The mechanisms of leptin induced steroidogenesis collapse in TM3 Leydig cells and an investigation into the potential protective role of Sutherlandia frutescens extract

Abstract

Metabolic syndrome, often accompanied by hyperleptinemia, is frequently implicated in male hypogonadism, impacting approximately 40% of men aged 45 and older. Elevated leptin levels adversely affect Leydig cell function. This study aims to investigate leptin's role in Leydig cell dysfunction and explores the potential protective effects of Sutherlandia frutescens against leptin-induced hypogonadism. Two models were employed: a basal model with no hCG stimulation and another model stimulated with hCG. TM3 Leydig cells were exposed to increasing leptin concentrations (0.001-100 ng/ml) for 24, 48, and 72 hours. Morphological, proliferative, and apoptotic effects on TM3 cells were assessed using light microscopy, TUNEL, and ApoTox assays and caspase 3/7 activation. Steroidogenesis was evaluated by quantifying testosterone concentrations, and oxidative stress was determined using a dihydroethidium (DHE) staining kit. In the hCGstimulated model, the potential protective effects of S. frutescens were evaluated using selected assays. Statistical analysis was performed using MedCalc version 16.4.3, and significance was set at p < 0.05. Leptin exposure led to time and dose-dependent morphological changes, reduced viability, increased apoptosis, and elevated ROS generation in both models. Significant DNA damage and decreased testosterone levels were also observed across a wide range of leptin concentrations, indicating severe Leydig cell dysfunction. Though the in vitro exposure to leptin induced TM3 Leydig cell dysfunction through oxidative stress, apoptosis, and impaired steroidogenesis.