Absorption and Fluorescence Studies of Curcumin Bound to Liposome and Living Cells

The absorption and fluorescence properties of curcumin were used, to study its average binding constants with phosphatidylcholine (PC) liposomes. The liposomal vehicle was examined for the delivery of curcumin to spleen lymphocyte cells, EL4 lymphoma cells and compared with aqueous DMSO vehicles. From these studies it was found that liposomal vehicle is capable of loading more curcumin in to cells than aqueous-DMSO. Lymphoma cells show preferential uptake of curcumin as compared to lymphocytes. The fluorescence of curcumin in EL4 lymphoma cells was found to be significantly higher as compared to the lymphocytes. I n t r o d u c t i o n Curcumin, a natural polyphenol, found in the rhizomes of Curcuma longa (turmeric), exhibits anti-inflammatory, anti-neoplastic, anti-oxidant and chemopreventive activities and has been shown to be pharmacologically safe even at high doses [1-3]. It is a hydrophobic molecule and is practically insoluble in aqueous solutions. Because of this hydrophobic nature, its bioavailability is poor after oral administration and therefore it needs a carrier vehicle to transport it to the desired targets. Curcumin has preferential interaction with lipid membranes [4-5]. Liposome is one of the most commonly used transporting vehicles for drugs, proteins, hormones, diagnostic agents etc [6]. In this paper following absorption and fluorescence changes in curcumin in different systems, quantitative estimations were made on the loading of curcumin from phosphatidylcholine (PC) liposomes to cellular systems. Materials and Method Reagents and equipment Curcumin, cholesterol, acrylamide, potassium iodide, cell culture medium and egg yolk phosphatidylcholine (PC) were procured from local dealers. Whenever