Angiotensin-Converting Enzyme and Hypertension: A Systemic Analysis of Various ACE Inhibitors, Their Side Effects, and Bioactive Peptides as a Putative Therapy for Hypertension

Ile-Pro-Pro attenuates sympathetic activity and hypertension

Isoleucine-proline-proline (Ile-Pro-Pro, IPP) is a natural food source tripeptide that inhibits angiotensin-converting enzyme (ACE) activity. The aim of this study was to determine the central and peripheral roles of IPP in attenuating sympathetic activity, oxidative stress and hypertension. Male Sprague-Dawley rats were subjected to sham-operated surgery (Sham) or two-kidney one-clip (2K1C) surgery to induce renovascular hypertension. Renal sympathetic nerve activity and blood pressure were recorded. Bilateral microinjections of IPP to hypothalamic paraventricular nucleus (PVN) attenuated sympathetic activity (-16.1 ± 2.5%, P < 0.001) and hypertension (-8.7 ± 1.5 mmHg, P < 0.01) in 2K1C rats by inhibiting ACE activity and subsequent angiotensin II and superoxide production in the PVN. Intravenous injections of IPP also attenuated sympathetic activity (-15.1 ± 2.1%, P < 0.001) and hypertension (-16.8 ± 2.3 mmHg, P < 0.001) via inhibiting ACE activity and oxidative stress in both PVN and arteries of 2K1C rats. The duration of the effects of the intravenous IPP was longer than those of the PVN microinjection, but the sympatho-inhibitory effect of intravenous injections occurred later than that of the PVN microinjection. Intraperitoneal injection of IPP (400 pmol/day for 20 days) attenuated hypertension and vascular remodeling via inhibiting ACE activity and oxidative stress in both PVN and arteries of 2K1C rats. These results indicate that IPP attenuates hypertension and sympathetic activity by inhibiting ACE activity and oxidative stress. The sympathoinhibitory effect of peripheral IPP is mainly caused by the ACE inhibition in PVN, and the antihypertensive effect is related to the sympathoinhibition and the arterial ACE inhibition. Long-term intraperitoneal IPP therapy attenuates hypertension, oxidative stress and vascular remodeling.

Effects of n-hexane fraction of Piper guineense seed extract on Nω-nitro-L-arginine methyl ester hydrochloride-induced hypertension in rats

This study aimed to investigate the effects of the n-hexane fraction of the ethanolic seed extract of PG (NFESEPG) on hypertension induced by Nω-nitro-L-arginine methyl ester (L-NAME) in rats. Specifically, the study examined the impact of NFESEPG on blood pressure, oxidative stress markers, NO concentration, angiotensin-converting enzyme (ACE) and arginase activities, and cardiac biomarkers in hypertensive rats. The study involved collecting, identifying, and processing the PG plant to obtain the ethanolic seed extract. The extract was then partitioned with solvents to isolate the n-hexane fraction. Hypertension was induced in rats by oral administration of L-NAME for 10 days, while concurrent treatment with NFESEPG at two doses (200 and 400 mg/kg/day) was administered orally. Blood pressure was measured using a noninvasive tail-cuff method, and various biochemical parameters were assessed. Treatment with both doses of NFESEPG significantly reduced systolic and diastolic blood pressure in L-NAME-induced hypertensive rats. Additionally, NFESEPG administration increased NO concentration and decreased ACE and arginase activities, malondialdehyde (MDA) levels, and cardiac biomarkers in hypertensive rats. The findings indicate that NFESEPG effectively lowered blood pressure in hypertensive rats induced by L-NAME, potentially through mechanisms involving the modulation of oxidative stress, NO bioavailability, and cardiac biomarkers. These results suggest the therapeutic potential of NFESEPG in managing hypertension and related cardiovascular complications.

Exploring peptidomes of by-products generated during chhurpi production using Lactobacillus delbrueckii WS4 for identification of novel bioactive peptides

The considerable value of whey is evident from its significant potential applications and contributions to the functional food and nutraceutical market. The by-products were individually obtained during functional chhurpi and novel soy chhurpi cheese production using defined lactic acid bacterial strains of Sikkim Himalaya's traditional chhurpi. Hydrolysis of substrate proteins by starter proteinases resulted in a comparable peptide content in whey and soy whey which was associated with antioxidant and ACE inhibition potential. Peptidome analysis of Lactobacillus delbrueckii WS4 whey and soy whey revealed the presence of several bioactive peptides including the multifunctional peptides PVVVPPFLQPE and YQEPVLGPVRGPFPIIV. In silico analyses predicted the antihypertensive potential of whey and soy whey peptides with strong binding affinity for ACE active sites. QSAR models predicted the highest ACE inhibition potential (IC50) for the β-casein-derived decapeptide PVRGPFPIIV (0.95 μM) and the Kunitz trypsin inhibitor protein-derived nonapeptide KNKPLVVQF (16.64 μM). Chhurpi whey and soy whey can be explored as a valuable source of diverse and novel bioactive peptides for applications in designer functional foods development.

Updates in the management of hypertension

Hypertension is the leading cause of cardiovascular diseases and nephropathies. Its treatment and management require long-term follow-up which can be facilitated by the emergence of device-based therapies. Novel recommendations have been well described in the latest ESH guidelines as well as new risk factors have been identified. The authors summarized the published evidence on hypertension management. The authors also cited in this review novel treatment approaches in different settings and the intervention of medication adherence in treatment success. Such non-communicable disease requires long-term follow-up and monitoring, which is quite facilitated in the era of digitalization by cuff-less devices based on prediction tools.

Association of ACE*(Insertion/Deletion) Variant with the Elevated Risk of Preeclampsia Among Gestational Women

The renin-angiotensin-aldosterone system has an indispensable function in the uteroplacental circulation, placental growth, and blood pressure optimization. The angiotensin I converting enzyme (ACE) gene is a critical integrator for electrolyte balance, and water retention, along with inhibiting preeclampsia. The main goal of this pertaining study is to assess the contribution of ACE*(Ins/Del) variant with the susceptibility for preeclampsia with focus on the severity of the disease among gestational hypertensive women. This retrospective study included 225 participants [125 PE gestational women, and 100 normotensive healthy controls] matching with age, and geographical region. PE women classified into 82 early-onset PE women, accompanied with 43 late-onset PE women. Additionally, PE women categorized into 59 mild PE women, together with 66 severe PE women. The genotyping and characterization of ACE*(Ins/Del) variant were applied using the PCR technique. Our findings indicated higher frequency of the ACE*(Del/Del) genotype and ACE*(D allele) with elevated risk of preeclampsia compared to normotensive controls under recessive (OR = 2.09, and p-value = 0.007), and allelic (OR = 1.75, and p-value = 0.012) models. In addition, testing logistic regression revealed that the levels of endothelin-1 and malondialdehyde exposed significant difference for the ACE*(Del/Del) genotype among early-onset and late-onset PE women (p-value = 0.024, and 0.23, respectively). Furthermore, carriers of the ACE*(Del/Del) genotype observed statistically significant with lower sodium concentrations among severe PE women (p-value = 0.034). The ACE*(Del/Del) genotype and ACE*(D allele) were associated with increased risk preeclampsia among gestational women. Furthermore, early-onset PE and late-onset PE were correlated with endothelin-1 and malondialdehyde concentrations among Egyptian women.