No abstract

Background Botulinum toxin (BoNT) is a widely used therapeutic agent that blocks the excessive release of acetylcholine at the neuromuscular junction. Previously, repeated intracremasteric injections and slight overdose of BoNT have been reported to induce adverse effects in the testicular parameter of experimental rodents. However, a mild dose of BoNT is highly beneficial against skin ageing, neuromuscular deficits, overactive urinary bladder problems, testicular pain and erectile dysfunctions. Considering the facts, the possible therapeutic benefits of BoNT on the testis might be achieved at a very minimal dosage and via a distal route of action. Therefore, we revisited the effect of BoNT, but with a trace amount injected into the vastus lateralis of the thigh muscle, and analyzed histological parameters of the testis, levels of key antioxidants and sperm parameters in ageing experimental mice. Results Experimental animals injected with 1 U/kg bodyweight of BoNT showed enhanced spermatogenesis in association with increased activities of key antioxidants in the testis, leading to enhanced amount of the total sperm count and progressive motility. Conclusions This study signifies that a mild intramuscular dose of BoNT can be considered as a potent treatment strategy to manage and prevent male infertility.

Acetylcholine (ACh), a key neurochemical messenger that plays key roles in neuroplasticity and muscle contraction. While ACh is important for the physiological function of the testis, abnormal levels of ACh cause testicular atrophy and male infertility. BOTOX is a therapeutic form of the botulinum neurotoxin that blocks the excessive release of ACh at the neuromuscular junction. Previously, repeated intracremasteric injections and slight overdose of BOTOX have been reported to induce adverse effects in the testicular parameter of experimental rodents. However, a mild dose of BOTOX is highly beneficial against skin ageing, neurological deficits, overactive urinary bladder problems, testicular pain and erectile dysfunctions. Considering the facts, the possible therapeutic benefit of BOTOX on the testis might be achieved via its minimal dose and indirect mode of action rather than repeated high quantity in the local supply. Therefore, we revisited the effect of BOTOX but with a trace amount injected into the vastus lateralis of the thigh muscle, and analyzed histological parameters of testis and quality of semen in ageing experimental mice. Experimental animals injected with 1 U/kg bodyweight of BOTOX showed enhanced spermatogenesis in associations with increased activities of key antioxidants in the testis, leading to increased total sperm count and motility. This study signifies that a mild intramuscular dose of BOTOX can be considered as a potential treatment strategy to manage and prevent male infertility.