Essential Oil Variability in Natural Populations of Artemisia campestris (L.) and Artemisia herba-alba (Asso) and Incidence on Antiacetylcholinesterase and Antioxidant Activities.

The intraspecific variability of Artemisia herba-alba and A. campestris essential oils and the evaluation of their antioxidant and antiacetylcholinesterase activities were determined. Artemisia herba-alba essential oil was found rich in camphor (19.61%), α-thujone (19.40%), ß-thujone (9.44%), chrysanthenone (9.26%), and trans-sabinyl acetate (8.43%). The major compounds of A. campestris essential oil were germacrene D (16.38%), ß-pinene (16.33%), and limonene (9.17%). Significant variation in the essential oil composition was observed among populations of each species. The divergence between populations was attributed to the variation of some climatic factors such as altitude, annual rainfall, winter cold stress, summer precipitation, summer drought stress, evapotranspiration, and humidity. Artemisia herba-alba and A. campestris essential oils exhibited promising antioxidant and antiacetylcholinesterase activities. The level of activity varied significantly according to the species and the essential oil. The highest scavenging activity (IC50 = 0.14 mg/ml) and the uppermost capacity to prevent ß-carotene bleaching (IC50 = 0.10 mg/ml) characterized A. campestris from population 6. A. campestris population 3 possessed the uppermost ability to reduce ferric ions (450.7 µmol Fe2+ /g EO). The population 2 of A. campestris showed the strongest antiacetylcholinesterase activity (IC50 = 0.02 mg/ml). The variation of these activities between the essential oils was explained by their composition differences.

Argania spinosa var. mutica and var. apiculata: variation of fatty-acid composition, phenolic content, and antioxidant and α-amylase-inhibitory activities among varieties, organs, and development stages.

Argania spinosa includes two varieties, var. apiculata and var. mutica. These argan varieties were introduced into Tunisia in ancient times and are actually cultivated in some botanic gardens. Little is known about the chemical differentiation among these argan varieties. Hence, the aim of this study was to determine the fatty-acid composition, the total phenolic and flavonoid contents, and the antioxidant and α-amylase-inhibitory activities of leaf, seed, and pulp extracts of both argan varieties harvested during the months of January to April. The fatty-acid distribution was found to depend on the argan variety, the plant organ, and the harvest time. Significant variations in the phenolic contents were observed between the investigated varieties as well as between leaves, pulps, and seeds of each variety. As expected, phenolic compounds were found to be contributors to the antioxidant and α-amylase-inhibitory activities of both argan varieties. The chemical differentiation observed among the two argan varieties, based mainly on the fatty-acid composition, might have some chemotaxonomic value.

Total phenolic content and antioxidant activity of six wild Mentha species (Lamiaceae) from northeast of Algeria

Objective: To investigate the total phenolics, flavonoids and tannins content and the in vitro antioxidant activities of methanolic extracts of six wild Mentha species which are Mentha aquatica, Mentha arvensis, Mentha piperita, Mentha pulegium, Mentha rotun-difolia and Mentha villosa. Methods: The Folin–Ciocalteu method was used to determine the total phenols content while flavonoids were estimated according to the aluminum chloride colorimetric method. To evaluate tannins content, vanillin and HCl were added to methanolic extracts. The antioxidant potential was measured by 1,1-diphenyl-2-picrylhydrazyl radical scavenging, ferrous ion chelating and the inhibition ofβ-carotene bleaching assays. Results: The methanol extracts of Algerian mints were rich in phenolic compounds and exhibited powerful antioxidant activity ranging from 7.5μg/mL to 44.66μg/mL, which varied significantly among species. Mentha aquatica stood out with efficient antioxidant ability which was correlated to the high total phenolics content, followed by Mentha arvensis and Mentha piperita with very close values, comparing to Mentha pulegium, Mentha rotundifolia and Mentha villosa with lowest values. Conclusions: These results show that methanolic extracts of Mentha species from Algeria have a great potential of polyphenols which can be used as a natural food pre-servative and antioxidant source.