Aqueous Seed Extract of Nigella Sativa Ameliorated Metronidazole-Induced Testicular Damage Via Up-Regulations of the Antioxidant System

Abstract

Background: Infertility is a condition characterized by the failure to achieve a pregnancy after 12 months or more of regular, unprotected sexual intercourse.

Objectives: To determine the effect of aqueous seed extract of Nigella sativa on testicular antioxidant levels in metronidazole-induced infertility in male Wistar rats.

Methods: A total of thirty-five (35) male Wistar rats (aged 7-10 weeks old) were randomly distributed into five different groups (n = 7 each); Group A (Control group), Group B (Metronidazole only), Group C (Metronidazole + aqueous seed extract of Nigella sativa), Group D (Metronidazole Recovery), and Group E (Metronidazole + aqueous seed extract of Nigella sativa + Recovery). Experimental animals received 500 mg/kg of metronidazole and 300 mg/kg of aqueous seed extract of Nigella sativa orally. 

Results: Metronidazole treatment caused a significant (p<0.05) reduction in the level of testicular glutathione (Control group - 3.50±0.50; MTZ only - 2.00±0.30; MTZ+NS - 2.50±0.40; MTZ+ NS+ Recovery - 2.80±0.40). Similar reductions occurred in the activities of testicular superoxide dismutase (Control - 1.58±0.10; MTZ only - 0.23±0.06; MTZ+NS - 0.68±0.10; MTZ+ NS+ Recovery - 0.68±0.10) and catalase (Control - 2.70±0.35; MTZ only - 0.70±0.25; MTZ+NS - 1.23±0.20; MTZ+ NS+ Recovery: 1.25±0.30) which was followed by histo-architectural alterations in the testes of rats. Thereafter, aqueous seed extract of Nigella sativa treatment improved all the initial alterations caused by metronidazole treatment. Two - weeks recovery period was accompanied by a significant (p = 0.017) increase in antioxidant enzyme activities of group E when compared with group B and group D.

Conclusions: The aqueous seed extract of Nigella sativa exerts its ameliorative effect by improving antioxidant enzyme activities in the testes which then protect the testes against oxidative damage, enhancing sperm quality, preventing apoptosis, supporting testicular function, and aiding tissue repair.