Integrated morphology, chemical composition, and pharmacological efficacy to evaluate the quality changes of Maleic hydrazide treatment on Atractylodes macrocephala Koidz

Atractylodes macrocephala Koidz. is widely used in clinical practice due to its pharmacological efficacy. Maleic hydrazide (MH) is commonly applied to promote biomass accumulation, yet its effects on chemical composition and pharmacological efficacy remain poorly characterised. Here, field trials in two production regions compared untreated plants with those exposed to graded MH concentrations (80-, 160-, and 320-fold dilutions for the Hebei region; 60-, 120-, and 240-fold dilutions for the Zhejiang region). MH significantly increased yield and rhizome weight while elevating Indole-3-acetic acid, Starch, and Water-soluble polysaccharides. Conversely, key bioactive constituents, including Atractylenolide I, Atractylone, and Chlorogenic acid, declined significantly. Metabolomic profiling revealed increases in specific amino acids and reductions in oligosaccharides, and gas chromatography–mass spectrometry showed a broad decrease in volatile components. Pharmacological analyses further suggest that A. macrocephala without MH treatment may exhibit superior laxative activity. Collectively, MH applications enhance the yield of A. macrocephala but concurrently lead to a deterioration in its quality.