# Evaluating the Antioxidant Potential of Coumestrol in the Treatment of Tripterygium Glycoside-Induced Oligospermia in Rats and Its Potential Mechanisms

## TL;DR

This study shows that coumestrol can reduce testicular damage caused by tripterygium glycoside in rats by improving antioxidant defenses and sperm quality.

## Contribution

The study demonstrates coumestrol's novel protective effects against tripterygium glycoside-induced male reproductive toxicity in rats.

## Key findings

- COU treatment reduced oxidative stress markers like ROS and MDA in testicular tissue.
- COU restored antioxidant enzyme activity, including SOD and T-AOC, in TG-treated rats.
- COU improved sperm motility and concentration by counteracting TG-induced reproductive toxicity.

## Abstract

Tripterygium glycoside (TG) is recognized for its therapeutic potential against autoimmune conditions, including rheumatoid arthritis, glomerulonephritis, nephrotic syndrome, and lupus erythematosus. However, TG is also known to disrupt the oxidative balance in bio-systems, inducing oxidative stress-mediated toxic effects on testicular tissue. Coumestrol (COU) has been reported to ameliorate the deleterious impacts of cryo-damaged ovine semen by improving sperm antioxidant capacity, mitochondrial activity, acrosome, and DNA integrity. However, there is still limited knowledge about its reproductive efficacy in male animals. In this study, COU effectively ameliorated the oligospermia caused by TG toxicity in the testes of the experimental rats by increasing their antioxidant capacity through the production of antioxidant enzymes and reversing the oligospermia caused by TG toxicity in the testes of the experimental animals. Combining Western blot assays with network pharmacology analysis, we predicted that TG-induced reproductive toxicity may be associated with the PI3K-AKT/MAPK signaling cascades. Notably, the analysis suggested that COU might counteract this pathway activation, thereby alleviating TG-mediated damage and ultimately enhancing sperm motility and concentration.

Tripterygium glycoside (TG) is known to disrupt the oxidative balance in bio-systems, inducing oxidative stress-mediated toxic effects on testicular tissue. This study aimed to explore the therapeutic potential of coumestrol (COU) against these adverse effects. Sixty-four male Sprague–Dawley rats were randomized into control and Tripterygium glycoside (TG) groups for four weeks. Following initial intervention, eight rats per group were sacrificed to verify the establishment of the oligospermia model and hormonal dysfunction. The remaining rats were subdivided into five therapeutic subgroups, TG, TG + L-carnitine, and three COU dosage groups (low, medium, and high) to evaluate potential protective effects. The present study comprehensively analyzed its impacts on testicular histomorphology, circulating testosterone, follicle-stimulating hormone (FSH) and luteinizing hormone (LH) levels, and redox balance status, as well as a suite of serum biochemical and physiological biomarkers. Our results revealed that TG induced oligospermia in rats, causing significant testicular oxidative stress characterized by excessive accumulation of reactive oxygen species (ROS) and malondialdehyde (MDA), alongside depleted superoxide dismutase (SOD) activity and total antioxidant capacity (T-AOC). Conversely, COU treatment effectively mitigated these impairments by significantly downregulating ROS and MDA levels while restoring SOD activity and T-AOC.