The correlation between antioxidant, anti-inflammatory activity and the composition of free and bound phenolics in Chinese olive cultivars

Abstract

Abstract As the food of homologous of medicine and food in China, the Chinese olive (Canarium album L.) is a natural phenolic antioxidant and anti-inflammatory agent. However, the disparity of anti-inflammatory activity in different cultivars and existing forms may be due to peculiar phenolic compounds that are not yet well-explored in the literature. In this study, 44 phenolic compounds were found in three species of free phenolics (FP) and bound phenolics (BP) and 17 phenolic compounds including syringic acid, caffeic acid, esculetin and so on were first reported in Chinese olive. Among cultivars, ‘Tan xiang’ and ‘Na zhong’ showed the best antioxidant and inhibition (LPS-induced NO and TNF-α production) activities in FP and BP separately. Furthermore, clustering correlation analysis showed that gallic acid, catechin, syringic acid and nobiletin contribute similarly, galloyl-bis-HHDP-glucose, epigallocatechin, dihydrokaempferol, genistein, galloylquinic acid, 4-hydroxycinnamic acid, and methyl ellagic acid pentoside may cause discrepancies to inflammatory effects in FP and BP. Collectively, our study uncovered the relationship between the constitution of phenolic compounds and bioactivities in cultivars of Chinese olives.