The role of α2-adrenergic receptors in hypertensive preeclampsia: A hypothesis

Comprehensive mini-review: therapeutic potential of cannabigerol - focus on the cardiovascular system

Backgrounds

Cannabigerol (CBG) is a non-psychoactive phytocannabinoid with a broad spectrum of biological effects. However, there is still too little research on its safety especially its effects on the cardiovascular system. Due to its agonist effects on alpha-2-adrenergic receptors (α2AR), it is speculated that it may have applications in the pharmacotherapy of metabolic syndrome, particularly hypertension. Thus, the aim of our review was to analyse the therapeutic potential of CBG in cardiovascular diseases.

Methods

The review was based on searches of the PubMed and Web of Science databases. Keywords were used to identify literature containing therapeutic and mechanistic information on CBG and its potential effects on the cardiovascular system.

Results

A review of the literature shows that CBG exhibits hypotensive effects in mice probably through α2AR agonism. Other numerous in vitro and in vivo studies show that CBG has anti-inflammatory, antioxidant effects and also regulates cell apoptosis. Cannabigerol improved tissue sensitivity to insulin, and also showed efficacy in inhibiting platelet aggregation. However, there are reports of adverse effects of high doses of CBG on liver architecture and function, which calls into question its usefulness and safety profile.

Conclusion

Above mentioned beneficial properties of CBG suggest that it may be useful in treating hypertension and metabolic syndrome. However, there is still a lack of studies on the chronic administration of CBG and its effects on cardiovascular parameters in hypertension condition, which may be necessary to determine its safety and the need for future studies on other indications.

The pharmaco-epigenetics of hypertension: a focus on microRNA

Hypertension is a major harbinger of cardiovascular morbidity and mortality. It predisposes to higher rates of myocardial infarction, chronic kidney failure, stroke, and heart failure than most other risk factors. By 2025, the prevalence of hypertension is projected to reach 1.5 billion people. The pathophysiology of this disease is multifaceted, as it involves nitric oxide and endothelin dysregulation, reactive oxygen species, vascular smooth muscle proliferation, and vessel wall calcification, among others. With the advent of new biomolecular techniques, various studies have elucidated a gaping hole in the etiology and mechanisms of hypertension. Indeed, epigenetics, DNA methylation, histone modification, and microRNA-mediated translational silencing appear to play crucial roles in altering the molecular phenotype into a hypertensive profile. Here, we critically review the experimentally determined associations between microRNA (miRNA) molecules and hypertension pharmacotherapy. Particular attention is given to the epigenetic mechanisms underlying the physiological responses to antihypertensive drugs like candesartan, and other relevant drugs like clopidogrel, aspirin, and statins among others. Furthermore, how miRNA affects the pharmaco-epigenetics of hypertension is especially highlighted.

Depression and antidepressant treatment in the development of hypertensive disorders of pregnancy: Results from a prospective cohort study

BACKGROUND

Hypertensive disorders of pregnancy are associated with longer term cardiovascular risk. Understanding if depression or antidepressant use in pregnancy is associated with HDP is important in identifying those potentially vulnerable to poorer health in later life. This study examines if depression and antidepressants are associated with HDP.

METHODS

In all, 815 pregnant women were recruited within an Australian pregnancy cohort study at less than 20 weeks of pregnancy, all undertook the Structured Clinical Interview for the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, and were assigned to four groups for this paper: those with unmedicated depression meeting criteria for current depression (n = 97), those taking selective serotonin reuptake inhibitors in early pregnancy (n = 101), those taking serotonin and noradrenaline reuptake inhibitors in early pregnancy (n = 31), and those without depression or taking antidepressant medication (control; n = 586). Women were then assessed again following birth. Hypertensive disorders of pregnancy were diagnosed according to the Society of Obstetric Medicine in Australia and New Zealand Guidelines.

RESULTS

Use of serotonin and noradrenaline reuptake inhibitors (SNRIs) (adjusted risk ratio = 9.10, 95% confidence interval = [3.82, 21.67]) and unmedicated depression (adjusted risk ratio = 3.11, 95% confidence interval = [1.32, 7.35]) were independently associated with significantly higher risk for developing hypertensive disorders of pregnancy compared to controls. Selective serotonin reuptake inhibitors (SSRIs) use did not confer any increased risk. Higher doses of SNRIs, but not selective serotonin reuptake inhibitors, were associated with significantly higher risk for developing HDP (adjusted risk ratio = 4.83, 95% confidence interval = [1.50, 15.58]).

CONCLUSIONS

Our findings suggest that those with depression in pregnancy and/or on an serotonin and noradrenaline reuptake inhibitor should have closer surveillance for the development of hypertensive disorders of pregnancy. These findings support treatment of depression in pregnancy, however, also the consideration of class of antidepressant.

The hypertensive potential of estrogen: An untold story

Cardiovascular disease (CVD) is the major cause of morbidity and mortality worldwide. The implication of estrogen in this disease has been extensively studied. While the vast majority of published research argue for a cardioprotective role of estrogen in vascular inflammation such as in atherosclerosis, the role of estrogen in hypertension remains far from being resolved. The vasorelaxant effect of estrogen has already been well-established. However, emerging evidence supports a vasoconstrictive potential of this hormone. It has been proposed that the microenvironment dictates the effect of estrogen-induced type 1 nitric oxide synthase-1 (nNOS) on vasotone. Indeed, depending on nNOS product, nitric oxide or superoxide, estrogen can induce vasodilation or vasoconstriction, respectively. In this review, we discuss the evidence supporting the vasorelaxant effects of estrogen, and the molecular players involved. Furthermore, we shed light on recent reports revealing a vasoconstrictive role of estrogen, and speculate on the underlying signaling pathways. In addition, we identify certain factors that can account for the discrepant estrogenic effects. This review emphasizes a yin-yang role of estrogen in regulating blood pressure.