Background
Dependence on natural products for managing diabetes mellitus is an age-long practice in various parts of the globe for both preventive and curative purposes. Use of herbal medicines are increasing due to its easy availability and low cost with often wrongly perceived reduced toxicity. Therefore, with upsurging interests in natural products, there is an urgent need for thorough scientific investigations of herbal medicines for both efficacy and potential toxicities. However, determiniation of  specific active components with good pharmacological activities to be confirmed in controlled clinical trials still remains  as a challenge.
Aim
To evaluate the efficacy and safety of antidiabetic herbal medicine on type 2 diabetic (T2DM) subjects
Method
This was a open level 6 months preliminary trial with an antdiabetic herbal medicine (HM). This HM was developed and supplied by a local manufacturer from 11 herbs namely G sylvestre, S cumini, F racemose, M charantia, C anthelminticum, fenugreek seed, A sativum, A indica, P nigrum, P spinoseand and L specriosa. Fourty four newly diagonsed T2DM patients with (HbA1c level 7.1%) participated in the study. The study was conducted by the traditional practioners (TP) in conjunction with International Center for Natural Products Research at Bangladesh University of Health Sciences according to the approved protocol. Before participating each patient gave informed written consent. HM was provided as tablets to the T2DM patients by the designated TP whom they visit on prescheduled dates (0, 15th. 30th, 45th and 60th days, end of 3rd, 4th, 5th and 6th months). They were advised to come to their TP at fasting state and donate blood on appointed dates. Socio-demographic data, family history, medical history were taken on the first day of the visit using a pre-set questionnaire. Anthropometric measures and total body fat mass, fasting blood glucose (FBG), 2 h blood glucose (2hBG), lipid profile, HbA1c, serum creatinine and serum ALT levels were measured by standard methods. Serum insulin was measured by ELISA. Insulin secretory capacity (HOMA%B), and insulin sensitivity (HOMA%S) were calculated by HOMA-Sigma software. The statistical significance of differences between the values was assessed by paired ‘t’ test.
Results
Thirty seven patients [29 men & 8 Women, aged 46±0.8 yrs, BMI 24.53±2.65(M±SEM)] completed the study. Mean HbA1c decreased significantly after 3 (p< 0.001) and  6 months (p< 0.02) from baseline. FBG reduced significantly at the end of 3 (p<0.001) and 6 months (p<0.012) compared to baseline . Treatment with HM also caused significant reduction in 2hBG after 3 months (p<0.001) and 6 months (p<0.007). Significant reduction was found in T Cholesterol (M±SD, mg/dL baseline vs 3 months 198±36 vs 158±18; vs 6 months 167±30; p<0.001 at both time points). LDl-cholesterol also decreased significantly after 3 and 6 months  (p<0.001 for both times). Serum Triglyceride level of the study subjects increased although nonsignificantly at the end of 6 months. Serum HDL-cholesterol level increased significantly at the end of 3 and 6 months (<0.001 ). Treatment with HM enhanced HOMA%S after 6 months (baseline vs 6 months (43±19 vs 56±36;p<0.05). HOMA%B of the diabetic subjects was found to be increased at the end of 3 months (baseline vs 3 months 75±67 vs 128±57;p<0.001). Serum creatinine and serum ALT levels remained unaltered at the end of six months treatment
Discussion
This was a preliminary exploratory trial with one antidiabetic herbal drug. Six months trial in type 2 diabetic subjects revealed that the HM improves glycemic and insulinemic status of the subjects. This HM improved dyslipidemia by significantly decreasing total cholesterol & LDL- cholesterol and by increasing serum HDL-cholesterol of the study subjects. However, paradoxical result was found regarding serum triglyceride level that increased nonsignificantly at the end of 6 months. This increase may be due to not strictly maintaining diet, or exercise, or may be due to some other reason which remains to be explored. No harmful effect was detected regarding liver and kidney functions. Since this HM is a combination of 11herbs and plants, therefore, the challenge of determining specific active components with good pharmacological activities is essential. It may be concluded that the drug under study showed some promising effect in the preliminary exploratory trial. Further studies with bigger sample size and proper designing for a clinical trial with involvement of nutritionist is necessary.

A prelimenary exploratory clinical trial with antidiabetic herbal medicine