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Planta Med 2001; 67(5): 396-399
DOI: 10.1055/s-2001-15810
Original Paper
Pharmacology
© Georg Thieme Verlag Stuttgart · New York

Effect of an Extract of the Root of Scutellaria baicalensis and its Flavonoids on Aflatoxin B1 Oxidizing Cytochrome P450 Enzymes

Bok-Ryang Kim1 , Dong-Hyun Kim2 , RaeKil Park1 , Kang-Beom Kwon3 , Do-gon Ryu3 , Youn-Chul Kim4 , Na-Young Kim4 , Sejn Jeong1 , Byung-Ki Kang3 , Kang-San Kim3,*
  • 1 Department of Biochemistry, Microbiology and Medicinal Resources Research Center, School of Medicine, Wonkwang University, Iksan, Korea
  • 2 Bioanalysis and Biotransformation Research Center, Korea Institute of Science and Technology, Seoul, Korea
  • 3 Department of Internal Medicine and Physiology, School of Oriental Medicine, Wonkwang University, Iksan, Korea
  • 4 College of Pharmacy, Wonkwang University, Iksan, Korea
Further Information

Publication History

July 18, 2000

October 22, 2000

Publication Date:
31 December 2001 (online)

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Abstract

The inhibition of aflatoxin B1 (AFB1) metabolism by a water extract of the root of Scutellaria baicalensis and its flavonoids was examined in liver microsomes. AFB1 is known to be metabolized to aflatoxin M1 (AFM1), aflatoxin Q1 (AFQ1), and AFB1-8,9-epoxide (AFBO). The water extract potently inhibited the production of AFM1 by cytochrome P450 (CYP)1A1/2 and slightly reduced AFBO formation by CYP1A1/2, CYP2B1, CYP2C11 and CYP3A1/2 in TCDD-treated rat liver microsomes. IC50 values for AFM1 and AFBO formation were 6.8 and 122.4 μg/ml, respectively. Wogonin showed the highest inhibitory activity towards AFM1 formation among the flavonoids isolated from the extract. On the other hand, the extract had no effects on the formation of AFBO and AFQ1 in human liver microsomes, and on the activities of CYP2B1, CYP2C11 and CYP3A1/2 which were detected by hydroxylation patterns of testosterone. These results demonstrated that the extract of the root of Scutellaria baicalensis has a specific inhibitory effect on CYP1A1/2 among CYP enzymes involved in AFB1 metabolism by rat and human microsomes.

Key words

Scutellaria baicalensis - Labiatae - flavonoid - aflatoxin B1 - cytochrome P450 1A1/2 - testosterone

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Kang-San Kim

Department of Internal Medicine

School of Oriental Medicine

Wonkwang University

Iksan

Korea

Email: bokim@wonkwang.ac.kr

Fax: +82-63-841-1445

Phone: Tel: +82-63-850-6756