Phenolic Compounds and Antioxidant Capacities of 10 Common Edible Flowers from China

Abstract

The free and bound phenolic compounds in 10 common Chinese edible flowers were investigated using reversed phase high-performance liquid chromatography. Their antioxidant capacities were evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging activity, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical-scavenging activity, oxygen radical absorption capacity (ORAC), ferric reducing antioxidant power (FRAP), and cellular antioxidant activity (CAA). Free factions were more prominent in phenolic content and antioxidant capacity than bound fractions. Paeonia suffruticosa and Flos lonicerae showed the highest total phenolic content (TPC) 235.5 mg chlorogenic acid equivalents/g of dry weight and total flavonoid content 89.38 mg rutin equivalents/g of dry weight. The major phenolic compounds identified were gallic acid, chlorogenic acid, and rutin. P. suffruticosa had the highest antioxidant capacity in the DPPH, ABTS, and ORAC assays, which were 1028, 2065, 990 μmol Trolox equivalents/g of dry weight, respectively, whereas Rosa chinensis had the highest FRAP value (2645 μmol Fe(2+) equivalents /g of dry weight). The P. suffruticosa soluble phenolics had the highest CAA, with the median effective dose (EC50 ) 26.7 and 153 μmol quercetin equivalents/100 g of dry weight in the phosphate buffered saline (PBS) and no PBS wash protocol, respectively. TPC was strongly correlated with antioxidant capacity (R = 0.8443 to 0.9978, P < 0.01), which indicated that phenolics were the major contributors to the antioxidant activity of the selected edible flowers.

Polyphenol Profiles and Antioxidant Properties of Ethanol Extracts from Osmanthus Fragrans (Thunb.) Lour. Flowers

“…Oxygen radical absorbance capacity of OF fl owers was shown in Table 2. Literature provides no data for ORAC of OF, but the obtained value -333.23 μmol Trolox/g fl owers (dry weight) -was comparable to results noted for some edible fl owers used as herbs or food ingredients [Xiong et al, 2014].…”

Antioxidant activity of Rosa multiflora Thunb. flower extract and suppressive activity on proinflammatory mediator production in lipopolysaccharide- stimulated RAW 264.7 macrophages

“…Phenolic agents present in plants have strong in vitro and in vivo antioxidant activities associated with their ability to scavenge free radicals, break free-radical chain reactions, and chelate metals. Increased consumption of phenolic agents has been correlated with antiinflammatory activity and a reduced risk of cardiovascular disease and certain cancers [23]. We discovered that the antioxidant activity of the ethanol extract of RMF and the fractions from the extract were closely correlated with their total phenolic content or total flavonoid content.…”

Inhibition of the DNA polymerase and RNase H activities of HIV-1 reverse transcriptase and HIV-1 replication by Brasenia schreberi (Junsai) and Petasites japonicus (Fuki) components

“…There is no such report for Petasites japonicus; as far as we know, Rosa species contain polyphenolic compounds with antioxidant activities [12]. We examined the effects of the extracts on HIV-1 replication in human cells.…”

“…In the present study, we tested the inhibitory activities of 43 edible plants towards DNA polymerase and RNase H activities of HIV-1 RT. Edible flowers are now receiving much interest from researchers due to the various effects they can exert, such as antioxidant and antidiabetic effects [11,12]. The results of this study revealed that ethanol and water extracts of Brasenia schreberi and water extract of Petasites japonicus strongly inhibit the activities of both DNA polymerase and RNase H. We also showed that these extracts strongly inhibit HIV-1 replication in human cells, suggesting that this may involve the inhibition of both the DNA polymerase and RNase H activities of HIV-1 RT.…”