title: Encapsulated curcumin results in prolonged curcumin activity in vitro and radical scavenging activity ex vivo on skin after UVB-irradiation.
abstract: The phytochemical curcumin possesses antioxidant activity; however, it becomes unstable after being exposed to light or heat or loses activity during storage. This is especially important when curcumin is applied to the skin within a cosmetic or pharmaceutical formulation, since sun exposure is unavoidable. This drawback can be directly addressed by encapsulation of curcumin in photo-stable nanospheres. Therefore, curcumin was encapsulated into nanoparticles consisting of ethyl cellulose and/or methyl cellulose. Nanoparticles were subjected to processing conditions commonly used in industry, for example, temperature and pressure and thus retained their morphology. Furthermore, sun exposure resulted in the protection of curcumin by nanoparticles, whereas non-encapsulated curcumin degraded completely. Determination of the radical protection factor resulted in similar antioxidant activity of encapsulated and non-encapsulated curcumin indicating that curcumin maintains its antioxidant activity. Application of lotions containing curcumin or curcumin nanoparticles to the skin and subsequent UVB-irradiation resulted in less radical formation compared to lotion application only. Moreover, radical formation was even less after nanoparticle application compared to free curcumin. Nanoencapsulation protects curcumin from photo degradation and can therefore prolong the antioxidant activity of curcumin.
authors.affiliation: Suan Dusit Rajabhat University, Bangkok, Thailand. natthakitta_s@hotmail.com
authors.forename: N
authors.initials: N
authors.lastname: Suwannateep
authors.forename: S
authors.initials: S
authors.lastname: Wanichwecharungruang
authors.forename: S F
authors.initials: SF
authors.lastname: Haag
authors.forename: S
authors.initials: S
authors.lastname: Devahastin
authors.forename: N
authors.initials: N
authors.lastname: Groth
authors.forename: J W
authors.initials: JW
authors.lastname: Fluhr
authors.forename: J
authors.initials: J
authors.lastname: Lademann
authors.forename: M C
authors.initials: MC
authors.lastname: Meinke
mesh_terms: D000279:Administration, Cutaneous; D000818:Animals; D000975:Antioxidants / Q000008:administration & dosage / Q000737:chemistry / Q000494:pharmacology*; D002482:Cellulose / Q000031:analogs & derivatives / Q000737:chemistry; D003474:Curcumin / Q000008:administration & dosage / Q000737:chemistry / Q000494:pharmacology*; D004355:Drug Stability; D004356:Drug Storage; D016166:Free Radical Scavengers / Q000008:administration & dosage / Q000737:chemistry / Q000494:pharmacology*; D066298:In Vitro Techniques; D008747:Methylcellulose / Q000737:chemistry; D053758:Nanoparticles; D010782:Photolysis; D011312:Pressure; D012867:Skin / Q000187:drug effects / Q000378:metabolism; D013472:Sunlight; D013552:Swine; D013696:Temperature; D013997:Time Factors; D014466:Ultraviolet Rays
chemical_list: D000975:Antioxidants; D016166:Free Radical Scavengers; C013517:ethyl cellulose; D002482:Cellulose; D008747:Methylcellulose; D003474:Curcumin