Scholarly article on topic 'Review of Clinical Trials on Effects of Oral Antioxidants on Basic Semen and Other Parameters in Idiopathic Oligoasthenoteratozoospermia'

Review of Clinical Trials on Effects of Oral Antioxidants on Basic Semen and Other Parameters in Idiopathic Oligoasthenoteratozoospermia Academic research paper on "Clinical medicine"

Share paper
Academic journal
BioMed Research International
OECD Field of science

Academic research paper on topic "Review of Clinical Trials on Effects of Oral Antioxidants on Basic Semen and Other Parameters in Idiopathic Oligoasthenoteratozoospermia"

Hindawi Publishing Corporation BioMed Research International Volume 2014, Article ID 426951, 11 pages

Review Article

Review of Clinical Trials on Effects of Oral Antioxidants on Basic Semen and Other Parameters in Idiopathic Oligoasthenoteratozoospermia

Senka Imamovic Kumalic and Bojana Pinter

Reproductive Unit, Division of Gynecology and Obstetrics, University Medical Centre Ljubljana, Slajmerjeva 3,1000 Ljubljana, Slovenia Correspondence should be addressed to Bojana Pinter; Received 31 January 2014; Accepted 14 March 2014; Published 31 March 2014 Academic Editor: Irma Virant-Klun

Copyright © 2014 S. Imamovic Kumalic and B. Pinter. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Infertility affects 50 to 80 million people worldwide. Male factor is a cause of infertility in almost half of cases, mainly due to oligoasthenoteratozoospermia (OAT). With common diagnostic methods no cause can be found in approximately 30% of cases of male infertility due to OAT and these are considered idiopathic. Reactive oxygen species (ROS) play an important role in male infertility and are proved to be higher in infertile men; antioxidants could oppose their effect. The aim of this paper was to review the literature on clinical trials in the period from year 2000 to year 2013 studying the effects of various types of antioxidant supplements on basic and other sperm parameters and pregnancy rates in subfertile males with idiopathic OAT. The majority of studies were randomized and placebo controlled and confirmed beneficial effect of antioxidants on at least one of the semen parameters; the biggest effect was determined on sperm motility. In many of these trials combinations of more antioxidants were assessed. The optimal dosages of one or more antioxidants were not defined. We concluded that antioxidants play an important role in protecting semen from ROS and can improve basic sperm parameters in case of idiopathic OAT.

1. Introduction

Almost 15% of all couples trying to conceive are affected by infertility, and in almost half of these cases male infertility is the sole or a contributing factor [1]. While conditions such as varicocele, cryptorchidism, and hypogonadism are definable causes for infertility, no cause may be determined for an abnormal semen analysis in over 25% of cases [2]. Such idiopathic infertility and oligoasthenoteratospermia (iOATs) is a condition in which sperm concentration, the proportion of motile sperms, and the proportion of morphologically normal sperms are below the World Health Organization (WHO) reference values [3].

Elevated reactive oxygen species (ROS) levels in the semen may be an etiologic factor for male infertility [4]. It is estimated that 25% of infertile men possess high levels of semen ROS, whereas fertile men do not have high levels of semen ROS [5, 6]. ROS are needed for capacitation, the acrosome reaction, and ultimately fertilization [7]. However,

their uncontrolled production is detrimental to cell function as they damage a variety of biomolecules such as lipids, amino acids, carbohydrates, protein, and DNA and adversely affect sperm function [8] due to DNA damage [9, 10], reduced motility [11], and defective membrane integrity [12, 13]. Spermatozoa are particularly susceptible to oxidative injury due to the abundance of plasma membrane polyunsaturated fatty acids. These unsaturated fatty acids provide fluidity that is necessary for membrane fusion events (e.g., the acrosome reaction and sperm-egg interaction) and for sperm motility [14]. The human ejaculate contains a number of potential sources of ROS. These include leukocytes, germ cells, or abnormal sperms [15]. At the same time, a number of cellular molecules called antioxidants, which protect the cell from excessive ROS-induced lipid peroxidation, are also present within the ejaculate [16]. Studies have shown that seminal antioxidant capacity is suppressed in infertile men with high ROS levels compared to men with normal levels of ROS [17, 18].

2. Materials and Methods

We searched PubMed with keywords, including combinations of search terms such as "male infertility" and "antioxidants." We searched for reviews, controlled and randomized controlled clinical studies. From the numerous search results for the period between 1st January 2000 and 31st December 2013, 32 primary studies on idiopathic oligoas-thenoteratozoospermia (OAT) were chosen and their data were gathered in order to provide a complete overview of the literature. Given the different antioxidants used (both alone and in combination), the different dosages, different duration of treatment, and various number of participants (from very small groups to large researches), we looked up for statistical significance of changes in basic sperm parameters and pregnancy rates.

3. Results and Discussion

The review of the studies on antioxidants in clinical studies is illustrated in Table 1.

3.1. Sperm Concentration. Low sperm concentration or oligo-zoospermia is defined as concentration less than 15 x 106 spermatozoa/mL according to WHO reference value from 2010 [51] and less than 20 x 10 spermatozoa/mL according to WHO reference values from 1999 [52], which were considered in most of researches in this review. Many researches showed significant improvements in sperm concentration after oral intake of different antioxidants [19-31]. Most of these researches investigated combination of different antioxidants, like L-carnitine, coenzyme Q10 (CoQ10), vitamin C, vitamin E, zinc (Zn), selenium (Se), and so forth. But there are also some studies that investigated only one type of antioxidant. Safarinejad et al. showed that intake of 200 mg CoQ10 daily for 26 weeks improved sperm concentration in study group (28.7±4.6x 106 spermatozoa/mL) versus placebo group (16.8 ± 4.4 x 106 spermatozoa/mL) (P = 0.005) [23]. After 6 months of intake of combination of 25 mg clomiphene citrate and 400 mg vitamin E per day sperm concentration improvedfrom 10.2x10 ±4.14 spermatozoa/mL to 18x10 ± 15 spermatozoa/mL (P = 0.0025) [26]. There was also significant improvement in sperm concentration from 14.3 ± 7.38 x 106 spermatozoa/mL to 32.8 ± 10.3 x 106 spermatozoa/mL (P < 0.001) after consumption of 1 g of vitamin C twice daily taken for 2 months as proved by Akmal et al. [28].

3.2. Sperm Motility. Asthenozoospermia is defined as less than 40% of motile spermatozoa [51] and according to WHO reference value from 1999 less than 50% of motile spermatozoa [52]. 20 out of 32 studies in our review proved significant improvement in sperm motility after the use of antioxidants [19, 20, 22-39]. Improvement in sperm motility has been shown mostly in researches considering mixture of more antioxidants such as selenium and vitamin E [38, 39]. Most of studies with just one type of antioxidant were about CoQ10 but in different dosages and in different duration of consuming [22-24, 37]. Kumar et al. showed

that consumption of herbal-mineral supplement Addyzoa for 3 months improved total and progressive sperm motility in study group. Total motility improved from 23.2 ± 17.3% before the treatment to 33.4 ± 23.2% after the treatment (P = 0.008). Progressive motility improved from 15.7± 12.6% before treatment to 22.6±18.0% after treatment with Addyzoa (P = 0.024) [33]. Wang et al. showed that L-carnitine in combination with vitamin E taken for 3 months significantly improved forward sperm motility from 28.6% ± 9.2% to 45.4% ± 11.1% (P < 0.01), compared with just vitamin E [35]. After treatment with 200 mg CoQ10 twice daily for 6 months sperm motility improved from 9.13% ± 2.50% before the therapy to 16.34% ± 3.43% after the therapy (P < 0.05) [37].

3.3. Sperm Morphology. WHO reference values from 1999 [52] defined teratozoospermia as less than 14% of normal shape and form spermatozoa according to strict Krager criteria. Although WHO reference values from 2010 define teratozoospermia as less than 4% of normal shape and form spermatozoa [51] strict Krager criteria are still used as reference value for assessing sperm morphology. L-carnitine in combination with CoQ10, vitamins E and C, zinc, selenium [20, 40], CoQ10 alone [23, 24], pentoxifylline [25], N-acetyl-cysteine with Se [27], vitamin C alone [28], combination of papaya, beta-glucan, lactoferrin, vitamins C and E [36], Se, and vitamin E [38], and pycnogenol [41] significantly improved sperm morphology. Therapy with 200 mg CoQ10 daily for 26 weeks improved sperm morphology in 114 participants in study group to 17.6% ±4.4%versus 14.8% ±4.1%in 114 participants in placebo group (P = 0.01) [23]. Safarinejad also showed that intake of 400 mg of pentoxifylline twice daily for 24 weeks of treatment phase significantly improved percentage of sperm with normal morphology to 25.4 ± 4.3% in study group versus 17.4 ± 4.2% in placebo group (P = 0.001) [25]. Combination of 20 mg beta-glucan, 50 mg fermented papaya, 97 mg lactoferrin, 30 mg vitamin C, and 5 mg vitamin E, twice per day for 3 months, improved percentage of morphologically normal sperm in 36 participants from 17.0 ± 5.2% to 29.8 ± 6.5% (P < 0.01) [36].

3.4. Sperm DNA Fragmentation and Chromatin Integrity. ROS can cause sperm DNA damage and integrity of sperm DNA can be measured with DNA fragmentation. The levels of sperm-derived ROS (measured in sperm preparations having minimal leukocyte contamination) have been associated with sperm DNA damage [53]. High level of denatured DNA in spermatozoa with large nuclear vacuole could arise from precocious decondensation and disaggregation of sperm chromatin fibers [54]. Dietary antioxidants may be beneficial in reducing sperm DNA damage, particularly, in men with high levels of DNA fragmentation [5]. Five out of 32 studies confirmed that the usage of different antioxidants had important influence on DNA fragmentation and chromatin integrity [20, 42-46]. Song et al. showed that combination of Chinese medicine Compound Xuanju Capsule with vitamin E taken for 3 months decreased degree of DNA fragmentation index (DFI) after therapy to 29.57 ± 12.19 compared just to

Table 1: Study characteristics and the effect of oral antioxidants on basic and other semen parameters.

Study/author Year Patients/test Number of patients Antioxidant/duration of th. Significant improvement Nonsignificant improvement Negative effect

Wirleitner et al. [19] 2012 OAT versus non-OAT, MSOME 147 Fertilovit Mplus/2-12 months t concentration and motility of sperm Morphology

L-Carnitine 1500 mg;

Abad et al. [20] 2013 AT/DFI, basic sperm parameters 20 vitamin C 60 mg; CoQIO 20 mg; vitamin E10 mg; Zn 10 mg; vitamin B9 200 fig; Se 50 fig; vitamin B1 21 /fg/3 months DNA integrity (P < 0.01), the proportion of DDS I (P < 0.05). T in concentration, motility, vitality, and morphology parameters.

SG: Î of sperm cell total count (from

Safarinejad [21]

SG: eicosapentaenoic 238 (analysis on 211) (EPA) and

SG: 106 docosahexaenoic acids

PG: 105 (DHA), 1.84 g per day

versus PG/32 weeks

P = 0.001) and sperm cell concentration (from

15.6 ± 4.1 x 106/mL to

28.7 ± 4.4 x 106/mL, P = 0.001). Seminal plasma EPA and DHA conc. were positively correlated with seminal plasma SOD-like and catalase-like activity (both

P = 0.001).

In seminal plasma, both SOD-like and catalase-like activity were positively correlated with sperm count, sperm motility, and sperm morphology.

SG: T in sperm density and motility

iOAT/semen analyses, (each P = 0.01). | FSH and LH at the

AR, immunobead test for 26-week treatment phase (each

antisperm antibody and 212 CoQIO 300 mg/26 weeks P = 0.03). By the end of the

Safarinejad [22] 2009 determination of resting (SG: 106, versus PG: followed by a 30-week treatment phase the mean AR had

levels of LH, FSH, 106) treatment-free phase increased from 14% ± 8% and

prolactin, testosterone, 15% ± 8% to 31% ± 11% and

and inhibin B 16% ± 10% in the CoQIO and placebo groups, respectively (P = 0.01).

Safarinejad et al. [23] 2012

iOAT/semen parameters, 228

seminal plasma TAC, SG: 114

FSH, and inhibin B PG: 114

CoQIO 200 mg/day/26 weeks

SG: T in sperm density (28.7 ± 4.6 x 106/mL versus 16.8 ± 4.4 x 106/mL (P = 0.005)), sperm motility (35.8% ± 2.7% versus 25.4% ± 2.1% (P = 0.008)), and sperm morphology (17.6% ± 4.4% versus 14.8% ± 4.1% (P = 0.01)). FSH l(P = 0.02), inhibin B T (P = 0.01)

Study/author Year Patients/test Number of patients Antioxidant/duration of th. Significant improvement Nonsignificant improvement Negative effect

Safarinejad [24] 2012 iOAT/semen parameters and pregnancy rates 287 CoQIO 300 mg orally twice daily/12 months Mean sperm conc., sperm progressive motility, and sperm with normal morphology improved by 113.7,104.8, and 78.9%, respectively (all P < 0.05). The overall spontaneous pregnancy rate was 34.1% within a mean of 8.4 ± 4.7 months.

iOAT/semen parameters,

testosterone, LH, FSH, 254

Safarinejad [25] 2011 and inhibin B, seminal (SG:127,

plasma SOD-like activity, PG: 127) and acrosome reaction

SG: PTX (pentoxifylline) 400 mg twice daily/4-week screening phase, a 24-week treatment phase, and a 12-week treatment-free period

SG after PTX: ] sperm conc. (mean value, from 26.4 ± 4.6 x 106/mL to

16.2 ± 3.4 x 106/mL), sperm motility (mean value, from 35.8 ± 4.2% to 26.4 ± 2.4%), and sperm with normal morphology (mean value, from

25.4 ± 4.3% to 17.4 ± 4.2%) (all P = 0.001); mean SOD-like and catalase-like activity f than in the semen of PG (46.4 ± 2.4 versus

36.3 ± 1.3 U/mL and 371 ± 44 versus 301 ± 14 U/mL, respectively, both

P = 0.003). The AR was observed to be T in PTX group (P = 0.01)._

Ghanem et al. [26]

iOA/basic semen 2010 parameters, pregnancy incidence

SG: 30 PG: 30

Clomiphene citrate 25 mg/day + vit. E 400 mg/day/6 months

SG: sperm conc.: 10.2x10° ±4.14 -18 x 106 ± 15(P = 0.0025); progressive motility: 4% ± 6 -> 7% ±10 (P = 0.0286). Spontaneous pregnancy incidence, SG: 36.7%,versus PG: 13.3% (P = 0.037)

M. R. Safarinejad and S. Safarinejad [27]

iOAT/serum T estradiol, FSH, LH, prolactin, inhibin B, Se, and N-acetyl-cysteine. Semen analysis, seminal plasma Se, and N-acetyl-cysteine.

SG 1: Se 200 ftg/day 468 SG 2: N-acetyl-cysteine

SG 1:116 600 mg/day

SG 2:118 SG 3: Se 200 fig +

SG 3:116 N-acet-cys 600 mg/day/26

PG: 118 weeks ± 30-week

treatment-free period

A strong correlation was observed between the sum of the Se and N-acetyl-cysteine concentrations, and mean sperm concentration (r = 0.67, P = 0.01), sperm motility (r = 0.64, P = 0.01), and percent normal morphology (r = 0.66, P = 0.01).

Se + N-ac-cy.: | FSH, î T, inhibin B



.. , r .. . Antioxidant/duration of Number or patients ^

Significant improvement

Nonsignificant improvement

Negative effect

Akmal et al. [28]

O/semen parameters

vitamin C1 g twice daily/2 months

Mean sperm count: 14.3 ± 7.38 x 10 sperms/mL to 32.8 ± 10.3 x 106 sperms/mL (P < 0.001), mean sperm motility: 31.2 ±9.61% to 60.1 ± 8.47% (P < 0.001), and mean sperms with normal morphology: 43 ± 7.87% to 66.7 ± 4.77% (P < 0.001).

Shi et al. [29]

OA/seminal routine analysis

Xinxibao (Zn and Se tablets) three times a 34 day/90 days + five tablets

at a time for 90 days in succession

The sperm quality was improved 60 days and 90 days after treatment. 5 cases (14.7%) showed remarkable effect, 25 (73.5%) improved.

4 cases (11.8%) did not respond.

O and A versus SG: total sperm conc. (17.1 ± 20.0 to After th. serum hormones

normozoospermia/sperm 28.7 ± 35.5 x 106/mL, P = 0.02) and and SOD activity did not

parameters, serum SG: 47 CG: 16 sperm motility (30.1% ± 21.6 to change significantly in

Suzuki et al. [30] 2003 hormones, and SOD Sairei-to 9 g/day/3 months 45.8% ± 24.4, P < 0.0001) and the either group.

activity in the serum and pulsatility index of the testicular CG: no significant change

the seminal plasma + the artery I (2.03 ± 0.84 to 1.64 ± 0.48, in sperm conditions or

testicular artery P = 0.04) testicular artery flow.

Gupta and Kumar [31] 2002

Idiopathic nonobstructive O/A/T spermia/semen analysis

Lycopene 2000 meg, twice a day/3 months

20 patients (66%): T sperm conc., 16 (53%) T motility. The median change in concentration was 22 million/mL, motility 25%. Higher baseline concentrations (more than 5 million/mL) were associated with significant improvement and resulted in six spontaneous pregnancies in 26 patients (23%).

14 patients (46%) f in sperm morphology (median change 10%). Baseline sperm concentration less than 5 million/mL was associated with no significant improvement.

Busetto et al. [32]

Idiopathic AT/basic sperm parameters

114 (96 finished)

L-Carnitine 145 mg, acetyl-L-carnitine 64 mg, fructose 250 mg, citric acid 50 mg, Se 50 fig, CoQIO 20 mg, Zn 10 mg, ascorbic acid 90 mg, cyanocobalamin 1.5 fig, and folic acid 200 meg once a day/4 months

t Mean sperm progressive motility: 18.3 ± 3.8 to 42.1 ± 5.5, 16 patients achieved pregnancy during the study.

Concentration and morphology



Number of patients

Antioxidant/duration of th.

Significant improvement

Nonsignificant improvement

Negative effect

Kumar et al. [33]

At least one parameter of

OAT/basic semen parameters, ROS, TAC, and DPI (SCSA)

SG: 21 PG: 23

herbal-mineral supplement Addyzoa/3 months

SG: total motility:

23.2 ± 17.3% -> 33.4 ± 23.2%

(P = 0.008)

Progressive motility:

15.7 ± 12.6% -> 22.6 ± 18.0%

(P = 0.024)

Chen et al. [34]

O, A/sperm concentration and % of progressively motile sperm, the rate of clinical pregnancy

Oligosp: 64

(SG: 33 + CG: 31)

Astheno: 42 (SG: 22 + CG: 20)

Oligospermia: CG: tamoxifen 10 mg bid SG: tamoxifen 10 mg bid + vit. E100 mg tid Asthenospermia: CG: levocarnitine oral solution 1 bottle bid SG: levocarnitine oral solution 1 bottle bid + vit. E 100 mg tid/3 months

Oligospermia: the number of spontaneous pregnancies after th. were CG: 0, and SG: 6 (P < 0.01). Asthenospermia: after th. the numbers of cases evaluated as with no or slight improvement in the % of progressively motile sperm were 7 and 2 (P < 0.01), 4 and 8 (P < 0.01), and the number of spontaneous pregnancies CG: 5, and SG: 9 (P < 0.01).

Asthenosperm: after th, the number of cases evaluated as with moderate or marked improvement in the percentage of progressively motile sperm was 3 and 2 (P > 0.05) and 1 and 1 (P > 0.05)

Wang et al. [35]

2010 A/basic sperm parameters

Group A (n = 68) and B (n = 67)

Group A: L-carnitine 2 g/day + vitamin E Group B: vitamin E/3 months

SG: beta-glucan 20 mg, fermented papaya 50 mg, lactoferrin 97 mg, vit. C 30 mg, and vit. E 5 mg, twice per day/3 months

Group A: T % of forward motile sperm (28.6% ± 9.2% to 45.4% ± 11.1%, P < 0.01), the rate of spontaneous pregnancy f (31.1%) than in group B (3.8%) after the treatment (P < 0.01).

Group A: sperm density and the % of the sperm of normal morphology (P > 0.05).

Piomboni et al. [36]

AT + leukocytosis/sperm 2008 parameters, DNA damage (acridine orange)

51 (SG: 36 + CG: 15)

SG: % of morphologically normal sperm (17.0 ± 5.2 to 29.8 ± 6.5) and total progressive motility (19.0 ± 7.8 to 34.8 ± 6.8), J. in leukocyte conc. (2.2 ± 0.9 to 0.9 ± 0.2), all P < 0.01

Structural sperm characteristics as well as chromatin integrity were also improved after treatment.

Balercia et al. [37]

iA (WHO 1999)/basic sperm parameters, 2004 seminal plasma and sperm CoQIO, and phosphatidylcholine (PC)

CoQIO 200 mg 2x/day/6 months

CoQIO sem. plasma (ng/mL: 42.0 ± 5.1 to 127.1 ± 1.9 (P < 0.005)) CoQIO sperm cells (ng/106 cells): 3.1 ± 0.4 to 6.5 ± 0.3 (P < 0.05) PC sem. plasma (/iM): 1.49 ± 0.50 to 5.84 ± 1.15 (P < 0.05) PC sperm cells (nmol/106 cells): 6.83 ± 0.98 to 9.67 ± 1.23 (P < 0.05) Sperm cell motility 9.13 ± 2.50% to 16.34 ± 3.43% after th. (P < 0.05)

Sperm conc. and sperm morphology



Number of patients

Antioxidant/duration of th.

Significant improvement

Nonsignificant improvement

Negative effect

Moslemi and Tavanbakhsh [38]

iAT/semen parameters and pregnancy rates

690 (analysis on 525)

Se 200 /ig + vitamin E 400 units/min. 100 days

52.6% (362 cases) total improvement in sperm motility morphology, or both and 10.8% (75 cases) spontaneous pregnancy versus no treatment (95% confidence interval): 3.08 to 5.52; P< 0.001

No response to treatment occurred in 253 cases (36.6%)

Keskes-Ammar et al. [39]

Infertile men/basic sperm 2003 parameters, MDA, and serum vitamin E level.

SG: 28 (20 analyzed) CG: 26

SG: vitamin E 400 mg + Se 225 /.fg/day

CG: vitamin B 4.5 g/day/3 months

SG: J. in MDA concentrations and an t of sperm motility

Cavallini et al. [40]

Idiopathic OAT/basic 2012 sperm parameters and aneuploidy (FISH)

55 (analysis on 33: 22

responder—group 1 + 11

nonresponder— group 2)

L-carnitine 1 g given twice per day +

acetyl-L-carnitine 500 mg given twice per day + one 30 mg cinnoxicam tablet every 4 days/3 months

Group 1 versus group 2: improvement in morphology and number of aneuploid spermatozoa (P < 0.01); f % of biochemical pregnancy after ICSI (54.4% versus 9.1%, P < 0.01), clinical pregnancy after ICSI (50% versus 9.1%, P < 0.01), and live births (45.4% versus 9.1%, P < 0.01)

Numbers of oocytes fertilized and embryos transferred

Roseff [41]

Subfertile/basic sperm parameters before and after capacitation and mannose receptor binding

Pycnogenol 200 mg daily orally/90 days

The mean sperm morphology following Ham's F-10 capacitation f by 38% following th. (P < 0.001) and the mannose receptor binding assay scores improved by 19% (P < 0.005)

Baseline morphology Î after th. by 33%

The mean % change from baseline sperm count after th J. nonsignificantly by

Idiopathic OA/basic Song et al. [42] 2012 sperm parameters, DFI


SG: 24 CG: 26

SG: vit. E + xuanju caps CG: vit. E/3 months

SG versus CG: J. DFI after th.: 29.57 ± 12.19 versus 34.09 ± 10.32, P < 0.05

Ménézo et al. [43]

At least TWO pervious failures IVF or ICSI, DFI 2007 >15%/DFI and the degree of sperm decondensation (SCSA)

Vitamins C and E 400 mg each, ß-carotene 18 mg, Zn 500 /imol, and Se 1 /imol/90 days

J.DNA fragmentation: P < 0.0004


t in sperm decondensation (+22.8%, P < 0.0009).

Greco et al. [44]

TUNEL >15%/basic sperm parameters, TUNEL

38 (26 OAT + 6 OT + 6 normal)

Vit. C 1 g + vit. E 1 g/2 months

TUNEL positive sperm: 24.0 ± 7.9 to 8.2 + 4.3 (P < 0.001) Clinical pregnancy after ICSI: from 6.9% to 48.2% (P < 0.05) Implantation rate after ICSI: from 2.2% to 19.6% (P < 0.01)

Sperm conc: 17.9 ± 16.3 to 18.3 ± 17.9

Sperm motil.: 40.6 ± 24.8 to 39.9 ± 19.0 Normal sperm morph.: 10.5 ± 8.3 to 9.6 ± 0.4, all P > 0.05

Study/author Year Patients/test Number of patients Antioxidant/duration of th. Significant improvement Nonsignificant improvement Negative effect

Greco et al. [45] 2005 TUNEL >15%/basic sperm parameters, TUNEL SG: 32 PG: 32 Vit. Clg + vit. Elg/2 months SG: | fragm. DNA: 22.1 ± 7.7 -> 9.1 ± 7.2 (P < 0.001) PG: TUNEL: 22.4 ± 7.8 -> 22.9 ± 7.9

Raigani et al. [46] 2013 OAT/sperm quality, sperm mitochondrial function, sperm chromatin status, semen and blood folate, zinc, B12, TAC, and MDA concentr. 83 Folic acid 5 mg/day ± Zn sulphate 220 mg/day versus placebo/16 weeks Sperm chromatin integrity (%) f in group receiving only Zn sulphate treatment (P = 0.048) Sperm conc. f in group receiving the combined th. of folic acid and Zn sulphate and also in the group receiving only folic acid th.; (P = 0.056 and

P = 0.05, respectively).

Tremellen et al. [47] 2007 Male factor infertility, TUNEL >25%/embryo quality, pregnancy and fertilization rate after IVF-ICSI SG: 36 PG: 16 Menevit (likopen, vit. C, vit. E, Zn, Se, folate, and garlic)/3 months Pregnancy rate after ICSI in SG: 38.5%, versus PG: 16% (P = 0.046)

Safarinejad et al. [48] 2011 iOAT/semen parameters and TAC of seminal plasma 260 (SG: 130, PG: 130) Saffron 60 mg/day/26 weeks No statistically significant improvements in either group in any of the studied semen parameters

Nadjarzadeh et al. [49] 2011 iOAT/basic sperm parameters, TAC 47 CoQIO 200 mg/day/12 weeks versus placebo SG: T TAC (P < 0.05) Semen parameters of CoQIO group

Comhaire et al. [50] 2000 Infertile men/sperm characteristics, ROS, fatty acids of sperm membrane phospholipids, sperm oxidized DNA (8-OH-dG), and induced AR 27 N-acetyl-cysteine or vitamins A + E and essential fatty acids | ROS, T AR No improvement in sperm motility and morphology or J. of round cells and white blood cells in semen. Sperm concentration f in oligozoosp. men (7.4 ± 1.3 to 12.5 ± 1.9 million/mL).

Legend: Addyzoa: Gokshura (Tribuhis terrestris) 200 mg, Ashtavarga 200 mg, Guduchi (Tinospora cordifolia) 150 mg, Ashwagandha (Withania Somnifera) 150 mg, Amalaki (Emblica officinalis) 75 mg, Balamool (Sida cordifolia) 75 mg, Vridhadharu (Argyreia speciosa) 75 mg, Shatavari (Asparagus racemosus) 75 mg, Shwet musli (Chlorophytitm arundinaceum) 150 mg, Shuddha kapikachchhu (Purified Mucima pruriens) 150 mg, Varahikand (Tacca aspera) 30 mg, Chopchin (Smilax china) 30 mg, Vidarikand (Ipomoea digitata) 30 mg, Munjatak (Eitlophia campestris) 15 mg, Purnachandrodaya rasa 45 mg, Suvarnavang 30 mg, td Muktashukti bhasma 30 mg, Suvarnamakshik bhasma 30 mg, Shilajit shuddha 30 mg, Abhrak bhasma 15 mg, Makardhwaj rasa 15 mg, Rasa sindur 5 mg; AR: acrosome reaction; CG: control group; DDS: DNA degraded sperm; DPI: DNA fragmentation index; Fertilovit Mplus: L-citrulline (20.2 %), L-carnitine-L-tartrate, D-alpha-tocopheryl acetate, hydroxypropyl methylcellulose (capsule coating), acidifier tartaric acid, J^ L-ascorbic acid (6.7%), parting compound silicon dioxide, calcium carbonate, lycopene, N-acetyl-L-cysteine, glutathione (reduced), corn starch, zinc oxide, coenzyme Q10, vegetable oil, shellac coating, pteroyl-L-glutamate, sodium selenite, coloring agent titanium dioxide (capsule), coloring agent orange yellow S (capsule); CoQIO: coencyme Q10, FISH: fluorescent in situ hybridization; FSH: follicle-stimulating hormone; f? ICSI: intracytoplasmic sperm injection; iOAT: idiopathic OAT; IVF: in vitro fertilization; LH: luteinizing hormone; MDA: malondialdehyde; MSOME: motile sperm organelle morphology examination; OAT: g> oligoasthenoteratozoospermia; PG: placebo group; ROS: reactive oxygen species; Sairei-to: a Chinese herbal drug; SCSA: sperm chromatin structure assay; Se: selenium; SG: study group; T: testosterone; TAC: total ^ antioxidant capacity; TUNEL: TdT (terminal deoxyribonucleotidyl transferase)—mediated dUTP nick-end labeling; Xuanju: Formica fttsca, Herba epimedii, Fructus cnidii, and Frticttis lycii; Zn: zinc.

vitamin E with degree of DFI of 34.09 ±10.32 (P < 0.05) [42]. Greco et al. [44,45] had proved that 1 g of vitamin C and 1 g of vitamin E together taken for 2 months significantly decreased the degree of DNA fragmentation from 22.1 ± 7.7 to 9.1 ± 7.2 (P < 0.001) [45]. Raigani et al. showed that zinc sulphate significantly improved sperm chromatin integrity [46].

3.5. Pregnancy Rate. CoQ10 [24], clomiphene citrate with vitamin E [26], lycopene [31], L-carnitine with vitamin E [34, 35], and selenium with vitamin E [38] significantly improved spontaneous pregnancy rates during duration of treatment, while L-carnitine with cinnoxicam [40] and vitamins C and E together [44] significantly improved pregnancy rates per cycle after assisted reproductive technology with intracyto-plasmic sperm injection (ICSI). Ghanem et al. proved higher spontaneous pregnancy rate in 30 participants after the intake of combination of 25 mg clomiphene citrate and 400 mg vitamin E per dayfor 6 months (36.7%) than in placebo group (13.3%) with P = 0.037 [26]. L-Carnitine, 2 g, with vitamin E taken for 3 months improved spontaneous pregnancy rate to 31.1% compared to vitamin E group with pregnancy rate of 3.8% (P < 0.01) [35]. Another example in study by Greco et al. confirmed higher pregnancy rate after 2 months therapy with 1 g of vitamin C and 1 g of vitamin E daily. After ICSI clinical pregnancy rate was 48.2% after therapy versus 6.9% before therapy (P < 0.05) [44].

3.6. Negative or No Effect on Sperm Parameters. In this review we find out also rare negative effects of antioxidants on sperm parameters or no effect. Pycnogenol caused nonsignificant fall in baseline sperm count by 10% [41]. Similarly, treatment with vitamins C and E, fi-carotene, zinc, and selenium significantly increased sperm decondensation [43]. Large research on saffron showed no statistically significant improvements in any of the studied semen parameters [48].

3.7. Other Parameters. We looked at the basic sperm parameters but there were also many other positive influences; for example, CoQ10 and pentoxifylline caused improvements in total antioxidant capacity and acrosome reaction [22, 25, 49, 50]; FSH value [22, 23] decreased after CoQ10 treatment, semen leucocyte concentration decreased [36], and level of ROS [50] decreased after antioxidant mixtures. Antioxidants protect unsaturated fatty acids and so provide fluidity that is necessary for membrane fusion events like the acrosome reaction. Although hormonal abnormalities are not always evident, iOAT is sometimes associated with lower serum testosterone and inhibin levels and higher serum estradiol, LH, and FSH levels [55,56]. The increased serum FSH level in men with azoospermia or severe oligozoospermia indicates damaged seminiferous tubule [57] and is inversely associated with sperm concentration, motility, and morphology [58]. ROS has been found in the seminiferous tubules and seminal plasma of most patients with iOAT [59]. Decreased levels of ROS due to antioxidant consumption can cause fall in serum FSH level. Leukocytes are potential source of ROS and due to protective influence of antioxidants their concentration may decrease [15]. In addition, studies have found an increase in

inhibin B value [23] and in superoxide-dismutase- (SOD-) like and catalase activity [21, 25], which among others represent the total antioxidant capacity of seminal plasma [60]. Inhibin B in positively correlated with sperm concentration and is, like FSH, thought to be a marker of spermatogenesis and Sertoli cell function [61, 62].

4. Conclusions

Most of the published studies were randomized and placebo controlled. The majority of studies confirmed beneficial effect of different antioxidants on at least one of the semen parameters and the biggest effect was determined on sperm motility. In many of these trials combinations of more antioxidants were assessed. The optimal dosages of one or more antioxidants were not defined.

Most commonly antioxidants studied were vitamin E, vitamin C, selenium, CoQ10, N-acetyl-cysteine, L-carnitine, and zinc and their favorable effect was confirmed. According to this review favorable effects on iOAT have been determined with CoQ10, vitamin E, selenium, and also vitamin C and N-acetyl-cysteine treatments. In case of oligozoospermia vitamin E and CoQ10 were most often proved to be effective. Favorable effects on asthenozoospermia have most often been determined with vitamin E, CoQ10, and selenium treatments. In teratozoospermia selenium and CoQ10 treatments were most often proved to be effective. In addition, combination of vitamin C and E showed the biggest favorable effect on DNA fragmentation; similar effects were determined with zinc and selenium treatments.

In conclusion, antioxidants play an important role in protecting semen from ROS and can improve basic sperm parameters in case of idiopathic oligoasthenoteratozoosper-mia.

Conflict of Interests

The authors declare that they have no conflict of interests regarding the publication of this paper.


[1] I. D. Sharlip, J. P. Jarow, A. M. Belker et al., "Best practice policies for male infertility," Fertility and Sterility, vol. 77, no. 5, pp. 873882, 2002.

[2] F. M. Siddiq and M. Sigman, "A new look at the medical management of infertility," Urologic Clinics of North America, vol. 29, no. 4, pp. 949-963, 2002.

[3] T. G. Cooper, E. Noonan, S. von Eckardstein et al., "World Health Organization reference values for human semen characteristics," Human Reproduction Update, vol. 16, no. 3, Article ID dmp048, pp. 231-245, 2009.

[4] N. Desai, R. Sharma, K. Makker, E. Sabanegh, and A. Agarwal, "Physiologic and pathologic levels of reactive oxygen species in neat semen of infertile men," Fertility and Sterility, vol. 92, no. 5, pp. 1626-1631, 2009.

[5] A. Zini, M. San Gabriel, and A. Baazeem, "Antioxidants and sperm DNA damage: a clinical perspective," Journal of Assisted Reproduction and Genetics, vol. 26, no. 8, pp. 427-432, 2009.

[6] A. Agarwal, K. P. Nallella, S. S. R. Allamaneni, and T. M. Said, "Role of antioxidants in treatment of male infertility: an overview of the literature," Reproductive BioMedicine Online, vol. 8, no. 6, pp. 616-627, 2004.

[7] J. F. Griveau and D. Le Lannou, "Reactive oxygen species and human spermatozoa: physiology and pathology," International Journal of Andrology, vol. 20, no. 2, pp. 61-69,1997.

[8] J. Rivlin, J. Mendel, S. Rubinstein, N. Etkovitz, and H. Breitbart, "Role of hydrogen peroxide in sperm capacitation and acro-some reaction," Biology of Reproduction, vol. 70, no. 2, pp. 518522, 2004.

[9] S. Lopes, A. Jurisicova, J.-G. Sun, and R. F. Casper, "Reactive oxygen species: potential cause for DNA fragmentation in human spermatozoa," Human Reproduction, vol. 13, no. 4, pp. 896-900, 1998.

[10] R. J. Aitken, G. N. De Iuliis, J. M. Finnie, A. Hedges, and R. I. McLachlan, "Analysis of the relationships between oxidative stress, DNA damage and sperm vitality in a patient population: development of diagnostic criteria," Human Reproduction, vol. 25, no. 10, pp. 2415-2426, 2010.

[11] S.-H. Kao, H.-T. Chao, H.-W. Chen, T. I. S. Hwang, T.-L. Liao, and Y.-H. Wei, "Increase of oxidative stress in human sperm with lower motility," Fertility and Sterility, vol. 89, no. 5, pp. 11831190, 2008.

[12] R. J. Aitken, J. S. Clarkson, and S. Fishel, "Generation of reactive oxygen species, lipid peroxidation, and human sperm function," Biology of Reproduction, vol. 41, no. 1, pp. 183-197,1989.

[13] A. Agarwal, R. A. Saleh, and M. A. Bedaiwy, "Role of reactive oxygen species in the pathophysiology of human reproduction," Fertility and Sterility, vol. 79, no. 4, pp. 829-843, 2003.

[14] A. Zini and N. Al-Hathal, "Antioxidant therapy in male infertility: fact or fiction?" Asian Journal of Andrology, vol. 13, no. 3, pp. 374-381, 2011.

[15] J. G. Alvarez, J. C. Touchstone, L. Blasco, and B. T. Storey, "Spontaneous lipid peroxidation and production of hydrogen peroxide and superoxide in human spermatozoa. Superoxide dismutase as major enzyme protectant against oxygen toxicity," Journal of Andrology, vol. 8, no. 5, pp. 338-348,1987.

[16] R. K. Sharma and A. Agarwal, "Role of reactive oxygen species in male infertility," Urology, vol. 48, no. 6, pp. 835-850,1996.

[17] R. Smith, D. Vantman, J. Ponce, J. Escobar, and E. Lissi, "Total antioxidant capacity of human seminal plasma," Human Reproduction, vol. 11, no. 8, pp. 1655-1660,1996.

[18] P. P. Pahune, A. R. Choudhari, and P. A. Muley, "The total antioxidant power ofsemen and its correlation with the fertility potential of human male subjects," Journal of Clinical and Diagnostic Research, vol. 7, no. 6, pp. 991-995, 2013.

[19] B. Wirleitner, P. Vanderzwalmen, A. Stecher et al., "Dietary supplementation of antioxidants improves semen quality of IVF patients in terms of motility, sperm count, and nuclear vacuolization," International Journal for Vitamin and Nutrition Research, vol. 82, no. 6, pp. 391-398, 2012.

[20] C. Abad, M. J. Amengual, J. Gosalvez et al., "Effects of oral antioxidant treatment upon the dynamics of human sperm DNA fragmentation and subpopulations of sperm with highly degraded DNA," Andrologia, vol. 45, no. 3, pp. 211-216, 2013.

[21] M. R. Safarinejad, "Effect of omega-3 polyunsaturated fatty acid supplementation on semen profile and enzymatic anti-oxidant capacity of seminal plasma in infertile men with idiopathic oligoasthenoteratospermia: a double-blind, placebo-controlled, randomised study," Andrologia, vol. 43, no. 1, pp. 38-47, 2011.

[22] M. R. Safarinejad, "Efficacy of coenzyme Q10 on semen parameters, sperm function and reproductive hormones in infertile men," Journal of Urology, vol. 182, no. 1, pp. 237-248, 2009.

[23] M. R. Safarinejad, S. Safarinejad, N. Shafiei, and S. Safarinejad, "Effects of the reduced form of coenzyme Q10 (ubiquinol) on semen parameters in men with idiopathic infertility: a double-blind, placebo controlled, randomized study," Journal of Urology, vol. 188, no. 2, pp. 526-531, 2012.

[24] M. R. Safarinejad, "The effect of coenzyme Q10 supplementation on partner pregnancy rate in infertile men with idio-pathic oligoasthenoteratozoospermia: an open-label prospective study," International Urology and Nephrology, vol. 44, no. 3, pp. 689-700, 2012.

[25] M. R. Safarinejad, "Effect of pentoxifylline on semen parameters, reproductive hormones, and seminal plasma antioxidant capacity in men with idiopathic infertility: a randomized double-blind placebo-controlled study," International Urology and Nephrology, vol. 43, no. 2, pp. 315-328, 2011.

[26] H. Ghanem, O. Shaeer, and A. El-Segini, "Combination clomiphene citrate and antioxidant therapy for idiopathic male infertility: a randomized controlled trial," Fertility and Sterility, vol. 93, no. 7, pp. 2232-2235, 2010.

[27] M. R. Safarinejad and S. Safarinejad, "Efficacy of selenium and/or N-Acetyl-Cysteine for improving semen parameters in infertile men: a double-blind, placebo controlled, randomized study," Journal of Urology, vol. 181, no. 2, pp. 741-751, 2009.

[28] M. Akmal, J. Q. Qadri, N. S. Al-Waili, S. Thangal, A. Haq, and K. Y. Saloom, "Improvement in human semen quality after oral supplementation of vitamin C," Journal of Medicinal Food, vol. 9, no. 3, pp. 440-442, 2006.

[29] Y. Shi, Y. Huang, X. Shang, P. Zhu, and G. Liu, "Effects of xinxibao on sperm quality in oligoasthenozoospermic men," Zhonghua Nan Ke Xue, vol. 10, no. 10, pp. 758-760, 2004.

[30] M. Suzuki, T. Kurabayashi, Y. Yamamoto, K. Fujita, and K. Tanaka, "Effects of antioxidant treatment in oligozoospermic and asthenozoospermic men," Journal ofReproductiveMedicine for the Obstetrician and Gynecologist, vol. 48, no. 9, pp. 707-712, 2003.

[31] N. P. Gupta and R. Kumar, "Lycopene therapy in idiopathic male infertility—a preliminary report," International Urology and Nephrology, vol. 34, no. 3, pp. 369-372, 2002.

[32] G. M. Busetto, A. Koverech, M. Messano, G. Antonini, E. De Berardinis, and V. Gentile, "Prospective open-label study on the efficacy and tolerability of a combination of nutritional supplements in primary infertile patients with idiopathic astenoter-atozoospermia," Archivio Italiano Di Urologia, Andrologia, vol. 84, no. 3, pp. 137-140, 2012.

[33] R. Kumar, V. Saxena, M. B. Shamsi, S. Venkatesh, and R. Dada, "Herbo-mineral supplementation in men with idio-pathic oligoasthenoteratospermia: a double blind randomized placebo-controlled trial," Indian Journal of Urology, vol. 27, no. 3, pp. 357-362, 2011.

[34] X. F. Chen, Z. Li, P. Ping, J. C. Dai, F. B. Zhang, and X. J. Shang, "Efficacy of natural vitamin E on oligospermia and asthenosper-mia: a prospective multi-centered randomized controlled study of 106 cases," Zhonghua Nan KeXue, vol. 18, no. 5, pp. 428-431, 2012.

[35] Y.-X. Wang, S.-W. Yang, C.-B. Qu et al., "L-carnitine: safe and effective for asthenozoospermia," Zhonghua Nan Ke Xue, vol. 16, no. 5, pp. 420-422, 2010.

[36] P. Piomboni, L. Gambera, F. Serafini, G. Campanella, G. Morgante, and V. De Leo, "Sperm quality improvement after

natural anti-oxidant treatment of asthenoteratospermic men with leukocytospermia," Asian Journal of Andrology, vol. 10, no. 2, pp. 201-206, 2008.

[37] G. Balercia, F. Mosca, F. Mantero et al., "Coenzyme Q10 supplementation in infertile men with idiopathic asthenozoospermia: an open, uncontrolled pilot study," Fertility and Sterility, vol. 81, no. 1, pp. 93-98, 2004.

[38] M. K. Moslemi and S. Tavanbakhsh, "Selenium-vitamin E supplementation in infertile men: effects on semen parameters and pregnancy rate," International Journal of General Medicine, vol. 4, pp. 99-104, 2011.

[39] L. Keskes-Ammar, N. Feki-Chakroun, T. Rebai et al., "Sperm oxidative stress and the effect of an oral vitamin e and selenium supplement on semen quality in infertile men," Systems Biology in Reproductive Medicine, vol. 49, no. 2, pp. 83-94, 2003.

[40] G. Cavallini, M. C. Magli, A. Crippa, A. P. Ferraretti, and L. Gianaroli, "Reduction in sperm aneuploidy levels in severe oligoasthenoteratospermic patients after medical therapy: a preliminary report," Asian Journal of Andrology, vol. 14, no. 4, pp. 591-598, 2012.

[41] S. J. Roseff, "Improvement in sperm quality and function with French maritime pine tree bark extract," Journal of Reproductive Medicine for the Obstetrician and Gynecologist, vol. 47, no. 10, pp. 821-824, 2002.

[42] B. Song, X. J. He, H. H. Jiang, Y. W. Peng, H. Wu, and Y. X. Cao, "Compound Xuanju Capsule combined with vitamin E improves sperm chromatin integrity," Zhonghua Nan Ke Xue, vol. 18, no. 12, pp. 1105-1107, 2012 (Chinese).

[43] Y. J. R. Menezo, A. Hazout, G. Panteix et al., "Antioxidants to reduce sperm DNA fragmentation: an unexpected adverse effect," Reproductive BioMedicine Online, vol. 14, no. 4, article 2669, pp. 418-421, 2007.

[44] E. Greco, S. Romano, M. Iacobelli et al., "ICSI in cases of sperm DNA damage: beneficial effect of oral antioxidant treatment," Human Reproduction, vol. 20, no. 9, pp. 2590-2594, 2005.

[45] E. Greco, M. Iacobelli, L. Rienzi, F. Ubaldi, S. Ferrero, and J. Tesarik, "Reduction of the incidence of sperm DNA fragmentation by oral antioxidant treatment," Journal of Andrology, vol. 26, no. 3, pp. 349-353, 2005.

[46] M. Raigani, B. Yaghmaei, N. Amirjannti et al., "The micronutri-ent supplements, zinc sulphate and folic acid, did not ameliorate sperm functional parameters in oligoasthenoteratozoospermic men," Andrologia, 2013.

[47] K. Tremellen, G. Miari, D. Froiland, and J. Thompson, "A randomised control trial examining the effect of an antioxidant (Menevit) on pregnancy outcome during IVF-ICSI treatment," Australian and New Zealand Journal of Obstetrics and Gynaecology, vol. 47, no. 3, pp. 216-221, 2007.

[48] M. R. Safarinejad, N. Shafiei, and S. Safarinejad, "A prospective double-blind randomized placebo-controlled study of the effect of saffron (Crocus sativus Linn.) on semen parameters and seminal plasma antioxidant capacity in infertile men with idiopathic oligoasthenoteratozoospermia," Phytotherapy Research, vol. 25, no. 4, pp. 508-516, 2011.

[49] A. Nadjarzadeh, M. R. Sadeghi, N. Amirjannati et al., "Coenzyme Q10 improves seminal oxidative defense but does not affect on semen parameters in idiopathic oligoasthenoterato-zoospermia: a randomized double-blind, placebo controlled trial," Journal of Endocrinological Investigation, vol. 34, no. 8, pp. e224-e228, 2011.

[50] F. H. Comhaire, A. B. Christophe, A. A. Zalata, W. S. Dhooge, A. M. A. Mahmoud, and C. E. Depuydt, "The effects of combined

conventional treatment, oral antioxidants and essential fatty acids on sperm biology in subfertile men," Prostaglandins Leukotrienes and Essential Fatty Acids, vol. 63, no. 3, pp. 159165, 2000.

[51] World Health Organization, WHO Laboratory Manual for the Examination and Processing of Human Semen, WHO Press, Geneva, Switzerland, 5th edition, 2010.

[52] World Health Organization, WHO Laboratory Manual for the Examination of Human Semen and Sperm-Cervical Mucus Interaction, WHO Press, Geneva, Switzerland, 4th edition, 1999.

[53] D. S. Irvine, J. P. Twigg, E. L. Gordon, N. Fulton, P. A. Milne, and R. J. Aitken, "DNA integrity in human spermatozoa: relationships with semen quality," Journal of Andrology, vol. 21, no. 1, pp. 33-44, 2000.

[54] J. G. Franco Jr., R. L. R. Baruffi, A. L. Mauri, C. G. Petersen, J. B. A. Oliveira, and L. Vagnini, "Significance of large nuclear vacuoles in human spermatozoa: implications for ICSI," Reproductive BioMedicine Online, vol. 17, no. 1, pp. 42-45, 2008.

[55] E. H. Yanushpolsky, J. A. Politch, J. A. Hill, and D. J. Anderson, "Is leukocytospermia clinically relevant?" Fertility and Sterility, vol. 66, no. 5, pp. 822-825, 1996.

[56] K. C. Cheng, D. S. Cahill, H. Kasai, S. Nishimura, and L. A. Loeb, "8-Hydroxyguanine, an abundant form of oxidative DNA damage, causes G ^ T and A ^ C substitutions," The Journal of Biological Chemistry, vol. 267, no. 1, pp. 166-172,1992.

[57] M. Bergmann, H. M. Behre, and E. Nieschlag, "Serum FSH and testicular morphology in male infertility," Clinical Endocrinology, vol. 40, no. 1, pp. 133-136,1994.

[58] J. D. Meeker, L. Godfrey-Bailey, and R. Hauser, "Relationships between serum hormone levels and semen quality among men from an infertility clinic," Journal of Andrology, vol. 28, no. 3, pp. 397-406, 2007.

[59] A. Agarwal and L. H. Sekhon, "Oxidative stress and antioxidants for idiopathic oligoasthenoteratospermia: is it justified," Indian Journal of Urology, vol. 27, no. 1, pp. 74-85, 2011.

[60] R. Mahfouz, R. Sharma, D. Sharma, E. Sabanegh, and A. Agarwal, "Diagnostic value of the total antioxidant capacity (TAC) in human seminal plasma," Fertility and Sterility, vol. 91, no. 3, pp. 805-811, 2009.

[61] T. K. Jensen, A.-M. Andersson, N. H. I. Hjollund et al., "Inhibin B as a serum marker of spermatogenesis: correlation to differences in sperm concentration and follicle-stimulating hormone levels. A study of 349 Danish men," Journal of Clinical Endocrinology and Metabolism, vol. 82, no. 12, pp. 4059-4063, 1997.

[62] F. H. Pierik, A. Burdorf, F. H. De Jong, and R. F. A. Weber, "Inhibin B: a novel marker of spermatogenesis," Annals of Medicine, vol. 35, no. 1, pp. 12-20, 2003.

Copyright of BioMed Research International is the property of Hindawi Publishing Corporation and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use.