Abstract
This study aimed to investigate the dose-dependent protective effects of Capsella bursa-pastoris extract (CBPE) against the phytotoxic and genotoxic impacts of the insect growth regulator Triflumuron (TFM), using the Allium cepa assay. A comprehensive evaluation was performed by analyzing physio-morphological (germination rate, root elongation, biomass gain, chlorophyll a and b levels), cytogenetic (mitotic index, micronucleus formation, chromosomal abnormalities), biochemical (superoxide dismutase, catalase, malondialdehyde, and proline levels), and molecular endpoints. The phytochemical profile of C. bursa-pastoris was characterized through LC-MS/MS analysis to determine the bioactive phenolic constituents. Allium bulbs were exposed to 20 µg/L TFM and co-treated with two concentrations of CBPE (45 and 90 µg/mL). The results demonstrated that TFM exposure significantly inhibited germination and root growth, reduced mitotic activity (by 6.57%), and induced notable oxidative and genotoxic stress. However, CBPE co-treatment led to considerable recovery in all measured parameters, with the mitotic index increasing to 7.05%-7.55%. TFM exposure markedly increased micronucleus frequency, whereas co-treatment with CBPE led to a dose-dependent reduction in MN frequency, ranging from 15.88% to 35.7%. CBPE demonstrated a strong protective effect against TFM-induced growth suppression, genotoxicity, oxidative stress, and structural deterioration in meristem cells in A. cepa. This protective property is associated with the phenolic compounds contained in CBPE. The most abundant phenolic compound in the extract was p-coumaric acid. The findings provide compelling evidence that C. bursa-pastoris extract mitigates TFM-induced cellular and biochemical disruptions by modulating oxidative stress and preserving genomic integrity. This is the first comprehensive demonstration of plant-based mitigation of TFM phytotoxicity, supporting sustainable remediation strategies.