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.
