Effective Compounds From Caesalpinia sappan L. on the Tyrosinase In Vitro and In Vivo

Caesalpinia sappan L. has been used as an herbal medicine to treat skin damage as a facial cleanser. In this study, 8 known compounds (1-8), (3 R,4 S)-3-(3′,4′-hydroxybenzyl)-3,4-dihydro-2″,3″-dimethyl-3 H-[1,3]dioxolo [4,5-c]chromen-7-ol (1), brazilin (2), protosappanin A (3), protosappanin C (4), protosappanin B (5), caesalpin J (6), sappanone B (7), and sappanchalcone (8), were isolated from the 70% ethanol extract of C. sappan. The effects of 8 compounds and extracts of C. sappan on tyrosinase were assayed in vitro and in vivo. The results indicated that compounds 1, 2, 4, and 7 had activating effects on the tyrosinase. The experiments of enzyme kinetics showed that compounds 3 and 6 were competitive inhibitors on tyrosinase, while compound 6 was anticompetitive inhibitor. The 70% ethanol extract of C. sappan could reduce the contents of tyrosinase in rat serum, ie, the 70% ethanol extracts of C. sappan could inhibit the formation of melanin in vivo. Compounds 2, 3, 5, and 6 promoted the formation of tyrosinase in rat serum, while compound 7 inhibited the synthesis of tyrosinase in rat serum.