Plasma metabolomics combined with lipidomics profiling reveals the potential antipyretic mechanisms of Qingkailing injection in a rat model

• Non-targeted metabolomics combined with lipidomics profiling strategy was presented.
• New biomarkers related to antipyretic effect of Qingkailing injection were found.
• The antipyretic mechanism of Qingkailing injection was deciphered comprehensively.

Qingkailing injection (QKLI) has a notable antipyretic effect and is widely used in China as a clinical emergency medicine. To elucidate the pharmacological action thoroughly, following the investigation of the urine metabolome and hypothalamus metabolome, plasma metabolomics combined with lipidomics profiling of the QKLI antipyretic effect in a rat model is described in this paper. Compared with pure metabolomics profiling, this non-targeted plasma metabolomics combined with lipidomics profiling based on ultra-performance liquid chromatography-coupled with quadrupole time-of-flight mass spectrometry (UPLC Q-TOF/MS) could be used for a large-scale detection of features in plasma samples. The results showed that 15 metabolites at the 1 h time point and 19 metabolites at the 2 h time point after QKLI administration were associated with the antipyretic effect of QKLI, including amino acid, phosphatidylcholine and lysophosphatidylcholine. The metabolism pathway analysis revealed that the potential biomarkers, which were important for the antipyretic mechanism of QKLI, were closely responsible for correcting the perturbed pathways of amino acid metabolism and lipid metabolism. In conclusion, the use of complementary UPLC Q-TOF/MS based metabolomics and lipidomics allows for the discovery of new potential plasma biomarkers in the QKLI antipyretic process and the associated pathways, and aided in advancing the understanding of the holism and synergism of the Chinese drug.