Analysis of S3-Aminopropyl Thiosulforic Acid from Pterocarpus santalinoides in Modulating Antioxidant Enzymes under Cadmium-Induced Oxidative Stress: A Computational and Experimental Approach

Abstract

Cadmium (Cd) is an environmental toxicant that exerts oxidative stress by disrupting antioxidant defense mechanisms, causing damage to vital organs, including the liver and kidneys. This study presents a computational and experimental evaluation of S3-aminopropyl thiosulforic acid, a sulfur-containing bioactive compound identified from Pterocarpus santalinoides, as a potential modulator of antioxidant enzymes under cadmium-induced oxidative stress. Molecular docking was carried out to assess the binding affinity of S3-aminopropyl thiosulforic acid against superoxide dismutase (SOD), catalase (CAT), and Glutathione peroxidase (GPx), while the in vivo studies assessed enzyme modulation in cadmium-exposed Wistar rats treated with Pterocarpus santlinoides powder. Docking revealed that S3-aminopropyl thiosulforic acid demonstrated moderate binding affinities between -3.8 to -4.8 kcal/mol with the active residues of SOD, CAT and GPx, suggesting possible stabilization and protection of enzymatic activity. ADMET analysis indicated favorable pharmacokinetic properties and nontoxic profiles of S3-aminopropyl thiosulforic acid. Experimentally, cadmium exposure significantly decreased (p < 0.05) the hepatic SOD, CAT, and GPx activities, which were markedly restored toward the respective control levels by P. santalinoides treatment. The restoration correlated with the predicted molecular interactions, suggesting that the bioactives of P. santalinoides modulate antioxidant systems by preventing cadmium-induced inactivation of enzymes and possibly by cadmium chelation and upregulation of the antioxidant response pathways. This integrated computational and biochemical evidence demonstrates the strong antioxidant modulatory potential of Pterocarpus santalinoides against cadmium toxicity. These findings therefore suggest its promise as a natural protective agent or nutraceutical in the prevention of heavy metal-induced oxidative stress.