Vaccinium myrtillus L. Leaf Waste as a Source of Biologically Potent Compounds: Optimization of Polyphenol Extractions, Chemical Profile, and Biological Properties of the Extracts.

The aims of the present research include (1) optimization of extraction from Vaccinium myrtillus leaf waste via investigation of plant material:medium ratio, extraction medium, and extraction period, employing extractions at room and high temperatures, or using ultrasound and microwaves (M, HAE, UAE, and MAE, respectively), (2) physicochemical characterization, and (3) investigation of extract biological potential. The statistical analysis revealed that optimal levels of parameters for the greatest polyphenolic yield were a proportion of 1:30 g/mL, ethyl alcohol 50% (v/v) during 2 min of microwave irradiation. By LC-MS analysis, 29 phenolic components were detected; HAE showed the highest richness of almost all determined polyphenols, while chlorogenic acid and quercetin 3-O-glucuronide were dominant. All extracts showed a high inhibition of Staphylococcus aureus growth. The effect of different parameters on extracts' antioxidant capacity depended on the used tests. The extracts also showed a stimulative influence on keratinocyte viability and anti-inflammatory activity (proven in cell-based ELISA and erythrocyte stabilization assays). The extraction procedure significantly affected the extraction yield (MAE ≥ maceration ≥ UAE ≥ HAE), whereas conductivity, density, surface tension, and viscosity varied in a narrow range. The presented research provides evidence on the optimal extraction conditions and technique, chemical composition, and antioxidant, antimicrobial, anti-inflammatory, and keratinocyte viability properties of bilberry extracts for potential applications in pharmacy and cosmetics.

Liposomal and Liposomes-Film Systems as Carriers for Bioactives from Paeonia tenuifolia L. Petals: Physicochemical Characterization and Biological Potential.

Paeonia tenuifolia L. (steppe peony) petal extract was proficiently encapsulated into liposomes and biopolymer films in the current work, both times utilizing a single-step procedure. The encapsulation efficiency, size of the particles, and index of polydispersity (PDI), as well as the ζ potential of the obtained liposomes were determined, whereas in the case of films, the test included moisture content and mechanical property assessment. Fourier transform infrared spectroscopy (FT-IR) was used to evaluate the chemical composition and existence of numerous interactions in the systems. All the obtained encapsulates were subjected to antibacterial, antifungal and antibiofilm activity testing of the pathogens associated with human skin. The results indicated that the liposomes prepared using Phospholipon had the highest encapsulation efficiency (72.04%), making them the most favorable ones in the release study as well. The biological assays also revealed that Phospholipon was the most beneficial phospholipid mixture for the preparation of liposomes, whereas the film containing these liposomes did not have the ability to inhibit pathogen growth, making the double encapsulation of P. tenuifolia L. petal extract needless. These findings may be a first step toward the potential use of steppe peony extract-loaded films and liposomes in pharmaceutical and cosmetical industries.

Rosehip Extract-Loaded Liposomes for Potential Skin Application: Physicochemical Properties of Non- and UV-Irradiated Liposomes.

In the present study, rosehip (Rosa canina L.) extract was successfully encapsulated in phospholipid liposomes using a single-step procedure named the proliposome method. Part of the obtained liposomes was subjected to UV irradiation and non-treated (native) and UV-irradiated liposomes were further characterized in terms of encapsulation efficiency, chemical composition (HPLC analysis), antioxidant capacity, particle size, PDI, zeta potential, conductivity, mobility, and antioxidant capacity. Raman spectroscopy as well as DSC analysis were applied to evaluate the influence of UV irradiation on the physicochemical properties of liposomes. The encapsulation efficiency of extract-loaded liposomes was higher than 90%; the average size was 251.5 nm; the zeta potential was -22.4 mV; and the conductivity was found to be 0.007 mS/cm. UV irradiation did not cause a change in the mentioned parameters. In addition, irradiation did not affect the antioxidant potential of the liposome-extract system. Raman spectroscopy indicated that the extract was completely covered by the lipid membrane during liposome entrapment, and the peroxidation process was minimized by the presence of rosehip extract in liposomes. These results may guide the potential application of rosehip extract-loaded liposomes in the food, pharmaceutical, or cosmetic industries, particularly when liposomal sterilization is needed.

From Aloe vera Leaf Waste to the Extracts with Biological Potential: Optimization of the Extractions, Physicochemical Characterization, and Biological Activities.

In the study, the optimization of the extraction from Aloe vera leaf waste was performed via varying solid-to-solvent ratio, solvent type, extraction time, and technique (maceration, heat-, ultrasound-, and microwave-assisted extractions-HAE, UAE, and MAE, respectively). The optimal extraction conditions for achieving the highest polyphenol content are a 1:30 ratio, 70% ethanol, and 30 min of HAE. Total flavonoid and protein contents were significantly higher in the extract from MAE, while total condensed tannin content was the highest in HAE. LC-MS analysis quantified 13 anthraquinone and chromone compounds. The variations in the FT-IR spectra of the extracts obtained by different extraction procedures are minor. The influence of extraction conditions on the antioxidant ability of the extracts depended on applied antioxidant assays. The extracts possessed medium inhibition properties against Staphylococcus aureus and weak inhibitory activity against Enterococcus feacalis. The extracts had stimulative effect on HaCaT cell viability. Regarding the extraction yield, there was a significant difference between the used extraction techniques (MAE > HAE > maceration and UAE). The presented study is an initial step in the production of polyphenol-rich extracts from A. vera leaf waste aimed to be used for the potential preparation of pharmaceutical and cosmetic formulations for the skin.

Liposomal Bilayer as a Carrier of Rosa canina L. Seed Oil: Physicochemical Characterization, Stability, and Biological Potential.

Rosa canina L. seeds are rich in bioactive components that can add value to the various formulations. The focus of the study was the development of liposomes for R. canina oil to protect its sensitive compounds and prolong their shelf-life. Oil-loaded liposomes were characterized via the determination of the particle size, polydispersity index (PDI), zeta potential, conductivity, mobility, density, surface tension, viscosity, and stability. Raman and FT-IR spectroscopy were employed to investigate the chemical composition of the non-treated and UV-treated samples, and the presence of different interactions. Antioxidant and antimicrobial activities were examined as well. The liposome size was 970.4 ± 37.4 nm, the PDI 0.438 ± 0.038, the zeta potential -32.9 ± 0.8 mV, the conductivity 0.068 ± 0.002 mS/cm, the mobility -2.58 ± 0.06 µmcm/Vs, the density 0.974 ± 0.004 g/cm3, the surface tension 17.2 ± 1.4 mN/m, and the viscosity 13.5 ± 0.2 mPa•s. The Raman and FT-IR spectra showed the presence of lipids, fatty acids, polyphenols, and carotenoids. It was approved that the oil compounds were distributed inside the phospholipid bilayer and were combined with the membrane interface of the bilayer. The UV irradiation did not cause any chemical changes. However, neither the pure oil nor the oil-loaded liposomes showed any antimicrobial potential, while the antioxidant capacity of the oil-loaded liposomes was significantly low. The sizes of the liposomes did not change significantly during 60 days of storage. Due to the proven stability of the oil-loaded liposomes, as well as the liposome's ability to protect the sensitive oil compounds, their potential application in the pharmaceutical and cosmetic formulations could be investigated with a focus on the skin regeneration effects.

Freeze vs. Spray Drying for Dry Wild Thyme (Thymus serpyllum L.) Extract Formulations: The Impact of Gelatin as a Coating Material.

Freeze drying was compared with spray drying regarding feasibility to process wild thyme drugs in order to obtain dry formulations at laboratory scale starting from liquid extracts produced by different extraction methods: maceration and heat-, ultrasound-, and microwave-assisted extractions. Higher total powder yield (based on the dry weight prior to extraction) was achieved by freeze than spray drying and lower loss of total polyphenol content (TPC) and total flavonoid content (TFC) due to the drying process. Gelatin as a coating agent (5% w/w) provided better TPC recovery by 70% in case of lyophilization and higher total powder yield in case of spray drying by diminishing material deposition on the wall of the drying chamber. The resulting gelatin-free and gelatin-containing powders carried polyphenols in amount ~190 and 53-75 mg gallic acid equivalents GAE/g of powder, respectively. Microwave-assisted extract formulation was distinguished from the others by a higher content of polyphenols, proteins and sugars, higher bulk density and lower solubility. The type of the drying process mainly affected the position of the gelatin-derived -OH and amide bands in FTIR spectra. Spray-dried formulations compared to freeze-dried expressed higher thermal stability as confirmed by differential scanning calorimetry analysis and a higher diffusion coefficient; the last feature can be associated with the lower specific surface area of irregularly shaped freeze-dried particles (151-223 µm) compared to small microspheres (~8 µm) in spray-dried powder.

Effect of gentisic acid on the structural-functional properties of liposomes incorporating ß-sitosterol.

Multifunctional liposomes incorporating ß-sitosterol were developed for delivery of gentisic acid (GA). The interactions of both compounds with phospholipid bilayer were interpreted viaeffects of different ß-sitosterol content (0, 20 and 50 mol %) and different gentisic acid to lipid ratio (nGA/nlip from 10-5 to 1) on membrane fluidity and thermotropic properties. Multilamellar vesicles of phosphatidylcholines (with size range between 1350 and 1900 nm) effectively encapsulated GA (54%) when nGA/nlip was higher than 0.01. Suppression of lipid peroxidation was directly related to concentration of GA. The resistance to diffusion of gentisic acid from liposomes increased for ˜50% in samples incorporating 50 mol % ß-sitosterol compared to sterol-free liposomes. Finally, simulated in vitro gastrointestinal conditions showed that the release was mainly affected by low pH of simulated gastric fluid and the presence of cholates in simulated intestinal fluid, rather than by enzymes activity.