الفهرس 
Introduction and aim of workOnly 14 pages are availabe for public view
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Abstract
The present study was carried out to investigate if cilostazol could possibly protect against testicular damage caused by CIS (in a dose-dependent manner), investigate the underlying mechanisms and compare its effect to other PDEIs (tadalafil and pentoxifylline) on CIS–induced testicular toxicity in rats.
In this study, adult male wistar rats were used and divided into ten groups; each consists of seven rats and was given the drug regimen as follow; control, three drug control groups received TDF (5 mg/kg/day, P.O.), PTX (75 mg/kg/day, P.O.) and Cilo (20 mg/kg/day, P.O.) for 14 successive days, CIS–intoxicated group received CIS (7 mg/kg, i.p.) at the seventh day and five CIS–induced groups received the following drug regimen for 14 successive days; TDF (5 mg/kg/day, P.O.), PTX (75 mg/kg/day, P.O.), Cilo (5 mg/kg/day, P.O.), Cilo (10 mg/kg/day, P.O.) and Cilo (20 mg/kg/day, P.O.), respectively.
At the end of the experimental period, animals were anaesthetized and sacrificed. Blood samples were collected and centrifuged to obtain serum needed for analysis. Animal’s testes and epididymis were collected, weighed and flash-frozen in liquid nitrogen and stored at –80 °C till the time of analysis. Prior to analysis, testicular tissues were collected in PBS and homogenized to prepare homogenates then the supernatant was separated for different analysis.
To achieve these aims, the following experiments in CIS–induced testicular toxicity rats were conducted.
1. Detecting and comparing relative testicular weights of each group.
2. Semen analysis (sperm count, motility and percentage of abnormal sperm morphology).
3. Measuring serum testosterone level.
4. Evaluating the oxidative stress markers via measuring malondialdehyde (MDA) (an index of lipid peroxidation) in testicular tissues as well as measuring reduced glutathione (GSH) and total NOx- level in testicular tissues.
5. Determination of TNF–α, NF–κB and apoptotic marker (Caspase-3) using Western blot analysis.
6. Histopathological examination of testicular tissues taken from each group was made to confirm the results.
The results of the present study clearly demonstrated that rats treated with CIS (7 mg/kg, i.p.) exhibited a marked decline in relative testicular weight, as well as significantly low epididymal sperm count, impaired sperm motility and increased sperm morphological abnormality with concomitant decline in testosterone level. The histopathological findings that showed desquamated and disorganized germinal cells, as well as degeneration in germinal cells confirmed deterioration of sperm quality indices in these rats. CIS impaired oxidative status in testicular tissues by a significant elevation in MDA content, a marker of lipid peroxidation, and total nitrite levels that exceeded the antioxidant defense capacity presented as dramatic depletion in GSH level. Moreover, CIS caused a significant elevation of pro-inflammatory mediator (TNF¬–α), NF–κB and apoptotic marker caspase–3 protein expressions in testicular tissues compared to control group.
However, pretreatment with PDE inhibitors have ameliorative effects on CIS–induced testicular toxicity rats. CIS–treated groups pretreated with TDF, PTX and different doses of Cilo showed marked improvement in sperm quality indices along with serum testosterone level, testicular MDA level, total nitrite level, GSH level, TNF–α protein expression, NF–κB protein expression, caspase-3 protein expression and histopathological architecture compared to CIS–intoxicated group. Moreover, Cilo–treated groups showed marked protection over the use of TDF or PTX against CIS–induced testicular injury in a dose dependent manner with CIS+ Cilo 20 mg/kg group showing the best protective effect.
In conclusion, Cilostazol, a PDE3 inhibitor, has a great impact on male reproductive dysfunction in CIS–intoxicated rats in a dose dependent manner. In addition, All PDEIs showed protective effect with Cilo 20 mg/kg showed the best protective effect against CIS-induced testicular damage compared to TDF and PTX. These protective effects are possibly explained by scavenging free radicals along with targeting inflammatory and cell death signaling pathway through reduction of TNF–α, NF–κB and caspase–3 expressions. This calls for clinical studies to assess the protective role of cilostazol in cancer patients receiving CIS to reduce the risk of reproductive damage.