Analysis of Processing Impact on Raspberries Based on Broad-Spectrum Metabolomics

Objective: Our objective was to explore the regulatory mechanism of salt processing on the metabolome of the raspberry and its potential efficacy against diabetic nephropathy (DN), providing metabolomic and network pharmacological evidence for the scientific connotation of traditional Chinese medicine processing. Methods: Ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS)-based metabolomics was used to compare the metabolic profiles between raw and salt-processed raspberries. Network pharmacology was applied to screen the common targets of the active components in the salt-processed raspberry and DN-related pathways, followed by in vitro cell experiments to validate the regulation of the MAPK signaling pathway. Results: The metabolomic analysis identified 80 differentially expressed metabolites, among which 13 key components (VIP ≥ 1, FC ≥ 2) were significantly altered, including enriched flavonoids (e.g., luteolin-7-O-glucoside), triterpenoid saponins (Raspberryides H/F), and phenolic acids (ellagic acid). The network pharmacology revealed that the salt-processed raspberries regulated the DN-related pathways through 122 common targets, with the core nodes focusing on the signaling molecules (e.g., AKT1, EGFR) involved in the MAPK signaling pathway and apoptosis regulation. The in vitro experiments confirmed that the salt-processed raspberry extract (160-640 μg/mL) significantly inhibited the phosphorylation levels of p38/ERK/JNK in high-glucose-induced renal cells. Conclusions: This study firstly combines metabolomics and network pharmacology to reveal the regulatory mechanism of salt processing on the active components of raspberries. The salt-processing technology enhanced the inhibitory effect of raspberries on the MAPK signaling pathway, thereby ameliorating the progression of DN. These findings provide scientific support for establishing a metabolomics-based quality control system for traditional Chinese medicine processing. The current findings are primarily based on in vitro models, and in vivo validation using DN animal models is essential to confirm the therapeutic efficacy and safety of salt-processed raspberries.