[Evaluation of different procedures for the extraction of phenolic compounds from a medicinal plant: Verbena officinalis]

Since ancient times, plants have been the main source of bioactive molecules, such as phenolic compounds, capable of remedying various diseases. However, polyphenols' content and efficiency vary greatly as a function of several intrinsic and extrinsic factors. To optimize the procedure for the extraction of active molecules from the medicinal plant Verbena officinalis, effects of the plant origin, selected solvent, and extraction method were assessed. V. officinalis aerial parts were collected in two different regions of Tunisia (Bizerte and Ain Draham), and their bioactive molecules were extracted by maceration, decoction, and by the Soxhlet apparatus, either with water or with ethanol. Significant variability in the extracts' contents of phenolic compounds as well as their antioxidant and antimicrobial capacities were noted depending on the different studied factors. In particular, ethanol extracts were found to generally contain higher concentrations of phenolic compounds and more potent antioxidant capacities than water extracts. However, when tested against various pathogenic bacteria, water extracts were most often at least as active as ethanol extracts to inhibit bacteria growth in vitro. Finally, differences were also observed between V. officinalis samples from Bizerte compared to Ain Draham area. All of these results emphasize the need of adapting various parameters for the optimal extraction of bioactive molecules from a medicinal plant such as V. officinalis.

Protective effects of essential oil of Citrus limon against aspirin-induced toxicity in IEC-6 cells

Aspirin, one of the widely used nonsteroidal anti-inflammatory drugs, is the most highly consumed pharmaceutical product in the world. However, it has several side effects in cells. This study was designed to investigate the antioxidative activity and cytoprotective effects of essential oil of Citrus limon (EOC) extracted from leaves against aspirin-induced damages in the rat small intestine epithelial cells (IEC-6). Biochemical indicators were used to assess cytotoxicity and oxidative damages caused by aspirin treatment on IEC-6. Our results showed that the chemical characterization of EOC identified 25 compounds representing 98.19% of the total oil. The major compounds from this oil were z-citral (53.21%), neryl acetate (13.06%), geranyl acetate (10.33%), and limonene (4.23%). Aspirin induced a decrease in cell viability as well as an increase in superoxide dismutase (SOD) and catalase (CAT) activities. Contrariwise, the co-exposure of cells to aspirin and EOC alleviated every above syndrome by an increase in cell survival and decrease in SOD and CAT activities. In conclusion, the essential oil of C. limon has a potent cytoprotective effect against aspirin-induced toxicity in IEC-6 cells.