Clinical Utility of Plasma Lipid Peroxidation Biomarkers in Alzheimer’s Disease Differential Diagnosis

Background: Differential diagnosis of Alzheimer’s disease (AD) is a complex task due to the clinical similarity among neurodegenerative diseases. Previous studies showed the role of lipid peroxidation in early AD development. However, the clinical validation of potential specific biomarkers in minimally invasive samples constitutes a great challenge in early AD diagnosis. Methods: Plasma samples from participants classified into AD (n = 138), non-AD (including MCI and other dementias not due to AD) (n = 70) and healthy (n = 50) were analysed. Lipid peroxidation compounds (isoprostanes, isofurans, neuroprostanes, neurofurans) were determined by ultra-performance liquid chromatography coupled with tandem mass spectrometry. Statistical analysis for biomarkers’ clinical validation was based on Elastic Net. Results: A two-step diagnosis model was developed from plasma lipid peroxidation products to diagnose early AD specifically, and a bootstrap validated AUC of 0.74 was obtained. Conclusion: A promising AD differential diagnosis model was developed. It was clinically validated as a screening test. However, further external validation is required before clinical application.

Lactobacilli modulated AMPK activity and prevented telomere shortening in ageing rats

This study aimed to evaluate the anti-ageing effects of different strains of lactobacilli putative probiotics on an ageing rat model as induced by D-galactose and a high fat diet. Male Sprague-Dawley rats were fed with high fat diet (54% kcal fat) and injected with D-galactose daily for 12 weeks to induce ageing. The effects of putative probiotic strains on age-related impairment such as telomere length, plasma lipid peroxidation, hepatic 5’adenosine monophosphate-activated protein kinase (AMPK) expression, as well as endurance performance were evaluated. Administration of statin, Lactobacillus plantarum DR7 (LP-DR7), Lactobacillus fermentum DR9 (LF-DR9), and Lactobacillus reuteri 8513d (LR-8513d) significantly reduced the shortening of telomere and increased the expression of AMPK subunit-α1 (P<0.05). Plasma lipid peroxidation was lower (P<0.05) in groups administered with statin and LF-DR9 as compared to the control. AMPK subunit-α2 was elevated in rats administered with LP-DR7 as compared to the control (P<0.05). Using an in vivo ageing rat model, the current study has illustrated the potentials of lactobacilli putative probiotics in alleviation of age-related impairment in a strain-dependent manner.

Plasma Lipid Peroxidation as a Marker for Seminal Oxidative Stress in Stallion

This experiment aims to evaluate the correlation between lipid peroxidation levels in serum and seminal plasma in equines. Also, it investigates the lipid peroxidation in extended semen samples and its effects and sperm motility during a 72 hr refrigeration period. Blood and semen were collected from fertile Crioulo stallions. Serum and seminal plasma lipid peroxidation levels were analyzed by thiobarbituric acid reactive substances (TBARS) immediately after semen collection. After addition of extender (hour = 0), diluted semen was refrigerated and stored at 5 &deg;C. Semen analyses, TBARS and catalase activity were performed in extended semen at 0, 24, 48, and 72 hours. We noted that levels of plasma lipid peroxidation can be used as an indicative of seminal oxidative stress. Also, lipid peroxidation does not increase substantially during semen storage. Lipid peroxidation and the antioxidant enzyme catalase do not seem to be the major cause of loss and motility and consequently reduction in fertility in stallion semen during storage for 72 h at 5 &deg;C.