Chemical Profile, Cytotoxic Activity and Oxidative Stress Reduction of Different Syringa vulgaris L. Extracts

Abstract

Syringa vulgaris L. (common lilac) is one of the most popular ornamental species, but also a promising not comprehensively studied source of bioactive compounds with important therapeutic potential. Our study was designed to characterize the chemical composition and to assess the antioxidant and cytotoxic properties of ethanolic extracts obtained from S. vulgaris L. flowers, leaves, bark, and fruit. The chemical profile of the ethanolic extracts was investigated using chromatographic (HPLC-DAD-ESI+, GC-MS) and spectral (UV-Vis, FT-IR) methods, while the protective effect against free radicals was evaluated in vitro by different chemical assays (DPPH, FRAP, CUPRAC). The cytotoxic activity was tested on two tumoral cell lines, HeLa, B16F10, using the MTT assay. Significant amounts of free or glycosylated chemical components belonging to various therapeutically important structural classes, such as phenyl-propanoids (syringin, acteoside, echinacoside), flavonoids (quercetin, kaempferol derivatives) and secoiridoids (secologanoside, oleuropein, 10-hydroxy oleuropein, demethyloleuropein, syringalactone A, nuzhenide, lingstroside) were obtained for the flowers, leaves and bark extracts, respectively. Furthermore, MTT tests pointed out a significant cytotoxic potential expressed in a non-dose-dependent manner toward the tumoral lines. The performed methods underlined that S. vulgaris extracts, in particular belonging to flowers and leaves, represent valuable sources of compounds with antioxidant and antitumoral potential.

Biological Activities and Chemical Profile of Gentiana asclepiadea and Inula helenium Ethanolic Extracts

“…The absorbance was determined at 500 nm, and TPA content was expressed as g CAE per 100 g of dry material. All the determinations were performed using a UV–V is spectrophotometer (Specord 200 Plus, Analytik Jena, Germany) [ 58 , 59 , 60 , 61 ].…”

“…The absorbance of obtained solutions was read at 450 nm, using Trolox as standard for the calibration curve (R2 = 0.992). The results of FRAP assay were expressed as μmol of Trolox Equivalents (TE) per 100 mL of extract [ 58 , 59 , 60 , 61 ]…”

“…The results of the DPPH assay were expressed as IC 50 value (μg/mL), representing the concentration of antioxidant capable of reducing the DPPH radical concentration by half [ 58 , 59 , 60 , 61 ].…”

Antiproliferative and Antimicrobial Effects of Rosmarinus officinalis L. Loaded Liposomes

“…The SK-Hep-1 (HTB-52 ™ ) cells were maintained in Minimum Essential Medium Eagle (MEM) supplemented with 10% fetal bovine serum and 1% Antibiotic-Antimycotic 100× and 1% L-glutamine in a 5% CO 2 incubator (Advantage-Lab, Schilde, Belgium) at 37 • C in a humidified atmosphere, according to standard conditions. The LX-2 cell line was maintained in Dulbecco's modified Eagle's medium (DMEM, high glucose) supplemented with 10% fetal bovine serum and 1% Antibiotic-Antimycotic 100× and 1% L-glutamine [52,53].…”

“…The concentrations required to inhibit 50% of cell proliferation (IC 50 values) for L-R and L-DOX were calculated from the dose-response curve obtained using non-linear regression. Each experiment was performed in triplicate [52][53][54].…”