Piper sarmentosum Roxb. Inhibits Angiotensin-Converting Enzyme Activity in Phorbol 12-Myristate-13-Acetate-Induced Endothelial Cells.

Angiotensin-converting enzyme (ACE) plays a crucial role in the pathogenesis of hypertension. Piper sarmentosum Roxb., an herb known for its antihypertensive effect, lacks a comprehensive understanding of the mechanism underlying its antihypertensive action. This study aimed to elucidate the antihypertensive mechanism of aqueous extract of P. sarmentosum leaves (AEPS) via its modulation of the ACE pathway in phorbol 12-myristate-13-acetate (PMA)-induced human umbilical vein endothelial cells (HUVECs). HUVECs were divided into five groups: control, treatment with 200 µg/mL AEPS, induction 200 nM PMA, concomitant treatment with 200 nM PMA and 200 µg/mL AEPS, and treatment with 200 nM PMA and 0.06 µM captopril. Subsequently, ACE mRNA expression, protein level and activity, angiotensin II (Ang II) levels, and angiotensin II type 1 receptor (AT1R) and angiotensin II type 2 receptor (AT2R) mRNA expression in HUVECs were determined. AEPS successfully inhibited ACE mRNA expression, protein and activity, and angiotensin II levels in PMA-induced HUVECs. Additionally, AT1R expression was downregulated, whereas AT2R expression was upregulated. In conclusion, AEPS reduces the levels of ACE mRNA, protein and activity, Ang II, and AT1R expression in PMA-induced HUVECs. Thus, AEPS has the potential to be developed as an ACE inhibitor in the future.

Profiling of Differentially Expressed MicroRNAs in Human Umbilical Vein Endothelial Cells Exposed to Hyperglycemia via RNA Sequencing.

Hyperglycemia is the hallmark of diabetes mellitus that results in oxidative stress, apoptosis, and diabetic vascular endothelial dysfunction. An increasing number of microRNAs (miRNAs) have been found to be involved in the pathogenesis of diabetic vascular complications. However, there is a limited number of studies that characterize the miRNA profile of endothelial cells exposed to hyperglycemia. Therefore, this study aims to analyze the miRNA profile of human umbilical-vein endothelial cells (HUVECs) exposed to hyperglycemia. HUVECs were divided into two groups: the control (treated with 5.5 mM glucose) and hyperglycemia (treated with 33.3 mM glucose) groups. RNA sequencing identified 17 differentially expressed miRNAs between the groups (p < 0.05). Of these, 4 miRNAs were upregulated, and 13 miRNAs were downregulated. Two of the most differentially expressed miRNAs (novel miR-1133 and miR-1225) were successfully validated with stem-loop qPCR. Collectively, the findings show that there is a differential expression pattern of miRNAs in HUVEC following exposure to hyperglycemia. These 17 differentially expressed miRNAs are involved in regulating cellular functions and pathways related to oxidative stress and apoptosis that may contribute to diabetic vascular endothelial dysfunction. The findings provide new clues on the role of miRNAs in the development of diabetic vascular endothelial dysfunction, which could be useful in future targeted therapy.

Effects of Piper sarmentosum Roxb. on hypertension and diabetes mellitus: A systematic review and meta-analysis.

Hypertension and diabetes mellitus are among the most prevalent diseases affecting people from all walks of life. Medicinal herbs have garnered interest as potential agents for the prevention and treatment of diabetes mellitus and hypertension due to their multiple beneficial effects. Piper sarmentosum Roxb. (PS) is an edible medicinal plant that has been traditionally used in Asia for treating hypertension and diabetes mellitus. This review is aimed to provide comprehensive information from the literature on the effects of PS on hypertension and diabetes mellitus. A computerized database search was performed on Scopus, PubMed and Web of Science databases with the following set of keywords: Piper sarmentosum AND diabetes mellitus OR diabetic OR diabetes OR hyperglyc*emia OR blood glucose OR HbA1c OR glycated h*emoglobin OR h*emoglobin A1c OR hyperten* OR blood pressure. A total of 47 articles were screened and 14 articles published between the years 1998 until 2021 were included for data extraction, comprising of six articles on antihypertensive and eight articles on antidiabetic effects of PS. These studies consist of two in vitro studies and eleven in vivo animal studies. Meta-analysis of three studies on hypertension showed that PS versus no treatment significantly lowered the systolic blood pressure with mean difference (MD) -39.84 mmHg (95% confidence interval (CI) -45.05, -34.62; p < 0.01), diastolic blood pressure with MD -26.68 mmHg (95% CI -31.48, -21.88; p < 0.01), and mean arterial pressure with MD -30.56 mmHg (95% CI -34.49, -26.63; p < 0.01). Most of the studies revealed positive effects of PS against hypertension and diabetes mellitus, suggesting the potential of PS as a natural source of antidiabetic and antihypertensive agents.