Navigation Links
Tryptophan deficiency may underlie quinine side effects
Date:6/26/2009

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.

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.


'/>"/>

Contact: Nick Zagorski
nzagorski@asbmb.org
301-634-7366
American Society for Biochemistry and Molecular Biology
Source:Eurekalert  

Related biology news :

1. Is vitamin D deficiency linked to Alzheimers disease and vascular dementia?
2. Vitamin D deficiency related to increased inflammation in healthy women
3. Lamin A/C deficiency is unnerving
4. Vitamin D deficiency in infants and nursing mothers carries long-term disease risks
5. Why some primates, but not humans, can live with immunodeficiency viruses and not progress to AIDS
6. Worldwide mission to solve iron deficiency
7. Bloodless worm sheds light on human blood, iron deficiency
8. A genetic cause for iron deficiency
9. RNA interference therapy heals growth deficiency disorder in a live animal
10. Recruitment of reproductive features into other cell types may underlie extended lifespan in animals
11. Mayo Clinic: Brain disorder suggests common mechanism may underlie many neurodegenerative diseases
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Tryptophan deficiency may underlie quinine side effects
(Date:3/27/2017)... March 27, 2017  Catholic Health Services (CHS) ... Systems Society (HIMSS) Analytics for achieving Stage 6 ... sm . In addition, CHS previously earned a ... using an electronic medical record (EMR). ... level of EMR usage in an outpatient setting.  ...
(Date:3/24/2017)... MILAN , March 24, 2017 The Controller ... Deputy Controller Mr. Abdulla Algeen have received the prestigious international ... Continue Reading ... ... small picture) and Deputy Controller Abdulla Algeen (small picture on the right) ...
(Date:3/24/2017)... -- Research and Markets has announced the addition of ... - Industry Forecast to 2025" report to their offering. ... The Global Biometric Vehicle ... around 15.1% over the next decade to reach approximately $1,580 million ... estimates and forecasts for all the given segments on global as ...
Breaking Biology News(10 mins):
(Date:3/27/2017)... , March 27, 2017 DarioHealth Corp. (NASDAQ: ... health and big data solutions, today announced that it ... coverage option for U.S. consumers who want to have ... DarioHealth has signed strategic alliance agreements with partners across ... coverage benefits, and if approved, will supply and bill ...
(Date:3/24/2017)... MARIETTA, Ga. , March 24, 2017 ... and biopharmaceutical company utilizing human placental tissue allografts and ... therapies for multiple sectors of healthcare, announced today  that ... New York , NY.  Parker H. ... , Chief Financial Officer, Christopher M. Cashman , ...
(Date:3/24/2017)... Research and Markets has announced the addition ... Strategic Business Report" report to their offering. ... This report analyzes the Global ... Annual estimates and forecasts are provided for the period 2014 through ... research. The report profiles 25 companies including many ...
(Date:3/24/2017)... , March 24, 2017 On ... trading session at 5,817.69, down 0.07%; the Dow Jones ... and the S&P 500 closed at 2,345.96, marginally dropping ... sectors closed in green, 4 sectors finished in red, ... Friday, Stock-Callers.com has initiated reports coverage on the following ...
Breaking Biology Technology: