scholarly journals Toxicity Mechanisms of ZnO Nanoparticles in Nanochloropsis Oculata with a Comparative Approach with CuO and Ag Nanoparticles

2021 ◽  
Author(s):  
Nasrin Fazelian ◽  
Ali Mvafeghi ◽  
Morteza Yousefzadi
Keyword(s):  
Oxidative Stress ◽  
Cell Number ◽  
Nannochloropsis Oculata ◽  
Comparative Approach ◽  
Content Increase ◽  
Ag Nps ◽  
Zno Nps ◽  
Cuo Nps ◽  
Marine Microalga ◽  
Defensive Mechanisms

Abstract The purpose of present work was the investigation of different concentrations of zinc oxide nanoparticles on the marine microalga Nannochloropsis oculata and compare the results of this study with previous studies. Dissolution of ZnO NPs in nanopure water was 0.378-3.12 mg/L and the rate solubility decreased with increasing the concentrations of ZnO NPs. ZnO NPs were toxic to this microalga with EC50 of 153/72 mg/L. The toxicity of 200 mg/L ZnO NPs was 59.36% for the cell number, 61.27% for MTT test, and 57.34% for the chlorophyll content. Increase the content of malondialdehyde and hydrogen peroxide in response to increasing the concentration of ZnO NPs was indicated the induction of oxidative stress in N. oculata. The activity of catalase and lactate dehydrogenase increased in the treated cells, while the activity of ascorbate peroxidase was decreased. Concurrently, an increase in the content of carotenoids and phenolic compounds was observed in the treated cells. SEM and TEM analyses confirmed the aggregation of algal cells, damages in cell membrane and atypical changes in morphology of cell wall after NPs treatments. The FTIR results cofirmed the interaction of ZnO NPs with C-H, C-O and C=O groups on the cell surface. All of these changes were indicated the significant toxic impacts of ZnO NPs on the N. oculata cells. Comparison between the results obtained in previous studies with our results showed that the defensive mechanisms of N. oculata probably was not effective against the oxidative stress by >10 mg/L of ZnO NPs, > 5 mg/L of CuO NPs and > 1 mg/L of Ag NPs. Therefore, N. oculata is sensitive to such concentrations of these NPs.

Metallic nanoparticles and ions accelerate the uptake of extracellular antibiotic resistance genes through transformation

2020 ◽  
Author(s):  
Jianhua Guo ◽  
Shuai Zhang ◽  
Ji Lu ◽  
Yue Wang ◽  
Willy Verstraete ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Antibiotic Resistance ◽  
Cell Membrane ◽  
Resistance Genes ◽  
Natural Transformation ◽  
Antibiotic Resistance Genes ◽  
Acinetobacter Baylyi ◽  
Ag Nps ◽  
Zno Nps ◽  
Cuo Nps

Abstract Background: Antibiotic resistance genes (ARGs), heavy metal ions and nanoparticles (NPs) are emerging and ubiquitous contaminants in the environment. However, little is known about whether heavy metal-based NPs or ions could facilitate the dissemination of ARGs through natural transformation. This study evaluated the contributions of heavy metal-based NPs (Ag NPs, CuO NPs and ZnO NPs) and their ion forms (Ag + , Cu 2+ and Zn 2+ ) to the transformation of extracellular ARGs in Acinetobacter baylyi ADP1. Results: We found that these commonly-used NPs and ions from environmentally relevant concentrations can significantly promote the natural transformation frequency of ARGs by a factor of 11.0-folds, which is comparable to the effects of antibiotics. The enhanced transformation by Ag NPs, CuO NPs, Ag + and Cu 2+ was primarily associated with reactive oxygen species (ROS) over-production and cell membrane damage, which was also evident from up-regulations of both transcription and translation of ROS and outer membrane-related genes. Additionally, transmission electron microscope imaging revealed the roughened cell membrane after Ag NPs, CuO NPs, Ag + and Cu 2+ exposure. ZnO NPs and Zn 2+ might increase the natural transformation rate by stimulating the stress response and ATP synthesis. All tested NPs and ions resulted in up-regulating the competence and SOS response-associated genes. Conclusions: Our results demonstrate that Ag, CuO and ZnO-based NPs/ions from environmental concentrations could promote the natural transformation of plasmid-encoded ARGs into naturally competent A. baylyi . Our findings provide insights into the contributions of heavy metals and NPs to the spread of antibiotic resistance.

scholarly journals Remodeling of root morphology by CuO and ZnO nanoparticles: effects on drought tolerance for plants colonized by a beneficial pseudomonad

Botany ◽  
2018 ◽  
Vol 96 (3) ◽  
pp. 175-186 ◽  
Author(s):  
Kwang-Yeol Yang ◽  
Stephanie Doxey ◽  
Joan E. McLean ◽  
David Britt ◽  
Andre Watson ◽  
...  
Keyword(s):  
Calcareous Soils ◽  
Root Hairs ◽  
Triticum Aestivum L ◽  
Metal Stress ◽  
Root Tip ◽  
Zno Nps ◽  
Wheat Seedlings ◽  
Cuo Nps ◽  
Expression Of Genes ◽  
Induced Tolerance

Formulations that include nanoparticles of CuO and ZnO are being considered for agricultural applications as fertilizers because they act as sources of Cu or Zn. Currently, few studies of the effects of these nanoparticles (NPs) consider the three-way interactions of NPs with the plant plus its microbiome. At doses that produced root shortening by both nanoparticles (NPs), CuO NPs induced the proliferation of elongated root hairs close to the root tip, and ZnO NPs increased lateral root formation in wheat seedlings (Triticum aestivum L.). These responses occurred with roots colonized by a beneficial bacterium, Pseudomonas chlororaphis O6 (PcO6), originally isolated from roots of wheat grown under dryland farming in calcareous soils. The PcO6-induced tolerance to drought stress in wheat seedlings was not impaired by the NPs. Rather, growth of the PcO6-colonized plants with NPs resulted in systemic increases in the expression of genes associated with tolerance to water stress. Increased expression in the shoots of other genes related to metal stress was consistent with higher levels of Cu and Zn in PcO6-colonized shoots grown with the NPs. This work demonstrates that plants grown with CuO or ZnO NPs showed cross-protection from different challenges such as metal stress and drought.

scholarly journals Zinc Oxide and Silver Nanoparticle Effects on Intestinal Bacteria

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2489
Author(s):  
Ami Yoo ◽  
Mengshi Lin ◽  
Azlin Mustapha
Keyword(s):  
Electron Microscopy ◽  
Zinc Oxide ◽  
Morphological Changes ◽  
Intestinal Bacteria ◽  
Bacterial Cells ◽  
Ag Nps ◽  
Zno Nps ◽  
Bifidobacterium Animalis ◽  
Transmission Electron

The application of nanoparticles (NPs) for food safety is increasingly being explored. Zinc oxide (ZnO) and silver (Ag) NPs are inorganic chemicals with antimicrobial and bioactive characteristics and have been widely used in the food industry. However, not much is known about the behavior of these NPs upon ingestion and whether they inhibit natural gut microflora. The objective of this study was to investigate the effects of ZnO and Ag NPs on the intestinal bacteria, namely Escherichia coli, Lactobacillus acidophilus, and Bifidobacterium animalis. Cells were inoculated into tryptic soy broth or Lactobacilli MRS broth containing 1% of NP-free solution, 0, 12, 16, 20 mM of ZnO NPs or 0, 1.8, 2.7, 4.6 mM Ag NPs, and incubated at 37 °C for 24 h. The presence and characterization of the NPs on bacterial cells were investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and energy-dispersive X-ray spectroscopy (EDS). Membrane leakage and cell viability were assessed using a UV-visible spectrophotometer and confocal electron microscope, respectively. Numbers of treated cells were within 1 log CFU/mL less than those of the controls for up to 12 h of incubation. Cellular morphological changes were observed, but many cells remained in normal shapes. Only a small amount of internal cellular contents was leaked due to the NP treatments, and more live than dead cells were observed after exposure to the NPs. Based on these results, we conclude that ZnO and Ag NPs have mild inhibitory effects on intestinal bacteria.

scholarly journals Amino Acid Transporter LAT1 (SLC7A5) Mediates MeHg-Induced Oxidative Stress Defense in the Human Placental Cell Line HTR-8/SVneo

2021 ◽  
Vol 22 (4) ◽  
pp. 1707
Author(s):  
Sebastian Granitzer ◽  
Raimund Widhalm ◽  
Martin Forsthuber ◽  
Isabella Ellinger ◽  
Gernot Desoye ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Amino Acid ◽  
De Novo ◽  
Structural Similarity ◽  
Amino Acid Transporter ◽  
Cell Number ◽  
Mehg Exposure ◽  
Acid Transporter ◽  
And Oxidative Stress

The placental barrier can protect the fetus from contact with harmful substances. The potent neurotoxin methylmercury (MeHg), however, is very efficiently transported across the placenta. Our previous data suggested that L-type amino acid transporter (LAT)1 is involved in placental MeHg uptake, accepting MeHg-L-cysteine conjugates as substrate due to structural similarity to methionine. The aim of the present study was to investigate the antioxidant defense of placental cells to MeHg exposure and the role of LAT1 in this response. When trophoblast-derived HTR-8/SVneo cells were LAT1 depleted by siRNA-mediated knockdown, they accumulated less MeHg. However, they were more susceptible to MeHg-induced toxicity. This was evidenced in decreased cell viability at a usually noncytotoxic concentration of 0.03 µM MeHg (~6 µg/L). Treatment with ≥0.3 µM MeHg increased cytotoxicity, apoptosis rate, and oxidative stress of HTR-8/SVneo cells. These effects were enhanced under LAT1 knockdown. Reduced cell number was seen when MeHg-exposed cells were cultured in medium low in cysteine, a constituent of the tripeptide glutathione (GSH). Because LAT1-deficient HTR-8/SVneo cells have lower GSH levels than control cells (independent of MeHg treatment), we conclude that LAT1 is essential for de novo synthesis of GSH, required to counteract oxidative stress. Genetic predisposition to decreased LAT1 function combined with MeHg exposure could increase the risk of placental damage.

The effect of silver concentration and calcination temperature on structural and optical properties of ZnO:Ag nanoparticles

2015 ◽  
Vol 29 (01) ◽  
pp. 1450254 ◽  
Author(s):  
M. Shayani Rad ◽  
A. Kompany ◽  
A. Khorsand Zak ◽  
M. E. Abrishami
Keyword(s):  
Calcination Temperature ◽  
Sol Gel ◽  
Visible Emission ◽  
X Ray Diffraction ◽  
Ag Nps ◽  
Zno Nps ◽  
Calcination Temperatures ◽  
Transmission Electron ◽  
Xrd Patterns ◽  
Average Size

Pure and silver added zinc oxide nanoparticles ( ZnO -NPs and ZnO : Ag -NPs) were synthesized through a modified sol–gel method. The prepared samples were characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM) and photoluminescence (PL) spectroscopy. In the XRD patterns, silver diffracted peaks were also observed for the samples synthesized at different calcination temperatures of 500°C, 700°C, 900°C except 1100°C, in addition to ZnO . TEM images indicated that the average size of ZnO : Ag -NPs increases with the amount of Ag concentration. The PL spectra of the samples revealed that the increase of Ag concentration results in the increase of the visible emission intensity, whereas by increasing the calcination temperature the intensity of visible emission of the samples decreases.

Emerging investigator series: Chemical transformation of silver and zinc oxide nanoparticles in the simulated human tear fluids: Influence of biocorona

2021 ◽  
Author(s):  
Lingxiangyu Li ◽  
Ashfeen Ubaid Khan ◽  
Xiang Zhang ◽  
Xiaoting Qian ◽  
Yawei Wang
Keyword(s):  
Silver Nanoparticles ◽  
Zinc Oxide ◽  
Chemical Transformation ◽  
Zinc Oxide Nanoparticles ◽  
Biological Fluids ◽  
Rapid Development ◽  
Oxide Nanoparticles ◽  
Personal Care ◽  
Ag Nps ◽  
Zno Nps

With the rapid development of nanotechnology, personal care products with silver nanoparticles (Ag-NPs) or zinc oxide nanoparticles (ZnO-NPs) are being widely used because of their superior antibacterial efficacies. Biological fluids...

Μελέτη της τοξικής, κυτταροτοξικής και γενοτοξικής δράσης νεοσυντιθέμενων ενώσεων και νανοϋλικών σε in vitro συνθήκες

2021 ◽  
Author(s):  
Ιωάννα Ευθυμίου
Keyword(s):  
Humic Acid ◽  
Vibrio Fischeri ◽  
Anodic Stripping Voltammetry ◽  
Micronucleus Assay ◽  
Stripping Voltammetry ◽  
Neutral Red ◽  
Flame Spray ◽  
Ag Nps ◽  
Zno Nps

Η συνεχώς αυξανόμενη παραγωγή προϊόντων της Nανοτεχνολογίας εγείρει στις μέρες μας σημαντικά ερωτήματα σχετικά με τον περιβαλλοντικό αντίκτυπό τους. Συγκεκριμένα, νανοσωματίδια (Nanoparticles, NPs) όπως το οξείδιο του ψευδαργύρου (ZnO) και αργύρου (Ag), παρουσιάζουν ευρεία εξάπλωση και εφαρμογή, γεγονός που αυξάνει τις πιθανότητες να βρεθούν βιοδιαθέσιμα στο περιβάλλον. Παρόλο που υπάρχει εκτεταμένη βιβλιογραφία αναφορικά με τα προαναφερθέντα NPs, συνήθως κάθε μελέτη εστιάζει σε συγκεκριμένο παράγοντα κάθε φορά όπως για παράδειγμα στη σύνθεση των NPs, τα βελτιωμένα χαρακτηριστικά τους, τις πιθανές εφαρμογές τους ή τις τοξικές τους επιδράσεις σε συγκεκριμένο οργανισμό ή κυτταρική σειρά. Αν και κάθε έρευνα ενισχύει το μέχρι τώρα γνωσιακό υπόβαθρο και συμπληρώνει κενά αναφορικά με τη Νανοτεχνολογία, με την παρούσα μελέτη έγινε η προσπάθεια πραγματοποίησης μιας ολοκληρωμένης εργασίας. Συγκεκριμένα, το ερευνητικό πλάνο περιλαμβάνει (α) τη σύνθεση των ZnO, Ag και ZnO-Ag NPs, (β) το χαρακτηρισμό τους (μεμονωμένα και σε διασπορά μέσα σε υδατικά διαλύματα), (γ) την αξιολόγηση των πιθανών τοξικών, κυτταροτοξικών και γενοτοξικών τους επιδράσεων σε διαφορετικά βιολογικά συστήματα (ανθρώπινα λεμφοκύτταρα, βακτήρια και αιμοκύτταρα δίθυρου μαλακίου) σε in vitro συνθήκες, (δ) τη μελέτη της αλληλεπίδρασης των εξεταζόμενων NPs παρουσία χουμικών οξέων (Humic Acids, HAs), προσομοιάζοντας έτσι τις πραγματικές περιβαλλοντικές συνθήκες. Αναλυτικότερα, τα NPs (ZnO, Ag και ZnO-Ag NPs) παρασκευάστηκαν με την καινοτόμο τεχνική πυρόλυσης ψεκασμού φλόγας (Flame Spray Pyrolysis, FSP) που χρησιμοποιείται για τη σύνθεση μεμονωμένων και σύνθετων NPs με υψηλή καθαρότητα και βελτιωμένα μορφολογικά και φυσικοχημικά χαρακτηριστικά. Ακολούθησε χαρακτηρισμός των NPs με περίθλαση ακτίνων Χ (powder X ray Diffraction, pXRD), με ηλεκτρονική μικροσκοπία διέλευσης (Transmission Electron Microscopy, TEM) και με δυναμική σκέδαση φωτός (Dynamic Light Scattering, DLS). Στη συνέχεια, διερευνήθηκε η ενδεχόμενη γενοτοξική και κυτταροτοξική δράση των NPs παρουσία και απουσία δύο χαρακτηρισμένων HAs (Humic acid-like-polycondensate, HALP; Leonardite Humic Acid, LHA) σε ανθρώπινα λεμφοκύτταρα με την εφαρμογή της τεχνικής των μικροπυρήνων με χρήση της κυτταροχαλασίνης-Β (Cytokinesis Block Micronucleus assay, CBMN assay). Η έκπλυση ιόντων Zn2+ προσδιορίστηκε στα ιζήματα των λεμφοκυττάρων που προέκυψαν από την τεχνική CBMN, μέσω της ανοδικής αναδιαλυτικής βολταμμετρίας (Anodic Stripping Voltammetry, ASV). Έπειτα, οι τοξικές επιδράσεις των NPs παρουσία και απουσία των δύο HAs μελετήθηκαν στο βακτήριο Vibrio fischeri με τη χρήση του συστήματος Microtox. Τέλος, εξετάστηκαν οι κυτταροτοξικές και οξειδωτικές επιδράσεις των NPs σε αιμοκύτταρα του μυδιού Mytilus galloprovincialis, μέσω προσδιορισμού (α) της λυσοσωμικής αποσταθεροποίησης (Τεχνική ουδέτερου ερυθρού/Neutral Red Retention Time), (β) της παραγωγής σουπεροξειδικών ανιόντων, (γ) της παραγωγής οξειδίων του αζώτου (υπό μορφή νιτρωδών) και (δ) των επιπέδων λιπιδικής υπεροξείδωσης. Σύμφωνα με τα αποτελέσματα, στην περίπτωση της τεχνικής CBMN, δεν υπήρξε εκδήλωση γενοτοξικών φαινομένων σε καμία περίπτωση, για κανένα από τα υπό μελέτη NPs τόσο παρουσία όσο και απουσία των δύο HAs. Από την άλλη πλευρά, όλα τα NPs εκδήλωσαν κυτταροτοξική δράση. Ωστόσο, αν και τα Ag και ZnO-Ag NPs οδήγησαν σε επαγωγή κυτταροτοξικότητας παρουσία και απουσία των δύο HAs, τα μίγματα των ZnO NPs με τα δύο HAs ελάττωσαν την κυτταροτοξικότητα που προκλήθηκε από τα μεμονωμένα ZnO NPs. Αναφορικά με τα ποσοστά έκπλυσης ιόντων Zn2+, παρατηρήθηκε ότι οι μεγαλύτερες συγκεντρώσεις των μιγμάτων (ZnO, ZnO-Ag)NPs-HAs διατήρησαν ένα μικρό ποσοστό ιόντων, ενώ στις υπόλοιπες περιπτώσεις το ποσοστό ήταν αμελητέο. Στην περίπτωση προσδιορισμού της τοξικότητας των NPs έναντι του βακτηρίου Vibrio fischeri, διαπιστώθηκε ενισχυμένη τοξικότητα των ZnO και ZnO-Ag NPs ενώ τα Ag NPs εμφάνισαν τη μικρότερη τοξική δράση. Ο συνδυασμός με τα δύο HAs δεν οδήγησε σε κάποια σημαντική αλλαγή της τοξικότητας σε σύγκριση με τα μεμονωμένα NPs, στην περίπτωση των ZnO και ZnO-Ag NPs. Αντιθέτως, τα μίγματα Ag NPs-HAs ελάττωσαν την τοξικότητα που προκλήθηκε από τα μεμονωμένα Ag NPs. Όσον αφορά τις επιδράσεις των NPs στα αιμοκύτταρα των μυδιών, διαπιστώθηκε ότι κάθε NP διέθετε διαφορετικό μηχανισμό εκδήλωσης τοξικότητας. Συγκεκριμένα, τα ZnO NPs - μέσω του επιφανειακού τους φορτίου και της σωματιδιακής συσσωμάτωσης - ενδέχεται να εισέλθουν στα κύτταρα πριν την εκδήλωση κυτταρικής θνησιμότητας, ενώ η απελευθέρωση των ιόντων Zn2+ μπορούσε να οδηγήσει στην παραγωγή ριζών μέσω διέγερσης της διαδικασίας της αναπνευστικής έκρηξης. Αντιθέτως, η παρατηρούμενη κυτταρική και οξειδωτική καταπόνηση που προκλήθηκε από τα Ag NPs, πιθανότατα λόγω της απελευθέρωσης ιόντων Ag+, δε φάνηκε να σχετίζεται με την αναπνευστική έκρηξη. Ομοίως, οι κυτταρικές και οξειδωτικές βλάβες που προκλήθηκαν από τα ZnO-Ag NPs, υπέδειξαν την παρουσία ανταγωνιστικής/συνεργιστικής δράσης μεταξύ των μεταλλικών ιόντων (Zn2+, Ag+) που ανάλογα με τις εκάστοτε συνθήκες μπορούν να ρυθμίσουν τη συμπεριφορά και τις βιολογικές επιδράσεις του σύνθετου NP. Συμπερασματικά, τα αποτελέσματα υποδεικνύουν τη δυνατότητα των νεοσυντιθέμενων ZnO, Ag και ZnO-Ag NPs να προκαλούν τοξικές, κυτταροτοξικές και οξειδωτικές επιδράσεις. Παρόλα αυτά, διαπιστώθηκε ότι οι επιδράσεις των NPs ποικίλουν τόσο μεταξύ των ίδιων των NPs, όσο και μεταξύ των τεχνικών και των οργανισμών μοντέλων και/ή κυττάρων που χρησιμοποιήθηκαν. Κατά συνέπεια, είναι εμφανές ότι είναι αναγκαίο να αξιολογείται το τοξικολογικό προφίλ των NPs με τη χρήση ενός εύρους τεχνικών, βιοδεικτών και περιβαλλοντικών σεναρίων, καθώς και να γίνεται παράλληλα ένας ολοκληρωμένος και αξιόπιστος χαρακτηρισμός αυτών σε κάθε περίπτωση.

scholarly journals Human Physiological Responses to a Single Deep Helium-Oxygen Diving

2021 ◽  
Vol 12 ◽  
Author(s):  
Xiao-Chen Bao ◽  
Quan Shen ◽  
Yi-Qun Fang ◽  
Jian-guo Wu
Keyword(s):  
Oxidative Stress ◽  
Creatine Kinase ◽  
Blood Cell ◽  
Stress Responses ◽  
Physiological Stress ◽  
Open Water ◽  
Endothelial Activation ◽  
Cell Number ◽  
Cardiac Damage ◽  
Cell Counts

Objective: The objective of this study was to explore whether a single deep helium-oxygen (heliox) dive affects physiological function.Methods: A total of 40 male divers performed an open-water heliox dive to 80 m of seawater (msw). The total diving time was 280 min, and the breathing helium-oxygen time was 20 min. Before and after the dive, blood and saliva samples were collected, and blood cell counts, cardiac damage, oxidative stress, vascular endothelial activation, and hormonal biomarkers were assayed.Results: An 80 msw heliox dive induced a significant increase in the percentage of granulocytes (GR %), whereas the percentage of lymphocytes (LYM %), percentage of intermediate cells (MID %), red blood cell number (RBC), hematocrit (hCT), and platelets (PLT) decreased. During the dive, concentrations of creatine kinase (CK), a myocardial-specific isoenzyme of creatine kinase (CK-MB) in serum and amylase alpha 1 (AMY1), and testosterone levels in saliva increased, in contrast, IgA levels in saliva decreased. Diving caused a significant increase in serum glutathione (GSH) levels and reduced vascular cell adhesion molecule-1 (VCAM-1) levels but had no effect on malondialdehyde (MDA) and endothelin-1 (ET-1) levels.Conclusion: A single 80 msw heliox dive activates the endothelium, causes skeletal-muscle damage, and induces oxidative stress and physiological stress responses, as reflected in changes in biomarker concentrations.

177 ANTHOCYANIN ISOLATED FROM PURPLE SWEET POTATO IMPROVES DEVELOPMENT AND REDUCES OXIDATIVE STRESS OF BOVINE PRE-IMPLANTATION EMBRYOS EXPOSED TO HEAT SHOCK

2006 ◽  
Vol 18 (2) ◽  
pp. 196
Author(s):  
M. Sakatani ◽  
I. Suda ◽  
T. Oki ◽  
S.-I. Kobayashi ◽  
S. Kobayashi ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Heat Shock ◽  
Sweet Potato ◽  
Cell Number ◽  
Total Cell ◽  
Total Cell Number ◽  
Cell Stage ◽  
Intracellular Ros ◽  
Purple Sweet Potato

Development of cleavage-stage pre-implantation embryos is disrupted by exposure to heat shock. Heat shock also increases intracellular reactive oxygen species (ROS) in pre-implantation embryos. Therefore, reduction of intracellular ROS levels might improve the development of heat-shocked embryos. Recently the antioxidative activities of polyphenols have been widely reported to reduce the oxidative stress. In this study, we investigated the effect of purple sweet potato anthocyanin, a kind of polyphenol that is a strong ROS scavenger, on development and intracellular redox status of bovine pre-implantation embryos exposed to heat shock. Experiment 1: In vitro-produced 8-16-cell-stage embryos on Day 2 after fertilization were exposed to 41.5�C for 6 h in CR1aa containing 0, 0.1, 1, and 10 �g/mL anthocyanin at 5% CO2, 5% O2, and 90% N2. After heat shock, embryos were cultured at 38.5�C at 5% CO2, 5% O2 until Day 8. On Day 8, the proportion of embryos developing to the blastocyst stage was evaluated. Blastocyst total cell number and the ratio between inner cell mass and tropheoderm were evaluated by differential staining. The experiment was replicated five times with more than 70 embryos used in each treatment. Experiment 2: Heat shock treatment of in vitro-produced 8-16-cell-stage embryos was carried out as described in experiment 1. After heat shock, intracellular ROS and glutathione (GSH) levels were measured in individual 8-16 cell stage embryos with fluorescent probes (22,72-dichlorodihydrofluorescein diacetate for ROS and CellTracker" Blue (Invitrogen Japan K. K., Tokyo, Japan) for GSH). The fluorescence emissions of each treatment were normalized to those of 8-16 cell stage embryos cultured at 38.5�C without anthocyanin to obtain the relative fluorescence emission. This experiment was replicated four times. Embryos treated with heat stress without anthocyanin (0 �g/mL) showed low development (14.6 � 3.6%) and blastocyst total cell number (88.2 � 9.4). However, embryos treated with 0.1 �g/mL anthocyanin improved development (31.7 � 4.5%, P < 0.05) and increased the total cell number (96.5 � 11.3). The higher concentrations of anthocyanin (1 and 10 �g/mL) did not affect development and cell number. The intracellular ROS levels in heat-shocked embryos were significantly reduced by all concentrations of anthocyanin (P < 0.05). In addition, anthocyanin increased GSH levels at all doses tested (P < 0.05). These results indicate that an appropriate concentration of anthocyanin improves development by regulating intracellular redox balance in bovine embryos exposed to heat shock.

Sign in / Sign up

Export Citation Format

Share Document