Introduction: Hypertension is a major risk factor for cardiovascular diseases which is one of the leading causes of death worldwide. Piper sarmentosum (PS) has been widely used in traditional medicine with proven antihypertensive and antioxidant effects. This study aims to evaluate the antihypertensive potential of PS aqueous extract (PSAE) and to investigate the factors modulating nitric oxide (NO) production through its anti-oxidant activities. Methods: PS leaves were extracted with distilled water, freeze-dried and examined to quantify their antioxidant activities through 2,2-diphenyl-1-picrylhydrazyl and ferric reducing ability plasma test. The antihypertensive effect of PSAE in spontaneous hypertensive rats (SHR) was evaluated using four different groups (n=6); C (negative control), K (PSAE 500mg/kg), P (3 mg/kg perindopril) and M (PSAE 500 mg/kg + 1.5 mg/kg perindopril). PSAE and other treatments were given via oral gavage for 28 days. The blood pressure (BP) was determined using the non-invasive BP monitoring tail cuff technique and recorded weekly. SHR’s blood was collected to determine the serum NO level using Griess assay. Asymmetric dimethylarginine (ADMA) and arginine levels were determined using high performance liquid chromatography. Results: The extract showed good in-vitro antioxidant activities and a significant reduction in both systolic and diastolic BP compared to control group. They were also a decrease in plasma ADMA and an increase in serum NO level. Meanwhile, arginine level does not change significantly. Conclusion: High in-vitro antioxidant activities in PSAE enhances the clearance of ADMA that leads to an increase in serum NO production hence ameliorating the blood pressure of SHR.

This study observed the pattern of reported dengue infections, clinical manifestations, and circulating dengue serotypes in Negeri Sembilan, Malaysia. The aim of this study was to determine the co-circulation of the four different dengue virus serotypes in Negeri Sembilan. We analyzed the surveillance data (VEKPRO) from Negeri Sembilan State Health Department and National Public Health Laboratory, Malaysia on reported dengue infections from 1st January 2010 to 31st December 2010. There were 1466 reported dengue infections, 1342 (91.5%) cases were dengue fever (DF) and 124 (8.5%) were dengue hemorrhagic fever (DHF). The mean age was 32.2± 15.8 years old and most were young adults, aged 15 years old and older. Males (p < 0.05), and those residing in Seremban district (p < 0.05) were more likely to get dengue infections. Symptoms presented upon admission were fever (100%), headache (99.9%), myalgia and arthralgia (98.8%), rash(24.2%), petechiae (16.0%),bleeding tendencies (7.0%) and neurological deficits(1.2%). All four dengue serotypes (DEN 1 – 4) were present, the pre-dominant serotype was DEN-3, noted in January, then existed together with DEN-2 until around May. DEN-1 was the most pre-dominant circulating dengue serotype afterwards, reaching a peak in December 2010. Dengue affected all age groups particularly young adults and males. Most cases reported were in urban areas and Seremban district. Most of the dengue infections occurred in the first half of the year, with the DEN-2 and DEN-3 serotypes being the most predominant.