Phenolic composition, antioxidant and antinociceptive activities of Syringa vulgaris L. bark and leaf extracts.

Metabolite profile, antioxidant and antinociceptive activities of Syringa vulgaris bark and leaf methanolic extracts were investigated. By means of HPLC-DAD-ESI-TOF and HPLC-DAD-ESI-MS/MS, a total of 33 phenolics were identified, including 15 secoiridoids, 6 phenylpropanoids, 3 flavonoids, 3 lignans and 6 low molecular weight phenols. Validated quantitative analysis show that syringin (2.52%) and rutin (1.13%) are the main phenolic compounds in bark and leaf, respectively. Notable radical scavenging and antinociceptive activities of the bark and leaf extracts were confirmed by in vitro DPPH● and ABTS●+ assays and by in vivo hot-plate method in mice, respectively. Our results could lay the scientific basic of future clinical perspectives of lilac bark and leaf.

Contribution of individual flavonoids in Lysimachia species to the antioxidant capacity based on HPLC-DPPH assay.

Quantitative phytochemical characterisation of the chief flavonoid aglycones in the hydrolysed Lysimachia extracts revealed the dominance of kaempferol, quercetin and myricetin in L. vulgaris, L. nummularia, L. punctata, L. christinae, L. ciliata and L. clethroides, respectively. Due to the significant radical scavenging capacity of the samples, the contribution of the individual aglycones to the total antioxidant activity became of interest. Therefore, a HPLC method coupled to pre-column DPPH scavenging assay was developed. Differences in the six Lysimachia species' phenolic composition regarding their participation to the antioxidant activity were revealed. The participation of the three investigated flavonoids to the radical quenching activity was the highest (91.2%) in the L. vulgaris sample, the lowest in L. christinae sample with 29.6%. In L. vulgaris sample, the 76.3% contribution of quercetin to the scavenger capacity was the highest peak area decrement ratio among the investigated samples.

Three newly identified lipophilic flavonoids in Tanacetum parthenium supercritical fluid extract penetrating the Blood-Brain Barrier.

Feverfew (Tanacetum parthenium L.) as a perennial herb has been known for centuries due to its medicinal properties. The main sesquiterpene lactone, parthenolide is considered to be responsible for the migraine prophylactic effect, however the pharmacological benefits of the lipophilic flavonoid components can not be neglected. Supercritical fluid extraction (7% ethanol, 22MPa, 64°C) was carried out on the leaves of Tanacetum parthenium L. from which the presence of methylated flavonoids beside parthenolide and other sesquiterpene lactones were indicated by preliminary LC-MS analyses. Specific Parallel Artificial Membrane Permeability Assay (PAMPA) was applied to identify the components capable to cross the Blood-Brain Barrier (BBB). Three lipophilic flavonoids were detected on the acceptor side, that were isolated (Prep-HPLC) and identified as sudachitin, aceronin and nevadensin (LC-MS/MS, NMR). These flavonoids were also characterized individually by PAMPA-BBB model. The presence of sudachitin and nevadensin was proven in the Asteraceae family, but neither of the three flavonoids were reported in Tanacetum parthenium L.

Convergence chromatographic determination of camphor in the essential oil of Tanacetum parthenium L.

Feverfew (Tanacetum parthenium L., Asteraceae) is a perennial medicinal plant which has been used to alleviate the symptoms of migraine, headache and rheumatoid arthritis and possesses numerous pharmacological activities. An ultra-high-performance supercritical fluid chromatographic method (UHPSFC) was developed and validated in accordance with the International Conference on Harmonization guidelines in order to determine the camphor content of the volatile oil, which was accurate, precise, robust and selective. The method was validated for specificity, accuracy (100.2%), repeatability and intermediate precision, linearity (r2 > 0.999), limit of detection (2.055 µg/mL), limit of quantification (6.228 µg/mL) and robustness. The common range of accuracy and linearity was between 0.125 and 1.000 mg/mL. Steam distillation was carried out in order to study the essential oil yield of three different T. parthenium L. samples originating from Hungarian medicinal herb collections. The camphor content of the essential oils from the aerial parts of feverfew samples from different origin was compared. Although the composition of the essential oil is well reported, a validated quantitative UHPSFC method for the determination of the constituents is presented herein for the first time.

A new ultra-high pressure liquid chromatography method for the determination of antioxidant flavonol aglycones in six Lysimachia species.

UPLC-DAD method was developed and validated for the quantitative determination of free flavonol aglycones (kaempferol, quercetin and myricetin) after acidic hydrolysis in six Lysimachia species. Quantitative analyses showed that the amounts of various flavonol aglycones were significantly different in Lysimachia vulgaris, Lysimachia nummularia, Lysimachia punctata, Lysimachia christinae, Lysimachia ciliata and Lysimachia clethroides. The L. clethroides sample was found to be the richest in kaempferol (25.77 ± 1.29 µg/mg extract) and quercetin (97.67 ± 4.61 µg/mg extract), while the L. nummularia sample contained the highest amount of myricetin (20.79 ± 1.00 µg/mg extract). The antioxidant capacity of hydrolysed extracts was evaluated using in vitro DPPH(•) (2,2-diphenyl-1-picrylhydrazyl) and ABTS(•+) [2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulphonic acid)] decolourisation tests. The observed radical scavenging capacities of the extracts showed a relationship with the measured flavonol aglycone content and composition. The acidic treatment resulted in an increased free radical scavenging activity compared to the untreated methanol extract.

Polyphenol composition and antioxidant capacity of three Lysimachia species.

The polyphenol composition and antioxidant properties of three Lysimachia species (L. nummularia L., L. vulgaris L. and L. punctata L.) and their column chromatographic fractions were investigated. The antioxidant activity of herb extracts and 54 different column chromatographic fractions was evaluated using in vitro DPPH and ABTS+ decolorization tests. The total polyphenol content was determined by spectrophotometric methods. The phenolic compounds of extracts of different Lysimachia species and their bioactive fractions were characterized by online chromatographic methods. For identification of the compounds, UV spectral data, accurate molecular mass and formula, as well as MS and fragmentation patterns given by LC-DAD-ESI/MS/MS and LC-ESI- TOF analyses were used. Quantification of the compounds was performed by LC-DAD using an external standard method. In the extracts, caffeic acid derivatives, chlorogenic acid, free flavonoid aglycones, and 11 various flavonoid glycosides were identified. Flavonoid composition of Lysimachia extracts showed significant differences. L. punctata extracts had the strongest DPPH and ABTS+ radical scavenger activity (IC50=43.3 µg/mL and 21.3 µg/mL), due to their high myricitrin and quercetin-hexoside content. Correlation between polyphenol content and radical scavenging activity of each column chromatographic fractions is also included.