Studies on Saccharidases Inhibition and Anti-glycation Activities by Momordica charantia L. seed extracts

• Main Authors: Yu-Jung Chung, 鍾侑容
• Other Authors: 黃健政
• Format: Others
• Language: zh-TW
• Published: 2018
• Online Access: http://ndltd.ncl.edu.tw/handle/huygu7

碩士 === 國立嘉義大學 === 食品科學系研究所 === 106 === In this study, the seeds of Momordica charantia L. were employed as raw materials, and were extracted by different concentrations of ethanol solution. The contents of polyphenolic compounds and antioxidant capacity in the extracts were determined and inhibitive activities of α-amylase and α-glucosidase were also analyzed. In addition, the inhibition of glycation in BSA-Glucose and BSA-Methylglyoxal (MGO) systems were subjected to investigation. The results showed that using the 70% ethanol extraction method was able to obtain the maximum of total phenolic compound content (189.58 mg GAE/g extract) and total flavonoid content (10.28 mg Rutin/g extract) in the different resulting ethanol extracts. By using HPLC analysis, the main measured compounds were gallic acid. According to the antioxidative capacity assay, the 70% ethanol extracts was good at total antioxidant capacity (115.52 mg Trolox/g extract) and Ferrous ion chelating ability (8.62 mg EDTA/g extract). Inhibitory abilities of α-amylase and α-glucosidase by the 70% ethanol extracts of IC50 were 457 ppm and 107 ppm respectively, which was better than Acarbose (IC50 were 1380 ppm and 367 ppm respectively). The water extracts and 70% ethanol extracts were subjected to the evaluation of in vitro glycation simulation. In BSA-Glucose and BSA-MGO systems, water extracts and 70% ethanol extracts had been observed to be capable of capturing ketoamine compounds and α-dicarbonyl compounds, so it could effectively retard the occurrence of glycation and inhibit advanced glycation end- products formation. The inhibitory effect of 70% ethanol extracts on glycation was superior to that of other ethanol solution. Base on HPLC analysis, 70% ethanol extracts was evidently to be the existence of condensed tannin polymers. Further, utilized the hydrochloric acid to hydrolyze the 70% ethanol extracts with different hydration duration to obtain different hydrolysates (HAE 0, 30, 60, 90, and 120), accordingly, explored the acid treatment effects of 70% ethanol extracts on antioxidative capacity, saccharidase activity and glycation products inhibition. The results revealed that the contents of polyphenolic compound increased with the raising hydrolysis time, and HAE 90 provided the highest phenolic contents (260.31 mg GAE/g extract). When the hydrolysis time reached 120 minutes, the content decreased. Because the degree of acid hydrolysis reached the maximum. Further destroys the structure of the product under heat and acid. Gallic acid, protocatechuic acid, chlorogenic acid, and p-coumaric acid can be separated from the hydrochloric acid method by HPLC. Different hydrolysates had greater antioxidative capacity and digestive enzyme inhibitory effects than unhydrolyzed 70% ethanol extracts. Each hydrolysates provided the similar ability, including the total antioxidant capacity (201.68 mg Trolox/g extract). HAE 90 had the best inhibition of α-amylase and α-glucosidase activity. Therefore, The acid hydrolysis extract was analyzed for anti-glycation activity in the BSA-Glucose and BSA-MGO systems. And HAE 0 and HAE 90 were as the reaction days increase, the ability to gradually inhibit the carbonyl or dicarbonyl interaction of reducing sugars, Schiff bases and Amardori products. Moreover, this hydrolysate would also capture the α-dicarbonyl compounds, so it could effectively inhibit advanced glycation end-proucts formation. Therefore, condensed tannin can be decomposed with acid hydrolyzed at 80° C for 90 minutes in 70% ethanol extracts, and preserved the phenolic acids. In conclusion, it could be confirmed that the seed of bitter melon ethanol extracts can regulate the postprandial blood glucose levels and retard the in vitro glycation. The author expects bitter melon seeds not only could be used to develop natural antioxidants and healthy food, but to improve their economic value and utilization.