Protective effects of royal jelly in diabetic rat testis tissue through apoptotic and antiapoptotic pathways

Objective: Diabetic male subfertility and/or infertility represents an area of research that has attracted attention and therefore become a subject of investigation at the molecular level. The insulin-like effects, antihypertensive, antitumor, antioxidative, anti-inflammatory, and immunomodulatory roles of royal jelly (RJ) have been demonstrated by scientific research. This study was designed based on the hypothesis that RJ may have the potential to prevent apoptosis in testicular tissue and, consequently, exert a beneficial impact on spermatogenesis through its ability to mitigate the adverse effects of diabetes on testicular tissue. The aim is to identify some of the molecular factors that may be responsible for the therapeutic effects of RJ on diabetic testicular tissue. Methods: Apoptosis, proliferation, and Leydig cell functions were determined using the following markers: transferase dUTP nick end labeling analysis, c-Jun N-terminal kinase (JNK), p38, Fas, and FasL for apoptosis; proliferating cell nuclear antigen (PCNA) and extracellular signal-regulated kinase (ERK) for proliferation; and insulin-like peptide-3 (INSL3) for Leydig cell function. A total of 20 Wistar albino male rats were randomly assigned to 3 experimental groups. The control group (C) and the diabetic group (D) were administered a single dose of 50 mg/kg STZ (intraperitoneally), and the RJ group was given 400 mg/kg/day (ig.) RJ after a single dose of 50 mg/kg STZ. Results: While PCNA, ERK, and INSL3 immunoreactivities were significantly increased, the apoptotic cell and tubule indices, JNK, p38, Fas, and FasL immunoreactivities were significantly decreased in the RJ group compared to the D group. Conclusion: Royal jelly may have a protective effect in preventing diabetes-related male infertility through apoptosis and anti-apoptotic pathways.