Antioxidant enzymes activity,lipid peroxidation,oxidative damage in the testis and epididymis,and steroidogenesis in rats after co‐exposure to atrazine and ethanol

Concomitant alcohol use and exposure to xenobiotics can adversely affect gonadal functions. This study investigated the oxidative status of the testis and epididymis and steroidogenesis of rats co‐exposed to ethanol (EtoH, 5 mg kg^?1 b.wt.) and atrazine (ATZ, 50, 100, 300 mg kg^?1 b.wt.) for 3 weeks. The activities of catalase, superoxide dismutase, glutathione peroxidase, as well as the concentrations of glutathione and malondialdehyde, as indicators of oxidative stress were measured in the homogenates of the testis and epididymis. Testosterone and cholesterol concentrations as well as 17β‐hydroxysteroid dehydrogenase (17β‐HSD) activity were assayed in the plasma and testis respectively. After the administration of EtoH alone, or in combination with different doses of ATZ, oxidative damage as evident by malondialdehyde level was not observed in both the testis and epididymis. The combine exposure group showed dose‐dependent decrease in plasma testosterone and testis cholesterol level and increase in testis 17β‐HSD activity compared to the EtoH group. Furthermore, the testes and epididymis of the EtoH‐exposed rats treated with high dose of ATZ had severe histopathological damage. Therefore, ATZ‐exposed alcohol‐treated rats have histological damage of the testis and epididymis and lower testosterone level than EtoH‐treated rats.     

Gallic acid protects against cyclophosphamide‐induced toxicity in testis and epididymis of rats

The protective role of gallic acid (GA) on reproductive toxicity induced by cyclophosphamide (CPA), an antineoplastic drug, was investigated in male Wistar rats. Sixty rats were grouped into 10 rats per group. Group 1 (control) received distilled water. Rats in groups 2 and 3 received GA alone at 60 and 120 mg kg^?1 for 14 consecutive days, respectively. Group 4 received a single intraperitoneal dose of CPA at 200 mg kg^?1 on day 1. Groups 5 and 6 received a single dose of CPA (200 mg kg^?1) intraperitoneally on day 1 followed by treatment with GA at 60 and 120 mg kg^?1 for 14 consecutive days, respectively. In testes and epididymis of the treated rats, CPA administration resulted in significant elevation (P < 0.05) in malondialdehyde (MDA), nitrite and hydrogen peroxide levels. There was a significant decrease in the activities of superoxide dismutase and glutathione‐S‐transferase. Furthermore, there were significant reductions in plasma luteinising hormone (LH), follicle stimulation hormone (FSH) and testosterone levels, which were accompanied by significant decrease in sperm motility and viability in CPA‐treated rats. Histological examination revealed marked testicular and epididymal atrophy in CPA alone treated rats and these aberrations were reversed by GA. In conclusion, GA has capacity to protect against reproductive toxicity induced by cyclophosphamide.     

Dose‐dependent effects of ethanol extract of Salvia haematodes Wall roots on reproductive function and copulatory behaviour in male rats

This study was aimed to investigate the dose‐dependent effects of Salvia haematodes Wall roots (SHW) extract on male reproductive function and copulatory behaviour in rats. Sexually mature males were assigned to four groups: control and treated (5, 50 and 300 mg kg^?1 day^?1 for 30 days). At the end of treatment regimes, the reproductive activity viz. body/organ weights, testicular spermatogenesis, daily sperm production rate (DSP) and epididymal sperm counts, and sexual behaviour including mounting latency (ML), mounting frequency (MF), intromission latency (IL), intromission frequency (IF), ejaculation latency (EL), post‐ejaculatory interval (PEI) and penile reflexes (PE) were assessed. Results showed significant increase in body weight (at 300 mg kg^?1), testis/epididymis weights (at 50 and 300 mg kg^?1), testicular spermatids, DSP, tubular diameter and epididymal sperm counts (at 50 and 300 mg kg^?1doses) in treated compared with control rats. It also produced dose‐dependant changes in sexual behaviour. The 5 mg kg^?1 dose of extract increased MF and PE, whereas 50 and 300 kg^?1 doses caused significant increase in MF, IF, PE, EL (but less than sildenafil citrate treatment), hit rate and seminal plug weight. It is concluded that SHW extract enhances anabolic activity, testicular function and sexual behavioural performance in a dose‐dependant manner.     

Quercetin and rutin ameliorates sulphasalazine‐induced spermiotoxicity,alterations in reproductive hormones and steroidogenic enzyme imbalance in rats

Certain dietary flavonoids exhibit protective potentials against drug‐induced male reproductive toxicities. We investigated the protective effects of quercetin and rutin on sulphasalazine‐induced alterations in steroidogenic enzyme activity, hormone profile and spermiotoxicity in rats. Sulphasalazine (SASP, 600 mg/kg bw) was administered alone or in combination with quercetin (20 mg/kg bw) or rutin (10 mg/kg bw) for 14 days. SASP treatment significantly increased relative weights of the epididymis and seminal vesicles. Also, testicular and epididymal sperm numbers (TSN, ESN), motility, daily sperm production (DSP) and acrosome reaction (AR) significantly decreased. SASP altered plasma testosterone, luteinising hormone (LH) and follicle‐stimulating hormone (FSH) levels while testicular cholesterol levels, 3β‐hydroxysteroid dehydrogenase (3β‐HSD) and 17β‐hydroxysteroid dehydrogenase (17β‐HSD) activities were decreased. Elevated malondialdehyde levels and concomitant decrease in reduced glutathione, glutathione‐S‐transferase, peroxidase and superoxide dismutase activities were evident in testis and epididymis of SASP‐treated rats. Quercetin or rutin co‐treatment with SASP significantly reversed organ weights, preserved sperm integrity, restored plasma hormone levels and increased cholesterol levels, 3β‐HSD and 17β‐HSD activities in testis. Both flavonoids also prevented oxidative stress in testis and epididymis of SASP‐treated rats. Quercetin and rutin protect against the negative effects of SASP treatment on reproductive capacity in male rats.     

Antioxidant effect of manganese on the testis structure and sperm parameters of formalin‐treated mice

Manganese inhibits oxidative stress damage. The aim of this study was to investigate the protective role of manganese on testis structure and sperm parameters in adult mice exposed to formaldehyde (FA). Twenty adult male NMRI mice were selected and randomly divided into four groups: (i) control; (ii) sham; (iii) ‘FA’‐exposed group; and (iv) ‘FA and manganese chloride’‐exposed group. The FA‐exposed groups received 10 mg kg^?1 FA daily for 14 days, and manganese chloride was just injected intraperitoneally 5 mg kg^?1 on 2nd weeks. Mice were sacrificed, and spermatozoa were collected from the cauda of the right epididymis and analysed for count, motility, morphology and viability. The other testicular tissues were weighed and prepared for histological examination upon removal. Seminiferous tubules, lumen diameters and epithelium thickness were also measured. The findings revealed that FA significantly reduced the testicular weight, sperm count, motility, viability and normal morphology compared with control group (P ≤ 0.05). In addition, seminiferous tubules atrophied and seminiferous epithelial cells disintegrated in the FA group in comparison with the control group (P ≤ 0.05). However, manganese improved the testicular structure and sperm parameters in FA‐treated mice testes (P ≤ 0.05). According to the results, manganese may improve and protect mice epididymal sperm parameters and testis structure treated with FA respectively.     

Quercetin impairs the reproductive potential of male mice

Oxidative stress is a leading cause of male infertility. To combat this, germ cells and spermatozoa are endowed with various enzymes, vitamins and proteins. Certain other components of food, including bioflavonoids, also provide protection against free radicals. This study analysed the effect of quercetin, a bioflavonoid, on male reproductive function in adult mice, after intraperitoneal treatment with varying concentrations of quercetin (2, 8 and 20 mg kg^?1 b.wt.) for 2 weeks. Quercetin increased the generation of reactive oxygen species and lipid peroxidation in the testis with concomitant decrease in sperm count and motility in a dose‐dependent manner. Activities of antioxidant enzymes catalase, superoxide dismutase and levels of reduced glutathione were found to be decreased in a dose‐dependent manner. Also, the levels of oxidised glutathione were increased leading to a shift in redox ratio. The testicular histomorphology was also altered dose dependently. Germ cell kinetic study revealed significant loss of various germ cell populations with increasing dose of quercetin. Interestingly, there was a reduction in germinal epithelium thickness concomitant with an increase in seminiferous tubule lumen diameter. In conclusion, the deleterious effects of quercetin on germ cells could be attributed to its pro‐oxidant ability that might affect the Sertoli cell functions.     

Effect of kolaviron,a biflavonoid complex from Garcinia kola seeds,on the antioxidant,hormonal and spermatogenic indices of diabetic male rats

The antihyperglycaemic effect of kolaviron (KV), a biflavonoid from Garcinia kola has been established in previous studies. In this study, we investigated the effect of KV (200 mg kg^?1) on the antioxidant, hormonal and spermatogenic indices of alloxan‐diabetic male rats, and metformin hydrochloride (MET) (30 mg kg^?1) served as standard drug. The results showed that KV and MET significantly (P < 0.05) decreased the fasting blood glucose of the diabetic rats. Also, untreated and MET‐treated diabetic groups had significantly (P < 0.05) lower body‐weight gain and relative weights of testes. In addition, epididymal sperm abnormalities were increased, whereas sperm count, motility, testicular protein and sialic acid were decreased in untreated diabetic group. Also, antioxidant parameters, reduced glutathione, catalase, superoxide dismutase, glutathione‐S‐transferase and glutathione peroxidase were significantly (P < 0.05) reduced in the testes with a concomitant increase in lipid peroxidation in untreated diabetic group. Furthermore, untreated diabetic group had significantly (P < 0.05) lower levels of testosterone, luteinising and follicle‐stimulating hormones relative to controls. Treatment with KV restored the relative weights of testes, activities of antioxidant enzymes, sperm and hormonal indices of the diabetic animals. This study demonstrated the role of KV to promote fertility in diabetic male rats by enhancing the hormonal and antioxidant status of the rats.     

Oral administration of Moringa oleifera oil but not coconut oil prevents mercury‐induced testicular toxicity in rats

This study was conducted to compare the effects of administration of coconut oil (CO) and Moringa oleifera oil (MO) on testicular oxidative stress, sperm quality and steroidogenesis parameters in rats treated with mercury chloride (HgCl₂). After 15 days of oral administration of CO (2 ml kg^?1 body weight) and MO (2 ml kg^?1 body weight) along with intraperitoneal (i.p.) administration of HgCl₂ (5 mg kg^?1 body weight) alone or in combination, we found that CO treatment did not protect against HgCl₂‐induced poor sperm quality (motility, count) as well as decreased testosterone level and 17β‐hydroxysteroid dehydrogenase (17β‐HSD) activity. Treatment with CO alone decreased glutathione (GSH), and glutathione peroxidase (GSH‐Px) activities and increased malondialdehyde (MDA) level in rat's testis, whereas MO did not change these parameters. Cotreatment with MO prevented HgCl₂‐induced testicular catalase (CAT) and superoxide dismutase (SOD) activities, poor sperm quality and low testosterone level and also blocks the adverse effect of CO+HgCl₂ (2 ml kg^?1 body weight + 5 mg kg^?1 body weight) on the investigated endpoints. In conclusion, MO and not CO decreased the deleterious effects of HgCl₂ on sperm quality and steroidogenesis in rats and also strengthen the antioxidant defence of the testes. Therefore, MO is beneficial as an antioxidant in HgCl₂‐induced oxidative damage.     

Cytoprotective and anti‐apoptotic effects of Satureja khuzestanica essential oil against busulfan‐mediated sperm damage and seminiferous tubules destruction in adult male mice

We studied the protective effect of Satureja khuzestanica essential oil (SKEO) against damage caused by busulfan on testis in male mice. The NMRI mice (n = 40) were assigned to four groups including: G1: control, G2: treated with busulfan for 4 days (3.2 mg kg⁻¹), G3: receive busulfan (4 days, 3.2 mg kg⁻¹) and SKEO (28 days, 225 mg kg⁻¹) at the same time, G4: pre‐treated with SKEO (7 days, 225 mg kg⁻¹) and subsequently cotreated with busulfan (4 days, 3.2 mg kg⁻¹) and SKEO (28 days, 225 mg kg⁻¹). The histological changes of testis were analysed using H&E staining. Sperm parameters, cytotoxic and apoptotic factors were also studied by computer‐aided sperm analyzer, MTT and TUNEL assays respectively. Our results showed that SKEO pre‐administration significantly improved all parameters of epididymal spermatozoa and decreased germinal epithelium destruction following busulfan chemotherapy. We also found lower MTT levels and TUNEL‐positive cells in SKEO pre‐treated groups. In conclusion, SKEO possesses beneficial effects on sperm parameters when taken before chemotherapy and continued during and after chemotherapy for a long time, than when used short‐term coinciding with the chemotherapy. Our results support valuable data about the application of SKEO for protection against adverse effects of busulfan on male genital system in patients under chemotherapy.     

Ameliorative effect of polydatin on oxidative stress‐mediated testicular damage by chronic arsenic exposure in rats

Arsenic causes lipid peroxidation leading to alterations in antioxidant status in organisms. In this study, the reproductive effects of chronic exposure to arsenic and the protective effects of polydatin (PD) were evaluated in 35 Wistar male rats, which were divided equally into five groups. The control group received a normal diet and tap water, arsenic (100 mg l^?1, approximately 1/50 of oral LD₅₀) was given via drinking water to experimental groups except control group, and PD was orally given to the other groups at dose of 50, 100 and 200 mg kg^?1 for 60 days. Arsenic administration decreased sperm motility, glutathione level, superoxide dismutase and catalase activities in testicular tissue of rats. In contrast, malondialdehyde level and DNA damage were found to be high levels in arsenic‐treated group. Histopathologically, it was observed that decreased sperm concentration and degeneration of Sertoli cells in testicular tissue. PD administration, partially 200 mg kg^?1, reversed arsenic‐induced lipid peroxidation, DNA damage, antioxidant enzyme activity and cell integrity in testis of rats. These results demonstrate that PD decreases arsenic‐induced lipid peroxidation, enhances the antioxidant defence mechanism and regenerates tissue damage in testis of rats.     

Therapeutic effects of date palm (Phoenix dactylifera L.) pollen extract on cadmium‐induced testicular toxicity

Cadmium (Cd) is a well‐known testicular toxicant. This study was designed to explore the long‐term effects of a single low dose of Cd on spermatogenesis, and testicular dysfunction and oxidative stress, and the therapeutic potential of date palm pollen extract (DPP) in averting such reproductive damage. Adult male Wistar rats received a single intraperitoneal injection of CdCl₂ (0 or 1 mg kg^?1). Twenty‐four hours later, they started receiving DPP (0 or 40 mg kg^?1) orally, once daily for 56 consecutive days. Cd exposure caused significant reproductive damage via reduced weight of the reproductive organs, which includes spermatological damage (decreased sperm count and motility and increased rates of sperm abnormalities), increased oxidative stress (increased malondialdehyde and decreased reduced glutathione levels), histological alterations (necrosis, inefficient to completely arrest spermatogenesis and a reduced Johnsen's score) and decreased serum testosterone level. DPP restored spermatogenesis and attenuated the toxic effects of Cd on the reproductive system to the levels observed in the control animals. These findings support the hypothesis that the testis is particularly sensitive to Cd, which can cause testicular damage and infertility. Treatment with DPP can ameliorate the deleterious effects of Cd, probably by activating testicular endocrine and antioxidant systems.     

Evaluation of the protective effect of quercetin against cisplatin‐induced renal and testis tissue damage and sperm parameters in rats

The protective effect of quercetin on cisplatin‐induced renal and testicular tissue damage was investigated using biochemical, histopathological and histological approaches. A total of 40 male rats were divided into 5 groups as follows: control; cisplatin alone; quercetin alone; cisplatin + quercetin; and quercetin + cisplatin. Cisplatin was administered to rats at a single dose of 7 mg kg^?1 intraperitoneal. Quercetin was administered by gavage daily for 10 days at dosage 50 mg kg^?1. At the end of the study serum, total antioxidant capacity (TAC) levels and total oxidant status (TOS) were determined. Malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT) and xanthine oxidase (XO) were studied separately in serum, renal tissue and testicular tissue. Renal and testicular morphological alterations were assessed, histopathologically. Epididymal sperm concentration, motility and morphology were investigated. Testicular and renal TAC and TOS values did not alter significantly. Renal CAT levels were increased by cisplatin and cisplatin plus quercetin groups that is reversed by administration of quercetin before cisplatin. MDA, CAT, SOD ve XO levels of testicular tissue did not differ significantly. Cisplatin and cisplatin plus quercetin groups had decreased sperm motility ratio and increased abnormal spermatozoa. Quercetin partially reverses some of the cisplatin‐related pathological effects on kidney and testis.     

Protective role of Diospyros lotus on cisplatin‐induced changes in sperm characteristics,testicular damage and oxidative stress in rats

The aim of this study was to investigate the protective effect of Diospyros lotus (DL) on cisplatin (CP)‐induced testicular damage in male rats. Twenty‐eight male rats were randomly divided into four groups: group 1 – control, given isotonic saline solution; group 2 – CP 7 mg kg⁻¹ given intraperitoneally as single dose; group 3 – DL 1000 mg kg⁻¹ per day given orally for 10 days; group 4 – CP and DL given together at the same doses. CP caused a significant increase in thiobarbituric acid‐reactive substances (TBARS) level and a significant decrease in superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT) and glutathione (GSH) levels in rats testis tissues compared to the control group. CP caused a significant increase in lipid peroxidation in testis tissues compared to the control group, whereas DL led to a significant increase in SOD and GSH levels. However, there were no statistically significant changes in GPx and CAT levels. In addition, serum testosterone levels, sperm concentration and sperm motility were significantly decreased, but abnormal sperm rate and histological changes were increased with CP. However, these effects of CP on sperm parameters, histological changes and the tissue weights were eliminated by DL treatment. In conclusion, our study showed that the reproductive toxicity caused by CP may be prevented by DL treatment.     

Therapeutic effect of pentoxifylline on reproductive parameters in diabetic male mice

In this study, we aimed to investigate the effects of pentoxifylline (PTX) on male reproductive parameters in diabetic mice. Male adult mice (n = 24) were divided into control and three experimental groups (n = 6) including Diabetic, Diabetic + PTX and PTX groups. Diabetes was induced by single injection of streptozotocin (60 mg kg^?1). PTX was administered intraperitoneally at the dose of 12 mg kg^?1 for 14 days 1 week after diabetes induction. Serum levels of testosterone and blood glucose were determined and collected spermatozoa from cauda epididymidis analysed. Based on histological slides prepared from testis, the diameter of seminiferous tubules was determined using Motic camera and software and also apoptosis using TUNEL assay. Data were analysed using one‐way anova method, and P < 0.05 was considered statistically significant. The mean of seminiferous tubules diameter, final body weight, testis weight, sperm parameters and testosterone hormone level in PTX‐treated diabetic group indicated a significant increase compared to diabetic one, whereas apoptosis index and blood glucose were decreased in this comparison (P < 0.05). These results suggest that intraperitoneal administration of PTX is a potentially beneficial agent to reduce testicular damage and improves sperm parameters in diabetic mice by decreasing the ratio of apoptosis.     

Recovery of lead‐induced suppressed reproduction in male rats by testosterone

The objective of the present study was to investigate the effects of testosterone in recuperation of lead‐induced suppressed reproduction in adult male rats. Lead acetate was administered orally to adult male rats (95 ± 5 days) at dosage level of 0.05 and 0.15% for 55 days through drinking water and injected intraperitoneally with either testoviron depot at a dose of 4.16 mg kg^?1 body weight or vehicle alone on days 1, 7 and 14 respectively. At the end of treatment, control and treated males were cohabited with untreated normal‐cycling females. After cohabitation for 5 days, all the male rats were killed and weights of reproductive organs were determined. Significant increase in the indices of testis, epididymis, seminal vesicles, vas deferens and prostate glands was observed in testosterone (T)‐treated rats when compared to those of lead‐exposed rats. Testosterone treatment significantly increased epididymal sperm count, motile spermatozoa, viable spermatozoa and HOS tail‐coiled spermatozoa and also the activity levels of testicular 3β‐ and 17β‐hydroxysteroid dehydrogenases when compared to those of lead‐exposed males. From the results, it can be hypothesised that supplementation of testosterone mitigated lead‐induced suppressed reproduction in male rats.     

Protective effects of Eugenia jambolana extract versus N‐acetyl cysteine against cisplatin‐induced damage in rat testis

To assess the protective effects of Eugenia jambolana extract (EJE) or N‐acetyl cysteine (NAC) on testis, cisplatin (CIS, 5 mg kg^?1 bw, single dose) was administered either alone or along with EJE (25 mg kg^?1 bw, alternate day) or NAC (150 mg kg^?1 bw, Day 1 and 4) for 7 days. Significant alterations in serum LH, FSH and testosterone were observed in CIS group which were effectively modulated by EJE or NAC supplementation. Upregulation of 3β‐HSD gene indicated the rise in functional Leydig cells. This was further confirmed from the identical improvement in hCG‐stimulated testosterone production in isolated Leydig cells. Reduction in oxidative stress was associated with restoration of total antioxidant capacity and glutathione levels, and activation of antioxidant enzymes, SOD, catalase, glutathione s‐transferase (GST) and glutathione reductase (GR). CIS‐induced apoptosis of germ and Leydig cells was contained by both NAC and EJE intervention by effective modulation of apoptotic markers in the extrinsic, intrinsic and other pathways of metazoan apoptosis. Taken together, the study findings establish the potential of EJE as a therapeutically better antioxidant than NAC for use in curtailing the adverse effects of anticancer drugs on testicular function.     

Effect of etodolac hydrazone,a new compound synthesised from etodolac,on spermatozoon quality,testicular lipid peroxidation,apoptosis and spermatozoon DNA integrity

The aim of this study was to investigate the effect of etodolac hydrazone (EH), a new compound synthesised from etodolac, on spermatozoon quality, testicular lipid peroxidation, apoptosis and spermatozoon DNA integrity in rats. Group 1 (n = 8) received 1 ml dimethyl sulfoxide (DMSO) daily (Control); group 2 (n = 8) was treated with 5 mg kg^?1 day^?1 EH, dissolved in 1 ml DMSO (EH‐5); and group 3 (n = 8) was treated with 10 mg kg^?1 day^?1 EH, dissolved in 1 ml DMSO (EH‐10). All administrations were performed by gavage and maintained for 8 weeks. Both doses of EH administration caused significant decreases in absolute and relative weights of testis, whole epididymis, right cauda epididymis, and spermatozoon motility, spermatozoon count in comparison with the control group. Only 10 mg kg^?1 day^?1 EH administration caused significant decreases in absolute and relative weights of seminal vesicles and serum testosterone level, and significant increases in testicular lipid peroxidation level, and numbers of TUNEL+ apoptotic germ cells and spermatozoa with damaged DNA along with some histopathological damages when compared to the control group. However, body and ventral prostate weight, and testicular antioxidant markers (glutathione, glutathione‐peroxidase and catalase), were unaffected significantly by both doses of EH administration. In conclusion, two different doses of EH, in particular its high dose, damage to testicular spermatogenic cells and spermatozoon DNA and, it decreases spermatozoon motility, count and testosterone level in healthy rats.     

Rutin ameliorates cisplatin‐induced reproductive damage via suppression of oxidative stress and apoptosis in adult male rats

Cisplatin (CP) treatment causes damage in the male reproductive system. Rutin (RUT) is a naturally occurring flavonoid glycoside that has antioxidant and anti‐inflammatory properties. This study aimed to investigate effects of RUT against cisplatin‐induced reproductive toxicity in male rats. Twenty‐one adult male Sprague Dawley rats were used. The control group received physiological saline with oral gavage during 14 days, and physiological saline was injected intraperitoneally (IP) in 10th days of study. CP Group received physiological saline during 14 days, and 10 mg kg^?1 CP was injected IP in 10th day. RUT + CP group received RUT (150 mg kg^?1) during 14 days, and 10 mg kg^?1 CP was injected IP in 10th day. Spermatological parameters (including motility, cauda epididymal sperm density, dead sperm percentage and morphological sperm abnormalities), biochemical (MDA, GSH, GSH‐px, SOD and CAT), histological (H&E dye) and immunochemistry evaluations of testicles were evaluated. CP treatment caused damage on some spermatological parameters, increased the oxidative stress and induced testicular degeneration and apoptosis when compared to the control group. However, RUT treatment mitigates these side effects when compared to the CP alone group. IT is concluded that RUT treatment may reduce CP‐induced reproductive toxicity as a potential antioxidant compound.     

Quercetin prevents docetaxel‐induced testicular damage in rats

The protective effect of quercetin on docetaxel – an anticancer agent – induced testicular damage in rats was investigated. Thirty‐two rats were randomly divided into four groups: group 1 – control, carrier solutions were given; group 2 – quarcetin 20 mg kg^?1 day^?1 was given orally; group 3 – docetaxel 5 mg kg^?1 was given intraperitoneally as single dose; group 4 – docetaxel and quarcetin were given together. The histopathological changes; the specific biochemical markers, including antioxidants; and the sperm characteristics were evaluated. Docetaxel caused a significant increase in TBARS level and a significant decrease in SOD, GPX, CAT and GSH levels in the testicular tissues compared with the control group, whereas quercetin led to a significant decrease in lipid peroxidation, which was caused by docetaxel, via reducing TBARS level and increasing the levels of SOD, CAT, GPX and GSH. In addition, after docetaxel administration, sperm motility, sperm concentration, testicular and epididymis weights were significantly decreased and abnormal sperm rate and histopathological changes were increased. However, these effects of docetaxel on sperm parameters, histological changes and the tissue weights were eliminated by quercetin treatment. Our results show that the administration of docetaxel induced the testicular damage (oxidative stress, testes tissue damage and sperm parameters), and quercetin prevented docetaxel‐induced testicular damage in rats.