A Nanotechnological Approach to Exploit and Enhance the Bioactivity of an Extract from Onopordum illyricum L. Leaves

Abstract

Plant-derived products have been used for preventive and curative purposes from the ancient era to the present day. Several studies have demonstrated the efficacy of either multicomponent-based extracts, enriched fractions, or isolated bioactives. However, they often display low solubility and bioavailability, chemical instability, poor absorption, and even toxicity, which restrict application in therapy. The use of drug delivery systems, especially nanocarriers, can overcome these physicochemical and pharmacokinetic limitations. In this study, an extract from Onopordum illyricum leaves was produced by maceration in 80% ethanol, characterized by liquid chromatography coupled to mass spectrometry, and formulated in phospholipid vesicles with the aim of exploiting and possibly enhancing its bioactivity for skin delivery. The results showed that phenolic compounds were abundantly present in the extract, especially hydroxycinnamic acid and flavonol derivatives. The extract-loaded vesicles showed small size (<100 nm), high entrapment efficiency (even >90% for most phenolic compounds), and good long-term stability. Moreover, the extract-loaded vesicles exhibited remarkable antioxidant activity, as demonstrated by colorimetric assays and by enhanced reduction of intracellular reactive oxygen species (ROS) levels in cultured skin cells. Hence, our findings support the key role of nanotechnological approaches to promote the potential of plant extracts and strengthen their application in therapy.

Promising inhibition of diabetes-related enzymes and antioxidant properties of Ptilostemon casabonae leaves extract

“…All compounds, except for coumaroylquinic acid ( 2 ), isorhamnetin- O -glucoside-rhamnoside ( 10 ), quercetin O -hexoside ( 14 ), di- O -p-coumaroyl quinic acid ( 18 ), and succinyl di-p-coumaroylquinic acid isomers ( 20 and 21 ) have been previously found in this species 6 . The phytochemical profile of P. casabonae was also found to be similar to that described for other wild thistles 14 , 25 , 26 . The most representative specialised metabolites belong to the class of hydroxycinnamates, with succinyl-dicaffeoylquinic acid ( 12 ) and 1,5-dicaffeoylquinic acid ( 9 ) amounting to 99.82 ± 3.23 and 98.64 ± 1.50 mg/g of DE, respectively.…”

“…Ferric reducing antioxidant power assay (FRAP) was conducted as previously described 14 , with slight modifications. An amount of 10 µL of the extract was mixed with 2 ml of the TPTZ–ferric solution and than incubated for 4 min at room temperature in the dark.…”

“…Caco-2 cells (American Type Culture Collection ATCC, Manassas, VA, USA) were cultured at 37 °C in a humidified atmosphere with 5% CO 2 in Dulbecco’s Modified Eagle Medium (DMEM) containing 10% foetal bovine serum (FBS; Gibco, NY, USA), and 1% penicillin/streptomycin. As previously described 14 , cell viability was measured by using 3–(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) reagent after seeding 104 cells per well into a 96-well plate and incubating for 24 h with different concentrations of P. casabonae extract (0–100 μg/mL).…”

“…The fluorescence intensity of DCF was immediately measured with a fluorescent plate reader at the excitation wavelength of 485 nm and emission wavelength of 530 nm. Readings were taken every 5 min for 60 min 14 .…”

A Nano-Based Approach to Deliver Satureja thymbra Essential Oil to the Skin: Formulation and Characterization

“…These parameters were analyzed over 90 days to determine the storage stability (at 4 and 25 °C) of the vesicles. The S. thymbra liposomes and Et-PEVs were dialyzed against water to remove non-incorporated essential oil components [ 28 ]. Both non-dialyzed and dialyzed samples were diluted with methanol (1:50 v / v ) and analyzed by HPLC–DAD (see Section 4.4 ).…”