Lupeol, a pentacyclic triterpenoid isolated from Vernonia cinerea attenuate selenite induced cataract formation in Sprague Dawley rat pups

Abstract

This study investigated the inhibitory effects of active component isolated from flavonoid fraction of Vernonia cinerea (FVC), lupeol on selenite induced cataract formation. Previous reports suggest that phytochemicals or natural plant products retard the process of cataractogenesis by scavenging free oxygen radicals. Hence, the present study sought to assess the potential of lupeol on in vivo selenite induced cataract models. Lupeol, a pentacyclic triterpenoid, was isolated from the ethyl acetate fraction of methanolic extract of Vernonia cinerea, follows standard chromatographic techniques. Structural elucidation of the compound was carried out using (1)H NMR, (13)C NMR, Mass spectrometry together with other complementary techniques (UV and IR). From these, the isolated compound was identified as Lupeol (3'-hydroxylup-20(29)-ene). The antioxidant activity was comparatively studied using DPPH radical scavenging and FRAP assay. Lupeol exhibited higher DPPH radical scavenging activity as well as reducing power assay. In this study, cataract was induced by a single subcutaneous injection of sodium selenite (4 μg/g body weight) on rat pups. Lupeol was administered orally from 8th day upto 21st day at a concentration 25 μg/g body weight. Cataract was visualized on 16th day with the help of an ophthalmoscope and later on with the naked eye. On the 30th day, rats were euthanized by sodium pentothal injection, lenses were excised and the biochemical parameters such as activity of superoxide dismutase (SOD), catalase (CAT), Glutathione peroxidase (GPx), Glutathione reductase (GR), Glutathione-S-transferase (GST), Ca(2+) ATPase, glutathione content (GSH), reactive oxygen species (ROS), lipid peroxidation products (malondialdehyde) were estimated and found effective in the treatment of cataract by lupeol.

Keywords: Antioxidant; Cataract; Lupeol; Oxidative stress; Sodium selenite; Vernonia cinerea.