Modulation of mammalian sperm motility by quercetin

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.

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 necessity of antioxidant inclusion in caprine and ovine semen extenders: A systematic review complemented with computational insight

The inclusion of antioxidants (AOXs) has been proposed in various protocols to conserve the normal physiology of spermatozoa during (cryo) preservation. The main aim of this review was to understand the necessity of AOXs inclusion in semen extenders of caprine and ovine semen samples and to decipher physico-chemical space of AOXs used in semen extenders till now. A total 27 full-text relevant articles were finally discussed here. This systematic review showed that the inclusion of AOXs may improve the success of semen cryopreservation although at least three studies could not support this finding. AOXs have been not added after assaying total antioxidant capacity of the sample of interest, and this is principal measurement bias of all papers. Furthermore, no rational dose-response curve and precise posology have been considered in comparable studies. Furthermore, new methodologies are requested to detect the oxidative status of semen specimens before AXOs fortification and new methodologies like imaging are also needed to detect various injuries of sperms during semen (cryo)preservation. Defining computational chemical and physical spaces of AOXs which used in semen (cryo)preservation would be an interdisciplinary effort to hasten deciphering epoch-making compounds. In conclusion, more in-depth analytical, toxicological and pharmacological methodologies should be pursued in supplementation or addition of AOXs during caprine and ovine semen (cryo)preservation after determining the oxidative status of semen samples.

Quercetin supplemented casein-based extender improves the post-thaw quality of rooster semen

The advantageous influence of quercetin (Q) supplementation in an extender has not yet been evaluated for rooster semen cryopreservation. This research was purposely conducted in order to assess the effect of different quercetin concentrations added into an extender on the sperm quality of the rooster subsequent to a freezing-thawing process. After the freezing-thawing process, spermatozoa quality parameters (membrane functionality, acrosome integrity, motility, viability, and abnormal morphology), endogenous enzymes (SOD, CAT, and GPx), mitochondrial activity, DNA fragmentation index, lipid peroxidation (MDA), and ROS were all evaluated. A total of 75 neat pooled ejaculates (3 ejaculates/rooster) were collected from 25 arbor acres roosters (24 wks) twice a week using abdominal massage technique, then divided into five equal aliquots and diluted with an extender containing different doses of Q (CS-Q) as follows: casein extender without Q (control only), casein extender containing 0.040 mg/mL quercetin (CS-Q 0.040), 0.020 mg/mL quercetin (CS-Q 0.020), 0.010 mg/mL quercetin (CS-Q 0.010), and 0.005 mg/mL quercetin (CS-Q 0.005). Our results depicted that adding to the extender with a 0.010 mg/mL Q enhanced (P < 0.01) sperm motility, membrane function, viability, mitochondrial activity, intact acrosome (P < 0.05), SOD (P < 0.001), CAT, and GPx (P < 0.01) compared to the control group at post-thaw. Compared to the control group and other treatment groups after the freeze-thawing process, the addition of 0.005 mg/mL Q into the extender also showed higher (P < 0.05) improvement in the quality of sperm parameters and a higher (P < 0.01) SOD and CAT but did not improve mitochondrial activity and sperm viability. In addition, there was a lower degree of DNA fragmentation index, lower (P < 0.05) lipid peroxidation and ROS in frozen-thawed sperm treated with 0.010 mg/mL and 0.005 mg/mL Q than in control and the other treatment groups. In addition, 0.020 mg/mL Q supplementation into the extender also reduced DNA fragmentation and improved GPx activity compared to the control group at post-thaw. Different concentrations of Q 0.010 and 0.005 mg/mL added to the extender reduced the percentage of abnormal spermatozoa compared to the other groups. The results of this study showed for the first time that the inclusion of an extender with a suitable quercetin concentration of 0.010 mg/mL improved the post-thawed quality of rooster semen.

Antioxidant Effect of a Polyphenol-Rich Murtilla (Ugni molinae Turcz.) Extract and Its Effect on the Regulation of Metabolism in Refrigerated Boar Sperm

The production of reactive oxygen species (ROS) in boar spermatozoa increases in refrigeration; this can have an impact on sperm quality and fertilization capacity. We evaluated the effect of polyphenol-rich aqueous extract of murtilla (Ugni molinae Turcz) on boar sperm stored at 17°C in order to reduce oxidative stress and improve sperm quality in the long term. Five experiments were performed: first, characterization of the polyphenol content from five genotypes of murtilla; second, determination of the genotype with the best antioxidant effect (MT-Ex); third, the antioxidant capacity on O₂⁻ and lipid peroxidation; fourth, the influence of MT-Ex on motility, calcium movement, cAMP, and metabolic parameters; and fifth, analysis of long-term refrigeration. The average phenolic content was 344 ppm; gallic acid, catechin, quercetin, myricetin, and kaempferol were detected. All extracts evaluated presented a concentration-dependent antioxidant effect. MT-Ex reduces intracellular O₂⁻/peroxides but low lipid peroxidation. MT-Ex in nonstimulated ROS conditions reduces sperm motility, mitochondrial membrane potential, cAMP, and ATP, but the succinate dehydrogenase activity remained normal; also, we observed a reduction in calcium movement in in vitro sperm capacitation. The long-term analyses showed that MT-Ex improved sperm motility decay and reduced membrane damage and ROS at 168 h. Based on this study, we propose MT-Ex as a supplement in semen extenders.

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.

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

ABSTRACT The aim of this study was to evaluate the effect of different concentrations of trans-resveratrol or quercetin on the ability of goat sperm to withstand being frozen. Six pools of semen obtained from six male goats were processed with different concentrations of resveratrol or quercetin (Experiment 1: 0, 15, 25, 50, 75 or 100µM resveratrol; Experiment 2: 0, 15, 25, 50, 75 or 100µM quercetin) and frozen. After thawing, the semen was evaluated for sperm kinematics, plasma membrane and acrosome integrity, morphology and oxidative stress following 0 and 1h of incubation. Immediately after thawing (0h), wobble (oscillation index) in the groups treated with 100µM of quercetin or resveratrol was lower (P<0.05) than in those treated with 0 and 25µM resveratrol and 0µM quercetin, respectively. After 1h of incubation, the total motility in treatments with 15, 50 and 75µM quercetin, as well as the plasma membrane integrity in all quercetin concentrations were lower (P<0.05) than at 0h. In opposition, the linearity of semen samples treated with 100µM quercetin and the straightness of those treated with 75 and 100µM quercetin were lower (P<0.05) at 0h than at 1h after thawing. Thus, it can be concluded that resveratrol and quercetin at high concentrations (100µM) transiently reduce the wobble of goat sperm submitted to frozen storage, and that quercetin (75 and 100µM) increases the linearity and straightness over time, which can be favorable for fertility.

Male contraceptive efficacy of Ricinus communis L. extract

ETHNOPHARMACOLOGICAL RELEVANCE

Ricinus communis L. (Rc), of Euphorbiaceae family is a widespread plant in tropical regions and it is used in traditional medicines as an antifertility agent in India and different parts of the world.

AIM OF THE STUDY

The aim of the present study is to revalidate the ethnobotanical knowledge by evaluating the activity of only crude stem bark extracts of Rc. In this study, effects of extracts on male contraceptive efficacy were experimented in vitro with human sperm sample. The work is based on primordial and contemporary therapeutic uses of this plant.

MATERIALS AND METHODS

In this study, dose of petroleum ether extract, ethyl acetate extract, acetone extract and lyophilised aqueous extract of Rc were added to fresh human semen in 1:1 volumetric ratio. As the aqueous extract showed a promising result in 1:1 ratio, therefore, the Hypo-osmotic swelling test (HOS), Nuclear chromatin decondensation test (NCD) and Acrosomal status and function test (AFT) were also carried out with the aqueous extract of Rc.

RESULTS

The sperm immobilisation effects of the extract appeared immediately in a dose-dependent manner when the samples were treated with four different extracts of this plant. At a concentration of 100mg/mL, 100% (p<0.001 and p<0.05) sperms lost their progressive motility. At a concentration of 300 mg/mL, 100% (p<0.001 and p<0.05) became immotile when treated with aqueous extract. There was 88% (p<0.001 and p<0.05) morphological deformities in sperm sample due the effect of aqueous extract when they were tested for HOS and 91% (p<0.05) sperms behaved against NCD as compared to control group. Also there was a distinct decline (p<0.05) in AFT with increase in dosage concentration.

CONCLUSION

The findings of the study revealed that aqueous stem bark extract of the plant showed dose dependent loss of sperm motility by influencing the morphological deformation, blockage in nuclear envelope and distinct declination in acrosomal status of spermatozoa. This research, thus, opens up scope for future exploration of bark of the plant as commercial source of new male contraceptive.

Stimulating effects of quercetin on sperm quality and reproductive organs in adult male rats

AIM

To investigate effects of quercetin on weight and histology of testis and accessory sex organs and on sperm quality in adult male rats.

METHODS

Male Sprague-Dawley rats were injected s.c. with quercetin at the dose of 0, 30, 90, or 270 mg/kg body weight/day (hereafter abbreviated Q0, Q30, Q90 and Q270, respectively), and each dose was administered for treatment durations of 3, 7 and 14 days.

RESULTS

From our study, it was found that the effects of quercetin on reproductive organs and sperm quality depended on the dose and duration of treatment. After Q270 treatment for 14 days, the weights of testes, epididymis and vas deferens were significantly increased, whereas the weights of seminal vesicle and prostate gland were significantly decreased, compared with those of Q0. The histological alteration of those organs was observed after Q270 treatment for 7 days as well as 14 days. The sperm motility, viability and concentration were significantly increased after Q90 and Q270 injections after both of 7 and 14 days. Changes in sperm quality were earlier and greater than those in sex organ histology and weight, respectively.

CONCLUSION

Overall results indicate that quercetin might indirectly affect sperm quality through the stimulation of the sex organs, both at the cellular and organ levels, depending on the dose and the duration of treatment. Therefore, the use of quercetin as an alternative drug for treatment of male infertility should be considered.

A critical review of the data related to the safety of quercetin and lack of evidence of in vivo toxicity, including lack of genotoxic/carcinogenic properties

Quercetin is a naturally-occurring flavonol (a member of the flavonoid family of compounds) that has a long history of consumption as part of the normal human diet. Because a number of biological properties of quercetin may be beneficial to human health, interest in the addition of this flavonol to various traditional food products has been increasing. Prior to the use of quercetin in food applications that would increase intake beyond that from naturally-occurring levels of the flavonol in the typical Western diet, its safety needs to be established or confirmed. This review provides a critical examination of the scientific literature associated with the safety of quercetin. Results of numerous genotoxicity and mutagenicity, short- and long-term animal, and human studies are reviewed in the context of quercetin exposure in vivo. To reconcile results of in vitro studies, which consistently demonstrated quercetin-related mutagenicity to the absence of carcinogenicity in vivo, the mechanisms that lead to the apparent in vitro mutagenicity, and those that ensure absence of quercetin toxicity in vivo are discussed. The weight of the available evidence supports the safety of quercetin for addition to food.

Effects of Ca-ATPase inhibitors on the intracellular calcium activity and motility of human spermatozoa

Although evidence suggests that high intracellular calcium activity ([Ca2+]i) inhibits sperm motility, data concerning [Ca2+]i within, or slightly above, the physiological range are sparse, particularly in mammalian sperm. We investigated inhibitors of the sarcoplasmic/endoplasmic reticulum Ca-ATPase (SERCA) and the plasma membrane Ca-ATPase with the objective of increasing the intracellular calcium ion activity in human spermatozoa to study its effect on motility and other functions. Thapsigargin (20 micromol/L) increased [Ca2+]i from 140 +/- 7 nmol/L over an approximately 2-min period to reach a plateau of 530 +/- 84 nmol/L (mean +/- SEM, n = 3, p < 0.05). In sperm suspended in calcium-free medium thapsigargin increased [Ca2+]i from 13 +/- 3.3 to 35 +/- 7.5 nmol/L (p < 0.01), consistent with the release of calcium from intracellular stores. Cyclopiazonic acid (60 micromol/L) caused a transient decrease in [Ca2+]i. Quercetin, (200 micromol/L) caused a rapid increase in [Ca2+]i to 1280 +/- 90 nmol/L, after which [Ca2+]i fell quickly at first but then more slowly. Thapsigargin (20 micromol/L) caused approximately 70% of sperm to acrosome react in < or = 5 min, but once acrosome reacted, many sperm died over the next 30 min. Lower concentrations of thapsigargin caused fewer acrosome reactions but were less toxic. Both thapsigargin and quercetin caused rapid dose-dependent decreases in sperm motility. The results are consistent with high [Ca2+]i in the range observed in caput epididymal or cryopreserved spermatozoa inhibiting motility, but might be confounded by other events following the acrosome reaction.

Quercetin inhibits c-fos, heat shock protein, and glial fibrillary acidic protein expression in injured astrocytes

Quercetin, a bioflavonoid, is found widely in many kinds of fruits and vegetables. It is known to engage in many bioactivities, such as interfering with of the progress of stress responses to injury. In the present study, we investigated the effects of quercetin on some injury responses in primary cultures of astrocytes. These injury responses included the elevation of c-fos protein, heat shock protein (HSP70), and glial fibrillary acidic protein (GFAP). After heat shock insult, the levels of c-fos protein and HSP70 in astrocytes increased. With quercetin treatment, these proteins were significantly reduced. The inhibition of these injury responses by quercetin in astrocytes indicated a dose dependency, with the highest effect at 100 microM. We have previously established a scratch injury model in a primary culture of astrocytes. In that model, astrocytes responded to the scratch injury by an elevation in their GFAP level and formation of hypertrophic cell processes, which extend into the scratch areas. Quercetin treatment reduced the number of hypertrophic cell processes being extended into the scratch areas. With 100 microM of quercetin, there was a complete inhibition of the formation of the hypertrophic cell process. Western blot analysis for GFAP indicated that quercetin significantly reduced the induction of GFAP in the scratch model. At 100 microM, the total GFAP content in the injured cultures was reduced to a level lower than that of the control. This implied that quercetin might possess an antigliotic property.

Relationship between intracellular calcium, energy metabolism, and motility of ram sperm

Collective sperm motility is characterized in terms of periodic aggregation or cooperation among cells, which are seen under a microscope as a continuous wave motion. In this study, sperm motility that was made dependent on mitochondrial activity (glycolysis inhibited) was significantly inhibited by mM exogenous calcium while glycolytic-dependent (mitochondrial respiration inhibited) motility was not inhibited under these conditions. At intracellular Ca2+ above 400 nM, sperm motility was inhibited independently of the source of ATP. At [Ca2+]i of approximately 110 nM, mitochondrial- or glycomitochondrial-dependent motility showed 75 or 0% inhibition, respectively, indicating higher sensitivity of mitochondrial-dependent motility to [Ca2+]i in comparison to glycolytic-dependent motility. Under the latter conditions, intracellular level of ATP was reduced by 16% only, indicating that the 75% inhibition of mitochondrial-dependent motility was not due to reduction in ATP. The inhibition of mitochondrial-dependent motility by mM extracellular Ca2+ can be prevented by incubating the cells at pH 6.5 instead of 7.6. At pH 7.6, calcium probably interacts with negative sites on the cell surface and interferes in cell-to-cell interactions, which are important to achieve collective motility. At more acidic pH (6.5) these negative sites are probably protonated; thus Ca2+ cannot interact with them and no inhibition of motility could be seen. Glycolytic-dependent motility was not inhibited by extracellular Ca2+, since the pH of the medium becomes acidic under these conditions. Like Ca2+, mersalyl, which interacts with Ca2+ binding sites on the cell surface, showed significant inhibition of mitochondrial-dependent motility without any effect on glycolytic-dependent motility. Collective motility was directly correlated with fertility. These data are significant for establishing better conditions for spermatozoa treatment when artificial insemination or in vitro fertilization is concerned.