Alpha- and gamma-tocopherol levels in human semen and their potential functional implications.

Vitamin E is a potent antioxidant that has been considered involved in fertility, but studies have mostly focused on α-tocopherol. Our study aimed at measuring, by an isotope dilution gas chromatography-mass spectrometry method, α- and γ-tocopherol concentration in human semen in a large and well-characterised population (134 men with different semen parameters and in varicocele patients), as well as their potential role in male fertility. We carried out freeze/thaw experiments in 15 samples with the two isomers in the cryoprotective medium. Moreover, our study included 10 subjects supplemented in vivo with α-tocopherol for 90 days. In seminal plasma, γ-tocopherol concentration was significantly lower in the varicocele group than in the normozoospermic group. We observed that γ-tocopherol, supplemented to cryopreservation medium, induced a higher post-thaw human sperm viability and motility than α-tocopherol. The results of in vivo α-tocopherol supplementation showed a decrease in γ-tocopherol concentration with increasing α-tocopherol level in blood. This is the first report related to γ-tocopherol distribution in human semen analysed by gas chromatography-mass spectrometry. γ-tocopherol would not seem to be related to semen parameters but to cellular oxidative condition. This tocopherol may contribute to human health in a yet unexplored way.

Circulating oxysterol metabolites as potential new surrogate markers in patients with hormone receptor-positive breast cancer: Results of the OXYTAM study.

Accumulating evidence indicates that cholesterol oxygenation products, also known as oxysterols (OS), are involved in breast cancer (BC) promotion. The impact of Tam, as well as aromatase inhibitors (AI), an alternative BC endocrine therapy (ET), on OS metabolism in patients is currently unknown. We conducted a prospective clinical study in BC patients receiving Tam (n=15) or AI (n=14) in adjuvant or in metastatic settings. The primary end point was the feasibility of detecting and quantifying 11 different OS in the circulation of patients before and after 28days of treatment with Tam or AI. Key secondary end points were the measurements of variations in the concentrations of OS according to differences between patients and treatments. OS profiling in the serum of patients was determined by gas chromatography coupled to mass spectrometry. OS profiling was conducted in all patients both at baseline and during treatment regimens. An important inter-individual variability was observed for each OS. Interestingly 5,6ß-epoxycholesterol relative concentrations significantly increased in the entire population (p=0.0109), while no increase in Cholestane-triol (CT) levels was measured. Interestingly, we found that, in contrast to AI, Tam therapy significantly decreased blood levels of 24-hydroxycholesterol (24-HC), 7α-HC and 25-HC (a tumor promoter) (p=0.0007, p=0.0231 and p=0.0231, respectively), whereas 4ß-HC levels increased (p=0.0010). Interestingly, levels of 27-HC (a tumor promoter) significantly increased in response to AI (p=0.0342), but not Tam treatment. According to these results, specific OS are promising candidate markers of Tam and AI efficacy. Thus, further clinical investigations are needed to confirm the use of oxysterols as biomarkers of both prognosis and/or the efficacy of ET.

Effects of dietary fatty acids and cholesterol excess on liver injury: A lipidomic approach.

Lipid accumulation is the hallmark of Non-alcoholic Fatty Liver Disease (NAFLD) and has been suggested to play a role in promoting fatty liver inflammation. Previous findings indicate that during oxidative stress conditions excess cholesterol autoxidizes to oxysterols. To date, the role of oxysterols and their potential interaction with fatty acids accumulation in NASH pathogenesis remains little investigated. We used the nutritional model of high fatty acids (HFA), high cholesterol (HCh) or high fat and high cholesterol (HFA+FCh) diets and explored by a lipidomic approach, the blood and liver distribution of fatty acids and oxysterols in response to dietary manipulation. We observed that HFA or HCh diets induced fatty liver without inflammation, which was otherwise observed only after supplementation of HFA+HCh. Very interestingly, the combination model was associated with a specific oxysterol fingerprint. The present work provides a complete analysis of the change in lipids and oxysterols profile induced by different lipid dietary model and their association with histological alteration of the liver. This study allows the generation of interesting hypotheses on the role of interaction of lipid and cholesterol metabolites in the liver injury during NAFLD development and progression. Moreover, the changes in the concentration and quality of oxysterols induced by a combination diet suggest a novel potential pathogenic mechanism in the progression from simple steatosis to steatohepatitis.

Plasma fatty acid lipidome is associated with cirrhosis prognosis and graft damage in liver transplantation.

BACKGROUND: Knowledge regarding the plasma fatty acid (FA) pattern in patients with liver cirrhosis is fragmentary. OBJECTIVE: We evaluated plasma FA lipidome and its association with the prognosis of cirrhosis and severity of liver graft damage after transplantation. DESIGN: In this observational study, plasma FA lipidome was investigated in 51 cirrhotic patients before liver transplantation and in 90 age- and sex-matched healthy control subjects. In addition, we studied ischemia-reperfusion damage in the liver of 38 patients for whom a graft biopsy was available at transplantation. With the use of logistic regression, we modeled the presence of cirrhosis, the dichotomized model for end-stage liver disease score below and above the median, and the presence of severe liver graft ischemia-reperfusion damage. RESULTS: The FA pattern was markedly altered in cirrhotic patients, who showed, compared with healthy controls, higher monounsaturated FAs, lower n-6 and n-3 polyunsaturated FAs, and undetectable cerotic acid. Plasma di-homo-γ-linolenic acid was independently associated with the presence of cirrhosis (OR: 0.026; 95% CI: 0.004, 0.196; P < 0.0001), severity of its prognosis (OR: 0.041; 95% CI:0.005, 0.376; P = 0.006), postreperfusion graft hepatocellular necrosis (OR: 0.921; 95% CI: 0.851, 0.997; P = 0.043), and sinusoidal congestion (OR: 0.954; 95% CI: 0.912, 0.998; P = 0.039). Associations of di-homo-γ-linolenic acid with the presence of cirrhosis and severity of its prognosis were confirmed also after false discovery rate correction. CONCLUSIONS: Cerotic and di-homo-γ-linolenic acids may serve as markers of disease and prognosis in liver cirrhosis. Dietary supplementation with di-homo-γ-linolenic acid could be a reasonable interventional strategy to delay disease progression in liver cirrhosis.