Immunomodulatory Effects of Diterpene Quinone Derivatives from the Roots of Horminum pyrenaicum in Human PBMC

Table 1

Half maximal inhibitory concentration (IC₅₀) of Horminum pyrenaicum extract sub-fractions (HOR-a3 to HOR-a6) that had the largest effect on neopterin formation and IDO-1 activity, as indicated by the kynurenine to tryptophan ratio in phytohemagglutinin stimulated PBMC. More details are shown in the supplemental figure S1.

	Neopterin formation; IC50 [μg/mL]	IDO-1 activity; IC50 [μg/mL]
HOR-a3	63.8	7.02
HOR-a4	121	18.4
HOR-a6	159	34.0