Featured Research

from universities, journals, and other organizations

Anti-Malarial Drug: Tryptophan Deficiency May Underlie Quinine Side Effects

Date:
July 14, 2009
Source:
American Society for Biochemistry and Molecular Biology
Summary:
Researchers have found that the anti-malarial drug quinine can block a cell's ability to take up the essential amino acid tryptophan, a discovery that may explain many of the adverse side effects associated with quinine.

A screen of yeast strains each defective in a single gene reveals genes that are affected by the anti-malarial quinine.
Credit: Simon Avery, University of Nottingham

Researchers have found that the anti-malarial drug quinine can block a cell's ability to take up the essential amino acid tryptophan, a discovery that may explain many of the adverse side-effects associated with quinine. Once confirmed, these findings would suggest that dietary tryptophan supplements could be a simple and inexpensive way to improve the performance of this important drug.

Related Articles


Quinine is a very commonly used anti-malarial drug, yet to this day the principal mode of quinine action against the malaria parasite is still largely unclear, as is the basis for adverse reactions like nausea, headaches, and blurred vision. To address these gaps, Simon Avery and colleagues at the University of Nottingham took advantage of yeast genetics, examining the effects of quinine on a collection of 6000 yeast mutants, each one lacking exactly one of the yeast's 6000 genes. While quite different from humans, yeast is comparable on a cellular level and yeast is frequently, and successfully, used as front-line agents in testing chemicals and small molecule drugs.

Their screen revealed that strains unable to make tryptophan were extremely susceptible to quinine poisoning, which led them to identify a tryptophan transporter as a key quinine target (yeast that cannot make their own tryptophan have to rely exclusively on external sources, and thus die if tryptophan transport is blocked).

This discovery fits in well with evidence that quinine reactions are more severe in malnourished individuals. Unlike yeast, humans cannot make their own tryptophan and thus require dietary tryptophan, which is abundant in meat but limited in yams, a staple food crop in the tropics where malaria is prevalent. If quinine severely reduces tryptophan uptake, then it follows that people with preexisting tryptophan deficiencies would be especially at risk to this drug.

The authors also note that tryptophan is important as a precursor for the brain chemical serotonin, so the enhanced tryptophan deficiency induced by quinine could explain why many of quinine's side effects are localized to the head region. They also note that side-effects could be averted simply by taking dietary tryptophan supplements in conjunction with quinine treatments, though it is not yet known if tryptophan may affect quinine action against the malaria parasite.


Story Source:

The above story is based on materials provided by American Society for Biochemistry and Molecular Biology. Note: Materials may be edited for content and length.


Journal Reference:

  1. Khozoie et al. The Antimalarial Drug Quinine Disrupts Tat2p-mediated Tryptophan Transport and Causes Tryptophan Starvation. Journal of Biological Chemistry, 2009; 284 (27): 17968 DOI: 10.1074/jbc.M109.005843

Cite This Page:

American Society for Biochemistry and Molecular Biology. "Anti-Malarial Drug: Tryptophan Deficiency May Underlie Quinine Side Effects." ScienceDaily. ScienceDaily, 14 July 2009. <www.sciencedaily.com/releases/2009/06/090626141235.htm>.
American Society for Biochemistry and Molecular Biology. (2009, July 14). Anti-Malarial Drug: Tryptophan Deficiency May Underlie Quinine Side Effects. ScienceDaily. Retrieved December 22, 2014 from www.sciencedaily.com/releases/2009/06/090626141235.htm
American Society for Biochemistry and Molecular Biology. "Anti-Malarial Drug: Tryptophan Deficiency May Underlie Quinine Side Effects." ScienceDaily. www.sciencedaily.com/releases/2009/06/090626141235.htm (accessed December 22, 2014).

Share This


More From ScienceDaily



More Health & Medicine News

Monday, December 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Christmas Kissing Good for Health

Christmas Kissing Good for Health

Reuters - Innovations Video Online (Dec. 22, 2014) Scientists in Amsterdam say couples transfer tens of millions of microbes when they kiss, encouraging healthy exposure to bacteria. Suzannah Butcher reports. Video provided by Reuters
Powered by NewsLook.com
Brain-Dwelling Tapeworm Reveals Genetic Secrets

Brain-Dwelling Tapeworm Reveals Genetic Secrets

Reuters - Innovations Video Online (Dec. 22, 2014) Cambridge scientists have unravelled the genetic code of a rare tapeworm that lived inside a patient's brain for at least four year. Researchers hope it will present new opportunities to diagnose and treat this invasive parasite. Matthew Stock reports. Video provided by Reuters
Powered by NewsLook.com
Touch-Free Smart Phone Empowers Mobility-Impaired

Touch-Free Smart Phone Empowers Mobility-Impaired

Reuters - Innovations Video Online (Dec. 21, 2014) A touch-free phone developed in Israel enables the mobility-impaired to operate smart phones with just a movement of the head. Suzannah Butcher reports. Video provided by Reuters
Powered by NewsLook.com
Earthworms Provide Cancer-Fighting Bacteria

Earthworms Provide Cancer-Fighting Bacteria

Reuters - Innovations Video Online (Dec. 21, 2014) Polish scientists isolate bacteria from earthworm intestines which they say may be used in antibiotics and cancer treatments. Suzannah Butcher reports. Video provided by Reuters
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