No abstract

1-Deoxynojirimycin (DNJ) is a potent α-glucosidase inhibitor and thus beneficial for prevention of diabetes. While we have succeeded in obtaining the culture supernatant extract (CSE) rich in DNJ from microorganism source, information regarding its anti-hyperglycemic effect and safety were still limited. Therefore, this study was aimed to evaluate the anti-hyperglycemic effect and safety of microorganism DNJ. Oral sucrose tolerance test was performed, and the result showed that CSE was able to significantly suppress the blood glucose elevation and suggested DNJ as the main active compound. To determine its safety, the absorption and excretion of microorganism DNJ were evaluated using 15N labeling method. Our findings investigated the recovery rate of 15N from DNJ reached 80% up to 48 hours after oral administration, suggesting its rapid excretion, suggesting the safety of DNJ. This study verified the functional properties and safety of DNJ from microorganisms, suggesting its potential use for functional purpose.

1-Deoxynojirimycin (DNJ)is an effective sugar analogue that suppresses the elevation of postprandial blood glucose. Therefore, food products containing DNJ are expected to be promising functional foods in preventing the onset of diabetes. To examine the absorption kinetics of DNJ, we prepared 15 N-labeled DNJ from the culture medium of a Bacillus amyloliquefaciens DSM7 strain. In the process, we found that lactose markedly increased the production of DNJ at a carbon/nitrogen ratio of 6.25:1, reaching 1140 mg/L with 5 days of cultivation. Comparisons between lactose and glucose on cell growth and DNJ production suggested that lactose made the DSM7 strain grow more slowly and maintained DNJ production in the long term. These findings may be useful for efficient microbial DNJ production or in the development of DNJ-containing fermented food products.

Supplementation of Bacillus amyloliquefaciens AS385 culture broth powder in high-fat diet restored adiposity, glucose tolerance and insulin sensitivity in mice.

1-Deoxynojirimycin (DNJ) has been known as a potent a-glucosidase inhibitor from mulberry leaves and considered beneficial in prevention of type 2 diabetes. Due to limited amount of DNJ in mulberry leaves, recent studies have focused in finding alternative source that can produce higher amount of DNJ. Previously, we produced a high DNJ-containing culture medium from Bacillus amyloliquefaciens AS385 and constructed a concentration method of bacterial culture medium using cation exchange column. However, less complicated concentration procedure is necessary to save time and cost during the large-scale production. Therefore, we developed a simpler concentration method using anion exchange resin to yield B. amyloliquefaciens AS385 culture broth powder (CBP; 1% DNJ) and evaluated the physiological effects of 5-wk dietary CBP intake in C57BL/6J mice. CBP intake tended to suppress the elevation of blood glucose level during oral glucose tolerance test. Moreover, CBP intake significantly lowered the fasting plasma glucose level and white adipose tissue mass. Next, we evaluated the absorption and distribution of DNJ in mice organs after daily CBP intake. We found detectable amount of DNJ in organs with intestine and kidney as the major targeted organs. We concluded that the DNJ content in CBP is absorbed from digestive tract, distributed and accumulated in organs, which most likely to contribute to the alteration of blood glucose regulation and adiposity in C57BL/6J mice. Our study was the first to report the physiological effects of CBP produced from B. amyloliquefaciens AS385 and the organ distribution of DNJ from CBP.