Guilu Erxian oral liquid mitigates oxidative damage in spermatogonial cells via miR-6739-5p modulation and PI3K/AKT pathway activation: a functional histocytochemical study.

Oxidative stress is a major contributor to male infertility, particularly oligoasthenozoospermia. This study aimed to investigate the cytoprotective mechanism of Guilu Erxian Oral Liquid (GLEX) against H₂O₂-induced oxidative damage in spermatogonial cells, focusing on miR-6739-5p regulation and activation of the PI3K/AKT pathway using histocytochemical approaches. An oxidative stress model was established in rat spermatogonial stem cells (SSCs) with 250 µM H₂O₂. Cell proliferation, apoptosis, reactive oxygen species (ROS) accumulation, and DNA oxidative damage were assessed using EdU incorporation, flow cytometry, immunofluorescence, and 8-hydroxy-2'-deoxyguanosine (8-OHdG) ELISA. Expression of miR-6739-5p and Phosphatidylinositol 3-Kinase/Protein Kinase B (PI3K/AKT) pathway components (PIK3CA, p-PI3K, p-AKT) was evaluated by RT-qPCR and Western blotting. The interaction between miR-6739-5p and PIK3CA was confirmed via dual-luciferase reporter assay. The cytoprotective effects of GLEX were examined through pre-treatment and quantified using histochemical and cytological markers. H₂O₂ treatment significantly impaired cell viability, increased apoptosis and ROS production, and upregulated miR-6739-5p. Overexpression of miR-6739-5p exacerbated damage, while silencing reversed it and restored PI3K/AKT signaling. GLEX pretreatment effectively reduced miR-6739-5p expression, restored cell viability, suppressed oxidative and inflammatory markers (ROS, 8-OHdG, TNF-α, IL-1β), and enhanced PI3K/AKT activation. These effects were comparable to PI3K pathway activation. GLEX confers histocytochemical protection to spermatogonial cells under oxidative stress by downregulating miR-6739-5p and activating the PI3K/AKT pathway. This study highlights a novel regulatory mechanism and supports GLEX as a potential therapeutic agent for oxidative stress-associated male infertility.