Antioxidant Activities Of4Kinds Of Medicinal Plants

This dissertation is composed of three chapters. The first chapter discussed theantioxidant capacity of4kinds of plants used in medicine.The second chapter, contents of total polyphens and flavonoids of4kinds of plants used in medicine. The third chapter summarized progress in antioxidant activity of medicinal and edible plants.Chapter I Antioxidant activities of4kinds of medicinal plantsThe antioxidant capacity of (Foeniculum vulgare Mill, Areca catechu L., Psophocarpus tetragonolobus (L.) DC, Chaenomeles sinensis (Touin) Koehne leaves and fruits) had been determined by using2,2-diphenyl-l-picrylhydrazyl (DPPH),2,2-azinobis (3-ethyl-benzothiazoline-6-sulfonic acid)(ABTS) and ferric reducing antioxidant power (FRAP) assay. Results showed that ethyl acetate extract and n-Butanol extract of F. vulgare had certain antioxidant activity in vitro. Ethyl acetate extracthad the highest antioxidant activity (DPPH:IC50=37.67μg/mL,ABTS:IC50=24.88μg/mL, TEAC=281.23μmol/g, respectively). Antioxidant activity of ethyl acetate extract was lower than that of BHT (DPPH: IC50=18.71μg/mL, ABTS:IC50=7.72μg/mL, TEAC=1581.68μmol/g, respectively). Results showed that ethyl acetate extract and n-butanol extractof A. catechu had certain antioxidant activity in vitro. Ethyl acetate extracthad the highest antioxidant activity (DPPH:IC5o=14.60μg/mL,ABTS:IC50=2.04μg/mL,TEAC=4762.99μmol/g, respectively). Antioxidant activity of ethyl acetate extract was higher than that of BHT(DPPH:IC50=24.49μg/mL, ABTS: IC50=6.56μg/mL, TEAC=2503.17μmol/g, respectively).The results showed that ethyl acetate extract and n-butanol extract of P. tetragonolobushadcertain antioxidant activity in vitro. n-Butanol extract had the highest antioxidant activity (ABTS:IC50=46.91μg/mL,TEAC=596.62μmol/g, respectively). Antioxidant activity of n-butanol extract was lower than that of BHT (ABTS:IC50=6.56μg/mL, TEAC=2503.17μmol/g, respectively). Results showed that the ethyl acetate extract of C. sinensis leaves had the best ABTS radical scavenging (IC50=6.66μ/mL) and ferric reducing antioxidant power (TEAC=1293.25μmol/g), which were similar to the positive control BHT (IC50=6.56μg/mL) and ferric reducing antioxidant power was lower than that of BHT (TEAC=2503.17μmol/g). The ethyl acetate extract of C. sinensis fruits exhibited the highest free radical scavenging activity (IC50=48.99μg/mL), but it was still inferior to positive control BHT (IC50=24.49μg/mL).Chapter II Contents of total polyphenols and flavonoids of4kinds of medicinal plantsThis chapter is divided into three parts. The first part, total polyphenols content of4kinds of plants was evaluated by Folin-Ciocalteu method. Results showed that E vulgare and P. tetragonolobus of n-butanol extracts had the highest total polyphenols content, A. catechu and C. sinensis leaves and fruits of ethyl acetate extracts had the highest total polyphenols content. The second part, total flavonoids content was determined by AlCl3-NaNO2-NaOH colorimetric method. Results showed that F. vulgare and P. tetragonolobus of petroleum ether extracts had the highest total flavonoids content, A. catechu and C. sinensis leaves and fruits of ethyl acetate extracts had the highest total flavonoidscontent. The third part, the relation of the antioxidant activity and total polyphenols and flavonoids of4kinds of plants (F. vulgare, A. catechu, P. tetragonolobus, C. sinensis leaves and fruits) was studied. Results showed that all four kinds of plants of antioxidant activity had certain correlation with total polyphenols and total flavonoids.Chapter Ⅲ Research progress in antioxidant activity of medicinal and edible plant resourcesThis chapter summarized the bioactive components of antioxidants in medicinal and edible resources, containing mainly flavonoids, polyphenols, saponins, alkaloids, polysaccharides, tannins and vitamins. Research progress of the medicinal and edible plant resources of antioxidant activitywas also summarized.