Hypertension is one of the risk factors for cardiovascular diseases and has been associated with about 13% of global deaths
worldwide. Oxidative stress and reduced nitric oxide (NO) bioavailability contribute to the development of endothelial
dysfunction and subsequently hypertension. Nɷ-nitro-L-arginine methyl ester hydrochloride (L-NAME) inhibits NO synthesis;
leading to hypertension. Piper sarmentosum (PS) is an herb with antioxidant, antiatherosclerosis and antiinflammation
properties. PS also stimulated NO production by endothelial cells. The aim of this study was to determine the effects of
aqueous extract of Piper sarmentosum (AEPS) on blood pressure, oxidative stress and the level of nitric oxide in L-NAMEinduced hypertensive rats. Hypertension was induced by oral administration of L-NAME (100 mg/L) in drinking water for
four weeks. The rats were concurrently treated with AEPS by oral gavage in serial doses (125, 250 and 500 mg/kg/day).
Blood pressure was measured using non-invasive tail-cuff method at baseline and fortnightly thereafter. Serum level of
NO and an oxidative stress marker, malondialdehyde (MDA) were measured at baseline and at the end of treatment. The
results showed that treatment with three different doses of AEPS successfully reduced systolic blood pressure (p<0.001),
diastolic blood pressure (p<0.05) and mean arterial pressure (p<0.05) in L-NAME-induced hypertensive rats. Treatment
with AEPS also reduced MDA level (p<0.001) and increased serum NO (p<0.001) in L-NAME-induced hypertensive rats.
The findings showed that AEPS decreased blood pressure by protecting against oxidative stress and increasing NO in
L-NAME-induced hypertensive rats.
The use of photoplethysmography (PPG) as one of cardiovascular disease (CVD) marker has got more attention due to
its simplicity, noninvasive and portable characteristics. Two new markers had been developed from PPG namely PPG
fitness index (PPGF) and vascular risk prediction index (VPRI). The aim of the present study was to compare PPGF level
between young women with and without CVD risk factors, to investigate the relationship between PPGF with other CVD
markers and to assess the sensitivity of VRPI in classifying young women that have CVD risk factors. A total of 148 young
women aged 20-40 years old with and without CVD risk factors were involved in this study. CVD risk factors comprised of
abdominal obesity, hypertension, dyslipidemia, smoking and family history of premature CVD. Subjects were categorized
into healthy or having CVD risk factor. Measurements taken were anthropometric data, blood pressure, lipid profile,
pulse wave velocity (PWV), augmentation index (AIx), high sensitivity C-Reactive Protein (hs-CRP), PPGF and VRPI. SPSS
version 20 was used for data analysis with p<0.05 as significant value. The mean subjects’ age was 29.97±5.27 years
old. There was no difference in PPGF level between groups (p>0.05). PPGF was independently determined by PWV (β=-
0.31, p<0.001) and height (β=0.16, p=0.04). VRPI had 77.9% sensitivity in identifying subjects with CVD risk factor. In
conclusion, PPGF correlates with PWV and has potential to be an indicator of aortic stiffness while VRPI is sensitive to
classify those with CVD risk factor.
Endothelial cell death due to increased reactive oxygen species (ROS) may contribute to the initial endothelial injury, which promotes atherosclerotic lesion formation. Piper sarmentosum (PS), a natural product, has been shown to have an antioxidant property, which is hypothesized to inhibit production of ROS and prevent cell injury. Thus, the present study was designed to determine the effects of PS on the hydrogen peroxide (H(2)O(2))-induced oxidative cell damage in cultured human umbilical vein endothelial cells (HUVECs). In this experiment, HUVECs were obtained by collagenase perfusion of the large vein in the umbilical cord and cultured in medium M200 supplemented with low serum growth supplementation (LSGS). HUVECs were treated with various concentrations of H(2)O(2) (0-1000 micromol/L) and it was observed that 180 micromol/L H(2)O(2) reduced cell viability by 50% as denoted by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Using the above concentration as the positive control, the H(2)O(2)-induced HUVECs were concomitantly treated with various concentrations (100, 150, 250 and 300 microg/ml) of three different extracts (aqueous, methanol and hexane) of PS. Malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPX) levels showed a significant increase (P<0.05) in HUVECs compared to the negative control. However, PS extracts showed a protective effect on HUVECs from H(2)O(2)-induced cell apoptosis with a significant reduction in MDA, SOD, CAT and GPX levels (P<0.05). Furthermore, PS had exhibited ferric reducing antioxidant power with its high phenolic content. Hence, it was concluded that PS plays a beneficial role in reducing oxidative stress in H(2)O(2)-induced HUVECs.