Phytochemical content and antioxidant activity in aqueous extracts of Cyclocarya paliurus leaves collected from different populations

Abstract

Cyclocarya paliurus (Batal) Iljinskaja is a multiple function tree species, but its main utilization is for the harvesting of its leaves as materials for tea production and recently as ingredients for the food industry. In this study aqueous extracts of C. paliurus leaves collected from 21 natural populations were evaluated for their phytochemical content and antioxidant activity. The content of water-soluble polysaccharide, total flavonoid and total polyphenol varied from 66.05 to 153.32 mg/g, 9.01 to 19.65 mg/g and 20.80 to 52.69 mg/g, respectively. Quercetin-3-O-glucuronide, aemferol-3-O-glucuronide and 3-O-caffeoylquinic acid were the major phenolic components in aqueous extracts of C. paliurus leaves. Both redundancy analysis and Pearson's correlation analysis indicated that water-soluble polysaccharide, total polyphenol, total flavonoid, quercetin-3-O-glucuronide, 3-O-caffeoylquinic acid and 4-O-caffeoylquinic acid were significantly correlated with antioxidant activity, but total polyphenol showed the greatest contribution to antioxidant capacity. The antioxidant activity of the 21 populations was classified into six distinct groups based on the squared Euclidean distance. These results would provide a theoretical basis for obtaining the greatest yield of targeted antioxidant phytochemicals of C. paliurus leaves for tea and food ingredient production.

A Comprehensive Assessment of Bioactive Metabolites, Antioxidant and Antiproliferative Activities of Cyclocarya paliurus (Batal.) Iljinskaja Leaves

“…Our results corresponded with previous reports of Liu et al [20] and Zhou et al [17] who indicated that the antioxidant activity of C. paliurus varied with the geographical locations. The ethanol extracts of C. paliurus leaves showed stronger antioxidant capacity than the water extracts, which were in line with the extracts of F. beecheyana and S. chinensis [23,24].…”

“…Sample solvent (70% ethanol or distilled water) was used as the control. The scavenging capacity of DPPH and 2,2-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS )radicals, and the reducing power were determined and analyzed by the methods described by Zhou et al [17]. The percent inhibition of radical was calculated as ((A control − A sample )/A control ) × 100%, where A control and A sample are the absorbances of the control and sample, respectively.…”

“…Additionally, C. paliurus polysaccharides showed significant scavenging capacity on 2,2 -diphenyl-1-picrylhydrazyl (DPPH) radicals at IC 50 value of 52.3 µg/mL [16]. Total polyphenol among phenolics and polysaccharide exhibited the greatest contribution to antioxidant activity in aqueous extracts of C. paliurus leaves [17]. Quercetin and kaempferol glycosides of phenolic compounds were key antioxidant components in ethanol extracts of C. paliurus leaves [18].…”

“…Although polysaccharides, phenolics and triterpenoids have antiproliferation effects on cancer cells and antioxidant activity in some plants [15,19], the main bioactive constituents with antioxidant and antiproliferative activities remain unclear in leaf extracts of C. paliurus. Polysaccharide content and antioxidant activity of water extracts of C. paliurus leaves collected from different populations were investigated in previous studies [14,17]. Moreover, no polysaccharide was found in the ethanol extracts [13].…”

“…Geographical origin has a pivotal impact on phytochemicals and biological activities. The contents of polysaccharide, phenolics, triterpenoid and their antioxidant, hypolipidemic and hypoglycemic effects in C. paliurus leaves have been reported to vary with different geographical locations [13,17,18,20]. Phytochemical contents, antioxidant and anticancer activities in plant extracts also vary with extraction solvents such as water, aqueous mixtures of ethanol, ethanol and methanol [21,22].…”