Evaluation of Antioxidant Activity of Vernonia amygdalina Leaves and Its Flavonoid-Phenolic Content
Abstrak
Bitter leaf, Vernonia amygdalina (VA), is used in various alternative medicine in several countries,
including Indonesia. This study aims to evaluate the antioxidant activity of VA leaves by three different
in vitro methods. The antioxidant activity was evaluated by radical scavenging of 1,1-diphenyl-2-
picryl-hydrazyl (DPPH), ferric reducing antioxidant power (FRAP), and cupric reducing antioxidant
capacity (CUPRAC). The antioxidant capacity by FRAP and CUPRAC methods were expressed as
mg of quercetin equivalents (QE) per g extract (mgQE/g) and mg of ascorbic acid equivalents (AAE)
per g extract (mgAAE/g), respectively. All methods were measured by UV-Visible spectrophotometry
at maximum wavelength. The results exhibited that VA leaves ethanolic extract contains flavonoidphenolic.
The VA leaves ethanolic extract has an antioxidant activity by scavenging the DPPH method
with the half inhibition concentration (IC50) was 8,22 μg/mL. The antioxidant capacity of VA leaves
ethanolic extract by FRAP and CUPRAC methods was 21,03 mgQE/g and 160,64 mgAAE/g extract,
respectively. The VA leaves ethanolic extract has a powerful antioxidant potency which might correlate
to the flavonoid-phenolic content in the extract.
including Indonesia. This study aims to evaluate the antioxidant activity of VA leaves by three different
in vitro methods. The antioxidant activity was evaluated by radical scavenging of 1,1-diphenyl-2-
picryl-hydrazyl (DPPH), ferric reducing antioxidant power (FRAP), and cupric reducing antioxidant
capacity (CUPRAC). The antioxidant capacity by FRAP and CUPRAC methods were expressed as
mg of quercetin equivalents (QE) per g extract (mgQE/g) and mg of ascorbic acid equivalents (AAE)
per g extract (mgAAE/g), respectively. All methods were measured by UV-Visible spectrophotometry
at maximum wavelength. The results exhibited that VA leaves ethanolic extract contains flavonoidphenolic.
The VA leaves ethanolic extract has an antioxidant activity by scavenging the DPPH method
with the half inhibition concentration (IC50) was 8,22 μg/mL. The antioxidant capacity of VA leaves
ethanolic extract by FRAP and CUPRAC methods was 21,03 mgQE/g and 160,64 mgAAE/g extract,
respectively. The VA leaves ethanolic extract has a powerful antioxidant potency which might correlate
to the flavonoid-phenolic content in the extract.