Navigation Links
Tryptophan deficiency may underlie quinine side effects

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
American Society for Biochemistry and Molecular Biology

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:
Related Image:
Tryptophan deficiency may underlie quinine side effects
(Date:6/7/2016)... , June 7, 2016  Syngrafii Inc. and ... business relationship that includes integrating Syngrafii,s patented LongPen™ ... project. This collaboration will result in greater convenience ... credit union, while maintaining existing document workflow and ... ...
(Date:6/2/2016)... , June 2, 2016 ... Manned Platforms, Unmanned Systems, Physical Infrastructure, Support & Other ... provider visiongain offers comprehensive analysis of the ... this market will generate revenues of $17.98 billion in ... acquired DVTEL Inc, a leader in software and hardware ...
(Date:5/16/2016)... 16, 2016   EyeLock LLC , a market ... opening of an IoT Center of Excellence in ... the development of embedded iris biometric applications. ... convenience and security with unmatched biometric accuracy, making it ... from DNA. EyeLock,s platform uses video technology to deliver ...
Breaking Biology News(10 mins):
(Date:6/24/2016)... ... ... While the majority of commercial spectrophotometers and fluorometers use the z-dimension of 8.5 ... end machines that use the more unconventional z-dimension of 20mm. Z-dimension or ... the cuvette holder. , FireflySci has developed several Agilent flow cell product lines ...
(Date:6/23/2016)... ... June 23, 2016 , ... UAS ... the launch of their brand, UP4™ Probiotics, into Target stores nationwide. The company, ... proud to add Target to its list of well-respected retailers. This list includes ...
(Date:6/23/2016)... 2016 A person commits a crime, and the ... track the criminal down. An outbreak of foodborne ... Administration (FDA) uses DNA evidence to track down the bacteria ... far-fetched? It,s not. The FDA has increasingly used a complex, ... foodborne illnesses. Put as simply as possible, whole genome sequencing ...
(Date:6/23/2016)... MONICA, Calif. , June 23, 2016  The Prostate Cancer Foundation ... pioneer increasingly precise treatments and faster cures for prostate cancer. Members of the ... institutions across 15 countries. Read More About the Class ... ... ...
Breaking Biology Technology: