Magnesium-Dependent Ecto-ATP Diphosphohydrolase Activity in Leishmania donovani

Targeting P2 receptors in purinergic signaling: a new strategy of active ingredients in traditional Chinese herbals for diseases treatment

Adenosine triphosphate (ATP) and its metabolites adenosine diphosphate, adenosine monophosphate, and adenosine in purinergic signaling pathway play important roles in many diseases. Activation of P2 receptors (P2R) channels and subsequent membrane depolarization can induce accumulation of extracellular ATP, and furtherly cause kinds of diseases, such as pain- and immune-related diseases, cardiac dysfunction, and tumorigenesis. Active ingredients of traditional Chinese herbals which exhibit superior pharmacological activities on diversified P2R channels have been considered as an alternative strategy of disease treatment. Experimental evidence of potential ingredients in Chinese herbs targeting P2R and their pharmacological activities were outlined in the study.

ATP-Diphosphohydrolases in Parasites: Localization, Functions and Recent Developments in Drug Discovery

ATP-diphosphohydrolases (EC 3.6.1.5), also known as ATPDases, NTPases, NTPDases, EATPases or apyrases, are enzymes that hydrolyze a variety of nucleoside tri- and diphosphates to their respective nucleosides, being their activities dependent on the presence of divalent cations, such as calcium and magnesium. Recently, ATP-diphosphohydrolases were identified on the surface of several parasites, such as Trypanosoma sp, Leishmania sp and Schistosoma sp. In parasites, the activity of ATPdiphosphohydrolases has been associated with the purine recuperation and/or as a protective mechanism against the host organism under conditions that involve ATP or ADP, such as immune responses and platelet activation. These proteins have been suggested as possible targets for the development of new antiparasitic drugs. In this review, we will comprehensively address the main aspects of the location and function of ATP-diphosphohydrolase in parasites. Also, we performed a detailed research in scientific database of recent developments in new natural and synthetic inhibitors of the ATPdiphosphohydrolases in parasites.

Tinkering with targeting nucleotide signaling for control of intracellular Leishmania parasites

Nucleotides are one of the most primitive extracellular signalling molecules across all phyla and regulate a multitude of responses. The biological effects of extracellular nucleotides/sides are mediated via the specific purinergic receptors present on the cell surface. In mammalian system, adenine nucleotides are the predominant nucleotides found in the extracellular milieu and mediate a constellation of physiological functions. In the context of host-pathogen interaction, extracellular ATP is recognized as a danger signal and potentiates the release of pro-inflammatory mediators from activated immune cells, on the other hand, its breakdown product adenosine exerts potential anti-inflammatory and immunosuppressive actions. Therefore, it is increasingly apparent that the interplay between extracellular ATP/adenosine ratios has a significant role in coordinating the regulation of the immune system in health and diseases. Several pathogens express ectonucleotidases on their surface and exploit the purinergic signalling as one of the mechanisms to modulate the host immune response. Leishmania pathogens are one of the most successful intracellular pathogens which survive within host macrophages and manipulate protective Th1 response into disease promoting Th2 response. In this review, we discuss the regulation of extracellular ATP and adenosine levels, the role of ATP/adenosine counter signalling in regulating the inflammation and immune responses during infection and how Leishmania parasites exploit the purinergic signalling to manipulate host response. We also discuss the challenges and opportunities in targeting purinergic signalling and the future prospects.

Changes of Blood Pressure and Hemodynamic Parameters after Oral Magnesium Supplementation in Patients with Essential Hypertension-An Intervention Study

The objective of this study was to examine the changes of blood pressure and hemodynamic parameters after oral magnesium supplementation in patients with essential hypertension. The single-arm non-blinded intervention study comprised 48 patients (19 men; 29 women) whose antihypertensive therapy was not changed for at least one month. The participants were asked to consume (daily at home) 300 mg of oral magnesium-oxide supplementation product for one month and to have their blood pressure and hemodynamic parameters (thoracic fluid content, stroke volume, stroke index, cardiac output, cardiac index, acceleration index, left cardiac work index and systemic vascular resistance index, heart rate) measured in the hospital before and after the intervention. Measurements were performed with impedance cardiography. After magnesium supplementation, systolic and diastolic pressures were significantly decreased (mean ± standard deviation (SD)/mmHg/from 139.7 ± 15.0 to 130.8 ± 13.4 and from 88.0 ± 10.4 to 82.2 ± 9.0, respectively; both p < 0.001). The two significant hemodynamic changes were the decrease of systemic vascular resistance index (dyn s m²/cm⁵) and left cardiac work index (kg m/m²)/mean ± SD from 2319.3 ± 753.3 to 2083.0 ± 526.9 and from 4.8 ± 1.4 to 4.4 ± 0.9, respectively; both p < 0.05). The observed hemodynamic changes may explain lowering blood pressure after magnesium supplementation.