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Three Part Question

In [patients diagnosed with testicular torsion] do [antioxidants] lead to a [reduced risk of testicular ischaemia-reperfusion complications]?

Search Strategy

Databases: Medline (2000-2022), Embase (2000-2022), Cochrane.

Search terms: ("Testicular Torsion" OR "Spermatic Cord Torsion" OR "twisted testis").mp AND “antioxidant”.mp AND (“ischaemia-reperfusion” OR “ischemia-reperfusion” OR “reperfusion injury”).mp

Search Outcome

The search on Medline found 123 papers. The search on Embase found 163 papers. The search on Cochrane found no papers.

After duplications were removed, 177 papers remained; of these, 17 were relevant to the three-part question.

Relevant Paper(s)

Author, date and country	Patient group	Study type (level of evidence)	Outcomes	Key results	Study Weaknesses
Kemahli et al. 2016 Turkey	21 rats, split into 3 groups.	Animal Study	Pyrrolidine dithiocarbamate reduced ischaemia-reperfusion damage in those who underwent detorsion. This was seen with decreased malondialdehyde (p-value 0.025) and increased superoxide dismutase(SOD) levels (p-value 0.020).		Only some oxidative stress indicators were measured.
Kabay et al. 2014 Turkey	40 rats, split into 4 groups.	Animal Study	Pyrrolidine dithiocarbamate reduced malondialdehyde levels (p-value 0.000) and increased SOD levels (p-value 0.002) in those who underwent detorsion.		Animal study (no humans)
Demir et al. 2022 Turkey	18 rats, split into 3 groups.	Animal Study	Astaxanthin decreased malondialdehyde (p-value 0.0001)		Different TT durations and astaxanthin doses weren’t investigated
Baskovic et al. 2021 Croatia	32 rats, split into 4 groups	Animal study	Astaxanthin significantly increased mean seminiferous tubular diameter(MSTD), both when given immediately (p-value 0.001) and at 45 minutes after detorsion (p-value <0.001). This effect was greater when administered at 45 minutes (p-value 0.038).		Animal study (no human subjects).
Baskovic et al. 2022 Croatia	32 rats, split into 4 groups	Animal Study	Astaxanthin given 45 minutes after detorsion significantly reduced caspase-3 positive cells (p-value 0.016), reduced malondialdehyde levels (not significantly (p-value 0.574)) and increased SOD (p-value 0.000) compared to immediate administration.. Astaxanthin given at detorsion didn’t significantly lower germ cell numbers (p-value 0.077), and it did not affect malondialdehyde levels.		Animal study (no human subjects).
Sugiyama et al. 2012 Japan	40 rats, split into 5 groups	Animal Study	Epigallocatechin gallate increased SOD in TT(p-value <0.05). . Epigallocatechin gallate increased MSTD(p-value <0.01) and maintained normal histological tubular appearance.		Immediate histological changes were not investigated. Germ cell apoptosis wasn’t measured.
Chi et al. 2015 China	24 rats, split into 4 groups	Animal study	Quercetin reduced malondialdehyde more than resveratrol(p-value <0.05). Quercetin and resveratrol both reduced nitric oxide, but neither were significantly better than the other. Quercetin and resveratrol both reduced testicular injuries following TT(p-value <0.05). Quercetin caused milder tubular damage than resveratrol(p-value <0.05).		Exact p-values are not recorded. Optimal dosage and administration timing weren’t investigated.
Guzel et al 2015 Turkey	70 rats, split into 7 groups	Animal Study	Lycopene doesn’t improve disordering of epithelia or necrosis in TT. Lycopene increased MSTD after 3-days but had less effect after 10-days. Lycopene didn’t significantly affect malondialdehyde or SOD levels. Lycopene improved apoptotic cell numbers after 3-days (p-value<0.05), but this was not significant after 10-days.		Animal study (no humans)
Hekimoglu et al. 2009 Turkey	42 rats, split into 3 groups	Animal Study	Lycopene improved sperm motility after detorsion (p-value<0.05) but didn’t significantly affect malondialdehyde or catalase levels.		Long-term effects not investigated. Animal study (no humans)
Wei et al. 2017 China	60 rats, split into 3 groups	Animal Study	Probucol reduced malondialdehyde after detorsion (p-value<0.05). Probucol improved testicular weight, germ-cell number and MSTD compared to non-treated TT (p-value <0.05)		No numerical data was given (evidence was presented in figures).
Guimaraes et al. 2007 Brazil	48 rats, split into 8 sub-groups	Animal study	Alpha-lipoic acid increased glutathione and reduced thiobarbituric acid-reactive substances after detorsion compared to saline (p-value <0.0001). Alpha-lipoic acid increased plasma total antioxidant power during perfusion compared with saline (p-value<0.05)		No numerical data was given. Did not compare lipoic acid with no TT (only with saline in TT). Time periods to administer lipoic acid are not feasible in humans (21 hours pre-detorsion).
Ozbal et al. 2012 Turkey	35 rats, split into 4 groups	Animal Study	Lipoic acid significantly increased MSTD (p-value <0.001) and SOD (p-value <0.01) compared to detorsion without medication. Lipoic acid decreased malondialdehyde compared to detorsion alone(p-value 0.016). Lipoic acid reduced caspase-3 positive cell numbers compared to untreated torsion.		Animal study (no humans)
Romeo et al. 2004 Italy	40 rats, split into 4 groups	Animal study	Raxofelast significantly reduced free radical damage within testicular tissue compared to detorsion alone(p-value <0.05). Raxofelast reduced histological testicular changes in seminiferous tubules, germ, Sertoli and Leydig cells.		Optimal dose not investigated. Long-term effects weren’t investigated.
Payabvash et al. 2007 Iran	70 rats, split into 5 groups	Animal Study	N-acetylcysteine administered 30 minutes before torsion or detorsion significantly reduced malondialdehyde (p-values <0.01 and <0.05), reduced germ cell apoptosis (p-values<0.05) and increased SOD (p-values <0.01 and <0.05).. N-acetylcysteine had no significant effect when given post-detorsion.		Long-term effects weren’t investigated. Different doses weren’t investigated.
Cay et al. 2006 Turkey	24 rats, split into 4 groups	Animal Study	N-acetylcysteine significantly decreased malondialdehyde compared to detorsion alone (p-value 0.05). N-acetylcysteine decreased SOD and glutathione reductase levels, but not significantly. N-acetylcysteine significantly improved histological testicular architecture compared to detorsion alone(p-value <0.0005)		No numerical data was reported for the assays. Long term effects weren’t investigated
Wei et al. 2020 China	60 rats, split into 3 groups	Animal study	Sesamol significantly reduced malondialdehyde compared to detorsion alone (p-value<0.05). Sesamol significantly improved testicular weight, MSTD and germ cell layers compared to detorsion alone (p-value<0.05).		Animal study (no humans)
Afolabi et al 2021 Nigeria	32 rats, split into 4 groups	Animal study	Cysteamine reduced ischaemia-reperfusion injury in TT – shown by reduced levels of H2O2, malondialdehyde and nitrite. (100mg/kg of cysteamine had p-values <0.001, <0.05 and <0.05 respectively). 100mg/kg of cysteamine increased testosterone levels compared to no treatment (p-value<0.01). Cysteamine didn’t significantly improve sperm count or viability (p-value>0.05). Cysteamine improved sperm motility (p-value <0.01 for 100mg/kg and <0.05 for 200mg/kg)		Rats were pre-treated one week before TT, which is not realistic in humans.

Comment(s)

Ischaemic-reperfusion damage can be assessed using biochemical assays and histomorphological evaluations. SOD, catalase, and glutathione are oxidative stress biomarkers. Their levels are reduced when free radical levels are high, for example in ischaemia. Therefore, increased SOD, catalase or glutathione suggest reduced ischaemia-reperfusion injury. Thiobarbituric acid-reactive substance, similarly, correlates with ischaemia, whereby low levels of the substance suggest low levels of ischaemic damage. Malondialdehyde, nitrite, nitric oxide and H2O2 can be used to evaluate the extent of cellular damage (potentially due to ischaemia). Decreased levels suggest decreased damage, and therefore reduced ischaemia-reperfusion injury. Testosterone, sperm count, sperm viability and sperm motility directly assess testicular function, which is reduced when the testes become damaged. Low levels thus suggest testicular damage, which could be secondary to ischaemia-reperfusion injuries. Mean Seminiferous Tubular Diameter (MSTD) indicates the size of the seminiferous tubule within the testes. Smaller diameters indicate atrophied tubules, potentially secondary to ischaemia. Thus, smaller diameters can signify increased ischaemic damage. The testicular weight corresponds to germ cell numbers – more cells mean more weight. Germ cell apoptosis frequently occurs in ischaemia-reperfusion injuries, thus reduced weight/cell number suggests increased ischaemia-reperfusion damage. Moreover, a decrease in caspase-3 positive cells, suggests reduced germ cell apoptosis, which suggests reduced ischaemia-reperfusion damage. From the evidence in the 17 studies, it can be concluded that antioxidants do reduce the impact of ischaemia-reperfusion injuries. Early evidence suggests administration of the antioxidant up to one-hour before detorsion is best in reducing damage in rats, however, this wasn’t acknowledged in all papers, and no paper looked at the impact antioxidants have in human subjects. Twelve different antioxidants were investigated, with all but one showing promise. Although lycopene appeared to improve testicular damage in the short-term (3-days), there was less significant over time. Further research should be conducted to compare different antioxidants, to determine the optimal agent, dosage, and administration time in humans.

Clinical Bottom Line

Antioxidants are shown to reduce ischaemia-reperfusion injuries; however, the best antioxidant is not yet determined. Further research must be conducted before these agents are used in clinical practice.

References

1. Kemahli et al. An experimental study on effects of pyrrolidine dithiocarbamate on ischemia-reperfusion injury in testis
2. Kabay et al. Protective effects of the nuclear factor kappa b inhibitor pyrrolidine dithiocarbamate on experimental testicular torsion and detorsion injury
3. Demir et al. Astaxanthin Protects Testicular Tissue against Torsion/Detorsion-Induced Injury via Suppressing Endoplasmic Reticulum Stress in Rats
4. Baskovic et al. The effect of astaxanthin on testicular torsion-detorsion injury in rats - Detailed morphometric evaluation of histological sections
5. Baskovic et al. Astaxanthin Relieves Testicular Ischemia-Reperfusion Injury-Immunohistochemical and Biochemical Analyses
6. Sugiyama et al. Beneficial effects of (-)-epigallocatechin gallate on ischemia-reperfusion testicular injury in rats
7. Chi et al. Comparison of quercetin and resveratrol in the prevention of injury due to testicular torsion/detorsion in rats
8. Guzel et al Effectiveness of lycopene on experimental testicular torsion
9. Hekimoglu et al. Lycopene, an antioxidant carotenoid, attenuates testicular injury caused by ischemia/reperfusion in rats
10. Wei et al. Probucol Reduces Testicular Torsion/Detorsion-Induced Ischemia/Reperfusion Injury in Rats
11. Guimaraes et al. Protective effect of alpha-lipoic acid in experimental spermatic cord torsion
12. Ozbal et al. The effects of alpha-lipoic acid against testicular ischemia-reperfusion injury in rats
13. Romeo et al. Raxofelast, a hydrophilic vitamin e-like antioxidant, reduces testicular ischemia-reperfusion injury
14. Payabvash et al. Salutary effects of N-acetylcysteine on apoptotic damage in a rat model of testicular torsion
15. Cay et al. The effects of N-acetylcysteine on antioxidant enzyme activities in experimental testicular torsion
16. Wei et al. Sesamol Protects Testis from Ischemia-Reperfusion Injury through Scavenging Reactive Oxygen Species and Upregulating CREM tau Expression
17. Afolabi et al Cysteamine mitigates torsion/detorsion-induced reperfusion injury via inhibition of apoptosis