pTeroSol® is water-soluble standardized extract prepared from the heartwood of Pterocarpus marsupium and contains a minimum of 5% C-glycosides (as Pterocarposide and Sabioside) (Fig. 1). C-glycosides have an advantage over compounds with O-glycoside linkages in that they are resistant to hydrolysis by β-glucosidase enzymes in the gastrointestinal tract. pTeroSol is clinically studied and evaluated for its safety and usage in maintaining healthy blood sugar and cholesterol levels.
A novel therapeutic strategy to control diabetes is the inhibition of SODIUM GLUCOSE CO-TRANSPORTERS (SGLT2). SGLT2 catalyses the active transport of glucose into the blood stream and plays a key role in reabsorption of glucose in the kidney (Chao & Henry, 2010). Several structures with C-Glycosidic linkages are found to be SGTL2 inhibitors.
Figure 1: Chemical structures of Pterocarposide (I) and Sabioside (II)
Figure 2: Fasting and postprandial blood glucose levels
In a flexible-dose, 12-week, open trial on 124 subjects, involving newly-diagnosed type 2 (NIDDM) patients, supplemented with increasing doses of Pterocarpus extract (i.e. 2 g, 3 g and 4 g at a gap of 4 weeks each). At the end of 12 weeks, 69% patients showed significant control of blood glucose (both fasting and postprandial) levels (Fig. 2) (ICMR 1998).
In another 36-week, randomized, double-blind, multicenter, flexible-dose trial, subjects were supplemented with increasing dosage of Pterocarpus extract (2 g, 3 g and 4 g/day) and Tolbutamide (0.75 g, 1 g and 1.5 g/day) at a gap of 4 weeks each. Results demonstrated that Pterocarpus extract was able to lower blood glucose level in 86% patients, which was comparable to tolbutamide efficacy (i.e. 94%) (Table 1) (ICMR 2005).
Table 1: Mean blood glucose levels
pTeroSol® was found to be safe and there were no episode of hypoglycaemia in either group (active and placebo). The study also demonstrated sustainability of the blood glucose control for up to 72 weeks. Hence, pTeroSol® has the property to lower the blood glucose level and can be used as a safe supplement for newly diagnosed patients with type 2 diabetes mellitus.