Use of liposomes to evaluate the role of membrane interactions on antioxidant activity.

• Type: Article in International Scientific Journal
• Date: 2010

Authors

Reis, S (Author) FFUP; Lucio, M (Author) FEUP; Segundo, M (Author) FFUP; Lima, JL (Author) FFUP

Journal

Title: Methods in molecular biology (Clifton, N.J.)

Vol. 606

Pages: 167-188

ISSN: 1064-3745

Publisher: Springer Nature

Indexing

ISI Web of Knowledge

ISI Web of Science

Scopus - 7 Citations

Scientific classification

CORDIS: Health sciences

Other information

Authenticus ID: P-005-4F3

Resumo (PT): In this study the possibility of using liposomes as membrane mimetic systems was evaluated to estimate the antioxidant properties of oxicams and establish a relationship between the interactions of the drugs with the membrane and their consequent antioxidant activity. Different experiments were performed covering the study of the protective effect of oxicams in lipid peroxidation induced by the peroxyl radical (ROO) derived from 2,2′-azobis(2-amidinopropane) dihydrochloride (AAPH) and using two fluorescence probes with distinct lipophilic properties. Lipid peroxidation using the hydrophilic probe fluorescein was evaluated in lipid and aqueous media. Lipid systems labelled with the fluorescent probe diphenylhexatriene propionic acid (DPH-PA) were used to assess the effects of the drugs on membrane peroxidation simultaneously by fluorescence intensity decay and changes in membrane fluidity by steady-state anisotropy measurements. The use of different probes and liposomes as membrane mimetic systems allowed to conclude that membrane lipoperoxidation is related not only to the scavenging characteristics of the antioxidants but also to their ability to interact with the lipid bilayers. <br> <br> Keywords: Liposomes; Membrane models; Oxicams; Lipid peroxidation <br> <a target="_blank" href="http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TF4-4P1P6XW-2&_user=2460038&_coverDate=07%2F30%2F2007&_rdoc=25&_fmt=high&_orig=browse&_srch=doc-info(%23toc%235216%232007%23994029998%23663384%23FLA%23display%23Volume)&_cdi=5216&_sort=d&_docanchor=&_ct=26&_acct=C000057398&_version=1&_urlVersion=0&_userid=2460038&md5=4a5b8b60ea2d7d0a542da96080e81cb6"> Texto integral</a> <br> <br>

Abstract (EN): Cellular membranes, which contain abundant phospholipids, such as phosphatidylcholine, are major targets subjected to the damage caused by free radicals. Cellular damage due to lipid oxidation is strongly associated with ageing, carcinogenesis and other diseases. In addition, lipid oxidation is an important deteriorative reaction in the processing and storage of lipid-containing foods. Liposomes have been used extensively as biological models for in vitro lipid oxidation studies. The resemblance between the liposomal and membrane bilayer core makes liposomes a very useful tool to investigate the significance of the antioxidant-membrane interactions for antioxidant activity. The antioxidant activity of a compound is strongly influenced by numerous factors including the nature of the lipid substrate, the hydrophilic-lipophilic balance of the antioxidant, the physical and chemical environments of the lipids, and various other interfacial interactions. Thus, compounds that are effective antioxidants in one model system or food matrix may be unsuitable in other systems.This chapter describes fluorescent probes-based methods commonly used for testing antioxidant activity in liposomes and stresses the need to combine antioxidant assays and drug-membrane interaction studies to get a better description of the antioxidants' profile considering their location in lipid bilayer and their effect on membrane fluidity and consequently provide additional information to that obtained currently from assays performed in aqueous buffer media.

Language: English

Type (Professor's evaluation): Scientific