Mutton fat-processing enhances the anti-osteoporotic effect of Epimedium koreanum Nakai via regulating the metabolism-inflammation-bone axis.

Epimedium koreanum Nakai is a well-recognized tonic herb in traditional Chinese medicine that has been extensively used for thousands of years in the management of bone metabolic diseases. According to classic traditional Chinese medicine processing principles, stir-frying Epimedii Folium with mutton fat can synergistically augment its "kidney-warming and bone-strengthening" therapeutic effects. However, the modern pharmacological basis and precise molecular mechanisms underlying this processing-enhanced efficacy remain largely unexplored. This study aimed to compare the anti-osteoporotic effects of raw and mutton fat-processed Epimedii Folium in postmenopausal osteoporosis, and to reveal the underlying mechanisms. Multiple techniques were applied, including ultra performance liquid chromatography coupled with Q Exactive mass spectrometry, network pharmacology, cell and animal models, non-targeted metabolomics, Western blot analysis, and quantitative real-time reverse transcription polymerase chain reaction. These approaches enabled component analysis, mechanism prediction, and multi-level in vitro and in vivo validation. Processed Epimedii Folium contained more blood-absorbed constituents, and more effectively improved bone mass, trabecular structure, osteoclast activity and osteogenesis. It regulated glycerophospholipid metabolism, inhibited inflammatory signaling, and relieved stress on the osteoprotegerin/receptor activator of nuclear factor-κB ligand axis to restore bone homeostasis. Mutton fat-processed Epimedii Folium exerts anti-osteoporotic effects through a "metabolic remodeling-inflammation inhibition-bone homeostasis restoration" axis. This study provides modern scientific evidence for the processing method of Epimedium recorded in the Chinese Pharmacopoeia, and offers a valuable paradigm for research on traditional Chinese medicine processing.