Chemical Profiling, Bioactive Properties, and Anticancer and Antimicrobial Potential of Juglans regia L. Leaves

Abstract

The aim of this study was to assess the biological potential of the polyphenolic fraction isolated from J. regia leaves, collected in the Subcarpathian region (Poland). The phenolic profile was determined using the UPLC-PDA-MS/MS method. Biological activity was determined by evaluating the antioxidant, anticancer, antibacterial, and antifungal effects. Prior to this study, the purified polyphenolic fraction was not been tested in this regard. A total of 40 phenolic compounds (104.28 mg/g dw) were identified, with quercetin 3-O-glucoside and quercetin pentosides dominating. The preparation was characterized by a high ability to chelate iron ions and capture O2•− and OH• radicals (reaching IC50 values of 388.61, 67.78 and 193.29 µg/mL, respectively). As for the anticancer activity, among the six tested cell lines, the preparation reduced the viability of the DLD-1, Caco-2, and MCF-7 lines the most, while in the antibacterial activity, among the seven tested strains, the highest susceptibility has been demonstrated against K. pneumoniae, S. pyogenes, and S. aureus. Depending on the needs, such a preparation can be widely used in the design of functional food and/or the cosmetics industry.

‘Sorrento’ and ‘Tulare’ Walnut Cultivars: Morphological Traits and Phytochemical Enhancement of Their Shell Waste

“…Quercetin-3- O -(6″- O -galloyl)-β- d -galactopyranoside was recently isolated from an antidiabetic extract of Diaphragma juglandis Fructus, which is able to improve diabetes symptoms via the AKT/FoxO1 signaling pathway [ 64 ]. Lastly, the TOF-MS/MS spectra of compound 32 agreed with a quercetin deoxyhexoside, likely the quercetin rhamnoside ( Figure S13 ), which was previously found in green walnut liqueur [ 65 ] and walnut leaves [ 66 ]. Beyond these major classes of specialized metabolites, glansreginin A ( 31 ), a dicarboxylic acid derivative, ([M-H] − ion at m / z 592.2036) was tentatively identified.…”

Antifungal Activity of Juglans-regia-Mediated Silver Nanoparticles (AgNPs) against Aspergillus-ochraceus-Induced Toxicity in In Vitro and In Vivo Settings

“…Phytochemical analysis of J. regia-mediated leaf extract revealed a high content of TPC (72.68 ± 2.13 mg GAE/g DW) and TFC (18.89 ± 0.31 mg QE/g DW). Similar to our results, high TPC and TFC were found to be present in the leaf and bark extract of J. regia [62,63]. The FTIR examination revealed the presence of compounds, such as alkyl, amide, phenolic, and flavonoid, that were further involved in the reduction and capping of the synthesized AgNPs.…”

Antioxidant and Antiproliferative Activities of Phenolic Extracts of Eriobotrya japonica (Thunb.) Lindl. Fruits and Leaves

“…Interestingly, despite the composition being widely investigated, these compounds were not reported in the available literature as loquat constituents. It is well-known that the chemical composition of the plant may vary depending on species, season, growing conditions, and genetic differences [ 33 ]. Instead, the content of polyphenols in the leaf extract was at the level of 26.796 mg/100 g dw.…”

“…Hydroxyl radical scavenging activity was evaluated by the method of Żurek et al [ 33 ]. The plant extracts were mixed with 2.0 mL of 2-deoxyribose, 0.2 mL iron ammonium sulfate, 0.15 mL EDTA, 0.15 mL ascorbic acid, and 0.02 mL perhydrol.…”