It has been 200 years since Parkinson´s disease (PD) was first described, yet many aspects of its etiopathogenesis remain unclear. PD is a progressive and complex neurodegenerative disorder caused by genetic and environmental factors including aging, nutrition, pesticides and exposure to heavy metals. DNA methylation may be altered in response to some of these factors; therefore, it is proposed that epigenetic mechanisms, particularly DNA methylation, can have a fundamental role in gene-environment interactions that are related with PD. Epigenetic changes in PD-associated genes are now widely studied in different populations, to discover the mechanisms that contribute to disease development and identify novel biomarkers for early diagnosis and future pharmacological treatment. While initial studies sought to find associations between promoter DNA methylation and the regulation of associated genes in PD brain tissue, more recent studies have described concordant DNA methylation patterns between blood and brain tissue DNA. These data justify the use of peripheral blood samples instead of brain tissue for epigenetic studies. Here, we summarize the current data about DNA methylation changes in PD and discuss the potential of DNA methylation as a potental biomarker for PD. Additionally, we discuss environmental and nutritional factors that have been implicated in DNA methylation. Although the search for significant DNA methylation changes and gene expression analyses of PD-associated genes have yielded inconsistent and contradictory results, epigenetic modifications remain under investigation for their potential to reveal the link between environmental risk factors and the development of PD.

Moringa oleifera is a tree distributed in Mexican semiarid and coastal regions. M. oleifera is used in practice in the treatment of various diseases and is available without a medical prescription, often in the form of an herbal infusion for everyday use. The aim of the present study was to evaluate the chemical composition and nutritional values of dried M. oleifera leaf powder collected from two different regions in Mexico. All samples of M. oleifera exhibited moisture levels varying from 3.06 to 3.34%, lipids from 10.21 to 10.31%, fiber from 7.29 to 9.46%, ashes from 10.71 to 11.18%, crude protein from 10.74 to 11.48%, and carbohydrates from 54.61 to 57.61%. The predominant mineral elements in the leaf powder according to ICP‐MS were Ca (2016.5–2620.5 mg/100 g), K (1817–1845 mg/100 g), and Mg (322.5–340.6 mg/100 g). The HPLC analysis indicated the presence of phenolic acids (gallic and chlorogenic acids) and flavonoids (rutin, luteolin, quercetin, apigenin, and kaempferol). We concluded that Lombardia M. oleifera samples could be employed in edible and commercial applications. Our results showed that the highest mean value of As from the San Pedro samples exceeds the recommended level and may constitute a health hazard to consumers.

Cholesterol has been associated as a risk factor for cardiovascular disease. Recently, however, there is growing evidence about crucial requirement of neuron membrane cholesterol in the organization and function of the 5-HT1A serotonin receptor. For this, low cholesterol level has been reported to be associated with depression and suicidality. However there have been inconsistent reports about this finding and the exact relationship between these factors remains controversial. Therefore, we investigated the link between serum cholesterol and its fractions with depression disorder and suicide attempt in 467 adult subjects in Mexican mestizo population. Plasma levels of total cholesterol, triglycerides, and high-density lipoprotein cholesterol (HDL-c) and low density lipoprotein cholesterol (LDL-c) were determined in 261 MDD patients meeting the DSM-5 criteria for major depressive disorder (MDD), 59 of whom had undergone an episode of suicide attempt, and 206 healthy controls. A significant decrease in total cholesterol, LDL-cholesterol, VLDL-cholesterol and triglyceride serum levels was observed in the groups of MDD patients and suicide attempt compared to those without suicidal behavior (p < 0.05). After adjusting for covariates, lower cholesterol levels were significantly associated with MDD (OR 4.229 CI 95% 2.555 – 7.000, p<.001) and suicide attempt (OR 5.540 CI 95% 2.825 – 10.866, p<.001) These results support the hypothesis that lower levels of cholesterol are associated with mood disorders like MDD and suicidal behavior. More mechanistic studies are needed to further explain this association.

Degeneration of several brainstem nuclei has been long related to motor and non-motor symptoms of Parkinson's disease (PD). Nevertheless, due to technical issues, there are only a few studies that correlate that association. Brainstem auditory-evoked potentials (BAEP), and vestibular evoked myogenic responses (VEMPs) represent a valuable tool for brainstem assessment. Here, we investigated the abnormalities of BAEPs, ocular and cervical VEMPs (oVEMPs and cVEMPs) in patients with PD and its correlation to the motor and non-motor symptoms. Fifteen patients diagnosed as idiopathic PD were diagnostic using Unified Parkinson’s Disease Rating Scale (UPDRS) and its subscores, Hoehn and Yahr scale, Schwab and England scale, and Non-Motor Symptoms Scale (NMSS). PD patients underwent pure-tone, speech audiometry, and tympanometry, BBAEP, and ocular and cervical VEMPs and compared to fifteen age-matched control subjects. PD subjects showed abnormal BAEPs wave morphology, prolonged absolute latencies of wave V and I-V interpeak latencies. Absent responses were the marked abnormality seen in oVEMP. Prolonged latencies with reduced amplitudes were seen in cVEMP responses. Rigidity and bradykinesia were correlated to the BAEPs and cVEMPs responses contralateral to the clinically more affected (CMA) side. Contralateral and ipsilateral cVEMPs were significantly correlated to sleep (p=0.03 & 0.001), perception (p=0.03), memory / cognition (p=0.025), and urinary scores (p=0.03). The oVEMP responses showed significant correlations to cardiovascular (p= 0.01) and sexual dysfunctions (p=0.013). PD is associated with BAEPs and VEMPs abnormalities that are correlated to the motor and some non-motor clinical characteristics. These abnormalities could be considered as potential electrophysiological biomarkers for brainstem dysfunction and its associated motor and non-motor features.

Adult mammalian brains continuously generate new neurons, a phenomenon called neurogenesis. Both environmental stimuli and endogenous factors are important regulators of neurogenesis. Sleep has an important role in normal brain physiology and its disturbance causes very stressful conditions, which disrupt normal brain physiology. Recently, an influence of sleep in adult neurogenesis has been established, mainly based on sleep deprivation studies. This review provides an overview on how rhythms and sleep cycles regulate hippocampal and subventricular zone neurogenesis, discussing some potential underlying mechanisms. In addition, our review highlights some interacting points between sleep and neurogenesis in brain function, such as learning, memory and mood states, and provides some insights on the effects of antidepressants and hypnotic drugs on neurogenesis.

Head and neck squamous cell carcinomas (HNSCCs) are aggressive, recurrent, and metastatic neoplasms with a high occurrence around the world and can lead to death when not treated appropriately. Several molecules and signaling pathways are involved in the malignant conversion process. Epithelial–mesenchymal transition (EMT) has been described in HNSCCs, a major type of aggressive carcinoma. EMT describes the development of epithelial cells into mesenchymal cells, which depends on several molecular interactions and signaling pathways that facilitate mesenchymal conversion. This is related to interactions with the microenvironment of the tumor, hypoxia, growth factors, matrix metalloproteinases, and the presence of viral infections. In this review, we focus on the main molecules related to EMT, their interactions with the tumor microenvironment, plasticity phenomena, epigenetic regulation, hypoxia, inflammation, their relationship with immune cells, and the inhibition of EMT in the context of HNSCCs.