Interaction of curcumin with rhamnolipids, DSPC liposomes and cyclodextran MOF : curcumin as a molecular probe to investigate heterogeneous systems -

Abstract

Turmeric, extracted from the plant Curcuma longa, is a gold-colored spice commonly used for health care and for the preservation of food. Curcumin, the active ingredient in the turmeric herb has been shown to exhibit antioxidant, anti-inflammatory, antiviral, antibacterial, antifungal, and anticancer activities thus a therapeutic tool in various chronic illnesses. Rhamnolipids (RLs) are glycolipid biosurfactants produced mainly by Pseudomonas aeruginosa and can be described as glycosides that are composed, of a rhamnose moieties (that constitute the glycon part) and lipid part (that makes the aglycon part connected by an O-glycosidic bond). RLs are characterized by unique physiochemical properties namely surface activity, wetting ability, detergency, and other amphipathic- related qualities. For its applicability as a hydrophobic drug molecule and food spice, interaction of curcumin with rhamnolipids, a biosurfactant, bears importance. Here we have explored interaction of curcumin with rhamnolipids biosurfactant and its aggregation behavior. The impact of pH on critical micelle concentration (cmc) of rhamnolipids has been studied using fluorescence of curcumin and found that cmc of rhamnolipids increases with increase in pH of the medium. Moreover, liposomes an efficient tool of intense application in various fields of science and technology because its biocompatibility along with the ability to lodge both hydrophobic and hydrophilic molecules, in addition to unique structural and functional properties. Curcumin has been applied as a molecular probe to investigate the properties of 1, 2-Dioctadecanoyl-sn-glycero-3-phosphocholine (DSPC) liposomes and study the effect of rhamnolipids on permeability and fluidity of the membranes. Here, we have explored new insight on intercalation of rhamnolipids with DSPC liposomes using curcumin and pyrene as external fluorescence probes. Intercalation of rhamnolipids exceptionally increases (∼22-fold) partition of curcumin into solid gel phase of DSPC liposomes, whereas t