Basic Study
Copyright ©The Author(s) 2017. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Apr 28, 2017; 23(16): 2912-2927
Published online Apr 28, 2017. doi: 10.3748/wjg.v23.i16.2912
In vitro and in vivo antioxidative and hepatoprotective activity of aqueous extract of Cortex Dictamni
Lin Li, Yun-Feng Zhou, Yan-Lin Li, Li-Li Wang, Hiderori Arai, Yang Xu
Lin Li, Yun-Feng Zhou, Yan-Lin Li, Li-Li Wang, Yang Xu, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100193, China
Lin Li, Yun-Feng Zhou, Yan-Lin Li, Li-Li Wang, Yang Xu, Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine, Ministry of Education, Beijing 100193, China
Hiderori Arai, Department of Human Health Sciences, Kyoto University Graduate School of Medicine, Kyoto 606-8507, Japan
Author contributions: Li L performed the experiments, analyzed the data and drafted the article; Zhou YF, Li YL and Wang LL performed the experiments; Arai H supervised the study and revised the article; Xu Y conceived and designed the study.
Supported by National Science and Technology Major New Drugs Project of China, No. 2012ZX09103201-012.
Institutional review board statement: The study was reviewed and approved by the Chinese Academy of Medical Sciences and Peking Union Medical College Institutional Review Board.
Institutional animal care and use committee statement: All procedures involving animals were reviewed and approved by the Institutional Animal Care and Use Committee of the Chinese Academy of Medical Sciences and Peking Union Medical College (IACUC protocol number: SLXD-2016041279).
Conflict-of-interest statement: The authors declare no financial conflict of interest.
Data sharing statement: No additional data are available.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See:
Correspondence to: Yang Xu, PhD, Professor, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, 151 Malianwa North Road, Beijing 100193, China.
Telephone: +86-10-57833234 Fax: +86-10-57833234
Received: January 11, 2017
Peer-review started: January 12, 2017
First decision: February 9, 2017
Revised: February 28, 2017
Accepted: March 15, 2017
Article in press: March 15, 2017
Published online: April 28, 2017

To investigate the antioxidant and hepatoprotective effects of Cortex Dictamni aqueous extract (CDAE) in carbon tetrachloride (CCl4)-induced liver damage in rats.


The in vitro antioxidant effect of CDAE was investigated using α,α-diphenyl-β-picrylhydrazyl (DPPH), 2,2’-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) (ABTS), β-carotene bleaching, reducing power, and thiobarbituric acid reactive substance assays. A linoleic acid system, including ferric thiocyanate (FTC) and thiobarbituric acid (TBA) assays, was used to evaluate the inhibition of lipid peroxidation. The in vivo hepatoprotective and antioxidant effects of CDAE against CCl4-induced liver damage were evaluated in Sprague-Dawley rats. Silymarin was used as a positive control. Liver damage was assessed by determining hepatic histopathology and liver marker enzymes in serum. Enzyme and non-enzyme antioxidant levels and lipid peroxide content were measured in the liver. Cytochrome P450 2E1 (CYP2E1) protein expression was measured via immunohistochemical staining. Nuclear factor E2-related factor (Nrf2), heme oxygenase-1 (HO-1), NAD(P)H quinine oxidoreductase 1 (NQO1), and γ-glutamylcysteine synthetase catalytic subunit (γ-GCSc) protein expression was measured by Western blot.


Our results showed that CDAE exhibited a strong antioxidant activity in vitro. CDAE scavenged DPPH and ABTS radicals in a dose-dependent manner. CDAE inhibited lipid peroxidation with a lipid peroxide inhibition rate of 40.6% ± 5.2%. In the FTC and TBA assays, CDAE significantly inhibited lipid peroxidation (P < 0.01). In vivo histopathological studies indicated that CCl4-induced liver injury was alleviated following CDAE treatment in rats of both sexes. CDAE (160 and 320 mg/kg) significantly prevented CCl4-induced elevations of alkaline phosphatase, glutamate pyruvate transaminase, aspartate aminotransferase, and total bilirubin levels in rats of both sexes (P < 0.05, 0.01, or 0.001). Moreover, CDAE restored the decreased activities of hepatic antioxidant enzymes, including superoxide dismutase, catalase, and glutathione peroxidase, as well as non-enzyme antioxidant glutathione, which were induced by CCl4 treatment. CDAE significantly suppressed the up-regulation of CYP2E1 and promoted Nrf2, HO-1, NQO1, and γ-GCSc protein expression.


CDAE exhibits good antioxidant performance in vitro, with marked radical-scavenging and anti-lipid peroxidation activities. CDAE is effective in preventing CCl4-induced hepatic damage in rats of both sexes. The hepatoprotective activity of CDAE may be attributable to its antioxidant activity, which may involve Keap1-Nrf2-mediated antioxidant regulation.

Keywords: Cortex Dictamni, Antioxidant activity, Hepatoprotective, Carbon tetrachloride, Nrf2

Core tip: This study is the first to systematically investigate the antioxidant activity of Cortex Dictamni aqueous extract (CDAE) in vitro, especially its anti-lipid perioxidation activity, which is important for physiological function and pathological processes. In traditional Chinese medicine, Cortex Dictamni has been used to treat hepatic disease, but has lacked sufficient support and research. Therefore, to the best of our knowledge, our study is the first to demonstrate the effects of CDAE in CCl4-induced hepatic injury in rats.