Background
Free radicals, reactive oxygen species and oxidative stress
Oxidative stress in the ART setting
Sources of ROS
In vivo
Originating from the male
Immature spermatozoa
Leukocytes
Varicocele
Originating from the female
Oocyte
Cumulus mass cells
Follicular fluid
Originating from the embryo
In vitro
Visible light
Culture media
Antioxidant | Study type | Patient population | Intervention (therapeutic approach) | Control group (daily dose) | Outcome/effect of intervention/effect on parameters | Reference |
---|---|---|---|---|---|---|
Vitamin E
| Prospective | Sperm from normozoospermic and asthenozoospermic men | 5 mM vitamin E added to cryoprotective media prior to freeze-thaw procedure | 1. Improvement in post-thaw motility | Kalthur et al. [57] | |
2. Improvement in DNA integrity | ||||||
Vitamin E
| Prospective | Sperm from normozoospermic men and men with abnormal sperm parameters | 100 μmol or 200 μmol vitamin E added to cryopreservation media | Improved post-thaw motility of cryopreserved sperm from men with both normal and abnormal sperm parameters | Taylor et al. [58] | |
Vitamin E (alpha-tocopherol)
| Prospective | Sperm from teratozoospermic men (n = 15) | Sperm prepared by swim up incubated with 40 μmol alpha-tocopherol added to media x 1 hour | 1. Improved sperm motility | Keshtgar et al. [59] | |
2. Increased sperm viability | ||||||
Vitamin C
| Prospective | Sperm from male volunteers with teratozoospermia (n = 15) | Sperm prepared by swim up incubated with 600 μmol vitamin C added to media x 1 hour | 1. Reduced MDA levels | Fanaei et al. 2014 [60] | |
2. Reduced DNA damage | ||||||
3. Improved sperm progressive motility | ||||||
4. Improved sperm viability | ||||||
Vitamin C
| Prospective | DNA damaged sperm from infertile men | 10 mM ascorbic acid added to semen sample prior to adding cryomedia | Unsupplemented cryomedium | 1. No change in post-thaw sperm concentration or morphology | Branco et al. [61] |
2. Reduced number of sperm with cryopreservation-induced DNA damage in infertile men | ||||||
Vitamin C
| Prospective | Sperm from patients undergoing semen analysis (n = 134) | Supplementation of cryomedium with ascorbate or 100 μmol/L AA2G (ascorbic acid-2-glucoside) (stabilized form of ascorbate) | Unsupplemented cryomedium | Improved post-thaw sperm motility | Jenkins et al. [62] |
Coenzyme Q
10
| Prospective | Sperm from asthenozoospermic men (n = 22) | HAM’s medium alone, HAM’s medium +1% DMSO, HAM’s medium +5 μM CoQ10 or 50 μM CoQ10 x 24 hours | Samples with normal motility sperm (n = 16) | 50 μM CoQ10 increased sperm motility of asthenozoopsermic men in vitro | Lewin & Lavon [63] |
Melatonin
| Experimental | Sperm from both healthy and infertile men (n = 12) | Sperm co-incubated with 1 mM melatonin x 30 minutes | No treatment | 1. Increased percentage of motile and progressively motile cells | Ortiz et al. [64] |
2. Increased sperm vitality and sperm with normal morphology | ||||||
Melatonin
| Experimental | Sperm from healthy men (n = 12) | Sperm co-incubated with 2 mM melatonin x 120 minutes | No treatment | 1. Higher percentage of motility and progressive motility | du Plessis et al. [65] |
2. Increased sperm viability | ||||||
L-Carnitine
| Experimental | Peritoneal fluid from women with endometriosis | Frozen metaphase II mouse oocytes and embryos in peritoneal fluid (from endometriosis patients) incubated with 0.6 mg/mL L-Carnitine | Peritoneal fluid (from endometriosis patients) only, peritoneal fluid (from tubal ligation patients as control) only, human tubal fluid only, L-carnitine only | 1. Improved microtubule and chromosome structure in oocyte | Mansour et al. [66] |
2. Decreased level of embryo apoptosis | ||||||
L-Carnitine
| Experimental | Embryo | 0.3 mg/mL or 0.6 mg/mL L-Carnitine | Embryo culture medium without supplementation | 1. Improved percentage of blastocyst development rate with 0.3 mg/mL L-carnitine | Abdelrazik et al. [67] |
2. Both 0.3 mg/mL and 0.6 mg/mL L-carnitine reduced the blocking effect of actinomycin-D, hydrogen peroxide or tumor necrosis factor alpha and reduced the level of DNA damage |
pH and temperature
Oxygen concentration
Centrifugation
ART technique
Cryopreservation (freeze/thawing)
Antioxidants as ameliorating agents
Antioxidant | Study type | Patient population | Intervention (daily dose x duration) | Control group (daily dose) | Study outcome (effect on sperm parameters) | Reference |
---|---|---|---|---|---|---|
Vitamin E
| Double blind, placebo cross-over, RCT | Healthy men with high seminal ROS levels (n = 30) | 600 mg vitamin E x 3 months (n = 15) | Placebo (n = 15) | Improved in vitro sperm function (improved zona-binding assay) | Kessopoulou et al. [101] |
Vitamin E
| Double blind, placebo-controlled | Men with (n = 110) asthenozoospermia or oligoasthenozoospermia | 300 mg vitamin E x 6 months (n = 52) | Placebo (n = 55) | 1. Reduced MDA concentration (less LPO in spermatozoa) | Suleiman et al. [102] |
2. Improved sperm motility | ||||||
3. 20% of those on therapy achieved pregnancy | ||||||
Vitamin E + Anti-Estrogen (Clomiphene citrate)
| Prospective, placebo-controlled RCT | Infertile men with idiopathic oligozoospermia (n = 60) | 400 mg vitamin E +25 mg clomiphene citrate x 6 months (n = 30) | Placebo (n = 30) | 1. Improved sperm count and progressive motility | Ghanem et al. [103] |
2. Partners had higher incidence of pregnancy | ||||||
Vitamin E + selenium
| Open, randomized | Volunteers and infertile men (n = 54) | 400 mg vitamin E +225 μg selenium x 3 months (n = 28) | 4.5 g vitamin B x 3 months (n = 26) | 1. Reduced MDA concentration (less LPO in spermatozoa) | Keskes-Ammar et al. [104] |
2. Improved sperm motility | ||||||
Vitamin E + selenium
| Observational study | Infertile men with idiopathic asthenozoospermia (n = 690) | 400 IU vitamin E +200 μg selenium x 100 days | None | 1. Improvement in sperm motility/morphology or both (53%) | Moslemi & Tavanbakhsh [105] |
2. Increased spontaneous pregnancy rates (11%) | ||||||
Vitamin E + Vitamin C
| Double blind, placebo-controlled, RCT | Men (n = 31) with asthenozoospermia or moderate oligoasthenozoospermia | 1000 mg vitamin C +800 mg vitamin E x 8 weeks (n = 15) | Placebo (n = 16) | No improvement in sperm parameters | Rolf et al. [106] |
No improvement in 24 h sperm survival rate | ||||||
Vitamin E + Vitamin C
| Observational study, double-blind | Men with elevated sperm DNA fragmentation (≥15%) who have unexplained infertility | 1000 mg vitamin C +1000 mg vitamin E x 2 months (n = 32) | Placebo (n = 32) | Reduced percentage of DNA-fragmented sperm (TUNEL test) | Greco et al. [107] |
Vitamin E + Vitamin C
| Observational study involving assisted conception treatment | Men with elevated sperm DNA fragmentation (≥15%) who failed their 1st ICSI attempt | 1000 mg vitamin C +1000 mg vitamin E x 2 months (n = 38) | None | 1. Reduced percentage of DNA-fragmented sperm (TUNEL test) | Greco et al. [108] |
2. Marked improvement in implantation and clinical pregnancy rates in the 2nd ICSI attempt vs 1st attempt | ||||||
Vitamin C
| Men with sperm agglutination (>25%) (n = 30) | 200 mg vitamin C or 1000 mg vitamin C | Placebo | Improved sperm motility, viability, morphology after 4 weeks (more prominent improvement in 1000 mg vitamin C vs. 200 mg vitamin C) | Dawson et al. [109] | |
Vitamin C
| Men who are heavy smokers (n = 75) with normal reproductive function | 200 mg vitamin C or 1000 mg vitamin C | Placebo | 1. Improved sperm agglutination | Dawson et al. [110] | |
2. Improved 24 h viability | ||||||
3. Improved sperm morphology | ||||||
Folic acid + zinc sulphate
| Double blind, placebo-controlled, RCT | Fertile (n = 108) and subfertile men (n = 103) | 5 mg folic acid, 66 mg zinc sulphate or 5 mg folic acid +66 mg zinc sulphate x 26 weeks | Placebo or placebo + placebo | Increased sperm concentration in subfertile and fertile males after combined treatment | Wong et al. [111] |
Folic acid + zinc sulphate
| Double blind, placebo-controlled | Fertile (n = 47) and subfertile men (n = 40) | 5 mg folic acid +66 mg zinc sulphate x 26 weeks | Placebo | Increased sperm concentration in infertile males, but not fertile males | Ebisch et al. [112] |
Folic acid + zinc sulphate
| Double blind, placebo controlled, RCT | Subfertile men with OAT (n = 83) | 5 mg folic acid +220 mg zinc sulphate x16 weeks | Placebo | Zinc sulfate + folic acid did not improve sperm quality in men with OAT (severely compromised sperm parameters) | Raigani et al. [113] |
Folic acid + zinc sulphate
| Prospective, randomized controlled | Men with palpable varicocele (grade III) who underwent surgical repair of varicocele (n = 160) | 5 mg folic acid (n = 26), 66 mg zinc sulphate (n = 32) or 5 mg folic acid +66 mg zinc sulphate (n = 29) x 6 months | Placebo (n = 25) | 1. Zinc sulfate + folic acid improved sperm parameters and improved varicocelectomy outcomes | Azizollahi et al. [114] |
2. Improved protamine content and halo formation rate | ||||||
Coenzyme Q
10
| Systematic review and meta-analysis (3 RCTs) | Infertile men | CoQ10 (n = 149) | Controls (n = 147) | 1. Improved seminal CoQ10 levels | Lafuente et al. [115] |
2. Increased sperm concentration | ||||||
3. Increased sperm motility | ||||||
4. No increase in pregnancy rates | ||||||
5. Data on live births were lacking | ||||||
Coenzyme Q
10
| Double blind, placebo-controlled, RCT | Men with iOT (n = 60) | 200 mg CoQ10 x 3 months (n = 30) | Placebo (Lactose) (n = 30) | 1. Increased levels of CoQ10 in seminal plasma | Nadjarzadeh et al. [116] |
2. Decreased 8-isoprostane levels (biomarker of LPO) (attenuation of OS in seminal plasma) | ||||||
3. Increased sperm forward and total motility | ||||||
4. Increased catalase, SOD activity | ||||||
Coenzyme Q
10
| Double blind, placebo-controlled, RCT | Men with iOAT (n = 47) | 200 mg CoQ10 x 12 weeks | Placebo | 1. Reduced TBARS (reduced plasma MDA levels) | Nadjarzadeh et al. [117] |
2. Increased TAC in seminal plasma | ||||||
Coenzyme Q
10
| Double blind, placebo-controlled, RCT | Men with iOAT (n = 228) | 200 mg ubiquinol x 26 weeks (n = 114) | Placebo (n = 114) | Improved sperm quality (density, motility, normal strict morphology) | Safarinejad et al. [118] |
Coenzyme Q
10
| Double blind, placebo-controlled, RCT | Men with idiopathic infertility (n = 60) | 200 mg CoQ10 x 6 months | Placebo | 1. Increase in CoQ10 and ubiquinol in seminal plasma and spermatozoa | Balercia et al. [119] |
2. Increase in spermatozoa motility | ||||||
Coenzyme Q
10
| Prospective | Men with iOAT (n = 212) | 300 mg CoQ10 x 26 weeks (n = 106) | Placebo (n = 106) | 1. Improved sperm density, motility, normal strict morphology | Safarinejad [120] |
2. Improved acrosome reaction | ||||||
Coenzyme Q
10
| Open-label, prospective | Men with iOAT (n = 287) | 600 mg CoQ10 x 12 months (n = 106) | None | 1. Improved sperm quality (concentration, progressive motility, normal morphology) | Safarinejad [121] |
2. Improved pregnancy rates |
Antioxidant | Study type | Patient population | Intervention (daily dose x duration) | Control group (daily dose) | Study outcome | Reference |
---|---|---|---|---|---|---|
Vitamin E
| Women with unexplained infertility undergoing ovarian stimulation and then IUI | 400 IU/day vitamin E | 1. Increased endometrial thickness | Cicek et al. [122] | ||
2. No significant increase in implantation and pregnancy rates | ||||||
Vitamin C
| Prospective | Women undergoing IVF-ET (n = 76) | 500 mg vitamin C/day (slow release) to women smokers (n = 19) and women non-smokers (n = 19) | Placebo | Women non-smokers had higher pregnancy rates than women smokers | Crha et al. [123] |
Vitamin C
| Prospective, randomized | Infertile women with luteal phase defects (not on IVF-ET) | 750 mg ascorbic acid (n = 76) started on first day of third menstrual cycle until positive urine pregnancy test (maximum 6 months) | No treatment (n = 46) | 1. Increase in progesterone levels | Henmi et al. [124] |
2. Increase in clinical pregnancy rates | ||||||
Vitamin C
| Double blind, placebo-controlled, RCT | Women (<40y) undergoing first IVF-ET cycles (n = 620) | 1 g or 5 g or 10 g ascorbic acid +30 mg Dydrogesteron x 14 days after follicle aspiration for IVF-ET | Placebo (Lactose + citric acid +30 mg Dydrogesteron) | No difference in clinical pregnancy and implantation rates | Griesinger et al. [125] |
Myo-inositol + folic acid
| Placebo-controlled, RCT | Infertile PCOS patients undergoing ovulation induction for ICSI (n = 60) | 4 g myo-inositol +400 μg folic acid (n = 30) | 400 μg folic acid only (n = 30) | Reduced germinal vesicles and degenerated oocytes without compromising the number of oocytes retrieved at ovum pick-up | Papaleo et al. [126] |
Myo-inositol + folic acid
| Double blind | Infertile PCOS patients undergoing ovulation induction for IVF or ICSI (n = 34) | 4 g of myo-inositol +400 μg of folic acid, continuously for 3 months | 400 μg of folic acid only | 1. Greater number of oocytes recovered during pick up | Ciotta et al. [127] |
2. Greater number of oocytes with score S1 | ||||||
3. Reduced number of immature oocytes (vesicles germ and degenerated oocytes) | ||||||
Melatonin
| Follicular fluid sampled during oocyte retrieval during IVF-ET | Women with prior failure of IVF-ET cycle and who are attempting IVF-ET again (n = 115) | 3 mg melatonin (n = 56) given on the 5th day of the previous menstrual cycle until the day of oocyte retrieval | Without melatonin treatment (n = 59) | 1. Improved fertilization rate compared to previous IVF-ET cycle | Tamura et al. [128] |
2. Improved oocyte quality | ||||||
Melatonin
| Prospective, randomized | Women with primary infertility undergoing IVF-ET cycles (n = 85) | 3 mg melatonin (n = 40) administered continuously from day of GnRH | No treatment (n = 45) | 1. Higher percentage of morphologically mature oocytes retrieved (MII oocytes) | Batioglu et al. [129] |
2. Higher mean number of top quality (class I) embryos | ||||||
3. No improvement in fertilization rates | ||||||
4. Higher tendency of clinical pregnancy rate (not statistically significant) | ||||||
Melatonin
| Prospective, randomized | IVF patients with disturbed sleep (insomnia) who were undergoing IVF-ET (n = 60) | 3 g melatonin (n = 30) given 3rd to the 5th day of the previous menstrual cycle until the hCG injection day of the controlled ovarian hyperstimulation | No treatment (n = 30) | 1. Higher mean number of the retrieved oocytes, mean MII oocyte counts, and G1 embryo ratio | Eryilmaz et al. [130] |
2. No change in sleeping status | ||||||
Melatonin + myo-inositol + folic acid
| Prospective, randomized | Women undergoing IVF cycles (n = 65) | 3 g melatonin +4 g myo-inositol +200 mg folic acid (n = 32) administered continuously from day of GnRH | 4 g myo-inositol + folic acid (n = 33) | 1. Greater mean number of mature oocytes (and lower mean number of immature oocytes) | Rizzo et al. [131] |
2. Higher mean number of top quality embryos (class 1 and 2) | ||||||
3. No improvement in fertilization rates | ||||||
4. Higher tendency of clinical pregnancy rate and implantation rate (not statistically significant) | ||||||
Melatonin + myo-inositol + folic acid
| Prospective, longitudinal, cohort | Women with failed IVF cycle (due to poor oocyte quality) who were undergoing a new IVF cycle | 3 mg melatonin +4 g myo-inositol +400 mcg folic acid x 3 months (n = 46) | Prior cycle of the same women but without treatment | 1. Higher number of morphologically mature oocytes retrieved (MII oocytes) | Unfer et al. [132] |
2. Higher total number of embryo transferred and higher number of top quality (score 1 & 2) embryo transferred | ||||||
3. Increased fertilization rate |