Resveratrol loaded nanoemulsions: in vitro activity on cancer cell lines of different origin

Introduction: Polyphenols like resveratrol (RV), curcumin, quercitin, catechin constitute a common groups of anti-oxidant substances present in plants and reported to have antimicrobial and anti-proliferative activities. Although natural bioactive substances hold promises for supporting more conventional therapies, inconsistent results due to the low level of aqueous solubility, stability, bioavailability are often found in the literature. Nanoemulsions (NEs) are colloidal dispersion in which main components are oil, emulsifying agents, and aqueous phases: nanometric oil droplets are dispersed in an external aqueous phase and the system can be stabilized by a suitable surfactant or surfactant mixture. The aim of our research is to study the efficiency of newly designed NEs as carriers of natural bioactive compounds, such as resveratrol, in cancer cell lines of different origin. Materials and Methods: Water based NEs from neem seed oil and Tween 20 or 80 as a surfactants were loaded with RV and characterized in terms of size and stability. The anti-proliferative activity of the synthesized polyphenol-loaded NEs on the tumoral and macrophage cell lines was tested by MTT and trypan blue assays. Cell lines used in the study were: Hep-2 (larynx derived epithelial cells), Caco-2 (colon epithelial cells), PC-3 (prostate; derived from metastatic site: bone),T-24 (from urinary bladder,carcinoma), Raji (B Lymphocytes from Burkitt’s Lymphoma), RAW 264.7 (murine macrophages). Results: Among the different preparations, RV-loaded NEs of different size with Tween 20 or with Tween 80, were chosen to evaluate anti-proliferative activity. In general, all RV-loaded NEs moreefficiently reduced cell proliferation as compared to the empty NE controls as well as to RV alone. Conclusions: NEs are widely used in pharmaceutical systems for targeted drug delivery of various therapeutic agents. Oil-in-water NEs delivery of hydrophobic phytochemicals such as resveratrol, could represent a good strategy to improve intracellular availability of these compounds and boost their potential effects on tumors and cancer cells.