Phytochemical screening, antifungal and antioxidant activities of three medicinal plants from Algerian steppe and Sahara (preliminary screening studies)

Abstract

The contamination of foodstuffs by fungi and their mycotoxins, emergence of resistance to fungicides and unwanted side effects of pesticides on human and animal health currently present a challenge for researchers to create and innovate new and better solutions to fight against mycotoxigenic fungi with less harmful effects on the consumer and the environment. In the context of the valorization of natural products, this study aimed, first, to determine the phytochemical composition of methanolic and aqueous extracts of Pistacia lentiscus, Artemisia herba-alba and Citrullus colocynthis and, second, to evaluate the antifungal potential and antioxidant capacity of these extracts. The extraction of crude active compounds from selected plant species was carried out by methanolic and aqueous maceration. Antifungal activity against five fungal strains (Aspergillus flavus, Aspergillus parasiticus, Fusarium graminirium, Aspergillus ochraceus and Penicillium expansum) was evaluated by the dilution method in solid medium. Analysis of antioxidant activity was carried out by three tests, namely, the inhibition of ABTS·+radical cation, trapping of DPPH· radical and reduction of Fe2+ (FRAP). The results show that the crude extracts were rich in bioactive compounds and that the crude methanolic and aqueous extracts of A. herba-alba were the most active against the tested fungal strains and had a percentage of inhibition exceeding 8%. Regarding antioxidant activity, all the extracts exhibited remarkable antioxidant potential in the tests used. The methanolic extract of A. herba-alba had the highest iron-reducing capacity. The results show that the studied medicinal plants could be a good alternative for protecting foodstuffs against toxigenic fungi.