High resveratrol or quercetin concentrations reduce the oscillation index of frozen goat semen

Quercetin in semen extender curtails reactive oxygen and nitrogen species and improves functional attributes of cryopreserved buck semen

Cryopreservation of goat spermatozoa is challenging due to several factors, including one of the most essential, i.e., oxidative stress. It is particularly essential in goat semen due to its scanty ejaculate volume and high sperm concentration. This leaves a narrow sperm-to-seminal plasma ratio owing to marginal antioxidant support; moreover, semen extension further dilutes the antioxidant level, leading to an imbalance of oxidant-antioxidant equilibrium. The present study aimed to evaluate the effect of quercetin on curtailing oxidative stress and its reflection on the post-thaw survivability and membrane integrity of goat spermatozoa. For this study, six bucks were selected. Six ejaculates from each buck totaling 36 ejaculates were collected, which were then split into five parts; furthermore, each part was added with a semen extender having a particular concentration of additive. Group C without quercetin and T1 containing Vitamin E at 3 mmol/mL were considered the control and positive control respectively, whereas T2, T3, and T4 contain 10, 20, and 30 μmol/mL of Quercetin respectively. The final sperm concentration of each group was kept at 200 × 106 spermatozoa/mL. All groups were subjected to equilibration at 4 °C for 4 h, then filled in French mini (0.25 mL) straws, followed by sealing and cryopreservation. Samples after 72 h of cryopreservation were subjected to evaluation of plasma membrane integrity and viability through staining, acrosomal integrity, and mitochondrial membrane activity through flow cytometry. Evaluation of sperm kinematics as well as the oxidant-antioxidant status of sperm (ROS and nitric oxide) and seminal plasma (SOD, CAT, GPx, FRAP, and lipid peroxidation through MDA estimation) were also carried out. Quercetin, when supplemented at 20 μmol/mL in buck semen extender, significantly (p < 0.01) improved cryopreserved sperm functions in terms of plasma membrane integrity, viability, acrosomal integrity, mitochondrial membrane activity, and sperm kinematics of buck semen. Similarly, Quercetin supplementation at 20 μmol/mL significantly reduced reactive oxygen and nitrogen species (RONS) in sperm and improved the antioxidant status of seminal plasma, which was indicated by reduced oxidative damage and improved the antioxidant status of buck semen. In conclusion, Quercetin at 20 μmol/mL reduced oxidative stress, improved semen antioxidant status, and improved sperm membranes integrity and kinematics.

Quercetin in semen extender improves frozen-thawed spermatozoa quality and in-vivo fertility in crossbred Kamori goats

This study investigated the antioxidant effect of quercetin-treated semen on frozen-thawed spermatozoa quality and in-vivo fertility in crossbred Kamori goats. In total, 32 ejaculates from four fertile bucks were diluted in Tris-based egg yolk extender with varying levels of quercetin (0, 1, 5, 10, and 15 μM). Qualified semen samples were pooled and frozen in French straws. The results revealed that the addition of quercetin in the semen extender increased (p < 0.05) frozen-thawed sperm total motility (TM), progressive motility (PM), rapid velocity (RV), average path velocity (VAP), straight line velocity (VSL), curvilinear velocity (VCL), and amplitude of lateral head (ALH) displacement in contrast to the control group. Quercetin supplementation had no effect on beat cross frequency (BCF), straightness (STR), and linearity (LIN) (p > 0.05). Quercetin showed significantly higher (p < 0.05) plasma membrane and acrosome integrity and viability (p < 0.05) of spermatozoa in contrast to the control group. Quercetin in the semen extender significantly increased (p < 0.05) superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), ascorbate peroxidase (APX), and total antioxidant capacity (TAC) levels while reduced (p < 0.05) the contents of total oxidant status (TOS) and malondialdehyde (MDA), which were in contrast to the control group. Ultrasound results revealed that 24 out of 30 (80%) goats were found pregnant when semen was treated with 5 μM quercetin while the control group showed 18 out of 30 (60%) animals were pregnant. Thus, the study concluded that 5 μM quercetin-treated semen was found to be efficient, showed increased antioxidant status, and reduced oxidant production, leading to improved spermatozoa quality and in-vivo fertility in goats.

Effects of Nobiletin supplementation on the freezing diluent on porcine sperm cryo-survival and subsequent in vitro embryo development

Nobiletin (NOB) is a bioflavonoid compound isolated from citrus fruit peels. The present study aimed to elucidate whether NOB facilitates the porcine sperm cryosurvival and embryo development after in vitro fertilization (IVF). To this end, spermatozoa were diluted and cryopreserved in a freezing extender supplemented with 0 (control), 50, 100, 150, and 200 μM Nobiletin. The kinematic patterns of frozen-thawed (FT) sperm were assessed after 30 and 90 min incubation using a Sperm Class Analyzer (SCA). Viability, acrosome integrity, and mitochondrial membrane potential (MMP) were measured by fluorescence microscopy 30 min after thawing using SYBR-14/PI, PSA/FITC, and R123/PI, respectively. Lipid peroxidation was determined using MDA assay after incubation for 90 min. The addition of 100 μM and 150 μM NOB to the extender significantly improved sperm progressive motility, and acrosome integrity compared to the control group (P < 0.05). The proportion of viable spermatozoa was significantly higher in the 150 μM NOB group. MDA levels were less in 50 μM and 150 μM NOB treated groups compared to the control. In addition, IVF with FT sperm was used to assess the embryo developmental competence. Treatment with 150 μM NOB before cryopreservation increased the cleavage and blastocyst formation rates compared to the control group. Furthermore, the relative expression of POU5F1 and AMPK, genes related to pluripotency and cell differentiation were significantly upregulated in embryos resulting from NOB-treated sperm compared to the control group. These results suggest that Nobiletin is a functionally novel phytochemical to mitigate oxidative stress during the freezing-thawing of porcine spermatozoa as reflected by improved FT sperm quality and IVF outcome.

Quercetin: Putative effects on the function of cryopreserved sperms in domestic animals

Quercetin is one of the most used antioxidant flavonoids and largely exists in many fruits and vegetables because of its capability to scavenge the free reactive oxygen species (ROSs) by repressing lipid peroxy radical fusion, metal ion chelating through enzyme inhibition, and adopting the repair mechanisms. It also exhibits various biological actions, including antioxidative, anti-inflammatory and antimicrobial activities. Furthermore, it contributes well to sustaining the endogenous cellular antioxidant defence system. The process of cryopreservation is associated with increased oxidative stress, and some steps are potential sources of ROSs, including the method of semen collection, handling, cryopreservation culture media, and thawing, which result in impaired sperm function. Several antioxidants have been proposed to counteract the harmful impact of ROS during semen cryopreservation. The antioxidant capability of quercetin has been verified in different animal species for providing valuable defence to sperm during the cryopreservation process. The beneficial properties of quercetin on various parameters of fresh and post-thaw sperm in different species are clarified in this review. More in-depth investigations are required to clarify quercetin's mechanism of action in different animal species.

Impact of quercetin, carnosine, and ozone in the cryopreservation on Nellore (Bos indicus) semen

The objective of this study was to reduce the effects of cryoinjury caused in bovine semen by cryopreservation. Ejaculates were collected from Nellore bulls and subjected to freezing in C (control), ozone (15, 30, and 60 µg mL^-1 of ozone), quercetin (25, 50, and 100 µg mL^-1 of quercetin), and carnosine groups (100, 200, and 300 ng mL^-1 of carnosine). Samples were evaluated post-thaw (M0) and post-rapid thermoresistance test (M30) for sperm kinetics (total motility, progressive motility, curvilinear speed, linearity and amplitude of lateral head displacement) and cell structure viability (plasma membrane integrity, acrosomal integrity, mitochondrial potential, membrane fluidity, and lipid peroxidation). There were no differences (P > 0.05) between the control, quercetin, and carnosine-treated groups for the parameters evaluated at M0 and M30. In turn, supplementation with ozone resulted in lower values for sperm kinetics (P < 0.05) and lower mitochondrial potential at M30 (P < 0.05). Quercetin and carnosine at the concentrations used did not promote significant gains in frozen semen, nor did they demonstrate cytotoxicity. We expected to obtain positive results with the use of ozone. Nonetheless, the addition was harmful to the parameters of sperm kinetics, and its effect was not observed as a possible pro-antioxidant. We believe that the fact that the gas did not harm the sperm structure opens avenues for tests with lower dosages, since, by reducing its concentration, we could minimize the damage to sperm kinetics.

Supplementation of Beltsville extender with quercetin improves the quality of frozen-thawed rooster semen

1. Excessive reactive oxygen species (ROS) production during the sperm freeze-thawing process leads to membrane lipid peroxidation, DNA damage, and motility loss.2. This study examined the effect of supplementation of Beltsville poultry semen extender with different concentrations of quercetin (and antioxidants) on the cryopreservation of rooster sperm.3. Semen samples were collected from six Ross broiler breeders via abdominal massage twice a week for 4 weeks (eight replicates), and were divided into five equal aliquots to be diluted in Beltsville extenders that contained different concentrations of quercetin: 0, 5, 10, 15, and 20 mM. Motility, membrane functionality, abnormal morphology, lipid peroxidation, mitochondrial activity, viability, apoptosis status, and fertility potential were assessed post thaw.4. The addition of 10 and 15 mM quercetin to the semen extender significantly increased the total motility, straight-line velocity (VSL), and sperm membrane functionality compared with the other groups (P ≤ 0.05). Moreover, 10 mM quercetin caused higher progressive motility (34.86 ± 3.80%), curvilinear velocity (VCL; 175.11 ± 3.20 µm/s), average path velocity (VAP; 44.35 ± 11.06 µm/s), viability (59.14 ± 1.36%), mitochondrial activity (80.14 ± 2.07%), lower abnormal morphology (19.21 ± 0.45%), and lower lipid peroxidation (2.7 ± 0.13 nmol/ml) compared with the other groups (P < 0.05). The rate of fertility and hatchability after artificial insemination was not affected by experimental groups.5. In conclusion, supplementation of Beltsville extender with 10 mM quercetin could be a suitable method to improve post-thawed rooster sperm quality resulting in better freeze/thaw characteristics.

The Role of Selected Natural Biomolecules in Sperm Production and Functionality

Emerging evidence from in vivo as well as in vitro studies indicates that natural biomolecules may play important roles in the prevention or management of a wide array of chronic diseases. Furthermore, the use of natural compounds in the treatment of male sub- or infertility has been proposed as a potential alternative to conventional therapeutic options. As such, we aimed to evaluate the effects of selected natural biomolecules on the sperm production, structural integrity, and functional activity. At the same time, we reviewed their possible beneficial or adverse effects on male reproductive health. Using relevant keywords, a literature search was performed to collect currently available information regarding molecular mechanisms by which selected natural biomolecules exhibit their biological effects in the context of male reproductive dysfunction. Evidence gathered from clinical trials, in vitro experiments and in vivo studies suggest that the selected natural compounds affect key targets related to sperm mitochondrial metabolism and motion behavior, oxidative stress, inflammation, DNA integrity and cell death. The majority of reports emphasize on ameliorative, stimulating and protective effects of natural biomolecules on the sperm function. Nevertheless, possible adverse and toxic behavior of natural compounds has been indicated as well, pointing out to a possible dose-dependent impact of natural biomolecules on the sperm survival and functionality. As such, further research leading to a deeper understanding of the beneficial or adverse roles of natural compounds is necessary before these can be employed for the management of male reproductive dysfunction.

The use of resveratrol decreases liquid-extend boar semen fertility, even in concentrations that do not alter semen quality

In vitro and in vivo assays were conducted to investigate the effects of trans-resveratrol (RVT) on liquid-extended boar semen during 72 h of storage at 17 °C. Thirty-six ejaculates were collected from six boars, evaluated, and extended. RVT was then added at the indicated treatment concentration (0, 0.01, 0.1 or 1 mM), and the ejaculates were cooled to 17 °C and evaluated at 0, 24, 48, and 72 h. Samples were evaluated for sperm motility, kinetics, plasma and acrosome integrity, mitochondrial membrane potential, anion superoxide levels, lipoperoxidation, and antioxidant enzyme activity. In the follow-up experiment, twenty-eight gilts were fixed-time inseminated with 0 or 0.01 mM RVT liquid-extended boar semen. After five days, they were slaughtered, and their reproductive tracts were recovered. The embryos were collected, and the pregnancy, fertility, and viable embryo rates were calculated. In the in vitro assays, total motility, plasma and acrosome membrane integrity, mitochondrial membrane potential, anion superoxide levels, and lipoperoxidation did not change at any of the evaluation times with the use of RVT up to 0.01 mM. RVT decreased SOD activity without changes in GPx. RVT used at 1 mM showed harmful effects for almost all evaluated parameters. For the in vivo assay, the same pregnancy and fertility rates were observed for both groups, while the viable embryo rate was three-fold lower in the 0.01 mM group than in the 0 mM group. The results showed a dichotomous effect of RVT; a low concentration was not harmful in vitro but was catastrophic for embryo viability.

Effect of Quercetin Supplementation in Extender on Sperm Kinematics, Extracellular Enzymes Release, and Oxidative Stress of Egyptian Buffalo Bulls Frozen-Thawed Semen

Buffalo spermatozoa are more sensitive for cryopreservation compared to other species. This study aimed to evaluate the consequences of quercetin against cryodamage of buffalo frozen–thawed spermatozoa characteristics. Semen of Egyptian bulls (n = 4) was extended in OptiXcell extender incorporated with quercetin at 0 (control), 2.5, 5.0, 10.0, 20.0, 40.0, and 80.0 μM before cryopreservation. Frozen–thawed semen was evaluated for sperm motility by computer-assisted sperm analyzer (CASA), viability, morphology, membrane, and acrosome integrities. The kinematics parameters including average path velocity (VAP; μm/s), straight linear velocity (VSL; μm/s), curvilinear velocity (VCL; μm/s), amplitude of lateral head displacement (ALH; μm), beat cross frequency (BCF; Hz), linearity [LIN, (VSL/VCL) × 100], and straightness [STR, (VSL/VAP) × 100] were assessed. The sperm-free extender was evaluated for aspartate aminotransferase (AST), alanine aminotransferase (ALT), and H₂O₂. Homogenized sperm cells were evaluated for oxidative stress biomarkers [superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX)], and lipid peroxidation [malondialdehyde (MDA)]. The highest values of total motility, progressive motility, viability, intact acrosome, and membrane integrity substantially improved with 10 μM of quercetin. STR (%) was substantially low (P < 0.01), and VCL (μm/s) and ALH (μm) were markedly high (P < 0.05) in 10 μM of quercetin. The outflow of ALT enzyme to extracellular fluid was lower with 10 μM of quercetin (P < 0.001) and higher at 2.5 μM of quercetin. The spermatozoa leaked AST was markedly lower at 5.0, 10 (P < 0.001) and 20 μM (P < 0.05) of quercetin. The activity of antioxidant enzymes was eminently low at all quercetin concentrations, and this was accompanied by the decrease in H₂O₂ in the media. SOD activity at 10–80 μM, CAT at 5.0–40 μM, and GPX at 2.5–80.0 μM of quercetin in spermatozoa were substantially low. MDA level significantly (P < 0.001) decreased at all quercetin concentrations. In conclusion, the incorporation of quercetin at the level of 10 μM is promising in improving buffalo semen characteristics and lower the freezing–thawing oxidative stress.

Quercetin and Naringenin Provide Functional and Antioxidant Protection to Stored Boar Semen

In this study, we evaluated the impact of 5-50 μM quercetin (QUE) and naringenin (NAR) on extended boar spermatozoa in the BTS (Beltsville Thawing Solution) medium for 72 h. Spermatozoa motion, membrane, acrosome, and DNA integrity were investigated immediately after sample dilution (0 h) as well as after 24 h, 48 h, and 72 h of semen storage. Furthermore, reactive oxygen species (ROS) and superoxide production, as well as the extent of oxidative damage to the sperm proteins and lipids, were assessed to determine the potential of QUE and NAR to prevent a potential loss of sperm vitality due to oxidative stress development. Our results indicate that the most notable parameter influenced by QUE was the mitochondrial activity, which remained significantly higher throughout the experiment (p < 0.001 and p < 0.0001; 10 μM), and which correlated with the most prominent maintenance of sperm motility (p < 0.01, 48 h; p < 0.05, 72 h). A significant membrane stabilization (p < 0.01, 24 h and 48 h; p < 0.0001, 72 h) and prevention of lipid peroxidation (p < 0.05, 24 h and 48 h; p < 0.01, 72 h) was primarily observed following administration of 10 and 25 μM NAR; respectively. Administration of 10 μM QUE led to a significant decrease of superoxide (p < 0.0001, 48 h and 72 h) while the most notable decline of ROS generation was recorded in the case of 10 and 25 μM NAR (p < 0.001). This study may provide new information on the specific mechanisms of action involved in the favorable effects of natural biomolecules on spermatozoa.

The Role of Resveratrol in Mammalian Reproduction

Resveratrol is one of the most investigated natural polyphenolic compounds and is contained in more than 70 types of plants and in red wine. The widespread interest in this polyphenol derives from its antioxidant, anti-inflammatory and anti-aging properties. Several studies have established that resveratrol regulates animal reproduction. However, the mechanisms of action and the potential therapeutic effects are still unclear. This review aims to clarify the role of resveratrol in male and female reproductive functions, with a focus on animals of veterinary interest. In females, resveratrol has been considered as a phytoestrogen due to its capacity to modulate ovarian function and steroidogenesis via sirtuins, SIRT1 in particular. Resveratrol has also been used to enhance aged oocyte quality and as a gametes cryo-protectant with mainly antioxidant and anti-apoptotic effects. In males, resveratrol enhances testes function and spermatogenesis through activation of the AMPK pathway. Furthermore, resveratrol has been supplemented to semen extenders, improving the preservation of sperm quality. In conclusion, resveratrol has potentially beneficial effects for ameliorating ovarian and testes function.

Resveratrol supplementation and cryopreservation of buck semen

Resveratrol (Resv) was tested to assess its effects on buck semen freezability. Ejaculates of 4 bucks were collected, washed and diluted in a commercial extender at 30 °C. Extended semen was divided into 4 aliquots supplemented with increasing concentrations of Resv: 0 μM (control); 10 μM; 25 μM and 50 μM. Aliquots were cooled to 4 °C in 5h and frozen in LN₂. Thawing was performed at 37 °C for 30 s. At the 3 stages of the experiment (30 °C, 4 °C, thawing), motility (CASA), osmotic resistance (Hos test) and integrity of cytoplasm and acrosome membranes (PI/PSA staining) were assessed. Moreover, in thawed samples, the oxidative status (MDA assay) and early apoptosis (DNA fragmentation by TUNEL assay) were evaluated. Resveratrol supplementation did not affect most of the motility parameters analysed, except for total motility, ALH (lateral head displacement) and velocity distribution (P < 0.05). Functional and morphological integrity of membranes was not affected at any stage of the experiment (P > 0.05). In thawed spermatozoa, the oxidative status was not preserved by Resv (P > 0.05) while early apoptosis, was significantly decreased in the 50 μM Resv group (P < 0.05). Resveratrol did not improve buck semen freezability; the observed effects on motility and DNA were not dose dependent and not mediated by a potential anti-oxidant activity.

Improving the quality of cryopreserved goat semen with a commercial bull extender supplemented with resveratrol

The purpose of the current study was to evaluate the effects of resveratrol (RSV) on the quality of frozen-thawed goat sperm. Semen samples from four bucks were divided into five aliquots and diluted with a commercial bull semen extender containing: no antioxidant (RSV-0, control), 10 μM RSV (RSV-10), 50 μM RSV (RSV-50), 100 μM RSV (RSV-100) and 250 μM RSV (RSV-250). After thawing, sperm motility, abnormal morphology, membrane and acrosome integrity, mitochondrial activity, phosphatidylserine (PS) distribution, and oxidative stress were evaluated. The results indicated that in comparison with the control, when the concentration of RSV was 10 or 50 μM, the total motility, progressive motility, membrane and acrosome integrity, and mitochondrial activity of post-thaw spermatozoa was greater (P < 0.05). Additionally, the use of extenders containing RSV-10 or RSV-50 resulted in a greater percentage of viable spermatozoa as compared to the other groups (P < 0.05). Importantly, there were more viable spermatozoa (49.61 ± 0.61%) and less non-viable spermatozoa (49.16 ± 1.01%) in the RSV-50 group compared to the other extenders (P < 0.05). Furthermore, the use of the extenders containing RSV-10 and -50 resulted in a reduction in ROS production in frozen-thawed spermatozoa as compared to the control (P < 0.05). There, however, was no difference among extenders for abnormal morphology and PS distribution. In conclusion, supplementation with RSV, at a concentration of 10 or 50 μM in the semen extender, can improve the post-thaw goat sperm quality, which may occur as a consequence of inhibition of ROS generation.

Quercetin attenuates H2 O2 -induced toxicity of rooster semen during liquid storage at 4°C

Current study was carried out to examine the protective effects of quercetin against toxicity induced by hydrogen peroxide in rooster semen in vitro. Semen samples were collected from ten roosters (Ross 308 broiler breeder males, 32 weeks old) twice a week by abdominal massage method. Samples with ≥70% progressive motility were selected, pooled, diluted and used for the study. Experimental groups consisted of negative control, control that received solvent of quercetin, H₂ O₂ (40 μM) and combination groups which incubated with constant dose of H₂ O₂ (40 μM) plus various levels of quercetin (20, 40 and 80 μM). Measurement of total hydroperoxide (HPO), malondialdehyde (MDA), nitric oxide (NO), total antioxidant capacity (TAC) and superoxide dismutase activity as well as routine sperm tests were done at 0, 24 and 48 hr of storage at 4°C. Results revealed that exposure to hydrogen peroxide significantly increased HPO (138.43 ± 7.32 vs. 66.08 ± 3.97 μmol/g protein), MDA (7.21 ± 0.08 vs. 5.71 ± 2.16 μmol/g protein) and NO (0.367 ± 0.013 vs. 0.215 ± 0.011 μmol/g protein) levels and decreased sperm progressive motility (27.28 ± 1.21 vs. 47.49 ± 1.29%), and amounts of TAC (11.49 ± 0.39 vs. 15.70 ± 0.79 mmol/g protein) compared to control at 24 hr (p < 0.05). Changes at mentioned variables were repeated at 48 hr of storage. Also, co-administration of quercetin (especially at 40 and 80 μM) with hydrogen peroxide restored the toxic effects of hydrogen peroxide on rooster semen parameters such as primary and secondary lipid peroxidative indicators and other evaluated variables. The study concluded that rooster semen enrichment with quercetin would protect lipid peroxidative and nitrosative hydrogen peroxide-mediated damage during cold liquid storage of rooster semen.

Supplementation of quercetin for advanced DNA integrity in bull semen cryopreservation

The aim of this study was to identify the effects of adding quercetin (Q) to Tris extender in order to identify levels of oxidative stress in bull sperm after freeze thawing. Ejaculates were collected via artificial vagina from Holstein bulls. Semen was divided into five tools and diluted to a final concentration of 15 × 106 spermatozoa/ml with the Tris extender containing Q (25, 50, 100 and 200 μg/ml) and no additive (control; C). All examples were equilibrated at 4°C during 4 hr then were loaded into 0.25-ml straws and frozen using a controlled rate. Sperm motility and motility characteristics were determined using the computer-assisted semen analyser. Sperm membrane integrity was assessed using the hypoosmotic swelling test. Sperm chromatin integrity was investigated using the single cell gel electrophoresis. Total antioxidant capacities were performed colorimetrically. Q supplementation used as an antioxidant did not produce better results in the proportion of sperm progressive and total motility, plasma membrane integrity and sperm abnormalities. Q supplementation exhibited the favourable tail length, tail DNA and tail moment. In conclusion, when whole parameters are considered, Q25 can be added to the Tris extender due to its positive effect on sperm DNA integrity and no adverse effect on the progressive and total motilities of sperm.

Avaliação in vitro do sêmen congelado de carneiros com diluidor suplementado com miricetina

RESUMO O objetivo deste estudo foi avaliar o efeito da suplementação do diluidor de congelação de sêmen ovino com o flavonoide miricetina contra os danos ocasionados aos espermatozoides. Oito pools de sêmen, obtidos de quatro reprodutores ovinos, foram congelados com diferentes concentrações de miricetina (0, 1, 10, 100 e 1000nM). Após o descongelamento, o sêmen foi avaliado quanto à cinética espermática, à integridade das membranas plasmática e acrossomal, ao potencial de membrana mitocondrial, aos níveis de ROS intracelular, à peroxidação lipídica e à estabilidade de membrana. Amostras tratadas com miricetina 10nM apresentaram menor percentual de células rápidas (P≤0,05), quando comparadas ao grupo miricetina 1000nM. Amostras do grupo controle apresentaram maior (P≤0,05) VAP que o grupo 10nM de miricetina, enquanto amostras criopreservadas com miricetina (10, 100 e 1000nM) evidenciaram maior (P<0,05) BCF, quando comparadas ao grupo controle. O grupo tratado com miricetina 1000nM apresentou maior percentual (P<0,05) de células com peroxidação lipídica, quando comparado ao grupo controle. Em conclusão, a suplementação do diluidor de criopreservação de sêmen ovino com 10 e 100nM de miricetina afeta a cinética espermática sem provocar alterações na estrutura geral do gameta, enquanto 1000nM de miricetina provoca mudanças na cinética associadas à danos peroxidativos.