Nsikak Michael Umoh¹ , Effiong M Oku¹, Eru E Mba¹, Victor K Uno², Eric A Agim¹, Kelechi C Uruakpa¹, Cyril A Agbor¹, Emmanuel I Odom¹, Godwin A Bekwapu¹

¹Department of Anatomical Sciences, Faculty of Basic Medical Sciences, College of Medical Sciences, University of Calabar,; ²Department of Human Anatomy, Arthur Jarvis University, Cross River State, Nigeria.

For correspondence:-  Nsikak Umoh   Email: nsikakumoh@unical.edu.ng   Tel:07039413733

Received: 25 July 2026        Accepted: 20 October 2026        Published: 31 October 2026

Citation: Umoh NM, Oku EM, Mba EE, Uno VK, Agim EA, Uruakpa KC, et al. Protective effects of combined extracts of Allium cepa, Allium sativum and Citrullus lanatus on the testis and semen parameters in Streptozotocin-induced diabetes in adult male wistar rats. Trop J Pharm Res 2026; 25(10):1417-1423 doi: 10.4314/tjpr.v25i10.9

© 2026 The authors.
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Abstract

Purpose: To investigate the protective and androgenic effects of combined extracts of Allium cepa (onion), Allium sativum (garlic), and Citrullus lanatus (watermelon) on testicular histology and semen parameters in streptozotocin-induced diabetic male Wistar rats. Methods: Twenty male Wistar rats were divided into five groups: control given distilled water (10 mL/kg), diabetic control, Viagra-treated (10 mL/kg), low-dose combined extracts (250 mg/kg), and high dose combined extracts (500 mg/kg) orally administered through a gavage. Diabetes was induced with a single intraperitoneal injection of streptozotocin at 45 mg/kg. Following confirmation of hyperglycemia, animals received once-daily oral administration of the combined plant extracts for 21 days at doses of 250 and 500 mL/kg or Viagra (10 mL/kg). The experiment was terminated on day 22. Semen analysis assessed pH, sperm motility, viability, and count. Testicular tissues were examined histologically. Data were analyzed using one-way ANOVA with Tukey's post-hoc test, considering p < 0.05 as statistically significant. Results: Diabetic control rats exhibited significant reductions in sperm motility, viability, and sperm count (p < 0.05), and histological abnormalities such as thickened seminiferous tubules and vacuolations in comparison with control. Treatment with low and high doses of the combined extracts significantly improved semen parameters, approaching control levels (p < 0.05), with histology revealing near-normal testicular architecture. The effects of the combined extracts show improvements in sperm quality approaching the levels of the control and Viagra, likely via their antioxidant and androgenic mechanisms. Conclusion: The combined extracts of Allium cepa, Allium sativum, and Citrullus lanatus effectively mitigate diabetes-induced reproductive impairments in male rats, supporting their potential as natural, safe interventions for improving male reproductive health in diabetic conditions.

Keywords: Allium cepa, Allium sativum, Citrullus lanatus, Male reproductive health, Semen parameters, Streptozotocin-induced diabetes, Testicular histology

Impact Factor
Thompson Reuters (ISI): 0.6 (2023)
H-5 index (Google Scholar): 49 (2023)