Chemical composition of roman chamomile extracts and their effects on Caenorhabditis elegans

To explore the potential nematicidal activity of Roman chamomile extracts, Roman chamomile volatile oil was extracted via steam distillation (EO), ethanol extraction (EE) and petroleum ether extraction (PE). Sensory evaluation, gas chromatography-mass spectrometry (GC-MS), orthogonal partial least squares discriminant analysis (OPLS-DA), combined with Pearson correlation and partial least squares regression (PLSR) analysis were used to screen potential toxic components against nematodes in volatile oil. Meanwhile, Caenorhabditis elegans was used as a model organism to study the effects of Roman chamomile volatile oil on nematodes. The results showed that GC-MS detection identified abundant esters, terpenes, alcohols and other compounds in the volatile oil; among them, ester compounds contributed prominently to the intense floral and fruity notes of the oil. Roman chamomile volatile oil exerted inhibitory effects on nematodes, among which the EO showed the best efficacy. OPLS-DA screened 10 differential compounds with VIP > 1 and p < 0.05. Pearson and PLSR correlation analyses jointly indicated that 1,8-cineole, camphene, (+)-α-pinene, β-caryophyllene and pinocarvone exhibited significant correlations with the inhibitory effects on nematode physiological development and senescence. Compared with the control group, nematodes treated with the EO exhibited shortened lifespan, reduced locomotor activity, elevated intracellular ROS levels, and significantly enhanced lipofuscin autofluorescence, with more pronounced effects at higher concentrations. These findings provide a reference for the further development of botanical nematicidal products.