Ultrasound-Assisted Extraction Optimization of α-Glucosidase Inhibitors from Ceratophyllum demersum L. and Identification of Phytochemical Profiling by HPLC-QTOF-MS/MS.

Zhen Li,Hui Wang,Zongcai Tu,Lu Zhang

doi:10.3390/molecules25194507

Abstract

Ceratophyllum demersum L. (CDL) is a traditional Chinese herb to treat many diseases, but research on its anti-diabetic activity is not available. In this research, the α-glucosidase inhibitory ability and phytochemical constituents of CDL extract were firstly studied. Optimal ultrasound-assisted extraction conditions for α-glucosidase inhibitors (AGIs) were optimized by single factor experiment and response surface methodology (RSM), which was confirmed as 70% methanol, liquid-to-solid ratio of 43 (mL/g), extraction time of 54 min, ultrasonic power of 350 W, and extraction temperature of 40 °C. The lowest IC50 value for α-glucosidase inhibition was 0.15 mg dried material/mL (mg DM/mL), which was much lower than that of acarbose (IC50 value of 0.64 mg DM/mL). In total, 80 compounds including 8 organic acids, 11 phenolic acids, 25 flavonoids, 21 fatty acids, and 15 others were identified or tentatively identified from CDL extract by HPLC-QTOF-MS/MS analysis. The results suggested that CDL could be a potential source of α-glucosidase inhibitors. It can also provide useful phytochemical information for research into other bioactivities.

Highlights

Introduction α-Glucosidase is a vital carbohydrate hydrolase situated in the brush border surface membrane of the small intestine, which is involved in the last step of carbohydrate digestion by hydrolyzing the α-(1,4) glycosidic bond to release glucose at the non-reducing end [1]. α-Glucosidase inhibitors (AGIs) can effectively alleviate the release of glucose from dietary carbohydrates and delay the absorption of glucose by inhibiting the action of α-glucosidase, resulting in delayed postprandial blood glucose level [2]
The results indicate the effect of process variables on the α-glucosidase inhibition of Ceratophyllum demersum L. (CDL) extracts
30% and 70% methanol aqueous solutions are suitable for recovering the phenolics and flavonoids in CDL, respectively

Summary

Introduction

Introduction αGlucosidase is a vital carbohydrate hydrolase situated in the brush border surface membrane of the small intestine, which is involved in the last step of carbohydrate digestion by hydrolyzing the α-(1,4) glycosidic bond to release glucose at the non-reducing end [1]. α-Glucosidase inhibitors (AGIs) can effectively alleviate the release of glucose from dietary carbohydrates and delay the absorption of glucose by inhibiting the action of α-glucosidase, resulting in delayed postprandial blood glucose level [2]. Acarbose, miglitol, and voglibose are the commonly used AGIs to treat diabetes and its complications, but these drugs exhibit toxic side effects, such as flatus, diarrhea, abdominal colic, and so on [3]. Many highly active AGIs have been isolated and identified, such as flavones, phenolic acids, alkaloids, terpenes, anthocyanins, glycosides, and so on [4,5]. Zhang et al [6] evaluated the α-glucosidase inhibitory activity of four Acer species leaves, and the IC50 values were 167–433 fold of that of acarbose; hydrolysable tannins were the major. 3-Caffeyl-5-feruloylquinic acid was found to be the major AGI of Artemisia selengensis. (Solanaceae) root extracts [8] and Ocimum gratissimum leaf extracts [9] Datura stramonium L. (Solanaceae) root extracts [8] and Ocimum gratissimum leaf extracts [9]

Methods

Results

Conclusion