1. Institute of Oral Biosciences and BK21 Program; Chonbuk National University; Jeonju 561-756 South Korea
2. Graduate Center for Toxicology; University of Kentucky; Lexington Kentucky 40536-0001 USA
3. Department of Nursing; Chonnam Techno College; Chonnam 516-911 South Korea
4. Research Center of Bioactive Materials; Chonbuk National University; Jeonju 561-756 South Korea