ABSTRACT
This work aimed to evaluate the effect of different extraction solvents on the polyphenolic content, antioxidant and antibacterial activity of Pistacia lentiscus stems. The results obtained show that the extraction yield depends strongly on the polarity of the solvent and the extraction method. The ethanolic extract had the highest yield in both extraction methods investigated, namely Soxhlet (R = 9.89%) and cold maceration (R = 9.20%). The free radical scavenging activity of the extracts showed that the ethanolic extract had the highest antioxidant activity in both extraction methods with an IC50 = 0.023 mg/mL (cold maceration) and an IC50 = 0.034 mg/ml (Soxhlet). The HPLC analysis of the extracts indicates that gallic acid and catechin are the major phenolic compounds. The FTIR results showed that the shift of the stretching is responsible for O-H and C-H bonding. The GC-MS analysis revealed the presence of stearic acid and palmitic acid methyl ester as main compounds. The bacterial analysis of the extracts showed that the aqueous extract represents the most active one against Staphylococcus aureus and Pseudomonas aeruginosa; on the other hand, no antifungal activity was appreciated. Overall, the results indicate that the investigated extracts might be considered valuable sources of bioactive compounds.
The study provides an overview of the yield, phenolic composition, and biological activities of Pistacia lentiscus stems. No information is available on research conducted to compare extraction techniques and solvent effects on the recovery of phenolic components, flavonoids, and antioxidant activity; only one paper has reported so far the phenolic characterization of Pistacia lentiscus stems. The data can be useful for future in vivo studies to support their antioxidant and antimicrobial properties. In addition, the sample preparation technique used in this study can provide a basis for the extraction of similar phenolic compounds in other parts of the plant.
ABSTRACT
Throughout history, essential oils have been employed for their pleasing scents and potential therapeutic benefits. These oils have shown promise in various areas, including aromatherapy, personal care products, natural remedies, and even as alternatives to traditional cleaning agents or pest control solutions. The study aimed to explore the chemical makeup, antioxidant, and antibacterial properties of Origanum compactum Benth., Salvia officinalis L., and Syzygium aromaticum (L.) Merr. et Perry. Initially, the composition of the three essential oils, O. compactum (HO), S. officinalis (HS), and S. aromaticum (HC) was analyzed using GC-MS technology, revealing significant differences in the identified compounds. α-thujone emerged as the predominant volatile component in the oils, making up 78.04% of the composition, followed by eugenol, which constituted 72.66% and 11.22% of the HC and HO oils, respectively. To gauge antioxidant capabilities, tests involving DPPH scavenging capacity and total antioxidant capacity were conducted. Antioxidant activity was determined through the phosphomolybdate test and the DPPH⢠radical scavenging activity, with the HO essential oil displaying significant scavenging capacity (IC50 of 0.12 ± 0.02 mg/mL), similar to ascorbic acid (IC50 of 0.26 ± 0.24 mg/mL). Similarly, the TAC assay for HO oil revealed an IC50 of 1086.81 ± 0.32 µM AAE/mg. Additionally, the oils' effectiveness against four bacterial strains, namely Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Listeria monocytogenes, and five fungi, Geotrichum candidum, Aspergillus niger, Saccharomyces cerevisiae, Candida glabrata, and Candida albicans, was tested in vitro. The examined essential oils generally exhibited limited antimicrobial effects, with the exception of HC oil, which demonstrated an exceptionally impressive level of antifungal activity. In order to clarify the antioxidant, antibacterial, and antifungal effects of the identified plant compounds, we employed computational methods, specifically molecular docking. This technique involved studying the interactions between these compounds and established protein targets associated with antioxidant, antibacterial, and antifungal activities.
ABSTRACT
This paper presents a novel cheminformatics approach for the design and synthesis of hydroxyapatite/collagen nanocomposites, which have potential biomedical applications in tissue engineering, drug delivery, and orthopedic and dental implants. The nanocomposites are synthesized by the co-precipitation method with different ratios of hydroxyapatite and collagen. Their mechanical, biological, and degradation properties are analyzed using various experimental and computational techniques. Attenuated total reflection-Fourier-transform infrared spectroscopy, thermogravimetric analysis, and X-ray diffraction unveil the low crystallinity and nanoscale particle size of hydroxyapatite (22.62 nm) and hydroxyapatite/collagen composites (14.81 nm). These findings are substantiated by scanning electron microscopy with energy-dispersive X-ray spectroscopy, confirming the Ca/P ratio between 1.65 and 1.53 and attesting to the formation of non-stoichiometric apatites in all samples, further validated by molecular simulation. The antimicrobial activity of the nanocomposites is evaluated in vitro against several bacterial and fungal strains, demonstrating their medical potential. Additionally, in silico analyses are performed to predict the absorption, distribution, metabolism, and excretion properties and the bioavailability of the collagen samples. This study paves the way for the development of novel biomaterials using chemoinformatics tools and methods, facilitating the optimization of design and synthesis parameters, as well as the prediction of biological outcomes. Future research directions should encompass the investigation of in vivo biocompatibility and bioactivity of the nanocomposites, while exploring further applications and functionalities of these innovative materials.
