Fig. 2.

Insights on the development of anti-complement drugs from natural products. Firstly, the fingerprint of traditional Chinese medicine (TCM) can be established through LC/MS, GC/MS and NMR. Secondly, combining metabolomics and serum pharmacochemistry, the potential anti-complement medicinal ingredients are preliminarily filtered out through phytochemical separation, anti-complement experimental verification and network pharmacology. Thirdly, after the study of absorption, distribution, metabolism, excretion, and toxicity of drugs (ADMET), the effective multi-component Chinese medicines including prototype and metabolic components will be found. In this process, potential anti-complement compounds with definite efficacy and specific targets can be screened by biochromatography and experimental evaluation (in vivo and in vitro experiments). Finally, for products whose bioavailability has reached the development level, that can enter detailed and rigorous clinical studies after structure optimization and formulation development. Researches on patient response, treatment and/or toxicity is the key end-point control to promote the application of anti-complement strategies in critically ill patients with COVID-19