Extraction et activités biologiques des huiles essentielles de Pituranthos chloranthus Coss. & Dur. (Apiaceae)

Abstract

Much of the currentre search interest is in studying antioxidant and antimicrobial molecules of natural originin . Our work foucuses on the study of the effect of the state and the drying technique of the plant Pituranthos chloranthus on the biological properties of essential oils obtained by hydrodistillation. The study focuses on three points including the yield of essential oils, antioxidant power (reducing power test, DPPH) and antimicrobial power. The yields obtained show that drying in the shade represents the best drying technique for this plant; an oil yield of 1.082% is noted, followed by the fresh plant 0.88%. Sun drying negatively affects the yield of essential oils, a yield of about 0.46% is estimated. The antimicrobial activity is demonstrated by the disk diffusion method. The essential oil of Pituranthos chloranthus (fresh, dried in the shade, dried in the sun) proved to be inactive on the bacterials train tested Pseudomonas aeruginosa, and the bacterials train Escherichia Coli (10mm) and Staphylococcus aureus (11mm) which have a low sensitivity. Indeed, the diameters of the inhibition zones vary between 10 and 11 mm. It is also noted that all the microbials trains tested are sensitive to antibiotics (Ampicillin) with the exception of Pseudomonas aeruginosa. The antioxidant properties are estimated via the reducing power test, DPPH. At the concentration of 0.5 μg / ml, the inhibition percentages (to neutralize the DPPH radical) are equal to 17.66 % for essential oils extracted from a fresh plant and almost the same for the extracted HEs. from the plant dried in the shade 17.5%. On the other hand, the HE extracted from the plant dried in the sun, the percentage of inhibition (to neutralize the radical DPPH) is equal to 16.52%. The IC 50 concentration corresponds to each extract to better characterize the antioxidant power is, for the fresh plant and dried in the shade is equal to 13.11 μg / ml and 13,25 μg / ml, and the IC50

value of the extract of the sun-dried plant isequals 14, 17μg / ml.