Mechanisms underlying hypertension and obesity: a melanocortin linkage in the brain

Plants and Natural Products with Activity against Various Types of Coronaviruses: A Review with Focus on SARS-CoV-2

COVID-19 is a pandemic disease caused by the SARS-CoV-2 virus, which is potentially fatal for vulnerable individuals. Disease management represents a challenge for many countries, given the shortage of medicines and hospital resources. The objective of this work was to review the medicinal plants, foods and natural products showing scientific evidence for host protection against various types of coronaviruses, with a focus on SARS-CoV-2. Natural products that mitigate the symptoms caused by various coronaviruses are also presented. Particular attention was placed on natural products that stabilize the Renin–Angiotensin–Aldosterone System (RAAS), which has been associated with the entry of the SARS-CoV-2 into human cells.

Imbalanced insulin action in chronic over nutrition: Clinical harm, molecular mechanisms, and a way forward

The growing worldwide prevalence of overnutrition and underexertion threatens the gains that we have made against atherosclerotic cardiovascular disease and other maladies. Chronic overnutrition causes the atherometabolic syndrome, which is a cluster of seemingly unrelated health problems characterized by increased abdominal girth and body-mass index, high fasting and postprandial concentrations of cholesterol- and triglyceride-rich apoB-lipoproteins (C-TRLs), low plasma HDL levels, impaired regulation of plasma glucose concentrations, hypertension, and a significant risk of developing overt type 2 diabetes mellitus (T2DM). In addition, individuals with this syndrome exhibit fatty liver, hypercoagulability, sympathetic overactivity, a gradually rising set-point for body adiposity, a substantially increased risk of atherosclerotic cardiovascular morbidity and mortality, and--crucially--hyperinsulinemia. Many lines of evidence indicate that each component of the atherometabolic syndrome arises, or is worsened by, pathway-selective insulin resistance and responsiveness (SEIRR). Individuals with SEIRR require compensatory hyperinsulinemia to control plasma glucose levels. The result is overdrive of those pathways that remain insulin-responsive, particularly ERK activation and hepatic de-novo lipogenesis (DNL), while carbohydrate regulation deteriorates. The effects are easily summarized: if hyperinsulinemia does something bad in a tissue or organ, that effect remains responsive in the atherometabolic syndrome and T2DM; and if hyperinsulinemia might do something good, that effect becomes resistant. It is a deadly imbalance in insulin action. From the standpoint of human health, it is the worst possible combination of effects. In this review, we discuss the origins of the atherometabolic syndrome in our historically unprecedented environment that only recently has become full of poorly satiating calories and incessant enticements to sit. Data are examined that indicate the magnitude of daily caloric imbalance that causes obesity. We also cover key aspects of healthy, balanced insulin action in liver, endothelium, brain, and elsewhere. Recent insights into the molecular basis and pathophysiologic harm from SEIRR in these organs are discussed. Importantly, a newly discovered oxide transport chain functions as the master regulator of the balance amongst different limbs of the insulin signaling cascade. This oxide transport chain--abbreviated 'NSAPP' after its five major proteins--fails to function properly during chronic overnutrition, resulting in this harmful pattern of SEIRR. We also review the origins of widespread, chronic overnutrition. Despite its apparent complexity, one factor stands out. A sophisticated junk food industry, aided by subsidies from willing governments, has devoted years of careful effort to promote overeating through the creation of a new class of food and drink that is low- or no-cost to the consumer, convenient, savory, calorically dense, yet weakly satiating. It is past time for the rest of us to overcome these foes of good health and solve this man-made epidemic.

Ghrelin and obestatin levels in hypertensive obese patients

Objectives

To investigate plasma total ghrelin and obestatin levels and the ghrelin/obestatin ratio prospectively, in hypertensive obese patients.

Methods

Height, weight, and waist and hip circumferences were measured in hypertensive and normotensive obese patients and matched healthy controls; the body mass index and waist to hip ratio were calculated. Fasting glucose and insulin levels were measured and the homeostasis model assessment of insulin resistance (HOMA-IR) was determined. Fasting ghrelin and obestatin concentrations were measured by radioimmunoassay and the ghrelin/obestatin ratio was calculated.

Results

A total of 38 hypertensive obese patients, 40 normotensive obese patients and 38 controls were enrolled. Hypertensive obese patients had lower plasma levels of ghrelin and obestatin than normotensive obese patients or controls. In addition, normotensive obese patients had lower plasma ghrelin and obestatin levels than controls. In hypertensive obese patients, ghrelin and obestatin levels were negatively associated with systolic and diastolic blood pressure, fasting insulin and HOMA-IR. In normotensive obese patients, ghrelin, obestatin and the ghrelin/obestatin ratio were negatively associated with fasting insulin and HOMA-IR. In both patient groups, fasting obestatin and ghrelin concentrations were significantly and positively correlated with each other.

Conclusion

Changes in the levels of ghrelin and obestatin may play a role in the pathophysiology of obesity and hypertension.