Abstract:
Since ancient times, medicinal plants gained significant interest due to their numerous therapeutic and cosmetic properties. Algeria has a rich plant biodiversity, representing a promising opportunity for the valorization of natural resources, particularly through the extraction of essential and vegetable oils.
This study explored the methanolic extraction of the local plant Origanum majorana (marjoram) using the Soxhlet method. A design of experiments was implemented to assess the influence of three experimental variables—particle size, solvent volume, and plant material mass—in order to optimize the process using response surface methodology. Additionally, a comparison was made with dynamic maceration to evaluate both the extraction yield and the biological activities, especially antioxidant and antidiabetic properties.
The results demonstrated the superiority of Soxhlet extraction, with yields ranging from 11.82% to 30.46%, compared to a maximum yield of 23.99% obtained through maceration. The obtained data revealed a moderate to good antioxidant activity, with values of 72.61 μg TE/mL and 114.41 μg TE/mL in DPPH and ABTS radical scavenging assays, respectively, based on the Trolox equivalent method. Moreover, the extract exhibited significant enzymatic (antidiabetic) activity, comparable to that of the reference drug acarbose. These findings highlight the impact of the extraction method on both the quantitative yield and the qualitative bioactivity of plant extracts