Thanyaluk Muangman. Antioxidant activity and protective effects of Gymnema Inodorum decne. on red blood cell hemolysis and DNA damage in TK6 human lymphoblastoid cells. Master's Degree(Nutrition). Mahidol University. : Mahidol University, 2009-07-01.
Antioxidant activity and protective effects of Gymnema Inodorum decne. on red blood cell hemolysis and DNA damage in TK6 human lymphoblastoid cells
Abstract:
Epidemiological evidence indicates that diets high in fruits and vegetables are rich in many antioxidant nutrients, having capability of decreasing the risk of chronic degenerative diseases. The pathogenesis of these diseases is hypothesized to be the harmful effects of free radicals on DNA, protein, lipid, and small intracellular molecules. Recently, the search for natural antioxidants and other preparations of plants concerning the beneficial effect for good health has been intensified. Still, little information regarding free radical scavenging and/or antioxidant activity is available for a vast number of Thai local vegetables. Gymnema inodorum Decne. (Chiangda) is one of the Thai local vegetables that grows in the northern part of Thailand. It has been known to be effective for some diseases including diabetes mellitus, rheumatic arthritis, and gout. Interestingly, there are reports showing that Chiangda has many phytochemicals that act as antioxidants. Therefore, objectives of this study are to determine the antioxidant activity of various preparations of Gymnema inodorum. Gymnema inodorum (GI) was prepared in four fractions. Edible parts of Gymnema inodorum were divided into two parts: fresh juice (GIJ) and dried forms, which were extracted with water (GIW), 50% ethanol (GIE50) and 95% ethanol (GIE95). The antioxidant activities were determined by DPPH radical scavenging assay, deoxyribose degradation assay, hemolysis assay, and comet assay. The total phenolic compounds were determined by folin-ciocalteu method. The results showed that the GIJ fraction had the highest antioxidant activity in all tests as well as the highest content of vitamin E (22.6 mg/100 g freeze dry extract) and beta-carotene (25.9 mg/100 g freeze dry extract). The highest concentration of total phenolic compounds (3.95 g GAEs/100g freeze dry extract) was found in the GIE50 fraction. The GIE95 fraction had the lowest antioxidant activity and amount of total phenolic compound. In conclusion, this study reveals that juice of Gymnema inodorum has strong antioxidant activities including the highest protective effects on RBC hemolysis and DNA damage. In addition, juice of Gymnema inodorum has a high content of vitamins that act as antioxidants. This information can assist consumers in selecting a source of natural antioxidants for consumption