Pharmacological mechanism of indigenous herb Exacum lawii on cisplatin instigated toxicity in human embryonic kidney cells (HEK-293)

Abstract

Background: Exacum lawii C.B. Clarke (Gentianaceae) bitter medicinal herb, has been extensively applied for the treatment of kidney diseases and ailments by Indigenous medical practitioners and local communities in Maharashtra and Karnataka states of India. The pharmacognostical and phytochemical standardization has been performed, but its therapeutic mechanism is still unknown. Swertiamerin, a secoiridoid glycoside established as marker component. The aim of the current research is to investigate the cytoprotective ability and examine targets of action of Exacum lawii standardised extract against cisplatin exposed Human embryonic kidney cell line (HEK-293). Methods: Swertiamerin was isolated from standardised extract using column chromatography and characterized by various analytical techniques. In-vitro cellular assay (MTT cytotoxicity assay, iNOS expression, proinflammatory cytokine level, ROS estimation and cell cycle progression, DNA fragmentation assay and morphology of cells) were employed to understand the efficacy and mechanism of action of standardised extract and swertiamerin against cisplatin induced toxicity in HEK-293 cells. Results: Extract and swertiamerin summed up to be nontoxic to HEK-293 cells and the IC50 for cisplatin was 2.261 µg/ml. Molecular docking study showed the binding capacity of swertiamerin for iNOS enzyme (responsible for the nitrosative stress in cells). Various Scientific techniques validates the potential of extract and swertiamerin to reduce the nitrosative stress, oxidative stress, and inflammation in HEK-293 cells significantly (P < 0.05) at the dose of 50 µl (2 mg/ml) and 20 µl (0.5 mg/ml) respectively. Conclusion: This study validates the ethnomedicinal use herb Exacum lawii in nephrotoxicity. Swertiamerin as the characteristic bioactive compound might works synergistically with other phytoconstituents to prevent the cellular damage from nitrosative stress, oxidative stress, and inflammation. Therefore, present study emphasizes on the mechanism of action involved in pharmacological activity.