Résumé:
An ethnobotanical study of medicinal plants was conducted in the National Park of El Kala
(NPEK) in the object to inventory of medicinal plants and gathers all information on the therapeutic
uses practised by local population in the studied region. The results of this study have enumerated 111
medicinal plants belonging to 56 families. The mastic tree (Pistacia lentiscus L.) is the most medicinal
plant used by local people. The most treated diseases are gastrointestinal disease (20%).
Our study is undertaken to evaluate the chemical composition of phenolic compounds and
essential oils of 11 plant extracts that belong to the four species of northeastern Algeria (Centaurea
papposa, Hypochaeris laevigata var hipponensis, Bunium crassifolium and Oenanthe fistulosa) from
the families Asteraceae and Apiaceae, The result of LC-MS / MS of the 11 extracts studied reveals the
presence of 11 to 20 phenolic compounds. The essential oil of O. fistulosa revealed a 0.2% yield with
GC-MS identification of 18 chemical compounds, consisting mainly of 42.61% of alkanes, of which
heneicosane is the main product with 34.43% of the total components identified. The GC-HS of B.
crassifolium identified 20 volatile organic compounds (99.98%), with the presence of a high content of
hydrocarbon sesquiterpenes of 87.87%, of which β-cubebene is the majority product (44.64%). All
plant extracts showed significant antioxidant activity with β-carotene, DPPH, ABTS, CAT and
CUPRAC, whereas ferrous iron chelate showed a negative result in almost all the fractions studied,
except the extract. hydro-methanol of B. crassifolium (103.28 ± 12.20 μg / ml). In a general way, all
the extracts of O. fistulosa showed the best results of antioxidant activity compared to the other plants
studied. In addition, the anti-cholinesterase activity showed only good results in four extracts
compared to the others, while, all remaining fractions are inactive. While, anti-tyrosinase activity is
inactive in all plant extracts.
Finally, these results constitute a very important source of information for the study area and
for the national medicinal flora, which could constitute a source and a database for phytochemical and
pharmacological research.
