PTGS1 and pulmonary arterial hypertension: Kaempferol reverses the abnormal elevation of TCA cycle-related metabolites such as succinic acid and citric acid in the plasma of PAH rats by regulating amino acid metabolism and arachidonic acid metabolism, downregulates the pro-inflammatory metabolite 12-HETE, upregulates the anti-inflammatory metabolite DHA, and inhibits the expression of PTGS1 (Yi et al., 2022).