Proteomic and lipidomic characterization of Hemipyrellia ligurriens larval extracts using LC-MS/MS and GC-MS: Identification of putative antimicrobial molecules and preliminary functional assessment

Hemipyrellia ligurriens is a tropical blow fly (Diptera: Calliphoridae) of medical and forensic importance; however, the molecular composition of its larvae remains poorly characterized. Here, we provide the first integrative proteomic and lipidomic dataset describing the molecular composition of H. ligurriens larvae and comparing whole-body extracts (WE) with excretory-secretory (ES) products. Label-free LC-MS/MS analysis identified 9,444 proteins in WE and 10,977 proteins in ES products, revealing 7,896 shared proteins together with 1,548 WE-specific and 3,081 ES-specific proteins. The proportion of ES-specific proteins was significantly higher than that of WE-specific proteins ( P  < 0.001), highlighting pronounced compartment-specific molecular diversity. Among proteins with molecular weights below 20 kDa, several putative antimicrobial peptides and immune-associated proteins were detected, including defensin-like, diptericin-like, and attacin-like sequences, as well as lysozyme isoforms, serine proteases, and oxidative stress-related enzymes. Lipidomic profiling of WE by GC-MS identified 26 fatty acids, comprising both saturated and unsaturated fatty acids. Functional assays demonstrated selective but moderate antibacterial activity: WE inhibited Bacillus subtilis and Pseudomonas aeruginosa , whereas ES products inhibited only B. subtilis (MIC > 400 μg/ml), and no antifungal activity was detected under the tested conditions. Cytocompatibility assays in HaCaT keratinocytes showed no cytotoxic effects of WE across tested concentrations and increased MTT-based metabolic activity after 24 h exposure, whereas ES products slightly reduced cell viability at the highest concentration tested (100 μg/ml). These findings support compartment-specific molecular organization between larval tissues and secretions, expand the molecular resources available for tropical calliphorid flies, and provide a foundation for future purification, functional validation, and biomedical investigations.