Preclinical Trial of Propolis Extract in Prevention of High Salt Diet- Induced Hypertension

Background: Propolis has been widely reported as having various biological activities. However, Indonesian propolis seems to be less explored. Objective: The present study aimed to analyze the antihypertensive activity of Indonesian propolis in rats. Materials and Methods: Hypertension was induced by high-NaCl (8%) diet for 3 weeks. A total of 36 rats were divided into 6 groups, including standard diet group (SD), high-NaCl diet group (NaD), high-NaCl diet group + captopril (25 mg/ kg) (PD), high-NaCl diet + propolis from Riau Archipelago (NaDP1), high-NaCl diet + propolis from Lampung (NaDP2) and high-NaCl diet + propolis from South Sulawesi (NaDP3). Propolis was daily administered at dose of 200 mg/ kg on hypertensive rats for 1 week. Blood pressure and body weight were weekly measured. Moreover, routine urine analysis, haematological parameters and lipid profiles at week 4 were determined. Results: The results showed that high-NaCl diet successfully induced hypertension in rats after 3 weeks of intervention. However, the diet did not cause weight gain (p>0.05). All Indonesian propolis samples significantly reversed either systolic or diastolic blood pressure of hypertensive rats. From urine analysis, propolis from Riau Archipelago and Lampung showed diuretic effect. The haematological analysis mainly showed no significant difference compared standard diet group. Furthermore, LDL and HDL concentrations were significantly improved by propolis from Lampung and South Sulawesi, respectively (p<0.05). In addition, we only found significant decrease in relative weight of liver in all groups administered with high-NaCl diet (p<0.05). Conclusion: The present study suggests that all Indonesian propolis possessed antihypertensive activity.