Understanding the corrosion inhibition effectiveness using Senecio anteuphorbium L. fraction for steel in acidic media

•Different families of Senecio anteuphorbium L. are used as an eco-friendly corrosion inhibitor for S300 steel in 1M HCl using PDP and EIS techniques.•The essential oil and the alkaloid fractions reveal a good corrosion inhibition efficiency.•The excellent performance capacity of these compounds is due to the formation of the barrier film onto the steel surface.•Characterization of the steel surface shows the formation of a protective layer with hydrophobic character.