Acaricidal mechanism and active compounds of Ligusticum striatum methanol extract against Dermatophagoides farinae.

Dermatophagoides farinae is a species closely linked to human health. This study investigated the acaricidal efficacy of methanol extracts from 18 traditional Chinese medicinal plants against D. farinae. The extract from Ligusticum striatum DC. exhibited the highest acaricidal properties. Sequential extraction was applied to reveal the active component in the ethyl acetate extract, identified as senkyunolide A (SEA) by liquid chromatography-mass spectrometry (LC-MS) and nuclear magnetic resonance (NMR) analyses. Transcriptomic analysis was performed following SEA exposure for 6, 12, and 24 h, revealing a total of 8212, 4000, and 10 940 differentially expressed genes (DEGs) in D. farinae, respectively. Gene Ontology (GO) enrichment analysis indicated that the DEGs in the three time periods were mainly enriched in cellular processes, binding and catalytic activity, and cell and cellular parts. Kyoto Encyclopaedia of Genes and Genomes (KEGG) enrichment analysis identified substantial changes in the oxidative phosphorylation pathway over the three time periods. These findings suggest that the acaricidal mechanism of SEA may disrupt energy metabolism, leading to metabolic disorders. SEA also exhibited an inhibitory effect on carboxylesterase among the detoxification enzyme genes, as well as an up-regulatory effect on calmodulin (CaM), which may lead to nerve cell death, ultimately resulting in the mortality of D. farinae.