A UPLC-MS/MS method for determination of endogenous l-carnitine and acetyl-l-carnitine in serum of patients with depression

Matrix-assisted laser desorption/ionization mass spectrometry for the rapid and high throughput analysis of betaine and trigonelline in Lycium chinense Mill. and trigonelline in coffee

A rapid, simple, effective, and green method for the determination of betaine and trigonelline from Lycium chinense Mill. (LCM) and the quantification of the trigonelline in coffee was proposed and validated by matrix-assisted laser desorption ionization time-of-flight mass spectrometric (MALDI-TOF MS) detection. Due to without chromatographic separation, the method greatly shortened the detection time. The detection of betaine and trigonelline concentration showed good linearity in the range of 1-100 μg/mL and 0.01-100 μg/mL, with correlation coefficients r2 = 0.9962 and 0.9946, respectively. The good reproducibility and reliability of the method were demonstrated by excellent intraday and interday precisions with RSD <8.3%, and the recovery of betaine and trigonelline ranged from 92.2% to 116.0%. Analysis of LCM and coffee extracts (raw, light-roasted, and dark-roasted coffee beans) gave results in agreement with the literature. The method appeared as a fast and reliable alternative method for routine Lycium chinense and coffee analysis.

Plasma acetyl-l-carnitine and l-carnitine in major depressive episodes: a case-control study before and after treatment

BACKGROUND

Major depressive disorder (MDD) is the main cause of disability worldwide, its outcome is poor, and its underlying mechanisms deserve a better understanding. Recently, peripheral acetyl-l-carnitine (ALC) has been shown to be lower in patients with major depressive episodes (MDEs) than in controls. l-Carnitine is involved in mitochondrial function and ALC is its short-chain acetyl-ester. Our first aim was to compare the plasma levels of l-carnitine and ALC, and the l-carnitine/ALC ratio in patients with a current MDE and healthy controls (HCs). Our second aim was to assess their changes after antidepressant treatment.

METHODS

l-Carnitine and ALC levels and the carnitine/ALC ratio were measured in 460 patients with an MDE in a context of MDD and in 893 HCs. Depressed patients were re-assessed after 3 and 6 months of antidepressant treatment for biology and clinical outcome.

RESULTS

As compared to HC, depressed patients had lower ALC levels (p < 0.00001), higher l-carnitine levels (p < 0.00001) and higher l-carnitine/ALC ratios (p < 0.00001). ALC levels increased [coefficient: 0.18; 95% confidence interval (CI) 0.12-0.24; p < 0.00001], and l-carnitine levels (coefficient: -0.58; 95% CI -0.75 to -0.41; p < 0.00001) and l-carnitine/ALC ratios (coefficient: -0.41; 95% CI -0.47 to -0.34; p < 0.00001), decreased after treatment. These parameters were completely restored after 6 months of antidepressant. Moreover, the baseline l-carnitine/ALC ratio predicted remission after 3 months of treatment (odds ratio = 1.14; 95% CI 1.03-1.27; p = 0.015).

CONCLUSIONS

Our data suggest a decreased mitochondrial metabolism of l-carnitine into ALC during MDE. This decreased mitochondrial metabolism is restored after a 6-month antidepressant treatment. Moreover, the magnitude of mitochondrial dysfunction may predict remission after 3 months of antidepressant treatment. New strategies targeting mitochondria should be explored to improve treatments of MDD.

Carnitine and Depression

Depression has become one of the most common mental diseases in the world, but the understanding of its pathogenesis, diagnosis and treatments remains insufficient. Carnitine is a natural substance that exists in organisms, which can be synthesized in vivo or supplemented by intake. Relationships of carnitine with depression, bipolar disorder and other mental diseases have been reported in different studies. Several studies show that the level of acylcarnitines (ACs) changes significantly in patients with depression compared with healthy controls while the supplementation of acetyl-L-carnitine is beneficial to the treatment of depression. In this review, we aimed to clarify the effects of ACs in depressive patients and to explore whether ACs might be the biomarkers for the diagnosis of depression and provide new ideas to treat depression.