Paper Title
Antioxidant Activity of Hydrolyzed Melinjo (Gnetum Gnemon) Seeds Protein Against Neutrophil Superoxide Radical in Vitro
Abstract
Superoxide radical (O2
-) is one type of reactive oxygen species (ROS) that play important role in pathogenesis of
various inflammatory diseases. The main source of ROS is inflammatory cell neutrophil, that will produce a large amount of
ROS to response against antigen. This study purposed to analyze antioxidant activity of the hydrolyzed melinjo (Gnetum
gnemon) seeds protein (Gg-PH) against superoxide radical produced by neutrophil. This in vitro study used neutrophil
isolated from human peripheral blood vein using Histopaque Gradient Centrifugation method. Briefly, neutrophil were
incubated with antigen and antioxidant for 1 hour and 18 hours. Antioxidant activity were demonstrated by reduction of
superoxide production. Experiments were divided into three groups, (1) neutrophil + antigen + Gg-PH, (2) neutrophil +
antigen + glutathion (GSH), (3) neutrophil + antigen. The antigen is formyl-methionyl-leucyl-phenylalanine (fMLP).
Superoxide production was analyzed by means of Nitro Blue Tetrazolium (NBT) assay. Intracellular superoxide were
demonstrated microscopically, whereas extracellular superoxide spectrophotometrically. Result showed that incubation of
Gg-PH for 1 hour reduced intracellular superoxide production significantly (p<0,05), but not for extracellular superoxide
(p>0.05). Incubation for 18 hours could not prevent superoxide production, both intracellular and extracellular. Inconclusion
Gg-PH had antioxidant activity against intracellular superoxide radical for 1 hour incubation but not in extracellular. Effect
of dosis and duration of incubation need to be analyzed further.
Keywords— Antioxidants, Gnetum gnemon Protein, Neutrophil, Superoxide Radical, Nitro Blue Tetrazolium (NBT)