Preparation and characterization of PLGA nanoparticles containing demethylfruticulin A from Salvia corrugata Vahl. (Lamiaceae)

Demethylfruticulin A (SCO1) is the major diterpenoid component of the exudate produced by the trichomes of Salvia corrugata leaves. The activity of this new compound against Gram-positive pathogens [1] and the apoptosis effect on mammalian cell lines [2] were investigated in previous works. The aim of this study was to evaluate the possibility of incorporating this natural product into PLGA nanoparticles in order to improve its solubility in the aqueous medium and to favour the interaction with bacterial membrane. Nanoparticles were prepared by an emulsion-diffusion-evaporation method, using Poloxamer 407 as a stabilizer. A Doehlert design for two variables was used to study the influence of the stirring time and the final volume of water on the size (D) and the zeta potential (Z) of the nanoparticles. The obtained nanoparticles showed interesting features: small size (D=207±8nm), a negative zeta potential (Z=-14.0±0.4 mV), an increasable drug loading (3% w/w) and high encapsulation efficiency (95% w/w). They also showed a good stability after redispersion in water for 30 days. These preliminary results indicate that PLGA nanoparticles can be designed as a carrier for delivery of SCO1, possibly allowing this new compound to exceed the intrinsic resistance of some bacteria to several antibiotics and to carry out its potential antitumour activity.