Network pharmacology integrated with molecular docking reveals the common experiment-validated antipyretic mechanism of bitter-cold herbs

Bitter-cold herbs have been used to clearing heat and expelling damp in clinical practice in China for thousands of years. Aim of the study: This study aimed to investigate the common molecular mechanism of bitter-cold herbs through network pharmacology analysis, molecular docking and experimental validation in vivo. Network pharmacological analysis integrated with molecular docking was employed to identify the active compounds and core action targets of the bitter-cold herbs. Then, the yeast-induced pathological model was established, and the antipyretic effect of the herbs was evaluated by checking rectal temperatures of the mice hourly. Lastly, the protein expression of core targets was examined to reveal the antipyretic mechanism. A total of 52 lead compounds from the four bitter-cold herbs, Phellodendri Chinensis Cortex (PCC), Sophorae Flavescentis Radix (SFR), Gentianae Radix Et Rhozima (GRER) and Coptidis Rhizoma (CR), and 248 compounds-related targets were screened out with PTGS2 ranking the first. The results from molecular docking showed that 22 compounds adopted the same orientation as aspirin and had an excellent stability in the active site pocket of PTGS2. Furthermore, these herbs exerted potential therapeutic effects through 38 related pathways. On the other hand, the outcome of animal experiments showed that they could significantly attenuate the yeast-induced mice fever with dose-dependent relationship. Further experimental results demonstrated that administration of yeast suspension raised protein expression of PTGS2 significantly, which was evidently inhibited in the high or low-dose groups of GRER as well as in the low-dose group of SFR (P < 0.01) though a higher expression of PTGS2 was shown in the low-dose group of CR compared with FM group (P < 0.01). The bitter-cold herbs can alleviate fever response and their antipyretic effect may mainly be attributed to regulating the expression of PTGS2 after the formation of ligand-receptor/PTGS2 complexes, and their active compounds might be nominated as antipyretic lead-ligand candidates.