Expression of cyclin D1, p21, and estrogen receptor alpha in aflatoxin G1-induced disturbance in testicular tissue of albino mice

Res Pharm Sci. 2021 Mar 5;16(2):182-192. doi: 10.4103/1735-5362.310525. eCollection 2021 Apr.

Abstract

Background and purpose: Aflatoxin (AF) is a mycotoxin produced by various strains of the Aspergillus family. AFG1 as one of the most important types is highly found in cereals and grains. AF affects sperm production or even its quality. This study was designed to test the effects of AFG1 on mice testicular tissue.

Experimental approach: Twenty-four Albino mice were divided into four groups of 6 each; a control group (0.2 mL corn oil and ethanol), three treatment groups with different periods (20 μg/kg AFG1 for 7, 15, and 35 consecutive days). All treatments were applied intraperitoneally. Biosynthesis of cyclin D1, p21, and estrogen receptor alpha (ERα) proteins was evaluated by immunohistochemistry (IHC) staining. Levels of cyclin D1, p21, and ERα mRNA were evaluated by the real-time polymerase chain reaction (RT-PCR) technique. Tubular differentiation index (TDI), reproductive index (RI), and spermiogenesis indices were also analyzed.

Findings/results: AFG1 increased the percentage of seminiferous tubules with negative TDI, RI, and SPI compared to the control group (P < 0.05). RT-PCR and IHC analyses illustrated time-dependent enhancement in p21 expression and cyclin D1 biosynthesis in AFG1-treated groups significantly (P < 0.05). While the protein and mRNA levels of ERα were significantly (P < 0.05) decreased in a time-dependent manner.

Conclusion and implications: The chronic exposure to AFG1 reduced the expression and synthesis of ERα, increased the expression and synthesis of p21 and cyclin D1, impaired apoptosis, which in turn could impair spermatogenesis.

Keywords: Aflatoxin G1; Apoptosis; Cyclin D1; Estrogen receptor alpha; p21.