Metabolomic Analysis and Antioxidant Effect of Amla ( <i>Emblica officinalis</i> ) Extract in Preventing Oxidative Stress-Induced Red Cell Damage and Plasma Protein Alterations: An <i>In Vitro</i> Study

Abstract

Amla (Emblica officinalis) has antidiabetic, hypolipidemic, anti-inflammatory, and antioxidant properties, but its effect on free radical induced red cell damage and membrane and plasma protein alterations has not been adequately addressed. The aim of the present study was to evaluate the antioxidant property of amla against oxidative stress-induced red cell damage and plasma protein alterations. Red blood cells (RBCs) were preincubated with different concentrations of amla extract (50, 100, 150, and 200 μg/mL) and then treated with physiological (5 mM) and pathological (50 mM) concentrations of glucose for 24 h. In another in vitro study the plasma was pretreated with different concentrations of amla extract and then incubated with 2, 2'-Azo-Bis (2-methylpropionamidine) dihydrochloride (AAPH) for 2 h. After the incubation RBC-malondialdehyde (MDA), RBC-reduced glutathione (GSH), RBC indices, RBC morphometric study, plasma MDA, protein carbonylation, total protein, and albumin were estimated. The antioxidant property of amla was assessed by DPPH assay. RBC-MDA levels were significantly decreased and RBC-GSH levels were significantly increased with higher concentration of amla extract (150 and 200 μg/mL). Red cell count and its indices were improved with the increasing concentration of amla. In addition, at higher concentration, amla restored the RBC membrane integrity. The plasma in vitro study also showed that amla improved the plasma MDA, protein carbonylation, total protein, and albumin levels. Amla extract effectively protected the RBCs and plasma proteins from the reactive oxygen species induced oxidative damage. Liquid chromatography-mass spectrometry (LC-MS) analysis of the extract revealed the presence of gallic acid, quinic acid, and quercetin as the major constituents in addition to the other flavonoids.