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Iraqi Journal of Veterinary Sciences, Vol. 23, Supplement II, 2009 (155-160)
Proceedings of the 5
th
Scientific Conference, College of Veterinary Medicine, University of Mosul
155
Effect of royal jelly on sexual efficiency in adult male rats
A. A. Hassan
Department of physiology, College of Veterinary Medicine, University of Mosul, Mosul, Iraq
Abstract
The study was designed to investigate the efficacy of treating the adult male rats with royal jelly (1g/kg B. Wt. orally) for
one month with or without hydrogen peroxide (0.5%) in drinking water on sexual efficiency, glutathione and malondialdehyde
tissue testis levels. The current study demonstrated that male rats receiving hydrogen peroxide caused a significant decrease
(P<0.05) in the sperm count, percentage of live sperm and glutathione level, accompanied with a significant increase (P<0.05)
in the malondialdehyde level and percentage of abnormal sperm deformity compared with control group. No significant
difference was found in the weight of testis, epididymus, prostate, seminal vesicles, testosterone hormone level and body
weight compared with control group. The treatment of adult male rats with royal jelly concomitantly with hydrogen peroxide
caused a significant increase (P<0.05) in testicular weight and the body of epididymus, sperm count, testosterone hormone and
glutathione level, and decrease in sperm deformity percentage, while no significant differences in the prostate weight, seminal
vesicles, the percentage of live sperm, malondialdehyde level and body weight compared with hydrogen peroxide group. The
treatment of adult male rats with royal jelly alone produced a significant increase (P<0.05) in the weights of testis and body of
epididymus, sperm count, testosterone hormone, the percentage of live sperm, and glutathione level and retuned to control
value, accompanied with a significant decrease (P<0.05) in malondialdehyde level and the percentage of sperm abnormality. It
could be concluded from this study that royal jelly is a beneficial treatment of male adult rats receiving hydrogen peroxide (to
induced oxidative stress) specially on sperm count, testosterone hormone level, the percentage of live sperm, and improvement
of glutathione and malondialdehyde tissue testis.
Keywords: Royal jelly, Sexual efficiency, H
2
O
2,
Testosterone, Glutathione, Malondialdehyde.
Available online at http://www.vetmedmosul.org/ijvs
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(0.5%)
.
(P<0.05)
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.
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Iraqi Journal of Veterinary Sciences, Vol. 23, Supplement II, 2009 (155-160)
Proceedings of the 5
th
Scientific Conference, College of Veterinary Medicine, University of Mosul
156
.
(P<0.05)
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.
Introduction
Royal jelly is a thick, extremely nutrition, milky white,
creamy liquid secreted by the hypopharyngeal glands of
worker bees (Apis mellifera) in relation to sexual
determination of the bee (1). Considered as the major cause
for difference between queen and bee workers, royal jelly is
appreciated as a dietary complement because of its
composition (1).
Royal jelly is an essential food for the queen bee larvae
and the queen herself. All larvae fed royal jelly for three
days, but the queen bee eats royal jelly exclusively which
makes her fertile and able to live to seven years. Queen
bees will produce 2000 eggs per day, with each day brood
equal to 2.5 times her body weight (2). In contrast, worker
bees are sterile and live just seven to eight weeks. Royal
jelly contains considerable amounts of proteins, amino
acids including 8 essential amino acids (3), hormone rich
substance (testosterone has been identified in extremely
small quantities in royal jelly about 0.012g/g fresh weight
(4), lipid, and sugars, royal jelly also contains vitamin A, C,
D, and E, mineral salts are in descending order: (K, Ca, Na,
Zn, Fe, Cu, and Mn.), enzymes antibiotic components. It
also has an abundance of nucleic acid-DNA and RNA (5).
Gelatin, one of the precursors of collagen, is also found
in royal jell, collagen is a powerful anti-aging element that
helps preserve the youth of the body (6). And is known to
have several diverse physiological and pharmacological
functions, these include vasodilative, hypotensive, anti-
hypercholesterolemia, and anti-tumor activities (7). Royal
jelly has been found to be of great help in boosting the body
resistance to the harmful side effect of chemotherapy and
radiotherapy (8). Also contains gamma globulin, which
helps the immune system to fight infections. It also contains
sterols, phosphorous compounds and acetylcholine, which
is needed to transmit nerve messages from cell to cell (8).
Al-Tai (9) demonstrated that the reactive oxygen species
produced by administration of hydrogen peroxide are
responsible for the pathophysiological changes of the male
reproductive system and induced defect in the
histophysiological aspect of this system in rats.
Polyunsaturated fatty acids and phospholipids are key
constituents in the sperm cell membrane and are highly
susceptible to oxidative damage. Sperm produce controlled
concentrations of reactive oxygen species, such as the
superoxide anion, hydrogen peroxide, and nitric oxide,
which are needed for fertilization; however, high
concentrations of these free radicals can directly damage
sperm cells (10).
The current study designed to investigate effect the
administration of royal jelly orally for one month to the
male adult rats induced oxidative stress by hydrogen
peroxide on sexual efficacy and glutathione,
malondialdehyde levels.
Materials and methods
Twenty adult male albino rats were obtained from the
animal house of the Veterinary Medical College, University
of Mosul, at aged 3-4 month, weighing 200- 300g. They
were housed in polypropylene cages under controlled
condition of temperature (24-26°C) and lighting (12hours
light/12hours dark). The rats were supplied a standard diet
and tap water ad libitum.
The adult male rats were randomly divided into four
groups (5 rats /group). The first group received tap water
serve as control. The second group received hydrogen
peroxide (H
2
O
2
) (Laboratory reagent, India) (0.5%) in
drinking water for one month (11). The third group
received (H
2
O
2
) (0.5%) in drinking water for one month
concomitant with royal jelly (Peking, China) at 1g/kg B.
Wt. dissolved in distalled water and given at 1 ml/kg for
one month orally by gavage needle (12). The fourth group
received royal jell at a dose 1g/kg B. Wt. orally alone. The
weight of rats recorded weekly. At the end of experiment
blood samples were collected into clean dry centrifuge
tubes allowed to clot, serum separated after centrifugation
at 1500 rpm for 15 minute for testosterone hormone assay,
using Enzyme Linked Immunosorbent Assay (ELISA)
(BioCheck Company, USA). Rats were sacrificed by ether
administration. The abdominal cavity was then opened; the
weight of testis, epididymal, seminal vesicles and prostate
were recorded. The testis placed in ice normal saline for
glutathione estimation using Moron method as described by
(13) and malondialdehyde (MDA) estimation using Gilbert
method as described by (14). The epididymis was dissected
out, sectioned and immediately the content of the tail of
each epididymis was squeezed gently in clean watch glass,
Iraqi Journal of Veterinary Sciences, Vol. 23, Supplement II, 2009 (155-160)
Proceedings of the 5
th
Scientific Conference, College of Veterinary Medicine, University of Mosul
157
diluted 10 times with isotonic solution of sodium citrate
(2.9%) at (37° C), take one drop from isotonic solution on
slide and added one drop of eosin - nigrosin stain and made
smear, this technique was used for the percentage of
live/dead and for morphological abnormal sperms to be
counted (15). The content of the head of epididymis was
squeezed immediately in clean watch glass contained 9.8
ml. buffer formalin with 0.1 ml. eosin 5%, this was used for
counting the sperm concentration using hemocytometric
technique (16).
Data were analyzed statistically using one way analysis
of variance. Group differences were determined using
Duncan multiple range test. Statistical significance was
considered at (P< 0.05) (17).
Results
Table (1) showed that administration of hydrogen
peroxide (0.5%) in drinking water for one month did not
affect the weight of testis, epididymis (head, body, tail),
prostate and seminal vesicles compared with control group
value. Treatment of adult male rats with royal jelly (1g/kg
orally) for one month with or without hydrogen peroxide
produced a significant increase (P<0.05) in the weight of
testis and body of epididymis whereas no significant
changes in the weight of head and tail of epididymus,
prostate and seminal vesicles compared with hydrogen
peroxide group.
The current study revealed a significant decrease
(P<0.05) in sperm count in hydrogen peroxide group
compared with control group as shown in Table (2).
Treatment with royal jelly and hydrogen peroxide
caused a significant increase (P<0.05) in sperm count
compared with hydrogen peroxide group and retuned to the
normal control value. The data of current study showed a
significant increase (P<0.05) in the sperm count in royal
jelly treated group compared with hydrogen peroxide
group, and royal jelly concomitantly with hydrogen
peroxide group and retuned to the control value as shown in
(table 2).
The current study demonstrated that a significant
decrease (P<0.05) in glutathione level in hydrogen peroxide
group compared with control group, while administration of
royal jelly with or without hydrogen peroxide caused a
significant increase (P<0.05) in the glutathione level
compared with hydrogen peroxide group and returned to
the control group. The present study showed that a
significant increase (P<0.05) in malondialdehyde level in
hydrogen peroxide group compared with control group.
Treatment the royal jelly concomitant with hydrogen
peroxide did not affect significantly in malondialdehyde
level, but treatment with royal jelly alone caused a
significant increase (P<0.05) in malondialdehyde level as
shown in (table2).
Table 1. Effect the treatment of royal jelly on the weight of the testis, epididymis (head, body, tail) prostate and seminal vesicle
in rats receiving hydrogen peroxide for one month.
Treated animals
Testis
mg/100 g
B. Wt.
Head of
epididymu
s mg/100g
B.Wt..
Body of
epididymus
mg/100g
B.Wt
Tail of
epididymus
mg/100g B.
Wt.
Prostate
mg/100g B.
Wt.
Seminal
vesicle
mg/100B.
Wt.
Control b
473.4±27.7
a
79.2±4.2
b
21.1±0.9
a
93.2±7.4
a
447.5±44.2
a
100.9±5.9
Hydrogen peroxide (0.5%)in drinking
water for (1 month)
b
501.5±10.8
a
85.0±3.9
b
20.8±0.6
a
92.9±5
a
431±35.3
a
108.9±7.4
Hydrogen peroxide (0.5%)in drinking
water for (1 month)+ royal jelly
(1g/kg orally) for (1 month)
a
604.9±21.2
a
89.4±5.5
a
23.7±0.3
a
93.4±2.9
a
455.3±33.2
a
99.9±6
Royal jelly(1g/kg orally) for (1month)
a
636.1±21.7
a
76.5±4.1
a
24.1±0.3
a
90.4±1.5
a
427.1±26.7
a
105.7±6.4
Values were expressed as means ± SE from 5rats per treatment.
Values with different letters in the columns are significantly different at (P<0.05).
Iraqi Journal of Veterinary Sciences, Vol. 23, Supplement II, 2009 (155-160)
Proceedings of the 5
th
Scientific Conference, College of Veterinary Medicine, University of Mosul
158
Table 2. Effect the treatment of royal jelly on sperm count, glutathione, and malodialdehyde levels in rats receiving hydrogen
peroxide for one month.
Treated animals Sperm concentration
×
6
Glutathione
µmlg.
Malodialdehyde
nm/g.
Control ab
1.4320±0.02
a
1.04±0.02
b
264.82±12.48
Hydrogen peroxide (0.5%)in drinking water for (1
month)
c
0.8±0.02
b
0.59±0.02
a
311.0±17.6
Hydrogen peroxide (0.5%)in drinking water for(1
month)+ royal jelly (1g/kg orally) (1 month)
b
1.3440±0.13
a
1.23±0.14
ab
233.9±14.3
Royal jelly(1g/kg orally) for (1 month) a
1.6260±0.02
a
1.26±0.02
c
219.7±5.7
Values were expressed as means ± SE from 5rats per treatment.
Values with different letters in the column are significantly different at (P<0.05).
Table 3 demonstrated that a significant decrease
(P<0.05) in the percentage of the live sperms in hydrogen
peroxide group compared with control group. Treatment the
royal jelly concomitantly with hydrogen peroxide did not
effect significantly in the percentage of the live sperms
compared with hydrogen peroxide group, Whereas
treatment with royal jelly alone caused a significant
increase (P<0.05) in the percentage of the live sperms and
retuned to normal control value.
The data of the current study revealed that a significant
increase (P<0.05) in the percentage of sperms deformity in
hydrogen peroxide group compared with control group.
Treatment the royal jelly with or without hydrogen
peroxide caused a significant decrease (P<0.05) in the
percentage of sperm deformity compared with hydrogen
peroxide group as shown in Table (3).
Same table shows no significant differences in the
testosterone hormone level in hydrogen peroxide group
compared with control group.
Administration of royal jelly concomitant with or
without hydrogen peroxide caused a significant increase
(P<0.05) in testosterone hormone compared with hydrogen
peroxide group.
Table 4 demonstrated that no significant differences
between groups in the body weight after (1, 2, 3, weeks) of
treatment.
Table 3. Effect the treatment of royal jelly on the percentage number of live sperm, sperm deformity, and testosterone hormone
concentration in rats receiving hydrogen peroxide for one month.
Treated animals Live Sperm % Sperm
Deformity%
Testosterone
Hormone ng/ml
Control a
91.6±1.5
c
4.2±0.37
cb
2.37±0.16
Hydrogen peroxide (0.5%)in drinking water for (1
month)
b
84±1.51
a
11.2±1.06
c
1.72±0.30
Hydrogen peroxide (0.5%)in drinking water for (1
month)+ royal jelly (1g/kg orally)(1 month)
b
87±0.54
b
9.0±7.03
b
2.51±0.13
Royal jelly(1g/kg orally) for (1 month) a
94.6±0.81
c
4.6±0.4
a
4.24±0.27
Values were expressed as means ± SE from 5rats per treatment.
Values with different letters in the column are significantly different at (P<0.05).
Iraqi Journal of Veterinary Sciences, Vol. 23, Supplement II, 2009 (155-160)
Proceedings of the 5
th
Scientific Conference, College of Veterinary Medicine, University of Mosul
159
Table 4. Effect the treatment of royal jelly on body weights in rats receiving hydrogen peroxide for one month.
Treated animals Weight (zero
time)
Weight after
one weeks
Weight after
two weeks
Weight after
three weeks.
Control a
270.5±10.64
a
246.2±11.91
a
273.5±24.4
a
299.5±10.1
Hydrogen peroxide (0.5%)in drinking water for (1
month)
a
228.5±20.34
a
228.2±19.7
a
238.5±24.6
a
287.2±21.6
Hydrogen peroxide (0.5%)in drinking water (1
month)+ royal jelly (1g/kg orally) for (1 month)
a
263±8.09 223.5±20.01 a
235.2±21.9
a
286.2±14.3
Royal jelly(1g/kg orally) for (1 month) a
265±23.47
a
250.2±17.06
a
247±26.5
a
305±34.07
Values were expressed as means ± SE from 5rats per treatment.
Discussion
The result of the present study demonstrated that
administration of hydrogen peroxide resulted in a
significant decrease in the sperm count, percentage of live
sperm and glutathione level, accompanied with a significant
increase in the malondialdehyde level and percentage of
abnormal deformity sperm compared with control value.
Similar results were obtained by other investigators (9,18-
20).
Hydrogen peroxide caused an increase in oxidative
damage to sperm membranes, proteins, and DNA is
associated with alterations in signal transduction
mechanisms that affect fertility (21). Numerous studies by
Ollero et al., (22) and Gill-Guzman et al., (23) have shown
that levels of (ROS) production in semen were negatively
correlated with the percentage of normal sperm forms as
determined by World Health Organization (24). These
support the results of the present study which indicate that
there was a relationship between oxidative stress induced
by hydrogen peroxide and decrease in sperms count,
percentage of live sperm and increased in the percentage of
morphological abnormal sperms. Spermatozoa are
particularly susceptible to oxidative stress induced damage
because their plasma membranes contain large quantities of
polyunsaturated fatty acids (PUFAs) (25).
The current study demonstrated that treatment with
royal jelly produced a significant increase in the sperm
count, live sperm percentage, testosterone hormone and
glutathione levels and decreased in the malodialdehyde.
Royal jelly is known as sexual tonic and used for treatment
of impotence infertility, and significantly increase
leutinizing hormone (LH) levels; this effect could be
attributed to central effect of royal jelly. Royal jelly
contains acetylcholine (1mg/g dry weight) (26).
Acetylcholine is one of peripheral and central
neurotransmitters; Kobayashi et al (27) previously
demonstrated a cyclic fluctuation of the biosynthetic
enzyme choline acetyltransferase in the rats anterior
hypothalamus with the activity of gonad (27). However
some studies confirmed that acetylcholine helps to
stimulate gonadotropine secretion of the hypothalamic level
(28). Therefore, royal jelly could increase LH level by its
effect at level of hypothalamus via its content of
acetylcholine. This elevation of LH level, which is
responsible for stimulation of testosterone secretion from
interstitial cell (29).
Furthermore, testosterone could be elevated as a result
of exogenous supplied by royal jelly, so it contains
testosterone in amount 0.012g/g fresh weight (30). On the
other hand elevation of testosterone level could be
attributed to zinc found in royal jelly. So zinc deficiency
causes low testosterone level, while zinc supplementation
can raise testosterone level and increase fertility (31,32).
Zinc sulphate also elevated LH and testosterone hormone
(32).
Testosterone is essential for spermatogenesis from
spermatogonium to spermatide (33). Royal jelly also
contains L-argginine and carnitine amino acid, which
essential for spermatogenesis (34). This study also showed
that royal jelly increased in glutathione accompanied with
decreased in malodialdehyde levels. This effect could be
attributed to the royal jelly contain vitamin C, vitamin E
and arginine (35). Vitamin E and C is a well-documented
antioxidant and has been shown to inhibit free-radical-
induced damage to sensitive cell membranes of the testis
and reduced lipid peroxidation in tissue estimation by
malodialdehyde, so vitamin E and C significantly decreased
MDA, and increased in glutathione level (10).
Acknowledgements
This study was supported by the College of Veterinary
Medicine, University of Mosul.
Iraqi Journal of Veterinary Sciences, Vol. 23, Supplement II, 2009 (155-160)
Proceedings of the 5
th
Scientific Conference, College of Veterinary Medicine, University of Mosul
160
References
1. Antinelli J, Zeggane S, Davico R, Rognone C, Faucon J, Lizzani L.
Evaluation of (E)-10-hydroxydec-2-enoic acid as a freshness
parameter for royal jelly. Food Chem. 2003;80:85-89.
2. Leung R, Ho A, Chan J. Royal jelly consumption and hypersensitivity
in the community. Clin Exp Allergy. 1997;27:333-336.
3. Prichard M,Turner KJ. Acute hypersensitivity to ingested processed
pollen. Aust and New Zealand J Med. 1985;15:346-347.
4. A http://www.goldin nature. Com/apithera pylinks htm. Inter net.
2004.
5. Justin OS. Chemical Composition and Application. Published as a
chapter in: Bee products: (A Mizrahi and Y Lensky), Plenum: New
Yourk. 1996.pp.15-26.
6. Compston JE. Sex steroids and bone. Physiol Rev. 2001;8:419-447.
7. Narita Y, Nomura J, Ohta S, Inoh Y, Suzuki KM, Araki Y, Okada S,
Matsumoto I, Isohama Y, Abe K, Miyata T, Mishima S. Royal jelly
stimulates bone formation: physiologic and nutrigenomic studies with
mice and cell lines. Biosci Biotechnol Biochem 2006;70(10):2508-
2514.
8. American Apitherapy society. 5390 Grande road, Hillsboro, 45133.
(937) 364-1108. http:// www. Apitherapy. Org/. Gale Encyclopedia of
Alternative Medicine. Gale Group, 2001.
9. Al-Taei AYJ. Effect of vitamin C on some testicular function in rats
exposed to oxidative stress induced by h ydrogen peroxide. MSc.
Thesis College of Veterinary Medicine, University of Mosul. 2003.
10. Ebisch IMW, Pierik FH, Jong FH. Thomas CMG, Steeger-Theunissen
RPM. Does folic acid and zinc sulphate intervention affect endocrine
parameters and sperm characteristics in men. Intern J
Androl.2006;29(2):339-345.
11. Abdul-Rahman SY. Effect of starvation and experimental diabetes
mellitus on glutathione and lipid peroxidation in tissues rats. Doctor's
dissertation. College of Veterinary Medicine, University of
Mosul,1995.
12. Mishima S, Suzuki K, Isohama Y, Kuratsu N, Araki Y, Inoue M,
Miyata T. Royal jelly has estrogenic effects in vitro and in vivo. J
Ethnopharm. 2005;101:215-220..
13. Moron MS, Depierre JW, Mennervik B. Level of glutathione reductase
and glutathione S-transferase activities in rats lung and liver. Biochem
Biophys Acta. 1979;582-678.
14. Gilbert HS, Stump DD, Roth FF. A method to correct for errors
caused by generation of interfering compound during erythrocyte lipid
peroxidation.Anal Biochem.1984;37:282-286.
15. Alsadi AA. Fertility and Artifical Insemination. 2
nd
ed College of
Veterinary Medicine, University of Mosul.2001.
16. Bearden HJ, Fuguany TW,Willard ST. Applied animal reproduction.
6
th
ed Mississippi State University.2004.
17. Petrie A, Watson P. Statistic for veterinary and animal science.
Blackwell Publishing Company.1999
18. Aziz BN. Effect of hydrogen peroxide-induced oxidative stress on
epididymal sperms of mice. Iraqi J Vet Sci.2000;13:61-65.
19. El-Demerdash FM,Yousef MI, Kedwany FS, Baghdadi HH.
Cadmium-induced changes in lipid peroxidation, blood hematology,
biochemical parameters and semen quality of male rats: protective role
of vitamin E and beta- carotene. Food Chem
Toxicol.2004;42(10):1563-1571.
20. Aziz BN, Hassan AA, Rasheed SAK. Effect of vitamin E on sexual
efficiency in male rats treated with cadmium. Iraqi J Vet Sci.2007;
13:61-65.
21. Becker S. Berhane KA. A metal-analysis of sperm count studies
revisited. Fertil Steril 1997; 67:1103-1108.
22. Ollero M,Gil-Guzman E, Lopez MC. Characterization of subsets of
human spermatozoa at different stages of maturation: implications in
the diagnosis and treatment of male infertility. Hum Reprod
2001;16:1912-1921. (Cited by; Saleh RA, Agarwal A. Oxidative stress
and male infertility: From Research Bench to Clinical Practice. J
Androl 2002;23(6):737-752).
23. Gil-Guzman E, Ollero M, Lopez MC, Sharma RK, Alvarez JG,
Thomas AJ, Agarwal A. Differential production of reactive oxygen
Species by subsets of human spermatozoa at different stages of
maturation. Hum Reprod. 2001;16:1922-1930.
24. World Health Organization. WHO Laboratory Manual for the
Examination of Human Semen and Sperm–Cervical Mucus
Interaction. 4
th
ed Cambridge, United Kingdom: Cambridge University
Press; 1999(Cited by; Saleh RA. Agarwal A. Oxidative stress and
male infertility: From Research Bench to Clinical Practice. J Androl
2002;23 (6):737-752.
25. Alvarez JG, Storey BT. Differential incorporation of fatty acids into
and peroxidative loss of fatty acids from phospholipids of human
spermatozoa. Mol Reprod Dev. 1995;42:334-346. (cited by; Saleh
RA, Agawal A. Oxidative stress and male infertility: From Research
Bench to Clinical Practice. J Androl. 2002;23(26):737-752.
26. Nutritional supplements. Com. Bee Medical Uses and Benefits of Bee
Royal Jelly.2004.
27. Kobayashi T. Kato J. Minaguchi H. Fluctuation in choline acetylase
activity in hypothalamus of rat. Endocrinology 1963; 10:175-182.
28. Muller EE. Nistico G. Scapagnini U. Neurotransmitters and Anterior
Pituitary Function. New York Academic Press 1977.
29. Schally AV, Pedding JW, Matson HI., Arimura AB. Stimulation of
FSH and LH release in vitro by natural and synthetic LH and FSH
releasing hormones. Endocrinology 1972:(40)1561-1567.
30. Royal Jelly hmt. Royal Jelly Difference, healthy cell news.2004.
31. Hunt CD, Johnson PE, Herbal JL, Mu llen LK. Effect of dietary zinc
depletion on seminal volume and zinc loss, serum testosterone
concentration and sperm morphology in young men. Am J Cli
Nutr.1992;56;148-157.
32. Netter A. Hartoma R. Nahoul K. Effect of zinc administration on
plasma testosterone, dihydrotestosterone and sperm count. Arch
Androl.1981;1(7):69-73.
33. West JB. Best and Taylor s. Physiology Basis of Medical Practice 14
Ed Williams and Wilking, London. 1997,pp:907-933.
34. De Lamirande E. Gagnon C. Impact of reactive oxygen species on
spermatozoa: a balancing act between beneficial and detrimental
effects. Hum Reprod. 1995;10:15-21.
35. Bayer R. Treatment of infertility with vitamin E. Int J Fertil.1990;
5:70-78.
