The scavenging effect of curcumin, piperine and their combination against physiological relevant reactive pro-oxidant species using in vitro non-cellular and cellular models
Curcumin is a natural polyphenol isolated from the rhizome of Curcuma longa with recognised therapeutic potential, namely as an anti-inflammatory, antioxidant, anticancer, and antidiabetic agent. Despite its potential biological properties, the low bioavailability of curcumin hinders its systemic effects. Recently, it was reported that the combination of curcumin with piperine increases their biological potential (e.g. antioxidant activity), by enhancing curcumin’s bioavailability. However, it is not known whether the two compounds have a direct synergic effect. In this study, we evaluated and compared the scavenging activity of physiological relevant reactive species by commercial curcumin extract, commercial piperine extract and their combination, using in vitro non-cellular and cellular systems. The obtained results revealed that the commercial curcumin extract scavenges hypochlorous acid and nitric oxide, while no scavenging effect was found against superoxide anion radical and hydrogen peroxide. The commercial curcumin extract also proved to be an effective inhibitor of neutrophils’ oxidative burst. Commercial piperine extract per se did not display any activity. Nevertheless, the obtained results for the combination of commercial curcumin extract with commercial piperine extract (1%) suggest that the commercial piperine extract potentiates the effects exerted by the commercial curcumin extract.