title: Interaction between curcumin and human serum albumin in the presence of excipients and the effect of binding on curcumin photostability.
abstract: Curcumin (Cur) is known to bind to human serum albumin (HSA) which may lead to a reduced phototoxic effect of the compound in the presence of serum or saliva. The influence of excipients on the Cur-HSA binding was studied by HSA florescence quenching and Cur absorption and emission spectroscopy in the presence and absence of the selected excipients. Photostabilty of Cur in the presence of HSA was evaluated, as well as the effect of excipients on HSA bound Cur photodegradation. Cyclodextrins (CDs) (2-hydroxypropyl-β-cyclodextrin and 2-hydroxypropyl-γ-cyclodextrin) and polymers (polyethylene glycol 400, PEG 400 and Pluronic F-127, PF-127) were selected for the study. CDs and PF-127 seem to decrease Cur binding to HSA, probably through competitive binding. Cur was still bound to HSA in polyethylene glycol (PEG) solutions at the highest investigated concentration (5% w/v). However, high PEG concentration appears to have effect on the protein conformation, as shown by the fluorescence quenching study. Low Cur photostability in the presence of HSA could be improved by the addition of hydroxylpropyl-γ-cyclodextrin (HPγCD) to the samples, whereas PEG and PF-127 showed no effect.
authors.affiliation: a Department of Pharmaceutics, School of Pharmacy , University of Oslo , Oslo , Norway.
authors.forename: Milica
authors.initials: M
authors.lastname: Vukićević
authors.affiliation: a Department of Pharmaceutics, School of Pharmacy , University of Oslo , Oslo , Norway.
authors.forename: Hanne Hjorth
authors.initials: HH
authors.lastname: Tønnesen
mesh_terms: D000073738:2-Hydroxypropyl-beta-cyclodextrin; D000970:Antineoplastic Agents / Q000737:chemistry / Q000378:metabolism*; D004396:Coloring Agents / Q000737:chemistry / Q000378:metabolism*; D003474:Curcumin / Q000737:chemistry / Q000378:metabolism*; D005079:Excipients / Q000378:metabolism*; D006801:Humans; D010782:Photolysis / Q000187:drug effects; D020442:Poloxamer / Q000378:metabolism; D011092:Polyethylene Glycols / Q000378:metabolism; D011485:Protein Binding / Q000187:drug effects; D012709:Serum Albumin / Q000378:metabolism*; D047392:beta-Cyclodextrins / Q000378:metabolism; D047408:gamma-Cyclodextrins / Q000378:metabolism
chemical_list: D000970:Antineoplastic Agents; D004396:Coloring Agents; D005079:Excipients; D012709:Serum Albumin; D047392:beta-Cyclodextrins; D047408:gamma-Cyclodextrins; C479659:hydroxypropyl-gamma-cyclodextrin; D020442:Poloxamer; D000073738:2-Hydroxypropyl-beta-cyclodextrin; D011092:Polyethylene Glycols; D003474:Curcumin
keywords: Cyclodextrins; Pluronic F-127; Stern–Volmer plot; fluorescence quenching; polyethylene glycol