Acetyl-L-Carnitine

Authors:

Wenbo Wang

Study Quality Assessment:

Systematic Review. Published in Nutrients. DOI: 10.3390/nu16081232.

Authors:

Muneeb U Rehman

Findings:

This review focuses on the various established activities of natural products in vitro, particularly concerning neuroprotective effects, due to the scarcity of human studies in this area.

Participants:

Review focuses on in vitro studies. Scarcity of human studies on neuroprotective effects of natural products is noted.

Study Quality Assessment:

Review article. Focuses on various established activities of natural products in in vitro studies.

Authors:

Gustavo C Ferreira

Findings:

Serum L-carnitine (LC) and acetyl-L-carnitine (ALC) concentrations were significantly decreased in patients with Major Depressive Disorder (MDD) compared to healthy controls. Serum ALC levels were negatively correlated with depression severity (HDRS-24 scores). Both LC and ALC demonstrated good diagnostic value for differentiating MDD patients from healthy controls via ROC analysis. Furthermore, LC and ALC concentrations significantly increased in MDD patients who responded effectively to treatment, suggesting they may serve as novel biomarkers for MDD diagnosis and potentially for monitoring treatment efficacy.

Participants:

N=89 patients with Major Depressive Disorder (MDD) aged 18-70 years (first depression episode, not taking antidepressants at study start), and N=89 healthy controls (HC) matched for age, BMI, and gender. A subset of 55 MDD patients (38 who responded effectively to treatment, 17 who did not) were evaluated 2-6 weeks after unspecified treatment began.

Study Quality Assessment:

Observational study measuring serum L-carnitine (LC) and acetyl-L-carnitine (ALC) using ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Sample sizes: N=89 MDD patients and N=89 healthy controls for baseline comparison; N=55 MDD patients (38 effective treatment, 17 ineffective treatment) for pre-post treatment comparison. Statistical methods included Student’s t-test, χ2 analysis, Pearson correlation tests, multivariate linear regression analysis, and receiver operating characteristic (ROC) curve analysis. The study was approved by an Ethics Committee, and all subjects provided informed written consent. Acknowledged limitations include: single-center study design, small sample size (particularly for post-treatment subgroups), lack of detailed grouping for samples after treatment, not considering the effects of diet, exercise, sleep, and other external factors on LC and ALC concentrations, and not considering the effects of different specific drugs on post-treatment LC/ALC concentrations.

All Effects:

Findings:

After 1 year of oral acetyl-L-carnitine treatment, patients with Alzheimer's disease showed a slower rate of deterioration compared to placebo in 13 of 14 outcome measures, with statistical significance for the Blessed Dementia Scale, logical intelligence, ideomotor and buccofacial apraxia, and selective attention. Adjusting for initial scores with analysis of covariance, the treated group showed better scores on all outcome measures, reaching statistical significance for the Blessed Dementia Scale, logical intelligence, verbal critical abilities, long-term verbal memory, and selective attention. Reported adverse events were relatively mild, with no significant difference in incidence or severity between the treated and placebo groups.

Participants:

130 patients with a clinical diagnosis of Alzheimer's disease. The provided text includes MeSH terms indicating participants were Humans, including Aged, Aged, 80 and over, Female, Male, and Middle Aged individuals.

Dosage:

Long-term (1-year) oral treatment with acetyl-L-carnitine. The specific dosage in mg or frequency of administration is not detailed in the provided abstract text, though MeSH terms include "Acetylcarnitine / administration & dosage" and "Administration, Oral".

Study Quality Assessment:

The study was a double-blind, placebo-controlled, parallel-group, randomized clinical trial involving 130 patients over a 1-year period. Fourteen outcome measures were used to assess functional and cognitive impairment, and analysis of covariance was employed for adjusting initial scores. The text identifies the study with publication types "Clinical Trial" and "Randomized Controlled Trial", and MeSH terms such as "Double-Blind Method", "Analysis of Variance", and "Neuropsychological Tests" are listed.

All Effects: