Effect of lycopene supplementation to bovine oocytes exposed to heat shock during in vitro maturation

Effects of orange peel extract (Citrus sinensis) treatment on zebrafish oocytes (Danio rerio) exposed to heat stress

Background and Aim

Heat stress (HS) can negatively impact oocytes by disrupting mitochondrial activity, increasing the production of reactive oxygen species, and decreasing antioxidant levels. This study investigated the impact of orange peel (OP) exposure on zebrafish oocytes (ZOs) diameter, survival rate, and germinal vesicle breakdown (GVBD) during HS.

Material and Methods

We investigated the antioxidant effect of flavonoids (concentration = 328.58 ppm) derived from OP (Citrus sinensis) added to in vitro maturation (IVM) media of ZOs (Danio rerio) under non-heat stress (NHS) and HS conditions to mimic in vivo HS conditions due to the global warming phenomenon on females. ZO in stage 3 (n = 1080) was treated with 4 μL of OP extract (not treated/control) under HS: 32°C (Heat stress 32°C solution/Heat stress 32°C orange peel [HS32S/HS32O]) and 34°C (Heat stress 34°C solution/Heat stress 34°C orange peel [HS34S/HS34O]); and NHS: 28°C (Non-heat stress solution/Non-heat stress orange peel [NHSS/NHSO]), during maturation. After 24 h of maturation, we observed the oocyte diameter, survival rate, and GVBD rate. The data were analyzed with IBM Statistics 23 software using two-way analysis of variance and Kruskal-Wallis (p < 0.05).

Results

The highest oocyte diameter data were in NHS treated with OP extract (NHSO) group (0.759 ± 0.01; mean ± standard error) compared with HS group using and without OP extract (HS32S [0.583 ± 0.02]; HS32O [0.689 ± 0.02]; HS34S [0.554 ± 0.02]; and HS34O [0.604 ± 0.02]). The survival rate of OP treated group, namely, NHSO (93% ± 3%), HS32O (85% ± 2%), and HS34O (80% ± 2%) was higher than that of the group without treatment (NHSS [83% ± 3%], HS32S [71% ± 6%], and HS34S [63% ± 3%]). ZO treated with OP extract (NHSO [93% ± 3%], HS32O [85% ± 2%], and HS34O [80% ± 2%]) showed a higher GVBD rate than the group without treatment (NHSS [83% ± 3%], HS32S [71% ± 6%], and HS34S [63% ± 3%]).

Conclusion

It revealed that OP can enhance the oocyte diameter, survival rate, and GVBD rate of ZO under NHS and HS. Further investigation should be conducted to determine the effect of OP extract (C. sinensis) on in vivo conditions in females as an alternative treatment to face global warming.

Physicochemical properties, mechanism of action of lycopene and its application in poultry and ruminant production

Lycopene is a kind of natural carotenoid that could achieve antioxidant, anti-cancer, lipid-lowering and immune-improving effects by up-regulating or down-regulating genes related to antioxidant, anti-cancer, lipid-lowering and immunity. Furthermore, lycopene is natural, pollution-free, and has no toxic side effects. The application of lycopene in animal production has shown that it could improve livestock production performance, slaughter performance, immunity, antioxidant capacity, intestinal health, and meat quality. Therefore, lycopene as a new type of feed additive, has broader application prospects in many antibiotic-forbidden environments. This article serves as a reference for the use of lycopene as a health feed additive in animal production by going over its physical and chemical characteristics, antioxidant, lipid-lowering, anti-cancer, and application in animal production.

Ameliorating Effect of Sodium Selenite on Developmental and Molecular Response of Bovine Cumulus-Oocyte Complexes Matured in Vitro Under Heat Stress Condition

Selenium (Se), an essential trace element, plays an important role in the antioxidative defense mechanism, and it has been proven to improve fertility and reproductive efficiency in dairy cattle. The present study evaluated the potential protective action of Se supplement of in vitro maturation (IVM) media on the maturation and subsequent development of bovine cumulus-oocyte complexes (COCs) exposed to heat stress (HS). The treatment with Se improved the viability of cumulus cells (CCs) and oocytes (P < 0.05). The proportion of oocytes reached metaphase II (MII) and those arrested at metaphase I (MI) was greater and lower in treatment than control respectively (P < 0.05). Supplementation with Se increased the percentage of cleaved embryos, total blastocysts, and blastocyst/cleavage ratio (P < 0.05). Moreover, the upregulation of CCND1, SEPP1, GPX-4, SOD, CAT, and downregulation of GRP78, CHOP, and BAX in both Se-treated CCs and oocytes were recorded. The upregulation of NRF2 was detected in Se-treated CCs other than in oocytes, which showed upregulation of IGF2R and SOX-2 as the markers of quality as well. Se supplement in IVM media improved the viability, maturation, and the level of transcripts related to antioxidant defense and quality of heat-treated oocytes, which coincided with greater subsequent development outcomes. Se ameliorated the viability of CCs along with upregulation of antioxidative candidate gene expression and downregulation of apoptosis-related ones to support their protective role on restoring the quality of oocytes against compromising effects of HS.

5-Aminolevulinic acid/sodium ferrous citrate improves the quality of heat-stressed bovine oocytes by reducing oxidative stress

A high temperature-humidity index during summer has deleterious effects on mitochondrial function, reducing oocyte developmental competence. 5-Aminolevulinic acid (5-ALA) and sodium ferrous citrate (SFC) are both known to support mitochondrial function and have strong anti-oxidant and anti-apoptotic activities. This study aimed to determine the mechanism of action of 5-ALA/SFC on oocyte quality. Bovine oocytes were collected from medium-sized follicles during summer (July-September, temperature-humidity index:76.6), cultured with 0, 1, 2, 4, and 8 µM 5-ALA with SFC at a molar ratio of 1:0.125, fertilized, and cultured for 10 days. The addition of 8/1 µM 5-ALA/SFC had a deleterious effect on oocyte cleavage rate in comparison with control oocytes, but did not affect the blastocyst rate, while 1/0.125 µM 5-ALA/SFC had a significantly higher increase in blastocyst rate than 8/1 µM 5-ALA/SFC. The addition of 1/0.125 and 2/0.25 µM 5-ALA/SFC improved oocyte quality by increasing the mitochondrial distribution pattern and metaphase-II oocytes, reducing reactive oxygen species and upregulating nuclear factor erythroid-2-related factor 2, heme oxygenase-1, and superoxide dismutase-1 in oocytes, and nuclear factor erythroid-2-related factor 2 and mitochondrial transcription factor A in cumulus cells. These results indicate that 1/0.125 and 2/0.25 µM 5-ALA/SFC may support oocyte quality and developmental competence and provide anti-oxidant actions in cumulus-oocyte complexes.

Disorder of Biological Quality and Autophagy Process in Bovine Oocytes Exposed to Heat Stress and the Effectiveness of In Vitro Fertilization

The main problem in dairy herds is reproductive disorders, which are influenced by many factors, including temperature. Heat stress reduces the quality of oocytes and their maturation through the influence of, e.g., mitochondrial function. Mitochondria are crucial during oocyte maturation as well as the process of fertilization and embryonic development. Disturbances related to high temperature will be increasingly observed due to global warming. In present studies, we have proven that exposure to high temperatures during the cleaving of embryos statistically significantly (at the level of p < 0.01) reduces the percentage of oocytes that cleaved and developed into blastocysts eight days after insemination. The study showed the highest percentage of embryos that underwent division in the control group (38.3 °C). The value was 88.10 ± 6.20%, while the lowest was obtained in the study group at 41.0 °C (52.32 ± 8.40%). It was also shown that high temperature has a statistically significant (p < 0.01) effect on the percentage of embryos that developed from the one-cell stage to blastocysts. The study showed that exposure to a temperature of 41.0 °C significantly reduced the percentage of embryos that split relative to the control group (38.3 °C; 88.10 ± 6.20%). Moreover, it was noted that the highest tested temperature limits the development of oocytes to the blastocyst stage by 5.00 ± 9.12% compared to controls (33.33 ± 7.10%) and cleaved embryos to blastocysts by 3.52 ± 6.80%; the control was 39.47 ± 5.40%. There was also a highly significant (p < 0.0001) effect of temperature on cytoplasmic ROS levels after 6 and 12 h IVM. The highest level of mitochondrial ROS was found in the group of oocytes after 6 h IVM at 41.0 °C and the lowest was found in the control group. In turn, at 41.0 °C after 12 h of IVM, the mitochondrial ROS level had a 2.00 fluorescent ratio, and the lowest in the group was 38.3 °C (1.08). Moreover, with increasing temperature, a decrease in the expression level of both LC3 and SIRT1 protein markers was observed. It was proved that the autophagy process was impaired as a result of high temperature. Understanding of the cellular and molecular responses of oocytes to elevated temperatures will be helpful in the development of heat resistance strategies in dairy cattle.

Effect of carvacrol antioxidant capacity on oocyte maturation and embryo production in cattle

Carvacrol (C₁₀H₁₄O), an efficient phenolic antioxidant substance for several cell types, may become a useful antioxidant for female germ cells and embryo culture. This study investigates the effects of carvacrol supplementation on bovine oocytes in in vitro maturation (IVM) and embryo production. In total, 1222 cumulus-oocyte complexes were cultured in TCM-199⁺ alone (control treatment) or supplemented with carvacrol at the concentrations of 3 µM (Carv-3), 12.5 µM (Carv-12.5), or 25 µM (Carv-25). After IVM, the oocytes were subjected to in vitro fertilization and embryo production, and the spent medium post-IVM was used for evaluating the levels of reactive oxygen species and the antioxidant capacity (2,2-diphenyl-1-picryl-hydrazyl-hydrate and 2,2'-azinobis-3-ethyl-benzothiozoline-6-sulphonic acid quantification). A greater (P < 0.05) antioxidant potential was observed in the spent medium of all carvacrol-treated groups compared with the control medium. Moreover, the addition of carvacrol to the maturation medium did not affect (P > 0.05) blastocyst production on days 7 and 10 of culture; however, the total number of cells per blastocyst was reduced (P < 0.05) in two carvacrol-treated groups (Carv-3 and Carv-25). In conclusion, carvacrol demonstrated a high antioxidant capacity in the spent medium after oocyte maturation; however, although embryo production was not affected, in general, carvacrol addition to IVM medium reduced the total number of cells per blastocyst. Therefore, due to the high antioxidant capacity of carvacrol, new experiments are warranted to investigate the beneficial effects of lower concentrations of carvacrol on embryo production in cattle and other species.

Lycopene Reduces the In Vitro Aging Phenotypes of Mouse Oocytes by Improving Their Oxidative Status

Postovulatory aging is a major problem that limits the success of many assisted reproductive technologies (ARTs). Oxidative stress is a leading cause of oocyte aging. This study investigated the effects of lycopene supplementation of in vitro maturation (IVM) medium during the aging of mouse oocytes on the oocytes' morphology and oxidative stress status. Mouse cumulus-oocyte complexes (COCs) were collected and cultured in the IVM medium either for 17 h, (freshly matured oocytes), or for 48 h, (in vitro-aged oocytes), with or without lycopene. The rate of fragmented and degenerated oocytes and the oocyte levels of hydrogen peroxide (H2O2), malondialdehyde (MDA), total antioxidant capacity (TAC), reduced glutathione (GSH), catalase (CAT), and superoxide dismutase (SOD) were estimated and compared. Oocytes aged with 200 nM lycopene revealed significantly less fragmentation and degeneration, lower H2O2 and MDA levels, and higher TAC, GSH and SOD levels than those aged without lycopene. CAT levels were unchanged by lycopene treatment. Taken together, our data showed beneficial effects of lycopene during in vitro aging of mouse oocytes by reducing the oxidative stress damages that lead to their apoptosis. The present study introduces lycopene as a natural supplement to reduce the postovulatory aging-dependent abnormalities of mammalian oocytes.

Lycopene supplementation to serum-free embryo culture medium and its effect on development and quality of bovine blastocysts produced in vitro

Selenium is commonly used as an antioxidant in a serum-free culture medium setting. However, lycopene has emerged as a potent antioxidant being twice as efficient as β-carotene and 10 times as efficient as α-tocopherol with beneficial effects when supplemented in a serum-free maturation medium. Here, we aimed to evaluate the effect of lycopene supplementation in a serum-free culture medium on blastocyst development and quality. After in vitro maturation and fertilization, presumed zygotes were cultured in groups of 25 in 50 μl droplets of synthetic oviductal fluid. Culture medium supplementation was done using four experimental groups: insulin, transferrin, selenium (ITS, control); ITS + DMSO (diluent control); ITS + DMSO-lycopene 0.1 μM (ITSL); and IT + DMSO-lycopene 0.1 μM (ITL). DMSO was used as a diluent for lycopene. Blastocyst development among experimental groups was fitted in mixed-effects models, and blastocyst quality parameters (assessed via differential apoptotic staining) were evaluated in mixed linear regression models. The cleavage (85.3 ± 2.4, 82.6 ± 2.7, 86 ± 2.3 and 86.4 ± 2.3% for control, diluent control, ITSL and ITL, respectively) and day 8 blastocyst rates (37.4 ± 3.3, 36.9 ± 3.4, 39.7 ± 3.3 and 46.2 ± 3.4% for control, diluent control, ITSL and ITL, respectively) were not different (p > .1) among experimental groups. Embryos produced in the ITL group resulted in blastocysts with higher total cell numbers (TCN; 141 ± 19.2), inner cell mass (ICM; 65.3 ± 11.6) and trophectoderm cells (TE; 75.2 ± 8.8) compared with the control (129 ± 19.2, 56.3 ± 11.6 and 72.7 ± 8.8, for TCN, ICM and TE; p < .01, respectively). Lycopene-supplemented groups (ITSL and ITL) resulted in blastocysts with similar TCN, ICM and TE (p > .2). The number of apoptotic cells was not different among experimental groups (p > .1). Lycopene supplementation to the culture medium only produced a numerical increase in the blastocyst rate but replacing selenium with lycopene in a serum-free culture medium resulted in blastocysts with more cells.

Lycopene Supplementation to Serum-Free Maturation Medium Improves In Vitro Bovine Embryo Development and Quality and Modulates Embryonic Transcriptomic Profile

Bovine embryos are typically cultured at reduced oxygen tension to lower the impact of oxidative stress on embryo development. However, oocyte in vitro maturation (IVM) is performed at atmospheric oxygen tension since low oxygen during maturation has a negative impact on oocyte developmental competence. Lycopene, a carotenoid, acts as a powerful antioxidant and may protect the oocyte against oxidative stress during maturation at atmospheric oxygen conditions. Here, we assessed the effect of adding 0.2 μM lycopene (antioxidant), 5 μM menadione (pro-oxidant), and their combination on the generation of reactive oxygen species (ROS) in matured oocytes and the subsequent development, quality, and transcriptome of the blastocysts in a bovine in vitro model. ROS fluorescent intensity in matured oocytes was significantly lower in the lycopene group, and the resulting embryos showed a significantly higher blastocyst rate on day 8 and a lower apoptotic cell ratio than all other groups. Transcriptomic analysis disclosed a total of 296 differentially expressed genes (Benjamini–Hochberg-adjusted p < 0.05 and ≥ 1-log2-fold change) between the lycopene and control groups, where pathways associated with cellular function, metabolism, DNA repair, and anti-apoptosis were upregulated in the lycopene group. Lycopene supplementation to serum-free maturation medium neutralized excess ROS during maturation, enhanced blastocyst development and quality, and modulated the transcriptomic landscape.

Potential use of bacterial pigments as anticancer drugs and female reproductive toxicity: a review

Abstract Natural bioactive compounds obtained from microorganisms, have awakened particular interest in the industry nowadays. This attention comes when natural resources depletion is pronounced, and the acquisition of both new plant origin resources and bioactive products, represents a challenge for the next generations. In this sense, prospecting for large-scale production and use of bacterial pigments is a necessary strategy for the development of novel products. A wide variety of properties have been attributed to these substances and, among them, their therapeutic potential against important diseases, such as cancer. There is consensus that available chemotherapy protocols are known to detrimentally affect cancer patients fertility. Hence, considerable part of the deleterious effects of chemotherapy is related to the drugs cytotoxicity, which, in addition to cancer cells, also affect normal cells. Therefore, the intrinsic properties of bacterial pigments associated with low cytotoxicity and relevant cell selectivity, certified them as potential anticancer drugs. However, little information is available about reproductive toxicity of these new and promising compounds. Thus, the present review aims to address the main bacterial pigments, their potential uses as anticancer drugs and their possible toxic effects, especially on the female gonad.

Uso potencial de pigmentos bacterianos como drogas anticâncer e toxicidade reprodutiva feminina: uma revisão

Resumo Os compostos bioativos naturais obtidos de microrganismos têm despertado especial interesse da indústria nos últimos anos. Esta atenção ocorre em um momento em que o esgotamento de recursos naturais é pronunciado, e a aquisição de novos insumos e produtos bioativos de origem vegetal representa um desafio para as próximas gerações. Neste sentido, a prospecção para a produção e uso em larga escala dos pigmentos bacterianos tem representado uma importante estratégia para o desenvolvimento de novos produtos. Uma grande variedade de propriedades foi atribuída a estas substâncias, entre elas, o potencial terapêutico contra doenças importantes, como o câncer. Existe um consenso de que os protocolos quimioterápicos disponíveis são conhecidos por afetarem negativamente a fertilidade de pacientes com câncer. Grande parte dos efeitos deletérios da quimioterapia está relacionado à citotoxicidade das drogas usadas para este fim, que além das células cancerosas, afetam as células normais. Nesse sentido, as propriedades naturais atribuídas aos pigmentos bacterianos associadas à baixa citotoxicidade e relevante seletividade, os qualificaram como potenciais drogas anticâncer. No entanto, pouco se tem de informação a respeito da toxicidade reprodutiva destes novos e promissores compostos. Dessa forma, a presente revisão tem o objetivo de abordar os principais pigmentos bacterianos, suas utilizações potenciais como drogas anticâncer, bem como os seus possíveis efeitos tóxicos, sobretudo, sobre a gônada feminina.