Supercritical Fluid Extraction of Celery and Parsley Fruit-Chemical Composition and Antibacterial Activity.

Supercritical fluid extraction as an environmentally friendly technology was applied to isolate biologically active extracts from celery and parsley fruits for potential applications in the food industry. The extractions were performed under mild temperature conditions of 39.85 °C and at pressures of 10 and 30 MPa. The extracts were analyzed regarding their chemical composition, antibacterial activity, and cytotoxic effect. Sedanolide was the dominant component of the celery fruit extracts, comprising more than 70% of the obtained fraction, while the content of apiole in the parsley fruit SC CO2 extracts exceeded 85%. The celery fruit extracts showed strong and moderately strong antibacterial activity against tested Staphylococcus aureus, Bacillus (B.) cereus, B. subtilis, B. circulans, Listeria (L.) greyi, L. seeligeri and L. welshimeri, with minimal inhibitory concentration (MIC) values between 160 and 640 µg/mL, and weak activity against the selected Salmonella isolates with a MIC of 2560 µg/mL. The parsley extract obtained at 10 MPa showed strong and moderately strong antibacterial effects against Bacillus strains with obtained MICs of 160-640 µg/mL, and weak activity against Staphylococcus, Listeria, and Salmonella with a MIC of 2560 µg/mL. Cytotoxicity investigation showed that the extracts with proven antibacterial activity had no cytotoxic effect on rabbit kidney cells at concentrations of up to 640 µg/mL.

Usnea barbata CO2-supercritical extract in alkyl polyglucoside-based emulsion system: contribution of Confocal Raman imaging to the formulation development of a natural product.

Topical treatment of skin infections is often limited by drawbacks related to both antimicrobial agents and their vehicles. In addition, considering the growing promotion of natural therapeutic products, our objective was to develop and evaluate naturally-based emulsion system, as prospective topical formulation for skin infections-treatment. Therefore, alkyl polyglucoside surfactants were used for stabilization of a vehicle serving as potential carrier for supercritical CO2-extract of Usnea barbata, lichen with well-documented antimicrobial activity, incorporated using two protocols and three concentrations. Comprehensive physicochemical characterization suggested possible involvement of extract's particles in stabilization of the investigated system. Raman spectral imaging served as the key method in disclosing extract's particles potential to participate in the microstructure of the tested emulsion system via three mechanisms: (1) particle-particle aggregation, (2) adsorption at the oil-water interface and (3) hydrophobic particle-surfactant interactions. Stated extract-vehicle interaction proved to be correlated to the preparation procedure and extract concentration on one hand and to affect the physicochemical and biopharmaceutical features of investigated system, on the other hand. Thereafter, formulation with the best preliminary stability and liberation profile was selected for further efficiency and in vivo skin irritation potential evaluation, implying pertinent in vitro antimicrobial activity against G+ bacteria and overall satisfying preliminary safety profile.

Free-radical scavenging activity and antibacterial impact of Greek oregano isolates obtained by SFE.

The antioxidant and antibacterial properties of Greek oregano extracts obtained by fractional supercritical fluid extraction (SFE) with carbon dioxide were investigated and compared with the properties of essential oil obtained by hydrodistillation. According to DPPH, hydroxyl radical and superoxide anion radical scavenging activity assays, the supercritical extracts expressed stronger antioxidant activity comparing to the essential oil. The most effective was the supercritical extract obtained by fractional extraction at 30 MPa and 100°C after the volatile fraction had been extracted at lower pressure. At the same time this extract showed strong antibacterial activity against staphylococci, including MRSA strain, but did not affect Escherichia coli of normal intestinal flora. The essential oil obtained by hydrodistillation showed stronger antibacterial activity against E. coli, Salmonella and Klebsiella pneumoniae, comparing to the supercritical extracts but at the same affected the normal gut flora.

Estimation of dermatological application of creams with St. John's Wort oil extracts.

Oleum Hyperici, the oil extract of St. John's Wort (SJW), is one of the oldest folk remedies, traditionally used in the topical treatment of wounds, bruises, ulcers, cuts, burns, hemorrhoids and also as an antiseptic. Considering the advantageous characteristics of emulsion applications, in the present study we have formulated three O/W creams containing 15% (w/v) of SJW oil extract as an active ingredient. The aim was to estimate dermatological application of the prepared creams for the abovementioned indications. The extracts were prepared according to the prescriptions from traditional medicine, however with different vegetable oils used as an extractant, namely: Olive, palm and sunflower oil. The investigated O/W creams demonstrated significant antiinflammatory effects in an in vivo double-blind randomized study, using a sodium lauryl sulphate test. Both skin parameters assessed in the study (electrical capacitance and erythema index), were restored to the baseline value after a seven-day treatment with the tested creams. Almost all investigated SJW oil extracts and corresponding creams displayed the same antimicrobial activity against the most of the investigated microorganisms with obtained minimal inhibitory concentrations values of 1,280 µg/mL, 2,560 µg/mL or >2,560 µg/mL.