Comparative evaluation of antioxidant activities of some fresh and preserved herbal products of North East India by cyclic voltammetry

Abstract

<span style="font-size:11.0pt;font-family: " times="" new="" roman","serif";mso-fareast-font-family:"times="" roman";mso-bidi-font-family:="" mangal;mso-ansi-language:en-gb;mso-fareast-language:en-us;mso-bidi-language:="" hi"="" lang="EN-GB">Antioxidant activities of fresh and preserved forms of three herbal products, <i>Bambusa balcooa</i> Roxb., <i>Brassica nigra</i> (Linn.) Koch and <i style="mso-bidi-font-style:normal">Garcinia morella</i><span style="mso-bidi-font-style: italic"> Desr., used by the people of North East India have been evaluated by cyclic voltammetry. The antioxidative effects have been evaluated by monitoring the change of the oxidation potential in the redox cycle of 1,4-diaminobenzene in the presence of hexane, ethyl acetate and methanol extracts of the herbal products. 1,4-Diaminobenzene has two well defined reversible redox cycles with E_1/2 at 218 mV and E_1/2 at 535 mV in DMF with the oxidation waves due to formation of a radical cation and a diiminium dication, respectively. In the presence of herbal extracts either the oxidation(s) is delayed and/or the radical cation is scavenged as soon as it is formed. It is reflected by the delayed appearance of the oxidation waves and disappearance of the second oxidation wave in the cyclic voltammograms of 1,4-diaminobenzene in the presence of herbal extracts.</span></span>