Featured Research

from universities, journals, and other organizations

Licorice Compound Offers New Cancer Prevention Strategy

Date:
March 25, 2009
Source:
Vanderbilt University Medical Center
Summary:
A chemical component of licorice may offer a new approach to preventing colorectal cancer without the adverse side effects of other preventive therapies, researchers report.

A chemical component of licorice may offer a new approach to preventing colorectal cancer without the adverse side effects of other preventive therapies, Vanderbilt University Medical Center researchers report.

Related Articles


In the study published in the Journal of Clinical Investigation, Raymond Harris, M.D., Ming-Zhi Zhang, M.D., and colleagues show that inhibiting the enzyme 11β-hydroxysteroid dehydrogenase type 2 (11βHSD2) – either by treatment with a natural compound found in licorice or by silencing the 11βHSD2 gene – prevents colorectal cancer progression in mice predisposed to the disease.

Colorectal cancer is the second leading cause of cancer deaths in the United States. While prevention is the best approach for reducing colorectal cancer deaths, few medical strategies exist to prevent the disease.

One promising target for chemoprevention is the enzyme cyclooxygenase 2 (COX-2), which promotes colorectal cancer progression via the action of the enzyme's inflammatory products, the prostaglandins. Inhibiting this enzyme – with non-steroidal anti-inflammatory drugs (NSAIDs) like ibuprofen or with selective COX-2 inhibitors like Vioxx or Celebrex – reduces the number and size of colon polyps in mice and in patients with an inherited predisposition to colon cancer. However, both types of drugs cause serious adverse side effects that limit their utility for chemoprevention.

Harris and Zhang – nephrologists who are also members of the Vanderbilt-Ingram Cancer Center – have been investigating COX-2 regulation in the kidney. They previously found that inhibiting 11βHSD2 in the kidney suppresses COX-2 expression in that organ.

The colon is one of the only other organs (besides the kidney) with high expression of 11βHSD2, suggesting that this enzyme might play a role in colorectal cancer progression.

"Since studies here and elsewhere have shown the importance of COX-2 and colonic carcinogenesis, we postulated that maybe one of the mechanisms by which the normal colon might prevent excessive expression of COX-2 is by 11βHSD2," said Harris, the Ann and Roscoe R. Robinson Professor of Nephrology and director of the division. 


The researchers examined expression of 11βHSD2 in human colon polyps and in the colons of mice predisposed to colon cancer. They found that 11βHSD2 was increased in polyps found in both mice and humans and correlated with COX-2 expression and activity.

They then inhibited 11βHSD2 with glycyrrhizic acid, the main sweet-tasting component of licorice, and by silencing the gene for 11βHSD2.

Both treatments inhibited the production of prostaglandin E2 (an inflammatory molecule produced by the COX-2 enzyme) and prevented the development of polyps (adenomas) and tumor growth and metastasis.

Because 11βHSD2 is highly expressed only in kidney and colon, blocking the enzyme produces effects specific to those tissues – unlike NSAIDs, selective COX-2 inhibitors, and steroid treatments that can prevent cancer progression but also cause serious side effects like gastrointestinal irritation, cardiovascular events, and immunosuppression, respectively.

Licorice, Harris noted, has been used as a nutraceutical for thousands of years for ailments ranging from coughs to constipation. But even licorice is not without side effects; long-term consumption can lead to low blood potassium and increases in blood pressure – side effects linked to the inhibition of 11βHSD2.

"These are relatively minor compared to the cardiovascular side effects of COX-2 inhibitors," Harris said. "We didn't see (these side effects) in the mice we treated…but it would be something to be aware of, and something that could easily be treated with a diuretic."

Harris and colleagues are continuing to investigate the mechanism of 11βHSD2 inhibition. Zhang, an assistant professor of Medicine and of Cancer Biology, also plans to look at the enzyme's role in lung cancer and other tumors.

And although this natural chemical is an appealing drug lead in itself, the researchers are also working with the Vanderbilt Institute for Chemical Biology to develop more specific and potent inhibitors of 11βHSD2.

"We think we can make (an inhibitor) that is more specific and has better delivery to the target tissues," Zhang said.

The research was supported by grants from the American Cancer Society, the National Institutes of Health and the Department of Veterans Affairs. Vanderbilt co-authors include: Jie Xu, Bing Yao, Ph.D., Huiyong Yin, Ph.D., Qiuyin Cai, M.D., Ph.D., Martha Shrubsole, Ph.D., Xiwu Chen, M.D., Ph.D., Valentina Kon, M.D., Wei Zheng, M.D., Ph.D., and Ambra Pozzi, Ph.D.


Story Source:

The above story is based on materials provided by Vanderbilt University Medical Center. Note: Materials may be edited for content and length.


Journal Reference:

  1. Inhibition of 11-beta-hydroxysteroid dehydrogenase type II selectively blocks the tumor COX-2 pathway and suppresses colon carcinogenesis in mice and humans. Journal of Clinical Investigation, March 24, 2009

Cite This Page:

Vanderbilt University Medical Center. "Licorice Compound Offers New Cancer Prevention Strategy." ScienceDaily. ScienceDaily, 25 March 2009. <www.sciencedaily.com/releases/2009/03/090324081433.htm>.
Vanderbilt University Medical Center. (2009, March 25). Licorice Compound Offers New Cancer Prevention Strategy. ScienceDaily. Retrieved March 5, 2015 from www.sciencedaily.com/releases/2009/03/090324081433.htm
Vanderbilt University Medical Center. "Licorice Compound Offers New Cancer Prevention Strategy." ScienceDaily. www.sciencedaily.com/releases/2009/03/090324081433.htm (accessed March 5, 2015).

Share This


More From ScienceDaily



More Health & Medicine News

Thursday, March 5, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Bupa Eyes India Healthcare Opportunities

Bupa Eyes India Healthcare Opportunities

Reuters - Business Video Online (Mar. 5, 2015) — Bupa is hoping to expand in India&apos;s fast-growing health insurance market, once a rule change on foreign investment is implemented. The British private healthcare group&apos;s CEO tells Grace Pascoe why it&apos;s so keen on the new opportunity. Video provided by Reuters
Powered by NewsLook.com
Doctor in Your Pocket Is Getting Smarter

Doctor in Your Pocket Is Getting Smarter

Reuters - Business Video Online (Mar. 5, 2015) — Mobile apps are turning smartphones into a personal doctors, with users able to measure heart rate, blood pressure and even blood sugar. But will it change our behaviour? Ivor Bennett reports from the Mobile World Congress in Barcelona. Video provided by Reuters
Powered by NewsLook.com
AbbVie Inks $21B Deal To Buy Cancer Drugmaker Pharmacyclics

AbbVie Inks $21B Deal To Buy Cancer Drugmaker Pharmacyclics

Newsy (Mar. 5, 2015) — AbbVie announced Wednesday it will buy cancer drugmaker Pharmacyclics in a $21 billion deal. Video provided by Newsy
Powered by NewsLook.com
Adults Only Get The Flu Twice A Decade, Researchers Say

Adults Only Get The Flu Twice A Decade, Researchers Say

Newsy (Mar. 4, 2015) — Researchers found adults only get the flu about once every five years. Scientists analyzed how a person&apos;s immunity builds up over time as well. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins