Effect of the roselle (Hibiscus sabdariffa L.) calyces drink on the physiological parameters of healthy adult subjects

The calyx of roselle (Hibiscus sabdariffa L.) has been the focus of attention of several studies, and although earlier studies on this plant showed it to possess antilipidemic and antidiabetic activities, none of these studies have assessed the effects of this plant on the physiological parameters of healthy subjects. The present study determined the effects of roselle calyx beverages on blood pressure, abdominal circumference, body mass index (BMI), hematological and urinary parameters, and the lipid profile of healthy subjects. Healthy subjects (n=30) were treated with a 200 ml roselle calyx beverage each morning and evening for 30 consecutive days. Every week the subjects were asked to perform some physical activity by following the Young Men's Christian Association step test. This study used a pre-post quasi-experimental design. Blood samples were taken before (day-0) and after the intervention (day-30). There was an increase in the levels of high-density lipoproteins (from 47.0 to 49.5 mg/dl; P=0.015), and a significant decrease in both systolic and diastolic (P=0.036 and P=0.030, respectively), and the abdominal circumference of the subjects (P=0.005). However, total cholesterol levels (191.2 to 191.9 mg/dl; P=0.821) and low-density lipoprotein levels (129.8 to 133.5 mg/dl; P=0.249) were slightly increased, although not significantly. A lower level of triglycerides (114.3 to 107.4 mg/dl; P=0.269) and very-low-density lipoprotein levels (22.8 to 21.4 mg/dl; P=0.681) was observed. No significant differences were detected in the BMI or the urinalysis parameters were identified. Based on these results, roselle (Hibiscus sabdariffa L.) may be used as a supplement to prospectively improve the health status of subjects. No serious adverse effects were observed during this trial.