The discovery of the material basis and mechanism of gypsum as an antipyretic based on the theory of the diverse applications of raw and processed products

Ethnopharmacological relevance: Gypsum (CaSO₄·2H₂O), recognized as a classical mineral medicine in traditional Chinese medicine (TCM), has been traditionally used to treat fever. However, the specific bioactive constituents and the underlying molecular mechanisms of its action have yet to be fully elucidated.

Aim of the study: To address this knowledge gap, we systematically elucidated the antipyretic material basis and underlying mechanisms of gypsum through integrating the analysis of metal profile, gut microbiota profiling, and serum metabolomics.

Materials and methods: Metal chemical profiling was firstly used to elucidate the antipyretic composition by comparing the serum composition of gypsum and calcined gypsum. Subsequently, this research investigated the differential antipyretic effects of gypsum, calcined gypsum and key elements in a lipopolysaccharide (LPS)-induced fever model in rats by monitoring changes in body temperature and inflammatory cytokines. Furthermore, the underlying mechanism was explored through western blotting (WB), quantitative Real-Time PCR (qPCR), and gut microbiota in conjunction with metabolomics.

Results: The results reveal that Mg, CA, Zn, and Mo were the strong candidates for active substances of gypsum. Furthermore, the research proved that gypsum and key elements (Mg, CA, Zn, Mo) exhibits a notable antipyretic effect, while calcined gypsum does not. WB and qPCR analyses revealed a reduction in the expression of cyclooxygenase-2 (COX-2) in hypothalamic tissue in the gypsum-exposed group. Metabolomics profiling of serum suggests that the antipyretic effect of gypsum may involve primary bile acid biosynthesis. Association analysis involving gut microbiota indicated that gypsum may lead to the downregulation of five significant metabolites, including 15-Hydroxy-5,8,11,13-Eicosatetraenoic Acid, PC(16:1 (9Z)/0:0), PC(22:6 (4Z,7Z,10Z,13Z,16Z,19Z)/0:0) and PC(P-18:0/PGJ2), by downregulating Bacteroides, Ruminococcaceae and Roseburia to inhibit fever. Experiments involving fecal microbiota transplantation provide additional evidence for the involvement of gut bacteria in facilitating the antipyretic effects associated with gypsum.

Conclusions: This study pioneers in identifying the key elements (Mg, CA, Zn, Mo) as the core antipyretic component of gypsum while establishing a multidimensional "mineral composition-gut microbiota-host metabolism" interaction network. Our findings provide mechanistic insights for optimizing quality standards of mineral-based TCM formulations.

Action mechanism; Calcined gypsum; Effective material basis; Gypsum; Pharmacodynamics.