Year-end Sale % OFF 
Abstract
Background:High-protein diets promote weight loss and subsequent weight maintenance, but are difficult to adhere to. The mechanisms by which protein exerts these effects remain unclear. However, the amino acids produced by protein digestion may have a role in driving protein-induced satiety.Methods:We tested the effects of a range of amino acids on food intake in rodents and identified l-cysteine as the most anorexigenic. Using rodents we further studied the effect of l-cysteine on food intake, behaviour and energy expenditure. We proceeded to investigate its effect on neuronal activation in the hypothalamus and brainstem before investigating its effect on gastric emptying and gut hormone release. The effect of l-cysteine on appetite scores and gut hormone release was then investigated in humans.Results:l-Cysteine dose-dependently decreased food intake in both rats and mice following oral gavage and intraperitoneal administration. This effect did not appear to be secondary to behavioural or aversive side effects. l-Cysteine increased neuronal activation in the area postrema and delayed gastric emptying. It suppressed plasma acyl ghrelin levels and did not reduce food intake in transgenic ghrelin-overexpressing mice. Repeated l-cysteine administration decreased food intake in rats and obese mice. l-Cysteine reduced hunger and plasma acyl ghrelin levels in humans.Conclusions:Further work is required to determine the chronic effect of l-cysteine in rodents and humans on appetite and body weight, and whether l-cysteine contributes towards protein-induced satiety.
Highlights
High protein diets can drive weight loss and support subsequent weight maintenance.[1,2] Identifying the mechanisms by which protein drives satiety and weight loss may help identify therapeutic options for the treatment of obesity
To confirm that L-cysteine did not result in aversive effects, we investigated whether oral administration of L-cysteine at 1, 2 or 4 mmol kg − 1 resulted in conditioned taste aversion (CTA) using an established method[14]
The effect of L-amino acids on food intake in rats To investigate the anorectic potential of specific L-amino acids in vivo, the effect on food intake following oral and intraperitoneal administration of a range of amino acids was examined in rats
Summary
High protein diets can drive weight loss and support subsequent weight maintenance.[1,2] Identifying the mechanisms by which protein drives satiety and weight loss may help identify therapeutic options for the treatment of obesity. We investigated the effects of oral and intraperitoneal administration of a range of amino acids on food intake in rodents. These studies identified L-cysteine, a conditionally essential amino acid that acts as a precursor for biologically active molecules such as hydrogen sulphide (H2S), glutathione and taurine, as an anorectic agent. RESULTS: L-Cysteine dose-dependently decreased food intake in both rats and mice following oral gavage and intraperitoneal administration This effect did not appear to be secondary to behavioural or aversive side effects. L-Cysteine increased neuronal activation in the area postrema and delayed gastric emptying It suppressed plasma acyl ghrelin levels and did not reduce food intake in transgenic ghrelin-overexpressing mice. CONCLUSIONS: Further work is required to determine the chronic effect of L-cysteine in rodents and humans on appetite and body weight, and whether L-cysteine contributes towards protein-induced satiety
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
