title: The non-opioid receptor, antioxidant properties of morphine and the opioid peptide analog biphalin.
abstract: Opioids participate in a broad spectrum of regulatory effects. The discovery of the opioid receptor system led to the initial belief that all of the observed effects in this system were associated with receptor activation. However, it must be considered that certain opioid properties are the result of the properties of other chemicals and their distribution. The presence of a tyramine moiety in opioids is suggestive of their potential antioxidant properties. Therefore, this study evaluated the antioxidant properties of opioids that are not related to opioid receptor activation. The morphine antioxidant capacity (IC50=81μM) was 2.8 times lower than that of the reference ascorbic acid (IC50=29μM). Surprisingly, the biphalin antioxidant capacity (IC50=8μM) was 3.6 times higher than that of ascorbic acid and over 10 times higher than that of morphine. This unexpectedly high biphalin antioxidant capacity correlates with its neuroprotective properties.
authors.affiliation: Moldova Coordination Chemistry Department, Moldova State University, Chisinau, Republic of Moldova. Electronic address: olhamos@mail.ru.
authors.forename: Olga
authors.initials: O
authors.lastname: Garbuz
authors.affiliation: Moldova Coordination Chemistry Department, Moldova State University, Chisinau, Republic of Moldova. Electronic address: dociu1946@yahoo.com.
authors.forename: Aurelian
authors.initials: A
authors.lastname: Gulea
authors.affiliation: Mossakowski Medical Research Centre, Polish Academy of Sciences, Warsaw 02106, Poland. Electronic address: jolantadyniewicz@gmail.com.
authors.forename: Jolanta
authors.initials: J
authors.lastname: Dyniewicz
authors.affiliation: Mossakowski Medical Research Centre, Polish Academy of Sciences, Warsaw 02106, Poland. Electronic address: bzablocka@imdik.pan.pl.
authors.forename: Barbara
authors.initials: B
authors.lastname: Zablocka
authors.affiliation: Mossakowski Medical Research Centre, Polish Academy of Sciences, Warsaw 02106, Poland. Electronic address: andrzej@lipkowski.org.
authors.forename: Andrzej W
authors.initials: AW
authors.lastname: Lipkowski
mesh_terms: D052160:Benzothiazoles / Q000737:chemistry; D004745:Enkephalins / Q000737:chemistry*; D016166:Free Radical Scavengers / Q000737:chemistry*; D005609:Free Radicals / Q000737:chemistry; D009020:Morphine / Q000737:chemistry*; D011957:Receptors, Opioid; D013451:Sulfonic Acids / Q000737:chemistry
chemical_list: D052160:Benzothiazoles; D004745:Enkephalins; D016166:Free Radical Scavengers; D005609:Free Radicals; D011957:Receptors, Opioid; D013451:Sulfonic Acids; C002502:2,2'-azino-di-(3-ethylbenzothiazoline)-6-sulfonic acid; D009020:Morphine; C053673:biphalin
keywords: Antioxidation; Ascorbic acid; Biphalin; Morphine; Opioid