Scientific Researches On:
Betulinic Acid (Birch Bark Extract)
USA National Center for
Biotechnology Information
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101:
Oncology. 1991;48(1):72-6.
Sterol and triterpene
derivatives from plants inhibit the effects of a
tumor promoter, and sitosterol and betulinic
acid inhibit tumor formation in mouse skin
two-stage carcinogenesis.
Yasukawa K,
Takido M,
Matsumoto T,
Takeuchi M,
Nakagawa S.
College of Pharmacy, Nihon University, Chiba,
Japan.
A single topical application of 1 microgram of
12-O-tetradecanoylphorbol- 13-acetate (TPA) to
the ears of mice was shown to induce edema, and
this TPA-induced inflammation was inhibited by
4-methylsterol and triterpene derivatives. The
ED50 of these compounds against TPA-induced
inflammation was 0.1-3 mumol. Phytosterols had
only slight inhibitory effects. Furthermore,
application of 5 micrograms TPA to mouse skin
rapidly caused accumulation of ornithine
decarboxylase (ODC). Similarly, sitosterol and
lupane-type triterpene derivatives markedly
inhibited this TPA-induced ODC accumulation. In
addition, 5 mumol betulinic acid markedly
inhibited the promoting effect of 2.5 micrograms
TPA applied twice weekly on skin tumor formation
in mice initiated with 50 micrograms of
7,12-dimethylbenz[a]anthracene, and 5 mumol of
sitosterol caused slight suppression. Thus, the
inhibitory effects of sterol and triterpene
derivatives on TPA-induced inflammation roughly
parallelled their inhibitory activities against
tumor promotion.
Publication Types:
PMID: 1898988 [PubMed - indexed for MEDLINE]
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