The antidiabetic and antilipidemic effects of Hibiscus sabdariffa: A systematic review and meta-analysis of randomized clinical trials

Hibiscus sabdariffa (HS) is a woody-based subshrub of the Malvaceae family which has various uses in traditional medicine. This review systematically evaluates the evidence from clinical trials on the antidiabetic activity of HS. A random-effects model was used to obtain summary estimates. Five outcome measure, including fasting plasma glucose (FPG), total cholesterol (TC), high-density lipoprotein (HDL), low-density lipoproteins (LDL), and triglyceride (TG) were assessed in the study. The results of the overall pooled statics for the FPG level showed that there was a significant reduction in FPG (WMD = −3.964 mg/dL; 95% CI: −6.227 to −1.702 and P-value was 0.001) and in the level of LDL (WMD = −7.843 mg/dL; 95% CI: −14.337 to −1.350 and P-value was 0.018). However, the pooled estimate showed that there was no statistically significant change on the TC (WMD = −30.382 mg/dL; 95% CI: −66.752 to 5.989 and P value was 0.102), the HDL (WMD = 0.074 mg/dL; 95% CI: −1.986 to 2.135 and P value was 0.944) and the TG (WMD = −9.050 mg/dL; 95% CI, −30.819 to 12.719 and P value was 0.102) compared to the placebo. Egger's weighted regression P values suggested that there was no potential publication bias in the FPG (P = 0.664), HDL (P = 0.065), LDL (P = 0.677) and TG (P = 0.232) but there was a publication bias in the TC (0.056). Therefore, the result of this meta-analysis clearly shows that HS has antidiabetic activity, whereas its lipid-lowering effect needs further study.