Nanotechnology-Based Strategies for Extended-Release Delivery of Angiotensin Receptor Blockers (ARBs): A Comprehensive Review

There has been a significant shift in the perception of hypertension as an important contributor to the global disease burden. Approximately 6 % and 8 % of pregnancies are affected by hypertension, which can adversely affect the mother and the fetus. Furthermore, a hypertensive individual is at increased risk of developing kidney disease, arterial hardening, eye damage, and strokes. Using angiotensin receptor blockers (ARBs) is widespread in treating hypertension, heart failure, coronary artery disease, and diabetic nephropathy. Despite this, some ARBs have limited use due to their poor oral bioavailability and water solubility. To tackle this, a variety of nanoparticle (NP)-based systems, such as polymeric NPs (i. e., dendrimers), polymeric micelles, polymer-drug conjugates, lipid NPs, nanoemulsions, self-emulsifying drug delivery systems (SEDDS), solid lipid NPs (SLNs), nanostructured lipid carriers (NLCs), carbon-based nanocarriers, inorganic NPs, and nanocrystals, have been recently developed for efficient delivery of losartan, Valsartan (Val), Olmesartan (OLM), Telmisartan (TEL), Candesartan, Eprosartan, Irbesartan, and Azilsartan to target cells. This review article provides a literature-based comparison of the various classes of ARBs, their mechanisms of action, and an overview of the nanoformulations developed for ARB delivery and successfully applied to managing hypertension, diabetic complications, and other conditions.

Angiotensin II Type 1 Receptor Blockers Reduce Urinary Angiotensinogen Excretion and the Levels of Urinary Markers of Oxidative Stress and Inflammation in Patients with Type 2 Diabetic Nephropathy

Objective

To demonstrate that the administration of an angiotensin (Ang) II type 1 receptor (AT1R) blocker (ARB) inhibits the vicious cycle of high glucose (HG)-reactive oxygen species (ROS)-angiotensinogen (AGT)-Ang II-AT1R-ROS by suppressing ROSs and inflammation, thus ameliorating diabetic nephropathy (DN).

Research Design and Methods

Thirteen hypertensive DN patients were administered ARBs, and the following parameters were evaluated before and 16 weeks after the treatment: urinary AGT (UAGT), albumin (albumin-creatinine ratio: ACR), 8-hydroxyde-oxyguanosine (8-OHdG), 8-epi-prostaglandin F2α(8-epi-PGF2α), monocyte chemoattractant protein (MCP)-1, interleukin (IL)-6, and IL-10.

Results

ARB treatment reduced the blood pressure and urinary levels of AGT, ACR, 8-OHdG, 8-epi-PGF2α, MCP-1, and IL-6 but increased the urinary levels of IL-10. The reduction rate of UAGT correlated with the reduction rate of blood pressure; the reduction rates of the urinary ACR, 8-OHdG, 8-epi-PGF2α, MCP-1, and IL-6 levels; and the increase rate of the urinary IL-10 levels. Moreover, subjects who had high UAGT values at baseline exhibited higher reduction rates of urinary albumin excretion.

Conclusions

ARB-induced blockade of the abovementioned vicious cycle contributes to the renoprotective effects of ARBs in DN. The urinary levels of AGT could represent a predictive factor for reduced ACR in patients receiving ARB treatment.

The effect of 'Astressin', a novel antagonist of corticotropin releasing hormone (CRH), on CRH-induced seizures in the infant rat: comparison with two other antagonists

Corticotropin releasing hormone (CRH) has both neuroendocrine effects, promoting ACTH release from the anterior pituitary, and neurotransmitter properties, acting on specific neuronal populations. A recently designed CRH analogue has been shown to be highly potent in preventing activation of pituitary CRH receptors. The efficacy of this compound, 'Astressin', in blocking the effects of CRH in the central nervous system (CNS) has not been determined. CRH induces prolonged amygdala-origin seizures in neonatal and infant rats. This model was used in the current study, to compare Astressin to alpha-helical CRH-(9-41), and to [D-Phe12, Nle21.38, C-MeLeu37]CRH-(12-41), i.e. D-Phe-CRH-(12-41). Astressin (3 or 10 micrograms) was infused into the cerebral ventricles of infant rats prior to CRH infusion. Both doses of the analogue significantly delayed the onset of CRH-induced seizures when given 15, but not 30 min before CRH. No effect of the lower Astressin dose on seizure duration was demonstrated; the higher dose prevented seizures in 2/12 rats, and delayed seizure onset in the others (22.7 +/- 5 min vs 10.1 +/- 1.3 min). In the same paradigm, 10 micrograms of alpha-helical CRH-(9-41) and 5 micrograms of D-Phe-CRH-(12-41) had comparable effects on seizure latency and duration. Electroencephalograms confirmed the behavioral effects of Astressin. Therefore, in a CNS model of CRH-mediated neurotransmission, the potency of Astressin is not substantially higher than that of alpha-helical CRH (9-41) and D-Phe-CRH-(12-41).