Summary What is known and background:  Although paracetamol (acetaminophen), N‐(4‐Hydroxyphenyl)acetamide, is one of the world’s most widely used analgesics, the mechanism by which it produces its analgesic effect is largely unknown. This lack is relevant because: (i) optimal pain treatment matches the analgesic mechanism to the (patho)physiology of the pain and (ii) modern drug discovery relies on an appropriate screening assay. Objective:  To review the clinical profile and preclinical studies of paracetamol as means of gaining insight into its mechanism of analgesic action. Methods:  A literature search was conducted of clinical and preclinical literature and the information obtained was organized and reviewed from the perspective of its contribution to an understanding of the mechanism of analgesic action of paracetamol. Results:  Paracetamol’s broad spectrum of analgesic and other pharmacological actions is presented, along with its multiple postulated mechanism(s) of action. No one mechanism has been definitively shown to account for its analgesic activity. What is new and conclusion:  Further research is needed to uncover the mechanism of analgesic action of paracetamol. The lack of this knowledge affects optimal clinical use and impedes drug discovery efforts.

Objective: To explore the active ingredients of ECT and their targets of asthma and investigate the potential mechanism of ECT on asthma. Methods: Firstly, the active ingredients and target of ECT were screened for BATMAN and TCMSP, functional analysis was finished via DAVID. Then, animal model was induced by ovalbumin (OVA) and aluminum hydroxide. Eosinophil (EOS) counts, EOS active substance Eosinophilic cationic protein (ECP) and eotaxin levels were detected followed the instruction. Pathological changes of lungs tissue were examined by H&E staining and transmission electron microscopy. Interleukin (IL-4, IL-10, IL-13, TNF-α), TIgE and IgE level in bronchoalveolar lavage fluid (BALF) were measured by ELISA. Finally, the protein expression of TGF-β / STAT3 pathway to lung tissue was detected by Western Blot. Results: A total of 450 compounds and 526 target genes were retrieved in Erchen tang. Functional analysis indicated that its treatment of asthma was associated with inflammatory factor and fibrosis. In the animal experiment, the results showed that ECT significantly regulated inflammatory cytokine (IL-4, IL-10, IL-13, TNF-α) levels in (P<0.05, P<0.01) , reduced EOS number (P<0.05) and also ECP and Eotaxin levels in blood (P<0.05) in BALF and / or plasma. Bronchial tissue injury was obviously improved on ECT treatment. Associated protein in TGF-β / STAT3 pathway were significantly regulated by ECT (P<0.05). Conclusion: This study originally provided the evidence that the Erchen tang was effective against the treatment of asthma symptoms, and its underlying mechanism might be regulation of inflammatory factor secretion and TGF-β/STAT3 signaling pathway.