Antioxidant, antimicrobial, anti-inflammatory and anticancer activities of Carthamus tinctorius flowers

Carthamus tinctorius L. (Asteraceae) is an aromatic and folkloric medicinal plant thanks to its multiple virtues. However, few scientific studies investigated its biological activities. For that, this study aimed to investigate antioxidant, antibacterial, anti-inflammatory and anticancer activities of methanolic flower extracts of Carthamus tinctorius in order to validate some of its ethnopharmacological claims. Antioxidant activity was assessed via the ABTS radical scavenging and β-carotene inhibition tests, the antibacterial capacity were tested against human pathogen strains. Whereas, anti-inflammatory activity were estimated using inhibition NO release in LPS-stimulated Raw 264.7 macrophages, in comparison with N(G)-nitro-L-arginine methyl ester (L-NAME) which used as a positive control. In addition, anticancer activity was evaluated against Human lung carcinoma (A-549) and Human colorectal adenocarcinoma (DLD-1) cell lines. Main results showed that the flowers exhibit interesting biological activities. Indeed, flower extract displayed an inhibition percentage against ABTS equal to 30% and over 40% for the β-carotene inhibition assay. Antimicrobial activities were important especially against M. luteus strains (100% inhibition). Concerning anti-inflammatory activity, methanolic extract was able to inhibit NO release by 80% at 160µg/ml. Furthermore, C. tinctorius extract showed an anticancer activity against tumor cell lines DLD-1 with an IC₅₀ value of 72±9µg/ml. These findings demonstrate the interesting potentiality of Carthamus tinctorius flowers as valuable source of antioxidant compounds which exhibit novel biological activities as antibacterial, anti-inflammatory and anticancer capacities.

Keywords: Carthamus tinctorius, antioxidant capacity, antibacterial activity, anti-inflammatory activity, anticancer ability