The aim of our study was the detailed polyphenol profiling of Juglans nigra and the characterization of the membrane permeability and antiproliferative properties of its main phenolics. A total of 161 compounds were tentatively identified in J. nigra bark, leaf, and pericarp extracts by ultrahigh-performance liquid chromatography–high-resolution tandem mass spectrometry (UHPLC-HR-MS/MS). Eight compounds including myricetin-3-O-rhamnoside (86), quercetin-3-O-rhamnoside (106), quercetin-3-O-xyloside (74), juglone (141), 1,2,3,4-tetrahydro-7,8-dihydroxy-4-oxonaphthalen-1-yl-6-O-galloyl-glucoside (92), ellagic acid (143), gallic acid (14), and ethyl gallate (58) were isolated from J. nigra pericarp. The in vitro antiproliferative activity of the isolated compounds was investigated against three human cancer cell lines, confirming that juglone (141) inhibits cell proliferation in all of them, and has similar activity as the clinical standards. The permeability of the isolated compounds across biological membranes was evaluated by the parallel artificial membrane permeability assay (PAMPA). Both juglone (141) and ethyl-gallate (58) showed positive results in the blood–brain-barrier-specific PAMPA-BBB study. Juglone (141) also possesses logPe values which indicates that it may be able to cross both the GI and BBB membranes via passive diffusion.

Mitragynine is an “atypic opioid” analgesic with an alternative mechanism of action and a favorable side-effect profile. Our aim was to optimize the alkaloid extraction procedure from kratom leaves and to determine and isolate the most relevant compounds capable of penetrating the central nervous system. The PAMPA-BBB study revealed that mitragynine and its coalkaloids, speciociliatine, speciogynine, and paynantheine, possess excellent in vitro BBB permeability. An optimized sequence of CPC, flash chromatography, and preparative HPLC methods was used to isolate the four identified BBB+ alkaloids. To improve the bioavailability of the isolated alkaloids, their cyclodextrin (CD) complexation behavior was investigated via affinity capillary electrophoresis using almost 40 CD derivatives. The apparent alkaloid–CD complex stability constants were determined and compared, and the most relevant CDs phase-solubility studies were also performed. Both the neutral and negatively charged derivatives were able to form complexes with all four kratom alkaloids. It was found that cavity size, substituent type, and degree of substitution also influenced complex formation. The negatively charged Sugammadex, Subetadex, and the sufoalkylated-beta-CD analogs were able to form the most stable complexes, exceeding 1000 M⁻¹. These results serve as a good basis for further solubility and stability enhancement studies of kratom alkaloids.

In this study, based on ethnobotanical data recorded in Transylvania, the polyphenolic compounds and the permeability of the aerial part’s extract of Tanacetum balsamita were investigated. Ultrahigh-performance liquid chromatography-tandem mass spectrometry was applied for the analysis of the extracts. Parallel artificial membrane permeability assay (PAMPA) for the gastrointestinal tract and the blood–brain barrier was conducted. In the ethanolic and aqueous extracts of the species traditionally used for wound, furuncle, and liver disorders, 92 polyphenols were characterized (e.g., flavonoid, hydroxycinnamic acid, catechin, dihydroxybenzoyl, lignan derivatives, and a monoterpene) including 54 compounds identified for the first time in the plant. In the PAMPA tests, eight components were shown to be capable of passive diffusion across the studied membranes. These include apigenin and seven methoxylated flavonoid derivatives. Based on these results, methoxylated flavonoids might promote the pharmacological potential of T. balsamita to be applied in the enhancement of novel remedies.

The formation of biofilms by Salmonella is of considerable interest to the food production and medical industries. This study investigated the effects of a carrier medium (Luria–Bertani, Mueller–Hinton II, Brain Heart Infusion or chicken meat juice), temperature (14 °C, 23 °C or 37 °C) and surface type (adhesive, non-adhesive or suspension plate) on biofilm formation in 16 different Salmonella isolates belonging to the serovars S. Enteritidis (five isolates), S. Infantis (five isolates) and S. Typhimurium (six isolates). Chicken meat juice was found to have a moderate yet balanced supportive effect, while Mueller–Hinton II (MH-II) medium drastically supported biofilm formation at low temperatures, albeit with significant variation among the isolates. Temperature and medium also affected the antibacterial, biofilm inhibitory and destructive effects of essential oils. At 14 °C and 23 °C, 35% of essential oils exhibited antibacterial activity against Salmonella serovars at a concentration of 0.1%, as determined by the drop plate method. Ajowan, thyme, orange, clove and oregano EOs completely inhibited biofilm formation at a concentration of 0.1%. More than half of the 60 essential oils tested reduced the optical density of mature biofilms (OD: 0.15–0.36) to below 0.05; ajowan, lime, palmarosa, thyme, oregano and clove were the most effective, exhibiting antibacterial, biofilm inhibitory and biofilm destructive effects on all of the investigated Salmonella isolates.

Background/Objectives: Otitis externa is a common infection in dogs. The most important aetiological agent is Pseudomonas aeruginosa, and an increasing number of cases are proving difficult to treat due to this pathogen’s antibiotic resistance. Methods: We determined the composition of cinnamon (Cinnamomum verum J. Presl), petitgrain (Citrus x aurantium L.), rose geranium (Pelargonium graveolens L’Hér), and thyme (Thymus vulgaris L.) essential oils (EOs) using gas chromatography-mass spectrometry (GC-MS). We then used the bioautographic method to identify antibacterial components. Two-and-a-half- and five percent concentrations of the essential oils were added to four different ointment bases, such as hydrogelum methylcellulose, unguentum oleosum, unguentum stearini, and vaselinum cholesterinatum, and the in vitro antibacterial effects were tested on lawns of six P. aeruginosa isolates using the antibiotic-containing product Marbogen complex as a control. The keepability of the methylcellulose-based ointments was monitored at 4 °C and 27 °C for 12 months, with efficacy losses evaluated monthly. Results: Hydrogel methylcellulose (HM) was the most effective at supporting the therapeutic efficacy of each oil, reducing the bacterial count on the exposed area by 99.999%, 100%, 100%, and 100% in the case of 5% cinnamon, petitgrain, rose geranium, and thyme, respectively. EO-based HM ointments take effect within 15 min, with only slight improvement after 30, 45, and 60 min. Cinnamon was the most effective when applied in the HM matrix. In contrast to the HM and US gel matrices, the antibacterial supportive effects of Unguentum oleosum and Vazelinum cholestrinatum were drastically lower. The antimicrobial efficacy of essential oils in hydrogel formulation varied significantly depending on the type of oil (p < 0.001), its concentration (p < 0.001), the exposure time (p < 0.001), and the P. aeruginosa isolate used (p < 0.001). Cinnamon oil demonstrated the highest efficacy, achieving near-complete bacterial elimination across all isolates within 15 min. There was no significant difference between the 2.5% and 5% concentrations (EMM: 0.016 vs. 0.004; p = 0.904). Conclusions: Our results demonstrate that essential oil-based products can be effective alternatives to antibiotics when used in conjunction with an effective gel matrix.