Ethnopharmacological relevanceWhile the seasonal variations in the human immune function and many infectious diseases are well-known, to develop therapeutic strategies regarding such seasonality is quite challenging. However, some traditional medical practices have already taken the seasonality into account, such as the “Season Tea” (ST) decoctions investigated in the present study. Aim of the studyWe present a study of the ST decoctions from traditional Chinese medicine, which include four formulae designed for the four seasons, aiming to investigate their pharmacological commonality and distinction. Materials and methodsA rat model of acute pharyngitis was utilized for the pharmacological study, and the effects of the ST decoctions were evaluated through histology, biomedical assays, microarray analysis, real-time quantitative PCR and Western blot. ResultsThe experimental data show that all of the four ST formulae display good pharmaceutical effects on acute pharyngitis, and circadian rhythm appears to be a significant pathway for investigating their pharmacological commonality and distinction. Specifically, while all of the four ST decoctions can regulate the circadian-rhythm-related genes ARNTL and BHLHE40, the regulation is along different directions with the modification of the supplements and the substrates in each ST formula. ConclusionThese results indicate the correlation between the acute pharyngitis and circadian rhythm, and illustrate the possibility of synergistically and subtly regulating ARNTL and BHLHE40, which is significant for relevant drug development.