Establishing Gerger (<i>Eruca sativa</i>) Leaves as Functional Food by GC-MS and <i>In-vitro</i> Anti-lipid Peroxidation Assays

Abstract

Conventional food that safeguards against chronic illnesses is known as a functional food. Establishing functional foods starts with phytoconstituent analysis and in-vitro characterization of health benefits. Eruca sativa, popularly known as gerger or jarjeer in Saudi Arabia, is an annual edible shrub cultivated worldwide. Gerger leaves are consumed raw in salads and have additional health benefits. This study investigated the phytochemical profile of aqueous decoction of gerger leaves of the Saudi origin by GC-MS assay. We also performed in-vitro anti-lipid peroxidation and total antioxidant capacity assays using gerger decoction. Twenty-seven chemical compounds belonging to seven classes constituted the gerger decoction: organic siloxanes (39.75%), organic silyl esters (18.28%), phenolics (17.87%), aromatic and aliphatic esters (10.48%), terpenoids (7.09%), heterocycles (3.83%), and sulfur compounds (2.70%). This study reported the presence of compounds mentioned above for the first time in gerger leaves. The decoction method was efficient in the extraction of heat-stable terpenoids like astaxanthin (2.23%), cilonasterol (1.48%), ingol-12-acetate (0.4%), and phytol (2.98%). The in-vitro anti-lipid peroxidation study demonstrated the ability of gerger decoction to inhibit hepatic lipid peroxidation in a significantly dose-dependent (150 to 400 μg/ml) manner compared to quercetin. A dose of 400 μg/ml of gerger decoction resulted in 68.46 ± 0.01% inhibition of oxidation of hepatic lipids. The total antioxidant capacity of gerger leaves reported as the IC50 of the decoction was 217.90 ± 2.2 μg/ml and also statistically significant. The in-vitro models suggested the antioxidant mechanism of gerger was by hydrogen atom transfer and reduction of metal ions. The study substantiated that gerger is a functional food besides established the phytochemical profile contributing to the antioxidant activity. Given that the gerger decoction has a high silicon content and antioxidants, attempt to determine the bioavailability and to identify the molecular targets are essential to overcome bone disorders and oxidative stress.