Search Repository Universitas Fort De Kock

Beras hitam (Oryza sativa L. indica) merupakan salah satu komoditas pangan lokal
yang kaya metabolit sekunder, terutama antosianin, flavonoid, alkaloid, dan senyawa
fenolik yang berpotensi sebagai sumber antioksidan alami. Antioksidan berperan
penting dalam menetralisir radikal bebas yang dapat memicu stres oksidatif, sehingga
berhubungan dengan berbagai penyakit degeneratif seperti kanker, diabetes, dan
gangguan kardiovaskular. Penelitian ini bertujuan mengetahui aktivitas antioksidan
dari ekstrak etanol beras hitam serta fraksinya (n-heksana, etil asetat, dan air)
menggunakan metode penangkapan radikal bebas hidrogen peroksida (H2O2) dengan
vitamin C sebagai kontrol positif. Simplisia beras hitam diekstraksi menggunakan
pelarut etanol 96% melalui metode maserasi, kemudian difraksinasi bertingkat
menggunakan n-heksana, etil asetat, dan air. Selanjutnya dilakukan skrining fitokimia
untuk mengidentifikasi golongan metabolit sekunder, serta uji aktivitas antioksidan
dengan pengukuran persen inhibisi dan nilai IC50 yang dianalisis secara komparatif
antar fraksi. Hasil penelitian menunjukkan bahwa masing-masing fraksi memiliki
kandungan metabolit sekunder berbeda, di mana fraksi n-heksana cenderung
mengandung alkaloid dan terpenoid, sedangkan fraksi etil asetat kaya akan flavonoid
dan fenolik. Aktivitas antioksidan tertinggi ditunjukkan oleh fraksi etil asetat dengan
nilai IC50 mendekati vitamin C, sementara fraksi n-heksana memiliki aktivitas paling
rendah. Dengan demikian, dapat disimpulkan bahwa beras hitam berpotensi
dikembangkan sebagai bahan fitofarmaka sumber antioksidan, khususnya melalui
pemanfaatan fraksi etil asetat, dan hasil penelitian ini diharapkan memberikan
kontribusi ilmiah bagi pengembangan obat tradisional berbasis tanaman sekaligus
mendorong pemanfaatan sumber daya alam lokal.

Black rice (Oryza sativa L. indica) is a local food commodity rich in secondary
metabolites, especially anthocyanins, flavonoids, alkaloids, and phenolic compounds
that have the potential as a source of natural antioxidants. Antioxidants play an
important role in neutralizing free radicals that can trigger oxidative stress, thus being
associated with various degenerative diseases such as cancer, diabetes, and
cardiovascular disorders. This study aims to determine the antioxidant activity of
ethanol extract of black rice and its fractions (n-hexane, ethyl acetate, and water)
using the hydrogen peroxide (H2O2) free radical scavenging method with vitamin C
as a positive control. Black rice simplicia was extracted using 96% ethanol solvent
through the maceration method, then fractionated in stages using n-hexane, ethyl
acetate, and water. Furthermore, phytochemical screening was carried out to identify
secondary metabolite groups, as well as antioxidant activity testing by measuring the
percentage of inhibition and IC50 values which were analyzed comparatively between
fractions. The results showed that each fraction contained different secondary
metabolites, where the n-hexane fraction tended to contain alkaloids and terpenoids,
while the ethyl acetate fraction was rich in flavonoids and phenolics. The highest
antioxidant activity was shown by the ethyl acetate fraction with an IC50 value close
to vitamin C, while the n-hexane fraction had the lowest activity. Thus, it can be
concluded that black rice has the potential to be developed as a phytopharmaceutical
source of antioxidants, especially through the utilization of the ethyl acetate fraction,
and the results of this study are expected to provide scientific contributions to the
development of plant-based traditional medicines while encouraging the utilization of
local natural resources.