Effect of Bay Leaf Ethanol Extract on Blood Glucose Level in Patients with Type 2 Diabetes Mellitus

Abstract

Background: Previous studies showed that bay leaf or Syzygium polyanthum (Wight) Walp ethanol extract (SPEE) had antioxidant activity. It is safe for use in human. This study aimed to investigate SPEE effect on fasting blood glucose level (FBGL) among patients with type 2 diabetes mellitus. Subjects and Method: This was a pilot study using a randomized controlled trial (RCT) design. A total sample of 8 patients with type 2 diabetes mellitus were selected for this study. The intervention group were given 350 mg SPEE in capsule, once daily for 14 days. The control group were given placebo (Pl). The dependent variable was fasting blood glucose level (FBGL). The data were collected at day 0 and after 14 days administration. The effect of SPEE was determined by comparing mean FBGL in the SPEE-group and Pl-group after intervention. This effect is also shown by Effect Size (ES). The effect is large if ES >0.3. The mean difference after intervention was tested by Mann Whitney test. The means of FBGL of the two groups should be comparable as a result of randomization. Results: After the intervention, the FBGL (mg/dL) was lower in the SPEE-group (Mean= 169.75; SD= 43.72) than the Pl-group (Mean= 225.25; SD= 73.48), and it was not statistically significant (p= 0.438). This statistical non-significant effect was antici-pated in the pilot study, due to the very small sample size (n=8). Effect Size= -0.59, in-dicating large effect of SPEE in lowering the fasting blood glucose level (large if Effect Size > 0.30). Conclusion: Syzygium polyanthum (Wight) Walp ethanol extract (SPEE) is effective to lower fasting blood glucose level in patients with type 2 diabetes mellitus.