Free Radical Scavenging Activities Measured by Electron Spin Resonance Spectroscopy and B16 Cell Antiproliferative Behaviors of Seven Plants

Abstract

In an effort to discover new antioxidant natural compounds, seven plants that grow in France (most of them in the Limousin countryside) were screened. Among these plants, was the extensively studied Vitis vinifera as reference. For each plant, sequential percolation was realized with five solvents of increasing polarities (hexane, chloroform, ethyl acetate, methanol, and water). Free radical scavenging activities were examined in different systems using electron spin resonance (ESR) spectroscopy. These assays were based on the stable free radical 1,1-diphenyl-2-picrylhydrazyl (DPPH), the hydroxyl radicals generated by a Fenton reaction, and the superoxide radicals generated by the X/XO system. Antiproliferative behavior was studied on B16 melanoma cells. ESR results showed that three plants (Castanea sativa, Filipendula ulmaria, and Betula pendula) possessed, for the most polar fractions (presence of phenolic compounds), high antioxidant activities in comparison with the Vitis vinifera reference. Gentiana lutea was the only one that presented a hydroxyl scavenging activity for the ethyl acetate and chloroform fractions. The antiproliferative test results showed that the same three plants are the most effective, but for the apolar fractions (chloroform and hexane).

Characterization of phenolic compounds in wild medicinal flowers from Portugal by HPLC–DAD–ESI/MS and evaluation of antifungal properties

“…The available studies in literature described phenolic composition in C. sativa leaves (Calliste et al, 2001) and heartwood (Sanz et al, 2010), but not in its flowers. The phenolic composition of F. ulmaria flowers was studied, but with plant material from other European countries, i.e not growing under Mediterranean particular climatic and soil conditions Shilova et al, 2006;Pemp et al, 2007;Fecka, 2009;Harbourne et al, 2009;Krasnov et al, 2009).…”

Essential Oil and Extracts From Thymus Praecox Opiz Ssp. Polytrichus as Natural Antioxidants

“…The majority of natural antioxidantsare phenolic compounds or polyphenols and the antioxidant activity of many natural extracts and essential oils is due to such phenolic compounds. The antioxidant activity of phenolic compounds is mainly due to their redox properties, simultaneous hydrogen atom donation to free radicals, electron transfer and metal chelating [26]. Lee et al (2005) showed that the main components dichloromethane extract of T. vulgaris, particularly eugenol, thymol and carvacrol, have higher antioxidant activity than synthetic antioxidant BHT and α-tocopherol [27].Other compounds isolated from thyme that showed strong antioxidant activity are caffeic and rosmarinic acid, biphenyl compounds of monoterpenoid origin, flavanones (narirutin, eriodictyol, eriocitrin, hesperidin), methyl rosmarinate [28][29][30].…”

Modern Applied Science, Vol. 3, No. 3, March 2009, all in one file, Part B

“…Herbals and herbal extracts, which contain different classes of polyphenols, are very attractive, not only in modern phytotherapy, but also for the food industry, due to their use as preservatives. It has been reported (Calliste, Trouillas, Allais, Simon,& Duroux, 2001) that phenolic acids and their glycosides,aglycones, and monoglycosyl or diglycosyl flavonoids are distributed in the different solvents as a function of polarity and water extracts contain the most polar compounds. These facts might explain the strong scavenging and antioxidant activity of water extracts of Phoenix dactylifera, Citrus aurantifolia.…”