Roselle (Hibiscus sabdariffa)

what is Roselle?

Hibiscus sabdariffa in english is commonly known as roselle or red sorrel,meanwhile in arabic Hibiscus sabdariffa is known as karkadeh.roselle is widely grown in central, west african, and .

and south east asia.

Roselle is an errect annual herbs. it also have thick,red and fleshy, cup-shaped calyces of flower.this calyces were consumed worlwide as a cold beverages or as a hot drink.the red anthocyanin pigments in the calyces were used as food colouring agents.

Benefits of Roselle?

1)Hypertension

• according to a research that has been done, the intravenous injection of aqueous extract of  Hibiscus sabdariffa calyx to anaesthetized cats and rats lowered blood pressure in dose-dependent manner.
• in single clinical trial consist of 54 patient with moderate hypertension were consumed two spoonful of roselle extract daily and the result,there has been reduced about 11% of systolic and diastolic blood pressure after 12 days of treatment

2)Antioxidant and anticancer

• An 80% ethanol extract of Hibiscus sabdariffa was effective in reducing about 60%–90% of the mutagenicity induced by heterocyclic amines at a concentration of 12.5 mg/plate in the salmonella mutation assay.
• The extract of this herbs also inhibited the formation of colon cancer at the initiation stage. 
• roselle also been shown to inhibit the carcinogenic action of various chemicals in different tissues of the rat, including diethylnitrosamine in the liver.

3)antipyretic,antinociceptic,and antiinflammatory

• one of the study have reported that, in rats, an aqueous extract of Roselle was effective in inhibiting yeast-induced pyrexia, and in reducing the reaction time in a hot plate, tail-flick assay,these show that the extract has antipyretic and antinociceptive actions. 
• in one clinical trial involving 50 patients,administration of a decoction of dried fruit (3 g/person,three times every day for 7 days to 1 year) was shown to produce antiinflammatory activity.

4)reduce cholesterol

• The anticholesterol action of H. sabdariffa (0.5% or 1%) was confirmed in rabbits fed cholesterol for 10 weeks. This treatment was effective in reducing the serum concentrations of triglycerides, total cholesterol and low-density lipoprotein cholesterol, and in mitigating atherosclerosis in the aorta. 
• Histopathologically, it was found that feeding H. sabdariffa had reduced foam cell formation and inhibited smooth muscle cell migration and calcification in the blood vessel of treated rabbits

it is save to consumed this herbs?

best serve cold or hot.for me I prefered cold,so refreshing

• The LD50 of Roselle calyx extract in rats was found to be above 5000 mg/kg,this suggesting that the extract is virtually non-toxic. 
• one of the study suggested that, in rats, the average consumption of 150–180 mg/kg/day of an aqueous-ethanol extract of Hibiscus sabdariffa  calyces appeared to be safe, although higher doses might elevate the activity of some plasma enzymes indicative of tissue function (such as alanine aminotransferase and aspartate aminotransferase).
• However, the activity of some related plasma enzymes (alkaline phosphatase and lactate dehydrogenase) was not significantly affected, nor was there any evidence of histological damage to the heart and liver of the treated rats.

source:

• Phytochemical, pharmacological and toxicological aspects of Hibiscus sabdariffa L.: a review. Ali BH et al. Phytother Res. 2005 May;19(5):369-75