Comparative Study of the Chemical Composition and Antioxidant Activity of Aqueous and Ethanolic Extracts of Nigella (Nigella Sativa L.) And Anise (Pimpinella Anisum L.)

Abstract

Introduction: Nigella (black seed) and anise are aromatic medicinal plants that always remain the reliable source of active ingredients known for their therapeutic properties

Objectives: The study aims to determine the chemical composition ofthe primary metabolite from plant powders and to assess secondary metabolite and the antioxidant activity of two different extracts of Nigella sativa L. and Pimpinella anisumL.

Methods: The aqueous and hydroethanolic extraction of the two species was achieved using the reflux heating and maceration methods. The obtained extracts were estimated for phytochemical contents. Total phenolic content was measured by spectrophotometry according to the Folin-Ciocalteu procedure. The flavonoid content was estimated using aluminum chloride methods, the condensed tannins were determinate by the vanillin test and the Antioxidant ability was assessed by the method of DPPH free radical trapping.

Results:The both seeds are rich in organic matter and primary metabolites, the secondary metabolites and antioxidant properties differed significantly among selected species and extracts. The result revealed that the aqueous extraction by reflux heating obtained the highest extraction yield, thus, the concentration of the secondary metabolites compared with the hydroethanolic maceration for the two seeds. However, a high amount of (total phenol and flavonoid contents) was observed in the pimpinella anisum extracts compared with Nigella sativa extracts (29.74±0.51 and 37.6±0.7 µg E /mg extract). Even though, we recorded a moderate antioxidant activity in all various extracts studied. The Pimpinella anisum L. extracts exhibited the highest antioxidant capacities than the Nigella sativa L. extracts with average values (2 and 1.71 µg/ml for aqueous and hydroethanolic).

Conclusions: Our study provides basic information on chemical composition and the presence of bioactive and antioxidant capacity in the two seeds nigella and anise extracts which conferring their several biological properties.