Silymarin, the antioxidant component of Silybum marianum, protects against burn-induced oxidative skin injury Hale Z. Toklu a , Tuba Tunalı-Akbay b , Go ¨ zde Erkanlı c , Meral Yu ¨ ksel d , Feriha Ercan c , Go ¨ksel S ¸ ener a, * a Marmara University, School of Pharmacy, Department of Pharmacology, Tıbbiye Cad., 34668 Istanbul, Turkey b School of Dentistry, Department of Biochemistry, Istanbul, Turkey c School of Medicine, Department of Histology-Embryology, Istanbul, Turkey d Vocational School of Health Related Professions, Istanbul, Turkey 1. Introduction Major burn induces the activation of an inflammatory cascade resulting in local tissue damage to contribute to the develop- ment of subsequent immunosuppression, increased suscept- ibility to sepsis and deleterious systemic effects in all the organ systems distant from the original wound [1,2]. It is well known that the inflammatory response, which leads to hyperactivation of tissue neutrophils contributes to oxidative cell/tissue damage [3,4]. Macrophages are also major produ- cers of pro-inflammatory mediators and their productive capacity for these mediators, such as prostaglandin E2, burns 33 (2007) 908–916 article info Article history: Accepted 27 October 2006 Keywords: Silymarin Burn Skin Thermal Oxidative Injury abstract Background: Despite recent advances, severe burn is one of the most common problems faced in the emergency room. Major thermal injury induces the activation of an inflam- matory cascade resulting in local tissue damage, to contribute to the development of subsequent damage of multiple organs distant from the original burn wound. Objective: Silymarin, the major component of milk thistle has been shown to have anti- oxidant properties. In the present study, we investigated the putative antioxidant effect of local or systemic silymarin treatment on burn-induced oxidative tissue injury. Methods: Wistar albino rats were exposed to 90 8C bath for 10 s to induce burn. Silymarin either locally (30 mg/kg) applied on 4 cm 2 area or locally + systemically (50 mg/kg, p.o.) was administered after the burn and repeated twice daily. Rats were decapitated 48 h after injury and blood was collected for tumor necrosis factor-a (TNF-a) and lactate dehydrogenase (LDH) activity. In skin tissue samples malondialdehyde (MDA) and glutathione (GSH) levels, myeloperoxidase (MPO) activity, and luminol-lucigenin chemiluminescense (CL) were mea- sured in addition to the histological evaluation. Results: Burn caused a significant increase in TNF-a and LDH levels. MDA levels were increased and GSH levels were decreased in the skin at 48 h after-burn. Both local and systemic silymarin treatments significantly reversed these parameters. The raised MPO activity and luminol-lucigenin CL were also significantly decreased. Conclusion: Results indicate that both systemic and local administration of silymarin was effective against burn-induced oxidative damage and morphological alterations in rat skin. Therefore, silymarin merits consideration as a therapeutic agent in the treatment of burns. # 2006 Elsevier Ltd and ISBI. All rights reserved. * Corresponding author. Tel.: +90 216 414 29 62; fax: +90 216 345 29 52. E-mail addresses: gokselsener@hotmail.com, gsener@marmara.edu.tr (G. S ¸ ener). available at www.sciencedirect.com journal homepage: www.elsevier.com/locate/burns 0305-4179/$32.00 # 2006 Elsevier Ltd and ISBI. All rights reserved. doi:10.1016/j.burns.2006.10.407