Static magnetic field-induced metabolic shifting: coordinated phenylpropanoid induction and antioxidant system regulation in Calotropis procera callus culture

Abstract Background Calotropis procera is a medicinally significant plant valued for its diverse bioactive pharmacological compounds. Environmental stimuli, such as static magnetic field (SMF), can act as potent elicitors, altering its metabolic pathways. This study investigates the impact of SMF exposure (150 mT) for 0, 1, 2, or 3 h on primary and secondary metabolite components, antioxidant responses, and gene expression of C. procera callus cultures. Results SMF induced significant, time-dependent metabolic changes. Soluble sugars increased 1.6-fold after 3 h, while soluble proteins declined to 0.47-fold of controls. Phenylpropanoid biosynthesis was markedly enhanced, with phenolics and flavonoids increasing 7.5- and 3.2-fold, respectively. HPLC analysis revealed a coordinated upregulation of phenolic and flavonoid compounds. Kaempferol and ellagic acid showed a 115% increase, while gallic acid and quinic acid derivative increased by over 116%. Conversely, cardiac glycosides and saponins were suppressed. Concurrently, SMF exposure triggered ROS, with levels of O 2 −• , H 2 O 2 , OH • , and MDA increasing by 462, 117, 160, and 233%, respectively. However, the antioxidant capacity significantly improved, showing 6.91 and 25.93% increases in AsA and GSH levels, alongside 2.32- and 0.30-fold increases in DPPH • scavenging and total antioxidant activity. CAT, POD, and SOD activities declined, while GR activity increased. Gene expression analysis revealed profound upregulation of phenylpropanoid pathway enzymes, particularly PAL (549.89-fold), CHI (100.60-fold), and F3H (50.90-fold). Conclusions These results demonstrated that SMF elicited coordinated metabolic reprogramming in C. procera , enhancing non-enzymatic antioxidants and phenylpropanoid biosynthesis while suppressing steroidal pathways and enzymatic antioxidant activity, highlighting its potential as a biophysical tool for metabolic engineering.