The Dietary Supplement Creatyl-l-Leucine Does Not Bioaccumulate in Muscle, Brain or Plasma and Is Not a Significant Bioavailable Source of Creatine
Open accessAbstract
Creatine is an important energy metabolite that is concentrated in tissues such as the muscles and brain. Creatine is reversibly converted to creatine phosphate through a reaction with ATP or ADP, which is catalyzed by the enzyme creatine kinase. Dietary supplementation with relatively large amounts of creatine monohydrate has been proven as an effective sports supplement that can enhances athletic performance during acute high-energy demand physical activity. Some side effects have been reported with creatine monohydrate supplementation, which have stimulated research into new potential molecules that could be used as supplements to potentially provide bioavailable creatine. Recently, a popular supplement, creatyl-l-leucine, has been proposed as a potential dietary ingredient that may potentially provide bioavailable creatine. This study tests whether creatyl-l-leucine is a bioavailable compound and determines whether it can furnish creatine as a dietary supplement. Rats were deprived of dietary creatine for a period of two weeks and then given one of three treatments: a control AIN-93G creatine-free diet, AIN-93G supplemented with creatine monohydrate or AIN-93G with an equimolar amount of creatyl-l-leucine supplement in the diet for one week. When compared to the control and the creatine monohydrate-supplemented diet, creatyl-l-leucine supplementation resulted in no bioaccumulation of either creatyl-l-leucine or creatine in tissue.
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CLL is poorly absorbed by the intestine and is not a bioavailable source of creatine.
“The researcher concluded that provision of large doses of CLL to rats did not increase creatine bioaccumulation indicating that CLL is poorly absorbed by the intestine and is not a bioavailable source of creatine.”
From Bioavailability, Efficacy, Safety, and Regulatory Status of Creatine and Related Compounds: A Critical Review (2022) · cites this paper as [221]
Rats fed CLL did not increase blood, muscle, and brain creatine content above rats fed a control diet.
“Additionally, rats fed CLL did not increase blood, muscle, and brain creatine content above rats fed a control diet.”
From Bioavailability, Efficacy, Safety, and Regulatory Status of Creatine and Related Compounds: A Critical Review (2022) · cites this paper as [221]
da Silva found that rats fed creatine monohydrate experienced significant increases in creatine concentrations in arterial plasma, portal vein plasma, and muscle creatine content, and tended to increase brain creatine content compared to controls.
“As shown in Figure 16, rats fed CrM experienced significant increases in creatine concentrations in arterial plasma (+7-fold), portal vein plasma (+10-fold), muscle creatine content (+1.63-fold from control, and +1.53-fold from CLL) while tending to increase brain creatine content (p = 0.052) compared to controls.”
From Bioavailability, Efficacy, Safety, and Regulatory Status of Creatine and Related Compounds: A Critical Review (2022) · cites this paper as [221]
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Cites
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Kreider, R. B., Jäger, R., & Purpura, M. (2022) · Nutrients · doi:10.3390/nu14051035 · Cited by 103 · see citing works
- Authors
- da Silva, R. P.
- Affiliations
- Department of Physiology and Pathophysiology, Max Rady College of Medicine, University of Manitoba, Basic Medical Sciences Building, 745 Bannatyne Avenue, Winnipeg, MB R3E 0J9, Canada
- ORCID
- da Silva, Robin P.
- Venue
- Nutrients
- Publisher
- MDPI AG
- Published
- 2022-02-08
- Volume
- 14
- Issue
- 3
- Pages
- 701
- ISSN
- 2072-6643 (ISSN-L)
- PMC
- PMC8840086
- OpenAlex
- W4211198732
- Cited by
- 4
- References
- 4
- Citations by year
- 2025: 1 · 2023: 1 · 2022: 2
- FWCI
- 0.53
- Type
- journal article
- Language
- en
- Open access
- gold
- doi.org
- Licence
- Locations
- Nutrients (publishedVersion, cc-by)
- PubMed Central (publishedVersion, cc-by)
- PubMed (publishedVersion)
- DOAJ (DOAJ: Directory of Open Access Journals) (submittedVersion, cc-by-sa)
- Topics
- Life Sciences › Biochemistry, Genetics and Molecular Biology › Cell Biology › Muscle metabolism and nutrition
- Health Sciences › Medicine › Physiology › Biochemical effects in animals
- Life Sciences › Agricultural and Biological Sciences › Animal Science and Zoology › Animal Nutrition and Physiology
- Keywords
- creatine monohydrate, dietary supplements, muscle creatine, plasma creatine, creatine kinase, phosphocreatine, rats
- MeSH terms
- Animals, Brain, Creatine, Leucine, Muscle, Skeletal, Dietary Supplements, Rats
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