Biosynthesis of α-Glucosidase Inhibitors by a Newly Isolated Bacterium, Paenibacillus sp. TKU042 and Its Effect on Reducing Plasma Glucose in a Mouse Model.

Van Bon Nguyen,Yao-Haur Kuo,Anh Dzung Nguyen,San-Lang Wang

doi:10.3390/ijms18040700

Abstract

Paenibacillus sp. TKU042, a bacterium isolated from Taiwanese soil, produced α-glucosidase inhibitors (aGIs) in the culture supernatant when commercial nutrient broth (NB) was used as the medium for fermentation. The supernatant of fermented NB (FNB) showed stronger inhibitory activities than acarbose, a commercial anti-diabetic drug. The IC50 and maximum α-glucosidase inhibitory activities (aGIA) of FNB and acarbose against α-glucosidase were 81 μg/mL, 92% and 1395 μg/mL, 63%, respectively. FNB was found to be strongly thermostable, retaining 95% of its relative activity, even after heating at 100 °C for 30 min. FNB was also stable at various pH values. Furthermore, FNB demonstrated antioxidant activity (IC50 = 2.23 mg/mL). In animal tests, FNB showed remarkable reductions in the plasma glucose of ICR (Institute of Cancer Research) mice at a concentration of 200 mg/kg. Combining FNB and acarbose enhanced the effect even more, with an added advantage of eliminating diarrhea. According to HPLC (High-performance liquid chromatography) fingerprinting, the Paenibacillus sp. TKU042 aGIs were not acarbose. All of the results suggest that Paenibacillus sp. TKU042 FNB could have potential use as a health food or to treat type 2 diabetes.

Highlights

Diabetes mellitus (DM) is a chronic metabolic disorder and a serious worldwide health problem
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For the groups who received 25 and 50 mg of acarbose, diarrhea was observed in 3/8 mice (37.5%) and 5/8 mice (62.5%), respectively. These results show that oral FNB loading can reduce plasma glucose levels in mice, and the combination of FNB (200 mg/kg) and acarbose (12.5 mg/kg) can produce approximately the same effect as acarbose alone at 25 and 50 mg

Summary

Introduction

Diabetes mellitus (DM) is a chronic metabolic disorder and a serious worldwide health problem. Among diagnosed cases of DM, more than 90% are type 2 [1]. The estimated number of people worldwide suffering from type 2 diabetes will exceed 330 million by 2030 [2]. It has been reported that type 2 diabetes can be treated with α-glucosidase inhibitors (aGIs) [3]. Some commercial aGIs, such as acarbose, miglitol, and voglibose, are used for the treatment of type 2 diabetes. These treatments have several side effects, including diarrhea, flatulence, and abdominal discomfort, prompting the exploration of original, sufficient, and natural sources of aGIs instead

Methods

Results

Conclusion