Nine triterpene acids,
viz., six of the ursane type, ursolic acid (
1), corosolic acid (
2), 3-epicorosolic acid (
3), pomolic acid (
4), tormentic acid (
5) and hyptadienic acid (
6), and three of the oleanane type, oleanolic acid (
7), augustic acid (
8) and 3-epimaslinic acid (
9), among which
1 constituted the most predominant triterpene acid, were isolated and identified from ethanol extracts of the leaves of red perilla [
Perilla frutescens (L.) Britton var.
acuta Kudo] and green perilla [
P. frutescens (L.) Britton var.
acuta Kudo forma
viridis Makino]. These eight compounds,
1,
2,
4–
9, were evaluated for their inhibitory effects on 12-
O-tetradecanoylphorbol-13-acetate (TPA)-induced inflammation (1 μg/ear) in mice. All the compounds tested showed a marked anti-inflammatory effect, with a 50% inhibitory dose (ID
50) of 0.09–0.3 mg per ear. In addition, an evaluation against the Epstein-Barr virus early antigen (EBV-EA) activation induced by TPA showed five compounds,
1–
3,
5 and
9, with a potent inhibitory effect on EBV-EA induction (91–93% inhibition at 1×10
3 mol ratio/TPA). Furthermore, compound
5 exhibited strong antitumor-promoting activity in an
in vivo two-stage carcinogenesis test of mouse tumor by using 7,12-dimethylbenz(
a)anthracene (DMBA) as an initiator and TPA as a promoter.
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