Antioxidant, Anti-Inflammatory and Cytotoxicity Properties of Centaurea africanaLamk var. [Bonnet] M

Background: In Algerian traditional medicine, Centaurea species are well known in traditherapy. The Centaurea africana has been used in folk medicine for the treatment of several inflammatory disorders.

Objective: This study aims to examine the antioxidant, anti-inflammatory and anti-proliferative potential of both nButanol (BECA) and ethyl acetate (EAECA) extracts of Centaurea africana.

Methods: The phytochemical analysis of both BECA and EAECA were explored and the antioxidant activities were investigated by measuring the DPPH° scavenging effect, the reducing power and the inhibition of lipid peroxidation (LPO) induced by Fe2+/ascorbic acid system. The anti-inflammatory properties were determined by measuring the NO° scavenging effect and by using carrageenan-induced rat paw oedema. The antiproliferative activity was studied on HT29 (human colorectal adenocarcinoma), OV2008 (human ovarian cancer) and C6 (Rattus norvegicus brain glioma) cell lines using the Sulforhodamine B assay.

Results: The total polyphenol contents (TPC) of EAECA and BECA are recorded at 125.24±10.14 and 53.03±2.50 mgGAE/g extract, respectively. Both extracts revealed the antioxidant activity in a concentration-dependent manner; this effect is more pronounced with EAECA. The BECA exhibited a higher anti-inflammatory activity.This antiinflammatory activity was reflected in a reduction of swelling of carrageenan-evoked edemas (48.45 %), inhibition of nitric oxide (84.7 %), effective decrease in myeloperoxidase activity (58.82 %) and malondialdehyde level (65.58 %). The cytotoxic effect of BECA was found to be more pronounced against C6 cell lines (IC50 value: 131.93 µg/mL) while the cytotoxic activity of EAECA was more effective against HT29 and OV2008 cell lines.

Conclusion: The obtained results indicated that EAECA exhibited a high antioxidant activity while BECA has a significant anti-inflammatory activity. Both extracts showed cytotoxic effects against cancer cell lines at certain concentrations in a cell-specific manner.

Keywords: Anti-inflammatory activity; Antioxidant activity; Antiproliferativeactivity; Centaurea africana; Flavonoids; Oxidative stress.; Phenolic content.