Study on Antioxidant Activity of Vernonia amygdalina Ethanol Extract

• Main Authors: Siang-Rou Liang, 梁湘柔
• Other Authors: 林季千
• Format: Others
• Language: zh-TW
• Published: 2018
• Online Access: http://ndltd.ncl.edu.tw/handle/qst978

碩士 === 國立中興大學 === 生命科學院碩士在職專班 === 106 === Oxygen is essential for everyone''s survival. Under normal physiological metabolism, cells use oxygen to generate energy. When the bacteria invades, the defense system in the body will create superoxide anion free radicals to help remove damaged cells or pathogens. However, due to the stress in life, diet preference, and excessively harmful substances such as radiation and air pollution, people cause excessive oxidation. Too many free radicals will trigger a series of chain effects, so that normal cells are also oxidized to form free radicals. This continuous vicious cycle will affect the function of the body’s organs leading to disease. Therefore, it is the hope that natural and safe antioxidants can be sought to reduce the oxidative stress and prevent the occurrence of diseases. Vernonia amygdalina is a traditional Chinese herbal medicine that is commonly consumed in Taiwan. It contains flavonoid compounds and sesquiterpene lactones that have antioxidant effects. The antioxidant capacity of Vernonia amygdalina extract is evaluated by the scavenging assays of 1,1-diphenyl-2-picrylhydrazyl（DPPH）, 2,2''-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid（ABTS） and superoxide anion radicals in vitro and by the scavenging assay of reactive oxygen species in cell H1688. The results showed that the scavenging efficiency of DPPH and ABTS were 85.3% and 93.8% when the concentration of Vernonia amygdalina extract was 500 μg/mL, respectively. Vernonia amygdalina extract concentration with 50% free radical scavenging concentration（SC50） was 112.4 μg/mL and 214.3 μg/mL, respectively. As the dose increased, the clearance rate also increased. However, the scavenging ability of superoxide anion radicals was poor. When the concentration of Vernonia amygdalina extract was 500 μg/mL, the scavenging efficiency was 49.6%. SC50 was more than 500 μg/mL. The result showed that when the concentration of Vernonia amygdalina extract was 500 μg/mL for 24 hours, the ability to remove intracellular reactive oxygen species was significantly different. When dose in Vernonia amygdalina extract is higher and time is longer, the ability to remove the intracellular reactive oxygen species is more effective, that is, the antioxidant effect is better. Subsequent studies wish to explore the bioavailability and optimal doses of Vernonia amygdalina hoping it to be a safe antioxidant to use on living organisms.