STUDY OF ANTIOXIDANT CAPACITY OF THREE GENUS SOLANUM EXTRACTS USING FIVE \TEXTIT{IN VITRO} ANTIOXIDANT ASSAYS

• Main Author: Rizkiya Choirunnisa, Atina
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/78995
• Institution: Institut Teknologi Bandung

Background and objectives: Free radicals are atoms or groups of atoms that have one or more unpaired electrons. Reactivity of free radicals contributing to cell damage and degenerative diseases. Free radicals can be scavenged by using endogenous antioxidants but their activity decrease along with age, therefore exogenous antioxidants is required. There are some in vitro methods to determine antioxidant capacity of plant extracts whereas each method have different mechanism. Therefore it is imponant to use more than one method to determine antioxidant activity of plant extract. The objectives of this research were to study antioxidant capacity of black nightshade (Solanum americanum), turkey berry (Solanum torvum), and round green eggplant (Solanum melongena L. cv. Group Common Eggplant) extracts using five antioxidant assays by detenninining IC50 and EC50, correlation between total chemical content and antioxidant capacity, determine major contributor of antioxidant capacity in five methods, analyze correlation between extractable matter with antioxidant capacity and total chemical content, and correlåtion between five antioxidant assays. Methods: Extraction was canied out by reflux using gradient polarity solvents, namely n-hexane, ethyl acetate, and ethanol, respectively. Extracts were monitored by thin layer chromatography (TLC). Antioxidant capacity using five methods antioxidant assay which were FRAP, CUP RAC, hydrogen peroxide scavenging, beta carotene bleaching (BCB), and phosphomolybdenum assays, determination of total chemical content were done using UV-vislble spectrophotometly. Correlation between total chemical content with antioxidant capacity and extractable matter, and correlation between five antioxidant assays were performed by Pearson's method. Results: Ethanolic fruit extract of turkey berry had the highest antioxidant capacity using FRAP assay (EC50 41.32 gg/mL) and hydrogen peroxide scavenging assay (IC50 1.01 pg/mL). Meanwhile, the highest antioxidant capacity using CUP RAC assay was given by ethyl acetate fruit of turkey berry (EC50 117.56 gy/mL), ethyl acetate fruit extract of round green eggplant had the highest phosphomolybdenum capacity (EC50 375.47 gg/mL), and ethyl acetate fruit extract of black nightshade had the highest BCB capacity (EC50 158.66 gg/mL). Ethanolic fruit extract of turkey berry had the highest phenolic content (5.15 g GAE/100 g), Ethyl acetate fruit extract of black nightshade had the highest flavonoid content (9.37 g QE/100 g) and the highest carotenoid content (0.86 g BE/ 100 g). Phenolic content in all of Solanum fruit extracts had a tendency to correlate with FRAP capacity and hydrogen.eroxide scavenging antioxidant capacity, meanwhile flavonoid and carotenoid content had a tendency to correlate with CUP RAC, phosphomolybdenum, and BCB antioxidant capacity. Conclusions: Phenolic compounds were major contributor in antioxidant activity of black night shade, turkey berry, and round green eggplant fruit extracts using FRAP and hydrogen peroxide assays (except turkey berry fruit extract), meanwhile flavonoid and carotenoid compounds were major contributor in antioxidant activity using CUP RAC, phosphomolybdenum, and BCB assays in all of sample extracts. FRAP assay gave linear results with 1--1202 assay (except turkey ben•y fruit extract), while CUP RAC, phosphomolybdenum and BOB assays showed linear results in all of sample extracts.