Basic Study
Copyright ©The Author(s) 2020. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Dec 7, 2020; 26(45): 7131-7152
Published online Dec 7, 2020. doi: 10.3748/wjg.v26.i45.7131
Nimbolide inhibits tumor growth by restoring hepatic tight junction protein expression and reduced inflammation in an experimental hepatocarcinogenesis
Amit Kumar Ram, Balasubramaniyan Vairappan, BH Srinivas
Amit Kumar Ram, Balasubramaniyan Vairappan, Liver Diseases Research Lab,Department of Biochemistry, Jawaharlal Institute of Postgraduate Medical Education and Research (JIPMER), Dhanvantari Nagar, Puducherry 605006, India
BH Srinivas, Department of Pathology, Jawaharlal Institute of Postgraduate Medical Education and Research (JIPMER), Dhanvantari Nagar, Puducherry 605006, India
Author contributions: Ram AK and Vairappan B conceived and designed the study, analyzed the data statistically; Ram AK performed the experiments and wrote the manuscript; Vairappan B critically reviewed the manuscript; Srinivas BH interpreted histology and immunohistochemical findings.
Supported by JIPMER intramural research grant; Indian Council of Medical Research (ICMR), New Delhi, India, No. 3/1/3 J.R.F.-2016/LS/HRD; and Department of Biotechnology, Government of India, No. 102/IFD/SAN/22/2013-14.
Institutional review board statement: This study was reviewed and approved by the JIPMER scientific advisory committee (JSAC).
Institutional animal care and use committee statement: This study was reviewed and approved by JIPMER Institute Animal Ethics Committee (IAEC). All institutional and national guidelines for the care and use of laboratory animals were followed.
Conflict-of-interest statement: The authors declare that there is no conflict of interest related to this study.
ARRIVE guidelines statement: The authors have read the ARRIVE guidelines, and the manuscript was prepared and revised according to the ARRIVE guidelines.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (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:
Corresponding author: Balasubramaniyan Vairappan, PhD, Associate Professor, Liver Diseases Research Lab, Department of Biochemistry, Jawaharlal Institute of Postgraduate Medical Education and Research (JIPMER), Dhanvantari Nagar, Puducherry 605006, India.
Received: July 25, 2020
Peer-review started: July 25, 2020
First decision: September 14, 2020
Revised: September 28, 2020
Accepted: November 12, 2020
Article in press: November 12, 2020
Published online: December 7, 2020
Research background

Worldwide, hepatocellular carcinoma (HCC) is a prevalent lethal disease exhibiting the highest cancer mortality rate with limited chemotherapeutic options. The discovery of a new chemotherapeutic agent is an urgent demand for the treatment of HCC patients.

Research motivation

Tight Junction (TJ) proteins have been implicated to regulate various signal transductions in carcinogenesis. Recent evidence has shown that nimbolide possesses anticancer activity in various cancers; however, its specific mechanism in HCC remains elusive.

Research objectives

We aimed to study the effect of nimbolide on TJ proteins, cell cycle progression, and hepatic inflammation in an experimental hepatocarcinogenesis mouse model.

Research methods

Diethylnitrosamine (DEN) and N-nitrosomorpholine (NMOR) induced mouse model of HCC was performed in the present study. Nimbolide was given orally for four consecutive weeks to DEN/NMOR induced HCC mice from 28th to 32nd week. At the end of the study period (32nd week), all the mice were sacrificed, blood and liver samples were collected for various analysis. HCC tumor markers such as alpha-fetoprotein (AFP) levels and glypican-3 protein expression were analysed. Hepatic TJ proteins, cell cycle, and inflammatory marker protein expressions were evaluated by western blot analysis. Cell proliferation and oxidative stress markers were analyzed by immunohistochemistry. Molecular docking study was performed to confirm the interaction of nimbolide with zonula occludens 1 (ZO-1), nuclear factor of kappa light polypeptide gene enhancer in B-cells (NF-κB) and tumor necrosis factor alpha (TNF-α).

Research results

Hepatic tumor size and HCC tumor markers AFP and glypican-3 were reduced following nimbolide treatment. TJ protein (ZO-1 and occludin) expression levels were restored after nimbolide treatment, while ZO-1 associated nucleic acid binding protein expression was attenuated. Additionally, nimbolide treatment also reduced cell proliferation and cell cycle markers. Moreover, nimbolide treatment ameliorated hepatic inflammation and oxidative stress in HCC mice. The binding affinity and modulatory effects of nimbolide with ZO-1, NF-κB, and TNF-α were confirmed by molecular docking analysis.

Research conclusions

Nimbolide treatment showed anticancer effects by improving TJ proteins expression, suppressing cell cycle and cell proliferation, and ameliorating inflammation and oxidative stress in DEN and NMOR induced HCC mice.

Research perspectives

Nimbolide may be used as a potential chemotherapeutic agent for HCC treatment. Further molecular research and human studies may delineate nimbolide as a candidate drug for HCC treatment.