UJI AKTIVITAS PEREDAMAN RADIKAL BEBAS DPPH EKSTRAK ETANOL DAUN JERUK NIPIS (Citrus aurantifolia (Christm.) Swingle)

Abstract

Background: Free radicals are reactive molecules that cause oxidative stress and degenerative diseases. Antioxidants prevent cell damage by donating electrons. Lime leaves (Citrus aurantifolia (Christm.) Swingle) contain flavonoids, such as quercetin, with strong antioxidant activity. Their content and activity are influenced by the extraction method and solvent, with UAE using 96% ethanol being effective in extracting flavonoids. Research Objective: To determine the DPPH free radical scavenging activity of ethanol extract of lime leaves obtained using the UAE method based on IC₅₀ values.

Research Method: Lime leaves were extracted using the UAE method with 96% ethanol as the solvent at a ratio of 1:10. The extract was tested organoleptically, subjected to phytochemical screening, and evaluated for DPPH radical scavenging activity using quercetin as a standard. The DPPH radical scavenging activity was expressed as the 50% inhibition concentration (IC₅₀). The IC₅₀ values of the extract and standard were statistically analyzed using SPSS with an Independent T-test at a 95% confidence level. Research Results: The extraction of lime leaves yielded 5.4%, with organoleptic characteristics of dark green color, distinctive lime leaf odor, and thick texture. Phytochemical screening of the ethanol extract of lime leaves revealed the presence of alkaloids, flavonoids, phenolics, and tannins. The free radical scavenging activity of quercetin showed an IC₅₀ value of 2.212 ppm, while the ethanol extract of lime leaves showed an IC₅₀ value of 69.402 ppm. Conclusion: The ethanol extract of lime (Citrus aurantifolia (Christm.) Swingle) leaves exhibits strong free radical scavenging activity against DPPH.