Aktivitas Penangkalan Radikal Bebas dan Kemampuan Reduksi Ekstrak Kulit Kayu Akway (Drimys piperita Hook. f.) - Gino Nemesio Cepeda; Meike Meilan Lisangan; Mathelda Kurniaty Roreng; Elva Intan Permatasari; Dolly Citra Manalu; Wulan Tanlain (Faculty of Animal and Agricultural Sciences, Diponegoro University, 2018)
Akway (Drimys piperita Hook. f) merupakan tumbuhan yang termasuk dalam kelompok tumbuhan berkayu, berdaun tebal aromatik dan termasuk kerabat winteraceae. Tumbuhan ini dimanfaatkan sebagai obat tradisional untuk mengobati malaria dan untuk meningkatkan vitalitas tubuh. Beberapa penelitian kandungan fitokimia ekstrak akway telah dilakukan untuk mengetahui potensi bioaktivitas akway. Ekstrak kulit kayu akway dilaporkan mengandung kelompok senyawa alkaloid, saponin, tanin, flavonoid, terpenoid dan glikosida. Minyak atsiri kulit kayu akway mengandung linalool, β-pinen, α-pinen, nerolidol dan terpineol. Senyawa-senyawa tersebut dilaporkan memiliki aktivitas antioksidan yang tinggi. Tujuan penelitian ini adalah untuk menentukan kapasitas antioksidan ekstrak kulit kayu akway secara in vitro dan vitamin C sebagai kontrol positif. Pengujian kapasitas antioksidan yang dilakukan meliputi kandungan total fenol dengan metode Folin-Ciocalteu, kandungan flavonoid dengan metode aluminum klorida, kapasitas penangkalan radikal bebas menggunakan metode DPPH (1,1-Diphenyl-2-picrylhydrazyl)-radical scavenging assay dan daya reduksi menggunakan metode reduksi Fe+3 menjadi Fe+2. Hasil penelitian menunjukkan bahwa ekstrak metanol memiliki kandungan total fenol dan flavonoid yang tertinggi dibandingkan dengan ekstrak etanol dan etilasetat. Kandungan total fenol dan flavonoid ekstrak metanol masing-masing sebesar 18,22 dan 14,32%. Ekstrak metanol dan vitamin C memiliki kapasitas menangkal radikal bebas DPPH dan daya reduksi yang paling tinggi kemudian diikuti ekstrak etanol dan etilasetat. Kemampuan menangkal radikal bebas ekstrak metanol dan vitamin C pada konsentrasi 200 µg/ml masing-masing sebesar 90% dan 88,31% sedangkan daya reduksi masing-masing sebesar 0,54 dan 0,62. Kesimpulannya, ekstrak metanol memiliki kapasitas antioksidan yang paling tinggi dibandingkan dengan ekstrak etanol dan etilasetat. Abstract Free Radical Scavenging Activity and Reducing Power of Akway (Drimys piperita Hook. f.) Bark ExtractsAkway (Drimys piperita Hook. f) was a woody and aromatic plant of winteraceae. This plant was used as traditional medical plant to heal malaria and to enhance vitality of body. Some studies were done to know bioactivity potency of akway extracts. D. piperita bark extract contains alkaloid, saponin, tanin, flavonoid, terpenoid and glycoside. The bark essential oil of the plant consists of lynalool, β-pinene, α-pinene, nerolidol and terpineol. Those compounds were exhibited high antioxidant activity. The objectives of this research were to determine total phenol and flavonoid of the extracts and its antioxidant capacity which was compared to antioxidant capacity of vitamin C. The assay of antioxidant capacity comprised of total phenol and flavonoid content, free radical scavenging activity, and reducing power. Total phenol and flavonoid was determined using Folin-Ciocalteu and aluminum chloride method, respectively while determination of free radical scavenging activity and reducing power using DPPH-radical scavenging and Fe+3 to Fe+2 reducing power method, respectively. The results indicated that methanol extract had the highest in total phenol and flavonoid content. Total phenol and flavonoid of methanol extract were 18.22% and 14.32%, respectively. Vitamin C and methanol extract had the highest DPPH (1,1-Diphenyl-2-picrylhydrazyl)-radical scavenging activity and reducing power, respectively. DPPH-radical scavenging activity of methanol extract and vitamin C in concentration of 200 µg/ml were 90% and 88.31%, respectively while its reducing power were 0.54 and 0,62, respectively. As conclusion, methanol extract had the highest antioxidant activity compared with ethanol and ethyl acetate extracts.