170 The effects of linoleic and linolenic acid supplementation on the in vitro maturation of pig oocytes in a heat-stressed environment

2019 ◽  
Vol 31 (1) ◽  
pp. 209
Author(s):  
M. Mentler ◽  
J. Current ◽  
B. Whitaker

Elevated environmental temperatures induce heat stress, which can cause a depression in fertility and early embryonic development. Fatty acids initiate an endergonic reaction that is able to absorb cellular heat, causing a decrease in intracellular temperature. Supplementing linoleic and linolenic acids to the maturation medium of pig oocytes at elevated temperatures reduces the effects of heat stress-induced damage during fertilization and embryonic development. However, the mechanism of action of fatty acids during oocyte maturation is unknown. Therefore, the objective of this study was to minimize heat stress-induced damage and characterise the intracellular oocyte mechanisms. Oocyte maturation media was supplemented with linoleic and linolenic acid during oocyte maturation at either 38.5 or 41.5°C. Oocytes (n=3094, r=5) were supplemented with 50μM linoleic acid, 50μM linolenic acid, 25μM of both, or 50μM of both during 40 to 44h of maturation and then evaluated for the formation of reactive oxygen species (n=239), intracellular glutathione concentrations (n=1005), glutathione peroxidase (n=1005), catalase (n=987), and superoxide dismutase (n=863) activities. Data were analysed using ANOVA with the main effects including treatment, well, and replicate. There were no significant differences between the treatment groups matured at 38.5°C when comparing reactive oxygen species generation. Supplementation of linoleic or linolenic acid significantly decreased (P<0.05) reactive oxygen species generation in oocytes matured at 41.5°C compared with no supplementation at the same temperature. Supplementation of linoleic or linolenic acid or both significantly increased (P<0.05) intracellular glutathione concentrations compared with no supplementation at 38.5°C (23.37±1.23 pmol/oocyte) and 41.5°C (10.42±1.01 pmol/oocyte). There were no significant differences between the treatment groups matured at 38.5°C or 41.5°C when comparing glutathione peroxidase activity. Supplementation of linoleic or linolenic acid or both significantly increased (P<0.05) catalase and superoxide dismutase activities compared with no supplementation at 38.5°C and at 41.5°C. Superoxide dismutase activity was significantly higher (P<0.05) in oocytes matured at 41.5°C compared with those matured at 38.5°C. These results indicate that supplementing linoleic and linolenic acid to the maturation medium of pig oocytes at an elevated temperature reduces the effects of heat stress-induced damage by increasing intracellular glutathione concentrations and catalase and superoxide dismutase activities.

2019 ◽  
Vol 97 (Supplement_2) ◽  
pp. 243-243
Author(s):  
Emma Hicks ◽  
Miranda Mentler ◽  
Brian D Whitaker

Abstract Oxidative stress has a negative effect on embryonic development during the in vitro production of pig embryos. The imbalance of reactive oxygen species and antioxidants impact oocyte maturation. Berries from the elder plant (Sambucus sp.) have been identified as containing high levels of a broad spectrum of antioxidants. One of the predominant antioxidant classes of compounds found in elderberry extract is anthocyanin, which includes the antioxidant cyanidin. Therefore, the objective of this study was to determine the effects of cyanidin supplementation to the media during oocyte maturation. Oocytes (n = 815, r=3) were supplemented with 100 or 200 μM cyanidin during 40–44 h of maturation and then evaluated at the end of maturation for the formation of reactive oxygen species, fertilization characteristics, and rates of embryonic cleavage and blastocyst development at 48 h and 144 h after IVF, respectively. There were no significant differences between no cyanidin supplementation and 200 μM cyanidin supplementation when comparing reactive oxygen species generation at the end of oocyte maturation. Supplementation of 100 μM cyanidin significantly decreased (P < 0.05) reactive oxygen species generation in oocytes compared to the other groups. There were no significant differences between no cyanidin supplementation and 200 μM cyanidin supplementation when comparing penetration and polyspermic penetration rates and male pronuclear formation. Supplementation of 100 μM cyanidin significantly decreased (P < 0.05) polyspermic penetration rates and significantly increased (P < 0.05) male pronuclear formation rates compared to the other groups. There were no significant differences between the treatment groups when comparing the percentage of cleaved embryos by 48 h after IVF. Supplementation of 100 μM cyanidin significantly increased (P < 0.05) the blastocyst formation rates by 144 h after IVF compared to all other treatment groups. These results indicate that supplementing 100 μM cyanidin to the media during oocyte maturation reduces reactive oxygen species formation and improves in vitro fertilization and early embryonic development in pigs.


2020 ◽  
Vol 32 (2) ◽  
pp. 220
Author(s):  
E. Hicks ◽  
M. Mentler ◽  
B. D. Whitaker

Oxidative stress can have a negative effect on oocyte maturation during invitro production of pig embryos. Imbalance of reactive oxygen species and antioxidant levels can affect the progression of oocyte maturation up to the point of fertilization. Antioxidants are effective in maintaining more ideal reactive oxygen species levels, which help to protect oocytes from potential harmful effects of oxidative stress. Berries from the elder plant (Sambucus sp.) contain high levels of a broad spectrum of antioxidants. One of these antioxidants, cyanidin, when supplemented to maturation medium at 100μM concentrations, reduces reactive oxygen species formation and improves IVF and early embryonic development in pigs. However, changes in the enzyme mechanisms of action during oocyte maturation due to cyanidin supplementation are unknown. Therefore, the objective of this study was to characterise the intracellular oocyte enzyme mechanisms between oocytes supplemented with 100μM cyanidin during 40 to 44h of maturation (n=600) and oocytes without supplementation of cyanidin during maturation (n=558). At the end of maturation, oocytes were evaluated for either glutathione peroxidase (n=300), catalase (n=564), or superoxide dismutase (n=294) activities. Glutathione peroxidase activity was determined by following the rate of NADPH oxidation, catalase activity was determined by following the rate of hydrogen peroxide decomposition, and superoxide dismutase activity was determined by following the reduction rate of cytochrome c, utilising the xanthine-xanthine oxidase system. Data were analysed using ANOVA and Tukey's test. There were no significant differences between oocytes matured with 100μM cyanidin and those that were not when comparing glutathione peroxidase and superoxide dismutase activities. Supplementation of 100μM cyanidin to maturation medium increased (P&lt;0.05) catalase activity in oocytes (0.78±0.15 units/oocyte) compared with no cyanidin supplementation (0.14±0.11 units/oocyte). These results indicate that supplementing 100μM cyanidin to the maturation medium of pig oocytes could reduce the negative effects of oxidative stress by increasing intracellular catalase activity during oocyte maturation.


Author(s):  
Mojdeh Hosseinpoor Kashani ◽  
Mina Ramezani ◽  
Zeinab Piravar

Background: Acrylamide (AA) is a reactive molecule produced during food processing at temperatures above 120°C. Objective: To evaluate the impact of different concentrations of AA on human sperm parameters, oxidative stress and total antioxidant capacity (TAC). Materials and Methods: In this laboratory study, semen samples were obtained from healthy donors referred to the Taleghani Hospital, Tehran, Iran between June and July 2019. Samples were divided into four groups (n = 10/each): one control and three treatment groups (0.5, 1, and 2 mM of AA). After 2 hr of exposure to AA, the superoxide dismutase and malondialdehyde levels were measured based on colorimetric methods. The TAC was determined by the ferric-reducing antioxidant power assay. Flow cytometry was performed to measure the intracellular reactive oxygen species generation. Also, immunohistochemistry was done to determine the effect of AA on tyrosine phosphorylation and carboxymethyl-lysine expression. Results: Results of the study demonstrated that the motility and viability of spermatozoa were significantly decreased after AA exposure (p < 0.001). This decrease was also seen in the TAC and superoxide dismutase activity as well as in the phosphotyrosine percentage compared with the control (p < 0.01). However, the carboxymethyllysine and prooxidant activity including reactive oxygen species generation and lipid peroxidation level increased (p < 0.001). Conclusion: Overall, the results confirmed the detrimental effect of AA on human spermatozoa which may be due to oxidative stress and decreased total antioxidant levels. AA may reduce fertility by reducing sperm capacitation and motility. Key words: Acrylamide, Oxidative stress, Antioxidant, Spermatozoa, Infertility.


2019 ◽  
Vol 97 (Supplement_2) ◽  
pp. 242-243
Author(s):  
Miranda Mentler ◽  
Emma Hicks ◽  
Brian D Whitaker

Abstract The imbalance of reactive oxygen species levels and antioxidants impact oocyte matruation. Elderberries (Sambucus sp.) have been identified as possessing the ability to alleviate oxidative stress. An antioxidant class found in elderberry is anthocyanidin, which includes kuromanin. The objective of this study was to determine the effects of kuromanin supplementation to the media during oocyte maturation. Oocytes (n = 692, r=3) were supplemented with 100 or 200 μM kuromanin during 40-44 h of maturation and then evaluated at the end of maturation for the formation of reactive oxygen species, fertilization characteristics, and rates of embryonic cleavage and blastocyst development at 48 h and 144 h after IVF, respectively. There were no significant differences between no kuromanin supplementation and 100 μM kuromanin supplementation when comparing reactive oxygen species generation at the end of oocyte maturation. Supplementation of 200 μM kuromanin significantly increased (P < 0.05) reactive oxygen species generation in oocytes compared to the other groups. There were no significant differences between no kuromanin supplementation and 100 μM kuromanin supplementation when comparing penetration and polyspermic penetration rates and male pronuclear formation. Supplementation of 200 μM kuromanin significantly decreased (P < 0.05) penetration and polyspermic penetration rates and male pronuclear formation compared to the other groups. There were no significant differences between no kuromanin supplementation and 100 μM kuromanin supplementation when comparing the percentage of cleaved embryos by 48 h after IVF and the percentage of those reaching the blastocyst stage by 144 h after IVF. Supplementation of 200 μM kuromanin significantly decreased (P < 0.05) the cleavage rates by 48 h after IVF and the blastocyst formation rates by 144 h after IVF compared to all other treatment groups. These results indicate that supplementing 200 μM kuromanin is detrimental to oocyte maturation and lower levels (100 μM) do not have a significant effect compared to not supplementing the oocytes when evaluating in vitro fertilization and early embryonic development characteristics.


The eff ect of the non-opiate analog of leu-enkephalin (peptide NALE: Phe – D – Ala – Gly – Phe – Leu – Arg) on the reactive oxygen species generation in the heart of albino rats in the early postnatal period was studied. Peptide NALE was administered intraperitoneally in the dose of 100 μ/kg daily from 2 to 6 days of life. Reactive oxygen species generation was assessed by chemiluminescence in the heart homogenates of 7-day-old animals. Decreasing of reactive oxygen species generation nearly by 30 % and an increasing in antioxidant system activity by the 20-27 %, compared with the control parameters, were found. The antioxidant eff ect of peptide NALE is associated with the presence of the amino acid Arg in the structure of the peptide. An analogue of NALE peptide, devoid of Arg (peptide Phe – D – Ala – Gly – Phe – Leu – Gly), had a signifi cant lower antioxidant eff ect. The NO-synthase inhibitor NG-nitro-L-arginine methyl ester (L-NAME) in the dose 50 mg/kg, administered with NALE peptide, reduced the severity of the NALE antioxidant eff ect. The results of the study suggest that the pronounced antioxidant eff ect of NALE peptide in the heart of albino rats, at least in part, is due to the interaction with the nitric oxide system.


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