The total antioxidant capacity and fluorescence imaging of selected plant leaves commonly consumed in Brunei Darussalam

Abstract

Abstract. We investigated the total antioxidant capacity and fluorescence imaging of several selected plants, namely Centella asiatica, Aidia borneensis and Anacardium occidentale, which are grown and traditionally consumed in Brunei Darussalam. The total antioxidant capacities of aqueous-methanolic infusions of their leaves were measured by 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activity, and microscopic fluorescence images were measured to identify the fluorescent substances bound in the leaves. We found that the total antioxidant capacity of their infusions is estimated to be 150, 25, 15 folds, respectively, lower compared with that of the standard gallic acid. Accordingly, we demonstrated that the relative antioxidant activity of young and matured leaves agrees with the intensity of red light emission of their fresh leaves upon UV excitation. Thus, this non-invasive spectroscopic method can be potentially utilized to indicate the antioxidants in plant leaves qualitatively.

Radical Scavenging Activity Assay and Red Fluorescence Microscopy Studies: Antioxidant Properties of Selected Young and Mature Leaves for Application in Pharmaceutical Industry

“…The antioxidant capacity of the plant leaves which was determined using DPPH radical scavenging assay was then related to their red fluorescence intensity. With this method, the antioxidant capacity of the plant leaves can be qualitatively screened 18) . However, this method has only been applied on several plants 18) .…”

“…With this method, the antioxidant capacity of the plant leaves can be qualitatively screened 18) . However, this method has only been applied on several plants 18) . In order to prove the applicability of this method in general, in this study the relation between red fluorescence and antioxidant capacity of leaves was extended across different plant families, including Anacardiaceae and Piperaceae.…”