Identification of acetylshikonin as the novel CYP2J2 inhibitor with anti-cancer activity in HepG2 cells.

Abstract

BACKGROUND:

Acetylshikonin is one of the biologically active compounds derived from the root of Lithospermum erythrorhizon, a medicinal plant with anti-cancer and anti-inflammation activity. Although there have been a few previous reports demonstrating that acetylshikonin exerts anti-cancer activity in vitro and in vivo, it is still not clear what is the exact molecular target protein of acetylshikonin in cancer cells.

PURPOSE:

The purpose of this study is to evaluate the inhibitory effect of acetylshikonin against CYP2J2 enzyme which is predominantly expressed in human tumor tissues and carcinoma cell lines.

STUDY DESIGN:

The inhibitory effect of acetylshikonin on the activities of CYP2J2-mediated metabolism were investigated using human liver microsomes (HLMs), and its cytotoxicity against human hepatoma HepG2 cells was also evaluated.

METHOD:

Astemizole, a representative CYP2J2 probe substrate, was incubated in HLMs in the presence or absence of acetylshikonin. After incubation, the samples were analyzed by liquid chromatography and triple quadrupole mass spectrometry. The anti-cancer activity of acetylshikonin was evaluated on human hepatocellular carcinoma HepG2 cells. WST-1, cell counting, and colony formation assays were further adopted for the estimation of the growth rate of HepG2 cells treated with acetylshikonin.

RESULTS:

Acetylshikonin inhibited CYP2J2-mediated astemizole O-demethylation activity (Ki = 2.1µM) in a noncompetitive manner. The noncompetitive inhibitory effect of acetylshikonin on CYP2J2 enzyme was also demonstrated using this 3D structure, which showed different binding location of astemizole and acetylshikonin in CYP2J2 model. It showed cytotoxic effects against human hepatoma HepG2 cells (IC50 = 2μM). In addition, acetylshikonin treatment inhibited growth of human hepatocellular carcinoma HepG2 cells leading to apoptosis accompanied with p53, bax, and caspase3 activation as well as bcl2 down-regulation.

CONCLUSION:

Taken together, our present study elucidates acetylshikonin displays the inhibitory effects against CYP2J2 in HLMs and anti-cancer activity in human hepatocellular carcinoma HepG2 cells.

• Authors: See-Hyoung Park, Nguyen Minh Phuc, Jongsung Lee, Zhexue Wu, Jieun Kim, Hyunkyoung Kim, Nam Doo Kim, Taeho Lee, Kyung-Sik Song, Kwang-Hyeon Liu
• Journal: Phytomedicine : international journal of phytotherapy and phytopharmacology (Phytomedicine) Vol. 24 Pg. 134-140 (Jan 15 2017) ISSN: 1618-095X [Electronic] Germany
• PMID: 28160853 (Publication Type: Journal Article)
• Copyright: Copyright © 2016 Elsevier GmbH. All rights reserved.

Chemical References

• Anthraquinones
• Antineoplastic Agents
• Enzyme Inhibitors
• Plant Extracts
• Cytochrome P-450 Enzyme System

Topics

• Anthraquinones (therapeutic use)
• Antineoplastic Agents (therapeutic use)
• Apoptosis (drug effects)
• Carcinoma, Hepatocellular (drug therapy)
• Cytochrome P-450 Enzyme System (metabolism)
• Enzyme Inhibitors (pharmacology, therapeutic use)
• Hep G2 Cells (drug effects)
• Humans
• Liver Neoplasms (drug therapy)
• Microsomes, Liver (drug effects)
• Phytotherapy
• Plant Extracts (therapeutic use)