Eupafolin nanoparticles protect HaCaT keratinocytes from particulate matter-induced inflammation and oxidative stress

Zih-Chan Lin,1,* Chiang-Wen Lee,2,3,* Ming-Horng Tsai,4 Horng-Huey Ko,5 Jia-You Fang,1,2 Yao-Chang Chiang,6,7 Chan-Jung Liang,8,9 Lee-Fen Hsu,10 Stephen Chu-Sung Hu,11,12 Feng-Lin Yen5,8,13 1Graduate Institute of BioMedical Sciences, Chang Gung University, 2Research Center for Industry of Human Ecology, Chang Gung University of Science and Technology, Kweishan, Taoyuan, 3Division of Basic Medical Sciences, Department of Nursing, Chang Gung Institute of Technology and Chronic Diseases and Health Promotion Research Center, Chiayi, 4Division of Neonatology and Pediatric Hematology/Oncology, Department of Pediatrics, Chang Gung Memorial Hospital, Yunlin, 5Department of Fragrance and Cosmetic Science, College of Pharmacy, Kaohsiung Medical University, Kaohsiung, 6Center for Drug Abuse and Addiction, China Medical University Hospital, 7Center for Drug Abuse and Addiction, China Medical University, Taichung, 8Center for Lipid and Glycomedicine Research, Kaohsiung Medical University, Kaohsiung, 9Center for Lipid Biosciences, Kaohsiung Medical University Hospital, 10Department of Respiratory Care, Chang Gung University of Science and Technology, Chiayi Campus, Chiayi, 11Department of Dermatology, College of Medicine, Kaohsiung Medical University, 12Department of Dermatology, Kaohsiung Medical University Hospital, 13Institute of Biomedical Sciences, National Sun Yat-Sen University, Kaohsiung, Taiwan, Republic of China *These authors contributed equally to this work Abstract: Exposure to particulate matter (PM), a major form of air pollution, can induce oxidative stress and inflammation and may lead to many diseases in various organ systems including the skin. Eupafolin, a flavonoid compound derived from Phyla nodiflora, has been previously shown to exhibit various pharmacological activities, including antioxidant and anti-inflammatory effects. Unfortunately, eupafolin is characterized by poor water solubility and skin penetration, which limits its clinical applications. To address these issues, we successfully synthesized a eupafolin nanoparticle delivery system (ENDS). Our findings showed that ENDS could overcome the physicochemical drawbacks of raw eupafolin with respect to water solubility and skin penetration, through reduction of particle size and formation of an amorphous state with hydrogen bonding. Moreover, ENDS was superior to raw eupafolin in attenuating PM-induced oxidative stress and inflammation in HaCaT keratinocytes, by mediating the antioxidant pathway (decreased reactive oxygen species production and nicotinamide adenine dinucleotide phosphate oxidase activity) and anti-inflammation pathway (decreased cyclooxygenase-2 expression and prostaglandin E2 production through downregulation of mitogen-activated protein kinase and nuclear factor-κB signaling). In summary, ENDS shows better antioxidant and anti-inflammatory activities than raw eupafolin through improvement of water solubility and skin penetration. Therefore, ENDS may potentially be used as a medicinal drug and/or cosmeceutical product to prevent PM-induced skin inflammation. Keywords: eupafolin, nanoparticles, particulate matter, oxidative stress, cyclooxygenase-2, keratinocytes