Background: Advanced type 2 diabetes mellitus (T2DM) needing insulin therapy is common. Most conventional anti-hyperglycemic drugs have limited efficacies and significant side effects, so that better anti-hyperglycemic agents are needed. Urtica dioica L. (nettle) leaves have insulin secretagogue, PPARgamma agonistic, and alpha-glucosidase inhibitory effects. Moreover, nettle leaves are used in traditional medicine as an anti-hyperglycemic agent to treat diabetes mellitus. Thus, efficacy and safety of nettle in the treatment of patients with advanced type 2 diabetes mellitus needing insulin were studied.
Methods: In this randomized double-blind placebo-controlled clinical trial, we evaluated the effects of taking nettle leaf extract (one 500 mg capsule every 8 hours for 3 months) combined with the conventional oral anti-hyperglycemic drugs on the blood levels of fasting glucose, postprandial glucose, glycosylated hemoglobin (HbA1c), creatinine and liver enzymes SGOT and SGPT, and systolic and diastolic blood pressures in 46 patients and compared with the placebo group (n = 46).
Results: At the endpoint, the extract lowered the blood levels of fasting glucose, 2 hours postprandial glucose, and HbA1c significantly (p < 0.001, p = 0.009, and p = 0.006, respectively) without any significant effects on the other parameters (p > 0.05) compared with placebo.
Conclusions: Nettle may safely improve glycemic control in type 2 diabetic patients needing insulin therapy.