Kandungan Total Polifenol dan Aktivitas Antioksidan dari Ekstrak Metanol Akar Imperata cylindrica (L) Beauv. (Alang-alang) - Dhianawaty, Diah; Ruslin, - (Majalah Kedokteran Bandung, 2015)
Hipertensi disebabkan oleh banyak faktor, di antaranya aktivitas enzim konversi angiotensin, angiotensin-converting enzyme (ACE), dan reactive oxygen species (ROS). Ekstrak metanol akar Imperata cylindrica (alang-alang) terbukti mempunyai aktivitas antihipertensi. Studi menunjukkan berbagai terapi antioksidan dapat menurunkan tekanan darah. Senyawa polifenol dari tumbuh-tumbuhan mempunyai banyak manfaat, di antaranya sebagai antioksidan, oleh karena itu dilakukan studi ekperimental untuk mengukur kandungan polifenol total menggunakan metode spektrofotometri sinar tampak pereaksi Folin-Ciocalteu, dan uji aktivitas antioksidan dengan metode 1,1-difenil-2-pikrilhidrazil (DPPH). Penelitian dilakukan periode Juli sampai Desember 2014. Hasilnya, ekstrak mempunyai kandungan total polifenol sebesar 1,53% ekivalen asam galat (EAG) dan aktivitas antioksidan IC50  sebesar 0,32 mg/mL. Senyawa fenol mempunyai kemampuan mendonorkan atom hidrogen pada radikal bebas DPPH yang menyebabkan DPPH tereduksi dan ditandai dengan perubahan warna DPPH dari ungu menjadi kuning. Dengan demikian, aktivitas antioksidan ekstrak metanol akar Imperata cylindrica didukung oleh senyawa polifenol. Simpulan, ekstrak mempunyai kandungan polifenol total 1,53% (EAG) dan aktivitas antioksidan IC50 0,32 mg/mL. Senyawa polifenol mendukung aktivitas antioksidan ekstrak. [MKB. 2015;47(1):60–4]Kata kunci: Aktivitas antioksidan, Imperata cylindrica, kandungan polifenol totalTotal Polyphenol Content and Antioxidant Activity of Methanol Extract of Imperata cylindrica (L) Beauv. (Alang-alang) RootHypertension is caused by many factors, including by the activity of angiotensin converting enzyme (ACE), reactive oxygen species (ROS). Methanol extract of Imperata cylindrica (alang-alang) root has been proven as having anti-hypertensive activities. Study shows various antioxidant therapies can decrease blood pressure. Polyphenol compounds of plants have many benefits, including as an antioxidant. Therefore, an experimental study was performed to measure the total polyphenol content using visible spectrophotometry method-Folin-Ciocalteu reagent as well as to test the antioxidant activity using 1,1-diphenyl-method 2-pikrilhidrazil (DPPH) from July to December 2014. The results showed that the extract had a total polyphenol content of 1.53% galad acid aquevalent (GAE) and antioxidant activity IC50 0.32 mg/mL. The polyphenol compounds have the ability to donate hydrogen atom to DPPH free radical, which leads to reduced DPPHmarked by the color change of DPPH from purple to yellow. Thus, antioxidant activity of methanol extract of Imperata cylindrica root was supported by the presence of polyphenol compounds. In conclusion, the extract has a total polyphenol content of 1.53% (GAE) and antioxidant activity IC50 0.32 of 0.32 mg/mL. The presence of polyphenol compounds supports the antioxidant activity of the extract. [MKB. 2015;47(1):60–4]Key words: Antioxidant activity, Imperata cylindrica, total polyphenol content DOI: 10.15395/mkb.v47n1.398