enhanced Control of the Fungus Gnat Bradysia odoriphaga (Diptera: Sciaridae) by Co-Application of Clothianidin and Hexaflumuron

The fungus gnat is a major pest of chive in China. Its control has been relied heavily on the application of clothianidin. Due to the intensive application, its control efficacy become reduced. The present study was intended to evaluate co-drenching of clothianidin with hexaflumuron on absorption and dissipation of clothianidin in chive plants and soils and determine the effect of such application on control efficacies. Chive production fields in Guangdong and Hubei Provinces were drenched with clothianidin alone and a mixture of clothianidin and hexaflumuron at low application rates. Concentrations of clothianidin in chive plants and soils were analyzed by HPLC. Results showed that co-application had higher control efficacies against the fungus gnat than clothianidin alone. The co-application enhanced clothianidin absorption and dissipation and extended the half-lives of clothianidin in chive. It was likely that hexaflumuron protected chive roots from larva damage, and healthy roots absorbed more clothianidin, resulting in the extension of the half-lives. Additionally, the terminal residues of clothianidin in chive after 14 days of application were lower than the maximum residue limit in chive set by the Codex Alimentarius Commission. This study for the first time documented that co-application of clothianidin and hexaflumuron improved chive plants in absorption and dissipation of clothianidin and enhanced fungus gnat control efficacies.

Translocation of residual ethoprophos and tricyclazole from soil to spinach

The dissipation of ethoprophos and tricyclazole in soil and their translocation tendency to spinach were investigated. Prior to field trials, the analytical method for the determination of these pesticide residues was optimized and validated on soil and spinach. The field trial was conducted under greenhouse conditions for two different pretreatment periods with the pesticides. After treating with pesticides 30 (PBI-30) and 60 days (PBI-60) before seeding, soil samples were collected on different days for the dissipation study of soil. Spinach samples were harvested from the soil, and 50% and 100% mature spinach samples were collected. The initial amounts of ethoprophos residue in the PBI-60 and PBI-30 soils were 0.21 and 2.74 mg/kg, respectively, and these both decreased to less than 0.01 mg/kg on the day of spinach harvest. Similar initial residues of tricyclazole were observed in the PBI-60 (0.87 mg/kg) and PBI-30 soils (0.84 mg/kg), and these decreased to 0.44 and 0.34 mg/kg, respectively. The half-lives of ethoprophos in the soils were calculated as 7.6 and 4.8 days, respectively, while relatively long half-lives of 36.5 and 77.0 days were calculated for tricyclazole. According to the pesticide residue amounts in the spinach, the translocation rate from the soil to the spinach was determined. In the case of ethoprophos, the residual amount was already rapidly degraded in the soil, and the translocation rate could not be confirmed. On the other hand, for tricyclazole, it was confirmed that 1.19 to 1.61% of the residual amount in soil was transferred to spinach. According to these results, safe management guidelines for tricyclazole in soil were suggested considering the maximum residue limit on spinach.