Avaliação do potencial protetor do extrato seco de Tribulus terrestris sobre o dano induzido por ciclofosfamida no sistema reprodutor masculino de camundongos

Abstract

Cyclophosphamide (CP) is an antineoplastic and immunosuppressive agent. It is a drug used to treat various tumours types, and also to prevent rejection in organ transplantation and autoimmune diseases such as rheumatoid arthritis and lupus erythematosus. The CP is a prodrug which is biotransformed in the liver by cytochrome P450 enzymes to generate active metabolites phosphoramide mustard and acrolein. Its metabolites can cause oxidative stress state, leading to damage in various organs, including the reproductive system. Tribulus terrestris (TT) is part of the family of Zygophyllaceae, it is a perennial creeping herb with a widespread distribution in the Mediterranean, subtropical climates and desert around the world. In traditional folk medicine, it has been used since ancient times as an aphrodisiac, to energize, vitalize and improve sexual function and physical performance in men and to treat urinary infections, inflammation, edema and other diseases. Although experimental and clinical studies partly confirm that some effects of TT on libido and sperm production are involved with the major component of this plant, protodioscin, there is still much debate about the possible mechanisms of action, as well as their therapeutic application. Considering the antioxidant and steroidogenic potential of TT, this study has the objective of investigating the protective potential of TT dry extract against testicular damage induced by cyclophosphamide in male mice. The male Swiss mice received the TT dry extract as pretreatment by gavage for 14 days at a dose of 11 mg kg-1. On day 14, animals received a single intraperitoneally injection of cyclophosphamide at a dose of 100 mg kg-1. After 24 hours, the animals were anesthetized and euthanized, and blood, testes and epididymis were removed for further biochemical analyzes, sperm and histological evaluation. The presence and quantification of protodioscin in TT extract were analyzed by HPLC (High Performance Liquid Chromatography), where a concentration of 1.48% of dry extract was verified. CP caused an imbalance in the reproductive system of these animals by increasing the reactive species (RS), ix lipid peroxidation (TBARS) and protein carbonylation, as well as change in antioxidant enzymes: superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione S-transferase (GST) and glutathione reductase (GR). The pre-treatment with TT was effective in protecting against this damage. Furthermore, a reduction in the activity of 17β-hydroxysteroid dehydrogenase (17β-HSD) was found, confirming the reduction of serum testosterone levels observed in this study. Additionally, when analyzing the histopathology of the animals’ testes, we perceived a moderate disruption of spermatogenesis epithelium, as well as a congestion of interstitial blood vessels. These findings corroborate the results found in seminal evaluation of the animals treated with CP, where we observed a decrease in motility (41.07%), vigor (23.52%), membrane integrity (43,44%) and curved-straight speed (25.43%), and the pre-treatment with TT was effective in protecting against this damage. In conclusion, this study aimed to demonstrate for the first time the protective potential of TT dry extract against damage to the male reproductive system of mice exposed to CP chemotherapy. Improvement of these parameters may be related to antioxidant and steroidogenic potential as well as the amount of protodioscin observed in this extract.