Thesis (MTech(Biomedical Technology) -- Cape Peninsula University of Technology, 2010 / Defective sperm function is the most prevalent cause of male infertility. Mammalian
sperm are rich in polyunsaturated fatty acids (PUFA) and are susceptible to attack by reactive
oxygen species (ROS), an important mediator of sperm function. Normally, a balance is
maintained between the amount of ROS produced and the antioxidant defense system. When
an imbalance exists between ROS production and antioxidants protection in the favour of ROS
activity, oxidative stress (OS) occurs which could lead to cellular damage. A shift in the levels of
ROS towards pro-oxidation in semen can induce oxidative stress on sperm.
This study compares the modulation of OS by an indigenous herbal tea (rooibos),
Chinese green tea, commercial rooibos and green tea supplements in rat epididymal sperm and
testicular function. Sixty male Wistar rats were supplemented with fermented or “green” rooibos,
Chinese green tea, rooibos supplement, green tea supplement or water for ten weeks while
inducing OS during the last two weeks. Rats consuming fermented rooibos and “green” rooibos
showed a significant higher sperm concentration and motility. The superoxide dismutase (SOD)
activity was significantly higher in the sperm of rats that consumed fermented rooibos, “green
rooibos” and green tea compared to the control. Also, the superoxide dismutase activity of the
groups that received fermented rooibos, rooibos supplement and green tea increased
significantly in the testicular tissue compared to control. Catalase (CAT) activity in the epididymal
sperm was significantly increased in the rats consuming fermented rooibos, “green rooibos” and
both rooibos and green tea supplements compared to the control. None of the tea treatments
showed a significant effect on catalase activity in the testicular tissue. A tendency to increase
this activity was observed in fermented rooibos, green tea, rooibos and green tea supplements.
The glutathione levels of rats fed with fermented rooibos and “green” rooibos were significantly
higher in the rat epididymal sperm compared to the control while the glutathione level of rats
consuming green tea supplement also increased significantly in the testicular tissue compared to the control. None of the tea treatments showed a significant effect on lipid peroxidation and ROS
levels in the rat sperm. Although rooibos fermented, “green” rooibos and rooibos supplements
showed a tendency to lower the levels of these biomarkers when compared with the control
group in epididymal sperm. However, the rooibos supplement showed a significantly reduced
ROS levels in the testicular tissue.
In conclusion, our study demonstrated that rooibos extract and green tea are effective as
antioxidants by increasing the antioxidant enzyme activities and glutathione levels in oxidative
stress-induced rats and could offer a measure of protection against oxidative damage, thereby
improving sperm quality and function.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:cput/oai:localhost:20.500.11838/1467 |
| Date | January 2010 |
| Creators | Awoniyi, Dolapo Olaitan |
| Publisher | Cape Peninsula University of Technology |
| Source Sets | South African National ETD Portal |
| Language | English |
| Detected Language | English |
| Type | Thesis |
| Rights | http://creativecommons.org/licenses/by-nc-sa/3.0/za/ |
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