Inhibition of Phospholipase Cγ1 Activity by Amentoflavone Isolated from Selaginella tamariscina

Abstract

Amentoflavone was isolated as an inhibitor of phospholipase Cγ1 (PLCγ1) and phosphoinositides (Pl)-turnover in PLCγ1 overexpressing NIH3T3 fibroblasts (NIH3T3γ1) from Selaginella tamariscina (Selaginellaceae) together with other related biflavonoids, isocryptomerin and cryptomerin B. Only amentoflavone inhibited the PLCγ1 activity with an IC₅₀ of 29 µM and the formation of total inositol phosphates (IP_t) in PDGF-stimulated NIH3T3γ1 with an IC₅₀ of 9.2 µM but did not show inhibitory activity against protein kinase C. Isocryptomerin and cryptomerin B did not show inhibitory activity against PLCγ1 at the concentration of 150 µM, and did not inhibit IP_t production in PDGF-induced NIH3T3γ1 at the concentration of 180 µM.

Key words

Phospholipase Cγ1 inhibitor - phosphoinositides (Pl)-turnover - amentoflavone - Selaginella tamariscina - Selaginellaceae - Kampo medicines