학술논문
Studies on postprandial anti-hyperglycemia effects of rice bran extract and taxifolin isolated from colored rice varieties (Oryzae Sativa L.)
Document Type
Dissertation/ Thesis
Author
Source
Subject
Language
Korean
Abstract
국내 농산물의 경쟁력을 높이기 위하여 고품질 고부가가치 명품 농산물을 개발하기 위한 농업생산 기술의 개량과 더불어 작물의 품종 개량에 대한 연구가 활발하게 진행되고 있으며, 이러한 연구기반을 토대로 쌀의 경우에도 복합기능성 신품종을 개발 육성하여 국제경쟁력을 향상을 위한 연구개발중이다. 현재 많은 신형질 벼 품종이 개발되고 있으나, 기능성이 검증된 물질 또는 신규물질의 구조분석 및 물리 화학적 자료가 부족하며, 이들 고순도 물질 기반의 작용기전 연구가 미흡하다.식사로 섭취한 다당류나 이당류는 소장 내에서 단당류로 분해되어 α-glucosidases에 의하여 흡수된다. 이 효소를 억제하게 되면 식후 급격히 상승하는 혈당을 감소시켜줄 수 있다. 따라서 식물 유래의 천연물 소재의 유색미 추출물과 그 지표물질인 Taxifolin의 α-glucosidases 억제 효과를 in vitro와 in vivo에서 조사하였다. 먼저, 유색미의 공정 및 소재 표준화를 비롯하여 차후 임상 시료제작등의 연구를 수행하기 위하여 지표성분으로 확인된 Taxifolin의 고순도 표준품을 분리정제하여 NMR 연구와 LC-MS/MS를 활용한 구조동정을 수행하였다. 그 결과 총 5 종의 활성물질 (1) Cyanidin 3-glucoside (C3G), (2) Taxifolin mono-glycoside, (3) Methyltaxifolin mono-glycoside, (4) Taxifolin, (5) Methyltaxifolin 을 확인할 수 있었다. 5 종의 활성물질들 중 Taxifolin 계열의 물질들은 현재까지 쌀에서 분리되었다는 보고가 없는 새로운 연구 결과였다. 또한 확보된 1 부터 5 까지 활성물질들을 NMR (C, H-NMR, 2D-NMR) 작업을 통해 구조 동정하였다. 활성이 가장 우수한 2번은 현재 보고되지 않은 신물질이므로 특허 출원등록을 진행하였다. 분리된 활성물질의 α-glucosidase sucrase assay 저해 활성 확인 결과, Taxifolin mono-glycoside (0.54 ± 0.03 mM IC50), C3G (0.97 ± 0.09 mM IC50), Taxifolin (1.74 ± 0.11 mg/mL IC50), methyltaxifolin mono-glycoside (> 3.00 mM IC50)순으로 활성을 보였다. 유색미의 품종 중 하나인 큰눈자미 추출물(미강, 배아)과 Taxifolin으로 분류하여 α-glucosidase, sucrase, maltase, glucoamylase 저해 활성 확인 결과, 각각 높은 저해 활성으로는 sucrase (Taxifolin - 1.76 mg/mL IC50), maltase (미강 추출물 - 8.55 mg/mL IC50), glucoamylase (taxfiolin - 7.203 mg/mL IC50)의 활성을 보였다. 또한 Sprague-Dawley(SD) rat을 이용한 in vivo 실험을 통해 0.5 g/kg-body weight 의 유색미 추출물(쌀겨, 배아)과 Taxifolin 군이 대조군에 비해 식후 혈당상승을 통계적으로 유의하게 감소시키는 것을 확인하였다.장기간의 실험을 통해 일반동물(C57BL/6)은 고탄수화물 식이를 4주간 자유롭게 섭취하였고, 선별된 시료인 유색쌀 추출물과 Taxifolin을 농도별로 첨가(KNJM - 0.3, 0.5 g/kg, 50% Taxifolin - 0.05, 0.3 g/kg)한 후 혈당 변화 측정 결과, 큰눈자미군 0.5 g/kg(189.13 ± 15.65 mg/dL) 및 Taxifolin군 0.3 g/kg(187.08 ± 17.40 mg/dL)은 대조군(214.49 ± 15.90 mg/dL)에 비해 농도 의존적으로 억제 활성을 보였다. 이는 당의 흡수를 억제하여 체중 감량 효과가 있는 것으로 사료된다.혈당이 증가함에 따라 혈액 내 포도당이 체내의 지방으로 축적되어 혈중 중성지방, 총 콜레스테롤 함량이 증가하게 된다. 그러나 큰눈자미 추출물과 Taxifolin을 섭취를 통하여 얻은 지표는 대조군 대비 낮은 수치를 나타내었다. 또한 HDL-콜레스테롤 함량은 대조군 대비 모든 군에서 높은 수치를 보였고, 이와 반대로 LDL-콜레스테롤 수치는 모든 군에서 유의적으로 감소하였다.따라서 유색미 추출물과 그 지표물질인 Taxifolin의 섭취로 인하여 유의적으로 혈당 감소하는 경향을 농도의존적으로 확인할 수 있었고, 이에 부가적으로 체중감소에도 효능이 있는 것으로 사료된다. 그리고 당뇨병, 비만 등의 경우로 증가하는 총 콜레스테롤등의 지표들도 유의적으로 감소하는 것을 확인하였다. 따라서 유색미는 식후 고혈당 및 당뇨병 합병증을 관리하기 위한 건강기능식품소재로 유용하게 사용될 것으로 사료된다. 이와 같은 결과들은 제 2형 당뇨병 예방을 위한 이론적 근거를 제공하며, 향후 인체임상시험을 통해 효능을 검증하여 혈당상승억제 건강기능식품소재로서의 개발이 가능할 것으로 사료된다.
In order to enhance the competitiveness of domestic agricultural products, R&D is actively conducted to develop high-quality, high-value-added agricultural products, and research on agricultural production technology and crop varieties improvement is being actively conducted. Based on this research basis, even in the case of rice, I am developing new multi-functional varieties and conducting R&D to enhance international competitiveness. Currently, many new trait rice varieties are being developed, but structural analysis and physicochemical data of functionally verified substances or novel substances are lacking, and research on these high-purity substance-based functional groups is insufficient. Dietary polysaccharides and disaccharides are broken down into monosaccharides in the small intestine and absorbed by α-glucosidases. By inhibiting this enzyme, blood glucose, which rises sharply after a meal, can be lowered. Therefore, the α-glucosidases inhibitory effect of natural plant-derived materials colored rice extract and its indicator substance Taxifolin on was investigated in vitro and in vivo.To carry out research on the process and material standardization of colored rice, as well as subsequent clinical sample production, high-purity standards of Taxifolin identified as an indicator component were separated and purified, and structure identification was performed using NMR research and LC-MS/MS. As a result, a total of 5 active substances (1) Cyanidin 3-glucoside (C3G), (2) Taxifolin mono-glycoside, (3) Methyl-taxifolin mono-glycoside, (4) Taxifolin, (5) Methyl-taxifolin were identified.Of these five active ingredients, the report that a Taxifolin-based substance was isolated from rice is a new research result not found in existing studies. In addition, the obtained active materials from 1 to 5 were structurally identified through NMR (C, H-NMR, 2D-NMR) work. No. 2 with the highest activity is a new substance that has not been reported at present, so I proceeded with patent application registration. As a result of confirming the α-glucosidase sucrase assay inhibitory activity of the isolated active substance, Taxifolin monoglycoside (0.54 ± 0.03 mM IC50), C3G (0.97 ± 0.09 mM IC50), Taxifolin (1.74 ± 0.11 mg/mL IC50), methyltaxifolin mono-glycoside (> 3.00 mM IC50) showed activity in that order.It was classified into Keun-nun-Jami (KNJM) extract (rice bran and germ) and Taxifolin, which are one of the colored varieties, and as a result of confirmation of α-glucosidase, sucrase, maltase, and glucoamylase inhibitory activity, sucrase (Taxifolin- The activities of 1.76 mg/mL IC50), maltase (rice bran extract, IC50 of 8.55 mg/mL), and glucoamylase (Taxifolin, IC50 of 7.203 mg/mL) were shown. In addition, through an in vivo experiment using Sprague-Dawley (SD) rats, it was confirmed that 0.5 g/kg-body weight of colored rice extract (rice bran and germ) and Taxifolin significantly inhibitory effect of postprandial blood glucose rise compared to the control group.Normal animals (C57BL/6) were allowed to freely eat a high-carbohydrate diet for 4 weeks, and the selected samples, the colored rice extract and Taxifolin, were added by concentration (KNJM - 0.3 and 0.5 g/kg, 50% Taxifolin - 0.05 and 0.3 g/kg, respectively) and the result of measuring changes in blood glucose, the concentration of Keun-nun Jami group 0.5 g/kg (189.13 ± 15.65 mg/dL) and the concentration of Taxifolin group 0.3 g/kg (187.08 ± 17.40 mg/dL) showed inhibitory activity in a concentration-dependent manner compared to the control group (214.49 ± 15.90 mg/dL). This is considered to have a weight loss effect by inhibiting the absorption of sugar.When blood sugar increases, glucose in the blood accumulates as fat in the body and the content of triglyceride and total cholesterol in the blood increases. However, the body fat index of the rats treated with the Keun-nun-Jami extract and Taxifolin was lower than that of the control group. Also, HDL-cholesterol content was higher in all groups compared to the control group, whereas LDL-cholesterol level was significantly decreased in all groups.Therefore, the intake of colored rice extract and its indicator material, Taxifolin, showed a tendency to significantly lower blood sugar, and in addition, it is considered effective for weight loss.In addition, it was confirmed that indicators such as total cholesterol, which increases in the case of diabetes and obesity, also decreased significantly. Therefore, it is thought that colored rice will be usefully used as a health functional food material for managing postprandial hyperglycemia and diabetes complications. These results provide a theoretical basis for the prevention of type 2 diabetes, and it is thought that it will be possible to develop it as a health functional food material for inhibiting blood sugar rise by verifying its efficacy through human clinical trials in the future.
In order to enhance the competitiveness of domestic agricultural products, R&D is actively conducted to develop high-quality, high-value-added agricultural products, and research on agricultural production technology and crop varieties improvement is being actively conducted. Based on this research basis, even in the case of rice, I am developing new multi-functional varieties and conducting R&D to enhance international competitiveness. Currently, many new trait rice varieties are being developed, but structural analysis and physicochemical data of functionally verified substances or novel substances are lacking, and research on these high-purity substance-based functional groups is insufficient. Dietary polysaccharides and disaccharides are broken down into monosaccharides in the small intestine and absorbed by α-glucosidases. By inhibiting this enzyme, blood glucose, which rises sharply after a meal, can be lowered. Therefore, the α-glucosidases inhibitory effect of natural plant-derived materials colored rice extract and its indicator substance Taxifolin on was investigated in vitro and in vivo.To carry out research on the process and material standardization of colored rice, as well as subsequent clinical sample production, high-purity standards of Taxifolin identified as an indicator component were separated and purified, and structure identification was performed using NMR research and LC-MS/MS. As a result, a total of 5 active substances (1) Cyanidin 3-glucoside (C3G), (2) Taxifolin mono-glycoside, (3) Methyl-taxifolin mono-glycoside, (4) Taxifolin, (5) Methyl-taxifolin were identified.Of these five active ingredients, the report that a Taxifolin-based substance was isolated from rice is a new research result not found in existing studies. In addition, the obtained active materials from 1 to 5 were structurally identified through NMR (C, H-NMR, 2D-NMR) work. No. 2 with the highest activity is a new substance that has not been reported at present, so I proceeded with patent application registration. As a result of confirming the α-glucosidase sucrase assay inhibitory activity of the isolated active substance, Taxifolin monoglycoside (0.54 ± 0.03 mM IC50), C3G (0.97 ± 0.09 mM IC50), Taxifolin (1.74 ± 0.11 mg/mL IC50), methyltaxifolin mono-glycoside (> 3.00 mM IC50) showed activity in that order.It was classified into Keun-nun-Jami (KNJM) extract (rice bran and germ) and Taxifolin, which are one of the colored varieties, and as a result of confirmation of α-glucosidase, sucrase, maltase, and glucoamylase inhibitory activity, sucrase (Taxifolin- The activities of 1.76 mg/mL IC50), maltase (rice bran extract, IC50 of 8.55 mg/mL), and glucoamylase (Taxifolin, IC50 of 7.203 mg/mL) were shown. In addition, through an in vivo experiment using Sprague-Dawley (SD) rats, it was confirmed that 0.5 g/kg-body weight of colored rice extract (rice bran and germ) and Taxifolin significantly inhibitory effect of postprandial blood glucose rise compared to the control group.Normal animals (C57BL/6) were allowed to freely eat a high-carbohydrate diet for 4 weeks, and the selected samples, the colored rice extract and Taxifolin, were added by concentration (KNJM - 0.3 and 0.5 g/kg, 50% Taxifolin - 0.05 and 0.3 g/kg, respectively) and the result of measuring changes in blood glucose, the concentration of Keun-nun Jami group 0.5 g/kg (189.13 ± 15.65 mg/dL) and the concentration of Taxifolin group 0.3 g/kg (187.08 ± 17.40 mg/dL) showed inhibitory activity in a concentration-dependent manner compared to the control group (214.49 ± 15.90 mg/dL). This is considered to have a weight loss effect by inhibiting the absorption of sugar.When blood sugar increases, glucose in the blood accumulates as fat in the body and the content of triglyceride and total cholesterol in the blood increases. However, the body fat index of the rats treated with the Keun-nun-Jami extract and Taxifolin was lower than that of the control group. Also, HDL-cholesterol content was higher in all groups compared to the control group, whereas LDL-cholesterol level was significantly decreased in all groups.Therefore, the intake of colored rice extract and its indicator material, Taxifolin, showed a tendency to significantly lower blood sugar, and in addition, it is considered effective for weight loss.In addition, it was confirmed that indicators such as total cholesterol, which increases in the case of diabetes and obesity, also decreased significantly. Therefore, it is thought that colored rice will be usefully used as a health functional food material for managing postprandial hyperglycemia and diabetes complications. These results provide a theoretical basis for the prevention of type 2 diabetes, and it is thought that it will be possible to develop it as a health functional food material for inhibiting blood sugar rise by verifying its efficacy through human clinical trials in the future.