Bachelor of science thesis Conditions of Extraction for improving the anti-amylase activity of Polygonum multiflorum

Abstract

Polygonum multiflorum Thunb. (P. multiflorum) has been used as a potential treatment for a wide range of conditions thousands of years ago. The crude material used was P. multiflorum Thunb. roots. For this research, Response Surface Methodology (RSM) was one of the best methods to optimize the extract conditions to get high the percentage of α-Amylase inhibition activity. There were 15 experiments that were set up by using a 3-factor-3-level Box-Behnken design with three factors included extraction time, extraction temperature, and the mass of sample. An iodine-starch method assay was used to determine the α-Amylase inhibition activity. Besides, due to limited time, the highest content of α-Amylase inhibition was used for testing reducing power assay. In this study, the purpose was to identify the best extraction conditions for improving the α-Amylase inhibition activity from P. mµltiflorum Thunb. root, which was grown in Vietnam by using decoction extraction method. RSM software was used to analyze all of data, and the results recorded that model’s P-value was significant with the lack of fit was not significant. The maximum value of anti-amylase activity from P. mµltiflorum root was 47.64% ± 1.46%, which was achieved at extraction time of 94.55min, extraction temperature of 76.97℃, and 7.38grams with the mass of sample. The α-Amylase inhibition activity of P. multiflorum was compared to the acarbose drug, which was commonly used for diabetes mellitus treatment. The IC50 of P. multiflorum and acarbose for α-Amylase activity inhibition were 343.81µg/mL and 421.88µg/mL, respectively. Additionally, for the reducing power assay, the results showed that the P. multiflorum extraction had antioxidant capacity. The models’ F values for the lack-of-fit were not significant (p > 0.05), mentioning that they were suitable for defining the response surface. As a result, this investigation showed the optimal conditions for decoction extraction of P. multiflorum root as a potentially natural product for use in diabetes mellitus treatment. And this sample extraction also has the ability of antioxidant capacity.