Inhibitory activity of liposomal flavonoids during oxidative metabolism of human neutrophils upon stimulation with immune complexes and phorbol ester

Author(s)

Landi-Librandi, Ana Paula ^[1] ; Caleiro Seixas Azzolini, Ana Elisa ^[1] ; de Oliveira, Carlos Alberto ^[2] ; Lucisano-Valim, Yara Maria ^[1]

Affiliation

^[1] Univ Sao Paulo, Fac Ciencias Farmaceut Ribeirao Preto, Dept Fis & Quim, BR-14040903 Ribeirao Preto, SP - Brazil

^[2] Univ Fed Uberlandia, Ctr Ciencias Exatas & Tecnol, Inst Quim, BR-38400 Uberlandia, MG - Brazil

• Document type: Journal article
• Source: DRUG DELIVERY; v. 19, n. 4, p. 177-187, MAY 2012.
• Web of Science Citations: 16

Abstract

Context and objective: The massive production of reactive oxygen species by neutrophils during inflammation may cause damage to tissues. Flavonoids act as antioxidants and have anti-inflammatory effects. In this study, liposomes loaded with these compounds were evaluated as potential antioxidant carriers, in attempt to overcome their poor solubility and stability. Materials and methods: Liposomes containing quercetin, myricetin, kaempferol or galangin were prepared by the ethanol injection method and analyzed as inhibitors of immune complex (IC) and phorbol ester-stimulated neutrophil oxidative metabolism by luminol (CLlum) and lucigenin-enhanced (CLluc) chemiluminescence (CL) assays. The mechanisms involved this activity of liposomal flavonoids, such as cytotoxicity and superoxide anion scavenging capacity, and their effect on phagocytosis of ICs were also investigated. Results and discussion: The results showed that the inhibitory effect of liposomal flavonoids on CLlum and CLluc is inversely related to the number of hydroxyl groups in the flavonoid B ring. Moreover, phagocytosis of liposomes by neutrophils does not seem to necessarily promote such activity, as the liposomal flavonoids are also able to reduce CL when the cells are pretreated with cytochalasin B. Under assessed conditions, the antioxidant liposomes are not toxic to the human neutrophils and do not interfere with IC-induced phagocytosis. Conclusion: The studied liposomes can be suitable carriers of flavonoids and be an alternative for the treatment of diseases in which a massive oxidative metabolism of neutrophils is involved. (AU)

• FAPESP's process: 07/00161-3 - Study of effect of composition of liposome containing flavonoids on Complement System activation and oxidative metabolism of human neutrophils: implications in the stability and application of this delivery system in the therapy of inflammatory diseases
• Grantee: Yara Maria Lucisano Valim
• Support Opportunities: Regular Research Grants
• FAPESP's process: 06/04398-5 - Study of the effect of Complement System activation in the stability of different compositions of liposomes containning flavonoids: selection of the delivery system more stable and evaluation of its applicability in the therapy of inflammatory diseases.
• Grantee: Ana Paula Landi Librandi
• Support Opportunities: Scholarships in Brazil - Post-Doctoral