Vehiculization of noscapine in large unilamellar vesicles. Study of its protective role against lipid peroxidation by electrochemical techniques

Abstract

In this contribution it is described an electrochemical procedure for the study of the protective effect of noscapine against lipid oxidation when incorporated into 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) LUVs (large unilamellar vesicles). Noscapine is a lipophilic alkaloid from poppy flowers with antioxidant activity, used as antitussive in drug formulations. It also has anti-cancer properties. Vesicles containing noscapine were immobilized onto a carbon paste electrode and exposed to the attack of free radicals according to the Fenton reaction. The rupture of LUVs is monitored by the electrochemical response of [Ru(NH3)]6Cl3 using Square Wave Voltammetry (SWV). When damage is produced, electrochemical signal increases. Results confirm the protective key role promoted by noscapine on the prevention of lipid peroxidation in vesicles, when are compared to noscapine-free DOPC vesicles. The percentage of protection is proportional to noscapine concentration, reaching a value of 75.5% for DOPC/noscapine ratio of 5:1. Furthermore, TEM images confirms that vesicles containing noscapine remain intact after 30 min exposure to OH[rad], while DOPC vesicles are destroyed in such period of time. The main finding is that noscapine can improve these vesicular media as drug delivery systems by increasing its resistance to oxidative stress.