Dragon’s blood for controlling high blood glucose

9 Jun 2016. Food scientists in NUS have identified a potent and highly selective inhibitor from traditional Chinese medicine, called dragon’s blood, to control high blood glucose.

For millions of diabetic patients, it is highly desired to control high blood glucose levels after meals. Currently, one common way to do so is to take medicine that works as starch hydrolase inhibitors, such as acarbose, to slow down the digestion of foods, such as noodles and Bee Hoon (rice noodles). This suppresses the rapid rise of blood glucose levels after meals. However, the major drawback for acarbose is that it has significant side effects, including flatulence and diarrhoea.

In search of better and natural starch hydrolase inhibitors, a team led by Ph.D. graduate (Dr WANG Hongyu, currently working at perfume and flavours company Firmenich) and Ph.D. student Mr TOH Zhi Siang from the Food Science and Technology programme at the Department of Chemistry in NUS, has successfully identified a potent and highly selective α-amylase inhibitor, dracoflavan B from traditional Chinese medicine called dragon’s blood, which is a resin from a type of palm tree (Daemonorops spp) found in South East Asia (see Figure). The discovery was made after painstaking screening of numerous traditional herbal medicines purchased from local TCM halls. This was made possible by a high throughput screening (HTS) assay they developed. The powerful HTS assay-also guided them to efficiently fractionate and isolate the active compound from the crude herbal extracts.

Dracoflavan B shows comparable activity as acarbose inhibiting against pancreatic α-amylase. Remarkably, dracoflavan B has no inhibitory activity for intestinal α-glucosidase, which is the primary target of acarbose. Such high selectivity makes dracoflavan B a promising natural alternative for controlling high blood glucose levels after meals with minimal flatulence and discomfort.

In addition, simple structural modification of dracoflavan B yielded dracoflavan B gallate which is three times more potent than dracoflavan B and is even more potent than acarbose towards α-amylase. The team’s findings may provide new means in controlling hyperglycemia.

Figure shows the new solution for controlling high blood glucose from traditional herbs. [Image credit: TOH Zhi Siang]

Reference

ZS Toh, H Wang, YM Yip, Y Lu, B J A Lim, D Zhang, D Huang. “Phenolic group on A-ring is key for dracoflavan B as a selective noncompetitive inhibitor of α-amylase.” Bioorganic & Medicinal Chemistry 23 (24) (2015) 7641.