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

Abstract

Cyclocarya paliurus (Batal.) Iljinskaja is an indigenous and multifunction tree species in China, but it is mainly used in pharmaceutical and nutraceutical ingredients. To make a comprehensive evaluation on its bioactive metabolites, antioxidant and antitumor potentials of C. paliurus leaves, the leaf samples were collected from 15 geographic locations (natural populations) throughout its distribution areas. High-performance liquid chromatography (HPLC) and colorimetric methods were used to detect the contents of bioactive metabolites. The antioxidant activity was evaluated by 2,2′-diphenyl-1-picrylhydrazyl (DPPH), 2,2-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and reducing power assays. The antiproliferative activity on different cancer cell types was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Contents of bioactive metabolites, and antioxidant and antiproliferative activities in the extracts were significantly affected by solvent and population. In most cases, the contents of flavonoids and triterpenoids, and the antioxidant and antiproliferative activities in the ethanol extracts were higher than the water extracts. The best scavenging capacity of DPPH (IC50 = 0.34 mg/mL) and ABTS (IC50 = 0.50 mg/mL) radical occurred in the ethanol extracts of S15 and S7 population respectively, while the strongest reducing power (EC50 = 0.71 mg/mL) was achieved in the ethanol extracts of S14 population. The antiproliferation effects of C. paliurus extracts on cancer cells varied with different cell types. The HeLa cell was the most sensitive to C. paliurus extracts, and their IC50 values of the ethanol extracts varied from 0.13 to 0.42 mg/mL among C. paliurus populations. Redundancy analysis showed that total polyphenol had the greatest contribution to the antioxidant activity, but total flavonoid was mostly responsible for the antiproliferation effects. These results would provide important scientific evidences not only for developing C. paliurus as a potent antioxidant and antitumor reagent, but also for obtaining the higher yield of bioactive compounds in the C. paliurus plantation.

Microencapsulation of Cyclocarya paliurus (Batal.) Iljinskaja Extracts: A Promising Technique to Protect Phenolic Compounds and Antioxidant Capacities

“…Quercetin-3- O -glucuronide was the second major phenolic component, occupied approximately 17% of the total in powder samples. The concentrations of quercetin-3- O -glucuronide in the original aqueous and ethanol C. paliurus extracts were 4.13 and 4.88 mg/g dw, respectively ( Table 4 ), which was much higher than the findings of Zhou et al (0.2–3.7 mg/g) [ 11 ]. This might be attributed to the plant diversity of C. paliurus , as the phenolic profiles of C. paliurus were found to be quantitatively and qualitatively different across geographical location [ 11 ].…”

“…Comparing the AOC of original extracts without encapsulation, the FRAP assay showed significantly higher values ( p < 0.05) than those from the DPPH assay (i.e., 567.61 vs. 447.54 µM TE/g dw for aqueous extracts and 688.23 vs. 593.87 µM TE/g dw for ethanol extracts). As two assays have different reaction mechanisms, it is necessary to consider both when evaluating the antioxidant capacities, and this has been a practice in many previous studies [ 11 , 29 , 37 ]. Both DPPH and FRAP assays have similar AOC ranges for powder products ( Figure 2 C,E), i.e., from 331.69 to 486.72 and from 354.43 to 513.49 µM TE/g dw, respectively.…”

“…The fine powder samples were kept at −20 °C until further requirement. MD [ 10 , 11 , 12 , 13 ], dextrose equivalent (DE) was purchased from Ingredion (Singapore) and GA was gifted by Hawkins Watts Limited (Auckland, New Zealand).…”

“…These bioactivities are associated with the presence of abundant phenolic compounds in leaves, such as myricetin-3- O - β - d -glucuronide, kaempferol, quercetin, caffeic acid, quercetin-3- O - β - d -glucuronide, and quercetin-3- O - α - d -glucuronide [ 5 , 9 ]. Other phytochemical compounds, for example polysaccharides and triterpenoids, also show antidiabetic, anticancer, anti-inflammatory, and hepatoprotective properties [ 10 , 11 , 12 , 13 ].…”

Forest, Foods, and Nutrition

“…The discussion of the role of forest foods rich in compounds with nutrients and biologically active compounds to complement people's diet and the contribution of forest foods to a healthy diet has been exploited, adding information to the area of interest. The beneficial potential of medicinal plants and herbs has been investigated in different papers [9][10][11][12]. Functionally, extracts and biologically active components [13][14][15][16][17][18] from forest products are experiencing great interest for both research and potential application in nutraceutical, pharmaceutical, and cosmetic fields [19,20].…”