Hibiscus sabdariffa L. (Roselle) grown in all over the world and has been considered as a health drink in many countries such as India, Indonesia, Malaysia, China, Australia, Thailand, Myanmar, Saudi Arabia, Sudan, Senegal, France, Gambia, Nigeria, Greece, Latin America, Panama. High levels of antioxidants in calyces of Hibiscus sabdariffa can inhibit the damaging effects of free radicals. Some chronic diseases are often found today largely caused by exposure to excessive free radicals, such as diabetes mellitus, coronary heart disease, kidney damage, to cancer  . Research proved that Hibiscus sabdariffa can lower blood glucose levels of rabbits with streptozotocin-induced diabetes which increases the activity of the enzyme catalase Hibiscus sabdariffa and glutathione. In histological experiments, roselle cause osmotic diuresis in the proximal renal tubule diabetic animals [2 & 3] .
Antidiabetic activity of various extracts of roselle calyces (Hibiscus sabdariffa L.) has been conducted by Rosemary et al 2014  from University of Sumatera Utara, Medan, North Sumatera, Indonesia in order to develop the utilization of herbs and natural antidiabetic and the information can be useful in extracting calyces of Hibiscus sabdariffa in order to find the optimal antidiabetic effect. Antidiabetic activity of Hibiscus sabdariffa was conducted consisting of 11 treatment groups of mice, ie groups of Carboxy Methyl Cellulose suspension 0.5% as a negative control; glibenclamide 0.65 mg/kg as a positive control; various extracts of roselle calyces dose of 200 – 600mg / kg, which is respectively administered orally every day. Blood glucose levels were measured by glucometer Accu Chek every seven days; the data were analyzed by analysis of variance followed by Duncan’s method. The results of this study exhibited that the ethanol extract of roselle calyces proven to reduce the blood glucose levels on diabetic mice. This investigation indicated that the blood glucose levels lowering effect of ethanol extract dose of 400 mg / kg and 600 mg / kg is the same as the effect of glibenclamide administration.
- Babalola, S.O., Babalola, A.O., and Aworh, O.C. (2001). Compositional attributes of the calyces of roselle (Hibiscus sabdariffa L.). The Journal of Food and Technology in Africa. 6(4): 133-134.
- Wang, S.C., Lee, S.F., Wang, C.J., Lee, C.H., Lee, W.C., and Lee, H.J. (2011). Aqueous Extract from Hibiscus sabdariffa Linnaeus Ameliorate Diabetic Nephropathy via Reglukosating Oxidative Status and Akt/Bad/14-3-3γ in an Experimental Animal Model. Hindawi Publishing Corporation: EvidenceBased Complementary and Alternative Medicine. Volume 2011. Artikel ID 938126. Page 9.
- Omotuyi, I.O., Ologundudu, A., Onwubiko, V.O., Wogu M.D., and Obi, F.O. (2010). Hibiscus sabdariffa Linn. anthocyanins alter circulating reproductive hormones in rabbits (Oryctolagus cuniculus). Journal of Diabetes and Endocrinology. 1(3): 36-45.
- Rosemary, Rosidah, Ginda Haro. Antidiabetic Effect of Roselle Calyces Extract (Hibiscus Sabdariffa L.) in Streptozotocin Induced Mice. International Journal of PharmTech Research, 2014, Vol.6, No.5, 1703-1711 pp.