1,1-Diphenyl-2-picrylhydrazyl Radical Scavenging Activity of Bee Products and Their Constituents Determined by ESR

Abstract

The aim of this work was to investigate the antioxidant property of honeybee products and their constituents using an ESR method. Antioxidative activity was evaluated as the scavenging activity of 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical. The DPPH radical scavenging activities, in descending order, were: ethanol extract of Chinese red propolisϾ Ͼethanol extract of Brazilian green propolisϾ Ͼwater extract of Brazilian green propolisϾ Ͼethanol extract of bee pollen. Many natural compounds are included in Brazilian green propolis, such as caffeoylquinic acid derivatives [3,4-di-caffeoylquinic acid (3,4-CQA), 3,5-di-caffeoylquinic acid (3,5-CQA), and chlorogenic acid (ChA)] and cinnamic acid derivatives [artepillin C, baccharin, r r-coumaric acid, and drupanin]. Caffeoylquinic acid derivatives exhibited DPPH radical scavenging activity as strong as that of ascorbic acid and trolox. Among the cinnamic acid derivatives, artepillin C exhibited relatively strong DPPH radical scavenging activity. Caffeic acid phenethyl ester (CAPE), a constituent of Chinese red propolis, exhibited potent DPPH radical scavenging activity, stronger than that of ascorbic acid and trolox. Caffeic acid, a metabolite of caffeoylquinic acid, exhibited powerful DPPH radical scavenging activity, while quinic acid, another metabolite of caffeoylquinic acid, had no such activity. Both Brazilian and Chinese propolis and their constituents (caffeoylquinic acid derivatives and CAPE) therefore appear to be powerful scavengers of DPPH radical, and the effects may be partly dependent on the nature of their caffeoyl groups.

Analysis and Functionality of Major Polyphenolic Components of Polygonum cuspidatum (Itadori)

“…As a result, DCQAs, in which two caffeoyl groups combine with quinic acid, showed stronger radical scavenging activity than chlorogenic acid. This fi nding is compatible with Izuta's report (20). They suggested that the effects of DCQAs on the radical scavenging activity may depend on the caffeoyl groups.…”

Traditional Chinese medicine formula Qing Huo Yi Hao as superoxide anion scavenger in high glucose-treated endothelial cells

“…The free radicals scavenged by QHYH in these cells were identified as superoxide anions. EPR is the only approach (other than enzymatic detection) that can provide direct evidence of the presence of a free radical [25] . Using spin traps, EPR allows the detection of free radicals with short life spans, such as HO • /O 2 •- [26] .…”

Phytochemical analysis and antioxidant activities of Trigona Apicalis propolis extract

“…Additionally, a report suggests antioxidant properties of propolis using different chemical assays such as scavenging of DPPH radical [4] and superoxide anion [5], may vary due to the differences in the chemical composition of propolis, which depends on its origin of the propolis [6].…”