Metabolic Effects of Glucose Lowering Substance of Urtica Dioica on Normal and Diabetic Mice, and Patients with Type I Diabetes Mellitus

Background: Urtica dioica is a plant that is used as an edible herb with capability of lowering blood glucose.  The aim of this study was to determine the effects of extracted and purified blood glucose lowering substance (BGLS) of Urtica Dioica on mice and then in patients with type I diabetes mellitus. 
Materials and Methods: The effective substance of the extract was prepared and identified by thin layer chromatography method and then by gel filtration, Fourier transform infra red, mass spectrometry gas chromatography and paper chromatography after acid hydrolysis. Different case control studies were done by this substance on mice. Eight hours before and during the tests all of the mice were fasted.  At the first stage 4 separate studies, each in 3 groups of normal mice were done, and blood glucose (BG), liver glycogen, serum insulin and muscle lactic acid were measured after intraperitoneal (ip) injection of BGLS in the first group, distilled water in second group and no injection in the third group. At second stage 20 mice became diabetic by administration of streptozotocin and then divided into two even case and control groups and blood glucose (BG) was measured before and after ip injection of BGLS. At the third stage, BG was measured before and after oral administration of BGLS to normal mice.  At fourth stage LD50 of substance was identified in mice and at the 5th stage, in a short 2 day study on 8 patients, the effect of oral administration of one dose of  BGLS at 00:07 h on the second day was evaluated.   
Results: In the first stage, BG of the first group with the mean of 76 ± 5 mg/dL was significantly lower than the second and third groups (108±8 mg/d and 105±9 mg/dL, respectively; p<0.001). Serum insulin level was not significantly different among the 3 groups. Liver glycogen of the 1st group (10.74 ± 0.23 mg/g) was significantly more than the 2nd group (10.08 ± 0.21 mg/g, p = 0.03) and the 3rd group (9.95 ± 0.24, p = 0.016). Lactic acid level of muscles in the 1st group (1.4 ± 0.07 mg/dL) was higher than the 2nd & 3rd group (1.07 ± 0.07 mg/dL and 1.02 ± 0.06 mg/dL respectively) (P < 0.001). In the second stage, BG level was 158 ± 8 mg/dL after 4 hr of ip injection of BGLS in the case group vs 319 ± 14 mg/dL in control group (P < 0.001 . In the third stage).  BG decreased from 137 ± 7.1 to 77 ± 17 mg/dL in normal mice after oral administration of BGLS, that was significantly more than decrement in control group (from 146 ± 11 to 120 ± 19 mg/dL) (P < 0.01). In the fourth stage, The amount of LD50 of BGLS was 8.9 mg/ 30 gram mouse.  Finally study on patients with type 1 DM resulted in decrement of blood glucose at 2200 h that was significantly lower than the previous day (P=0.001).
Conclusion: There is a glucose lowering substance in Urtica dioica that does not increase insulin secretion and can be absorbed through intestinal lumen.