Abstract
BACKGROUND/OBJECTIVES: Mastitis adversely affects human lactation, and there is a need for effective natural therapeutic agents. Poplar-type propolis is known for its anti-inflammatory properties, but its protective effects and mechanisms against mastitis remain unclear. This study aimed to investigate the therapeutic potential and underlying mechanisms of ethanol extract of Chinese propolis (EECP) against lipopolysaccharide (LPS)-induced mastitis. METHODS: An integrated approach combining network pharmacology and transcriptomics was employed. In vivo validation was conducted using an LPS-induced mouse mastitis model in female BALB/c mice. Molecular docking was used to confirm interactions between key EECP components and core targets. RESULTS: Network pharmacology identified 36 potential targets, primarily involved in inflammatory and immune pathways such as tumor necrosis factor (TNF), nuclear factor kappa B (NF-κB), janus kinase-signal transducers and activators of transcription (JAK-STAT), phosphatidylinositol 3-kinase/protein kinase B (PI3K-AKT), and interleukin (IL)-17 pathways. In vivo experiments demonstrated that EECP significantly alleviated LPS-induced histopathological damage, reduced neutrophil infiltration, and decreased the expression of proinflammatory cytokines (TNFα, IL1β, and IL6). Furthermore, EECP restored the expression and distribution of tight junction proteins (ZO-1 and occludin), thereby preserving blood-milk barrier integrity. Transcriptomic analysis confirmed that EECP reversed LPS-induced gene expression changes and downregulated key inflammation-related pathways, including TNF, NF-κB, JAK-STAT, and IL-17. Integrated analysis identified TNF, IL6, IL1B, interferon gamma (IFNG), STAT3, and CXCL8 as core targets. Molecular docking confirmed strong binding interactions between characteristic propolis polyphenols (e.g., chrysin, CAPE, and galangin) and these core targets. CONCLUSIONS: EECP exerts protective effects against LPS-induced mastitis through the synergistic actions of multiple components. This study lays the preclinical foundation for considering poplar-type propolis as a candidate for the prevention or alleviation of mastitis, meriting further evaluation.