DAYA ANTIOKSIDAN KOMBINASI EKSTRAK DAUN SAMBILOTO (Andrographis paniculata Nees.) DAN DAUN KUMIS KUCING (Orthosiphon aristatus) DENGAN METODE DPPH (2,2-difenil-1 pikrilhidrazil)

ABSTRAK

Latar Belakang : Indonesia merupakan negara dengan keanekaragaman hayati yang tinggi, termasuk berbagai tanaman obat yang berpotensi sebagai sumber antioksidan alami. Daun sambiloto (Andrographis paniculata Nees.) dan daun kumis kucing (Orthosiphon aristatus) diketahui mengandung senyawa bioaktif seperti flavonoid dan polifenol yang mampu menangkal radikal bebas. Radikal bebas yang berlebihan dapat menyebabkan stres oksidatif yang memicu kerusakan sel serta berbagai penyakit degeneratif. Secara empiris, kedua tanaman tersebut telah dimanfaatkan masyarakat, baik secara tunggal maupun dalam bentuk kombinasi, sehingga perlu dilakukan penelitian untuk mengetahui aktivitas antioksidannya.

Metode : Penelitian ini merupakan penelitian eksperimental dengan desain pre-eksperimen. Ekstrak daun sambiloto dan daun kumis kucing dikombinasikan dalam perbandingan 1:1, 1:2, dan 2:1, kemudian diuji aktivitas antioksidannya menggunakan metode DPPH (2,2-difenil-1-pikrilhidrazil). Pengujian dilakukanpada konsentrasi 2, 4, 6, 8, dan 10 ppm, kemudian diukur menggunakan Spektrofotometer UV-Vis. Aktivitas antioksidan dinyatakan berdasarkan persentase peredaman radikal bebas dan nilai IC₅₀ dengan kuersetin sebagai kontrol positif.

Hasil : Nilai IC₅₀ ekstrak daun sambiloto, daun kumis kucing, kombinasi 1:1, 1:2, 2:1, dan kuersetin berturut-turut sebesar 18,13 ppm; 16,93 ppm; 8,90 ppm; 11,15 ppm; 13,27 ppm; dan 2,77 ppm. Kombinasi 1:1 menunjukkan aktivitas antioksidan tertinggi.

Kesimpulan : Kombinasi ekstrak daun sambiloto dan daun kumis kucing menunjukkan aktivitas antioksidan yang paling tinggi dibandingkan ekstrak tunggal. Kombinasi perbandingan 1:1 memberikan aktivitas antioksidan terbaik dengan nilai IC₅₀ sebesar 8,90 ppm, dan seluruh sampel uji termasuk dalam
kategori antioksidan sangat kuat.

Kata Kunci : Antioksidan, Daun Sambiloto, Daun Kumis Kucing, Kombinasi Ekstrak, DPPH.

ABSTRACT

Background: Indonesia is a country with abundant biodiversity, including a wide variety of medicinal plants that have the potential to serve as natural antioxidant
sources. Andrographis paniculata Nees and Orthosiphon aristatus are known to contain bioactive compounds, such as flavonoids and polyphenols, which are capable of scavenging free radicals. Excessive free radicals can induce oxidative
stress, leading to cellular damage and various degenerative diseases. Empirically, both plants have long been used either individually or in combination; therefore, this study was conducted to evaluate their antioxidant activity.

Methods: This study employed an experimental research design with a pre-experimental approach. The extracts of Andrographis paniculata Nees. leaves and Orthosiphon aristatus leaves were combined at ratios of 1:1, 1:2, and 2:1, and their antioxidant activities were evaluated using the DPPH (2,2-diphenyl-1-picrylhydrazyl) method. The assay was performed at concentrations of 2, 4, 6, 8, and 10 ppm, and absorbance was measured using a UV-Vis Spectrophotometer. Antioxidant activity was determined based on the percentage of free radical scavenging and IC₅₀ values, with quercetin used as the positive control.

Results: The IC₅₀ values of sambiloto leaf extract, cat's whiskers leaf extract, 1:1 combination, 1:2 combination, 2:1 combination, and quercetin were 18,13 ppm; 16,93 ppm; 8,90 ppm; 11,15 ppm; 13,27 ppm; and 2,77 ppm, respectively. The 1:1 combination exhibited the strongest antioxidant activity.

Conclusion: The combination of sambiloto (Andrographis paniculata Nees.) leaf extract and kumis kucing (Orthosiphon aristatus) leaf extract exhibited higher antioxidant activity than the individual extracts. The 1:1 combination showed the strongest antioxidant activity, with an IC₅₀ value of 8.90 ppm, and all tested samples were classified as very strong antioxidants.

Keywords: Antioxidant, sambiloto leaves, kumis kucing leaves, combined extract, DPPH.