Combination of taurine and black pepper extract as a treatment for cardiovascular and coronary artery diseases

The shift in modern dietary regimens to “Western style” and sedentary lifestyles are believed to be partly responsible for the increase in the global burden of cardiovascular diseases. Natural products have been used throughout human history as treatments for a plethora of pathological conditions. Taurine and, more recently, black pepper have gained attention for their beneficial health effects while remaining non-toxic even when ingested in excess. Taurine, black pepper, and the major terpene constituents found in black pepper (i.e., β-caryophyllene; α-pinene; β-pinene; α-humulene; limonene; and sabinene) that are present in PhytoCann BP® have been shown to have cardioprotective effects based on anti-inflammatory, antioxidative, anti-hypertensive and anti-atherosclerotic mechanisms. This comprehensive review of the literature focuses on determining whether the combination of taurine and black pepper extract is an effective natural treatment for reducing cardiovascular diseases risk factors (i.e., hypertension and hyperhomocysteinemia) and for driving anti-inflammatory, antioxidative and anti-atherosclerotic mechanisms to combat coronary artery disease, heart failure, myocardial infarction, and atherosclerotic disease

Role of angiotensin II in cardiovascular diseases: introducing bisartans as a novel therapy for Coronavirus 2019

Cardiovascular diseases (CVDs) are the main contributors to global morbidity and mortality. Major pathogenic phenotypes of CVDs include the development of endothelial dysfunction, oxidative stress, and hyper-inflammatory responses. These phenotypes have been found to overlap with the pathophysiological complications of coronavirus disease 2019 (COVID-19). CVDs have been identified as major risk factors for severe and fatal COVID-19 states. The renin–angiotensin system (RAS) is an important regulatory system in cardiovascular homeostasis. However, its dysregulation is observed in CVDs, where upregulation of angiotensin type 1 receptor (AT1R) signaling via angiotensin II (AngII) leads to the AngII-dependent pathogenic development of CVDs. Additionally, the interaction between the spike protein of severe acute respiratory syndrome coronavirus 2 with angiotensin-converting enzyme 2 leads to the downregulation of the latter, resulting in the dysregulation of the RAS. This dysregulation favors AngII/AT1R toxic signaling pathways, providing a mechanical link between cardiovascular pathology and COVID-19. Therefore, inhibiting AngII/AT1R signaling through angiotensin receptor blockers (ARBs) has been indicated as a promising therapeutic approach to the treatment of COVID-19. Herein, we review the role of AngII in CVDs and its upregulation in COVID-19. We also provide a future direction for the potential implication of a novel class of ARBs called bisartans, which are speculated to contain multifunctional targeting towards COVID-19

Structural Features Influencing the Bioactive Conformation of Angiotensin II and Angiotensin A: Relationship between Receptor Desensitization, Addiction, and the Blood–Brain Barrier

The N-terminal portion of the octapeptide angiotensin II (DRVYIHPF; AngII), a vasopressor peptide that favorably binds to, and activates, AngII type 1 receptor (AT1R), has an important role in maintaining bioactive conformation. It involves all three charged groups, namely (i) the N-terminal amino group cation, (ii) the Asp sidechain anion and (iii) the Arg guanidino cation. Neutralization of any one of these three charged groups results in a substantial reduction (1R; however, replacement of Asp in AngII with sarcosine (N-methyl-glycine) not only restores bioactivity but increases the activity of agonist, antagonist, and inverse agonist analogues. A bend produced at the N-terminus by the introduction of the secondary amino acid sarcosine is thought to realign the functional groups that chaperone the C-terminal portion of AngII, allowing transfer of the negative charge originating at the C-terminus to be transferred to the Tyr hydroxyl-forming tyrosinate anion, which is required to activate the receptor and desensitizes the receptor (tachyphylaxis). Peptide (sarilesin) and nonpeptide (sartans) moieties, which are long-acting inverse agonists, appear to desensitize the receptor by a mechanism analogous to tachyphylaxis. Sartans/bisartans were found to bind to alpha adrenergic receptors resulting in structure-dependent desensitization or resensitization. These considerations have provided information on the mechanisms of receptor desensitization/tolerance and insights into possible avenues for treating addiction. In this regard sartans, which appear to cross the blood–brain barrier more readily than bisartans, are the preferred drug candidates

Preferential induction of apoptosis for primary human leukemic stem cells

Acute myelogenous leukemia (AML) is typically a disease of stem/progenitor cell origin. Interestingly, the leukemic stem cell (LSC) shares many characteristics with normal hematopoietic stem cells (HSCs) including the ability to self-renew and a predominantly G(0) cell-cycle status. Thus, although conventional chemotherapy regimens often ablate actively cycling leukemic blast cells, the primitive LSC population is likely to be drug-resistant. Moreover, given the quiescent nature of LSCs, current drugs may not effectively distinguish between malignant stem cells and normal HSCs. Nonetheless, based on recent studies of LSC molecular biology, we hypothesized that certain unique properties of leukemic cells could be exploited to induce apoptosis in the LSC population while sparing normal stem cells. In this report we describe a strategy using treatment of primary AML cells with the proteasome inhibitor carbobenzoxyl-l-leucyl-l-leucyl-l-leucinal (MG-132) and the anthracycline idarubicin. Comparison of normal and leukemic specimens using in vitro culture and in vivo xenotransplantation assays shows that the combination of these two agents induces rapid and extensive apoptosis of the LSC population while leaving normal HSCs viable. Molecular genetic studies using a dominant-negative allele of inhibitor of nuclear factor κB (IκBα) demonstrate that inhibition of nuclear factor κB (NF-κB) contributes to apoptosis induction. In addition, gene-expression analyses suggest that activation of p53-regulated genes are also involved in LSC apoptosis. Collectively, these findings demonstrate that malignant stem cells can be preferentially targeted for ablation. Further, the data begin to elucidate the molecular mechanisms that underlie LSC-specific apoptosis and suggest new directions for AML therapy