International Journal of Nanomedicine (Dec 2022)
Neem Oil or Almond Oil Nanoemulsions for Vitamin E Delivery: From Structural Evaluation to in vivo Assessment of Antioxidant and Anti-Inflammatory Activity
Abstract
Federica Rinaldi,1,* Patrizia Nadia Hanieh,1,* Linda Maurizi,2 Catia Longhi,2 Daniela Uccelletti,3 Emily Schifano,3 Elena Del Favero,4 Laura Cantù4 ,† Caterina Ricci,4 Maria Grazia Ammendolia,5 Donatella Paolino,6 Francesca Froiio,6 Carlotta Marianecci,1 Maria Carafa1 1Dipartimento di Chimica e Tecnologie del Farmaco, Sapienza Università di Roma, Rome, Italy; 2Dipartimento di Sanità pubblica e Malattie infettive, Sapienza Università di Roma, Rome, Italy; 3Dipartimento di Biologia e Biotecnologie Charles Darwin, Sapienza Università di Roma, Rome, Italy; 4Dipartimento di Biotecnologie Mediche e Medicina Traslazionale, Università di Milano, Milan, Italy; 5Centro Nazionale Tecnologie Innovative in Sanità Pubblica, Istituto Superiore di Sanità, Rome, Italy; 6Dipartimento di Medicina Sperimentale e Clinica, Università Magna Graecia di Catanzaro, Campus Universitario “S. Venuta”, Catanzaro, Italy*These authors contributed equally to this work†Professor Laura Cantù passed away on August 05, 2022Correspondence: Maria Carafa; Carlotta Marianecci, Dipartimento di Chimica e Tecnologie del Farmaco, Sapienza Università di Roma, Piazzale Aldo Moro 5, Roma, 00185, Italy, Tel +390649913603 ; +390649913970, Fax +39064913133, Email [email protected]; [email protected]: Vitamin E (VitE) may be classified in “the first line of defense” against the formation of reactive oxygen species. Its inclusion in nanoemulsions (NEs) is a promising alternative to increase its bioavailability. The aim of this study was to compare O/W NEs including VitE based on Almond or Neem oil, showing themselves antioxidant properties. The potential synergy of the antioxidant activities of oils and vitamin E, co-formulated in NEs, was explored.Patients and Methods: NEs have been prepared by sonication and deeply characterized evaluating size, ζ-potential, morphology (TEM and SAXS analyses), oil nanodroplet feature, and stability. Antioxidant activity has been evaluated in vitro, in non-tumorigenic HaCaT keratinocytes, and in vivo through fluorescence analysis of C. elegans transgenic strain. Moreover, on healthy human volunteers, skin tolerability and anti-inflammatory activity were evaluated by measuring the reduction of the skin erythema induced by the application of a skin chemical irritant (methyl-nicotinate).Results: Results confirm that Vitamin E can be formulated in highly stable NEs showing good antioxidant activity on keratinocyte and on C. elegans. Interestingly, only Neem oil NEs showed some anti-inflammatory activity on healthy volunteers.Conclusion: From the obtained results, Neem over Almond oil is a more appropriate candidate for further studies on this application.Graphical Abstract: Keywords: O/W nanodispersion, α-tocopherol, anti-inflammatory activity, HaCaT, C. elegans, healthy volunteers