Ebselen oxide attenuates mechlorethamine dermatotoxicity in the mouse ear vesicant model. (3rd July 2020)

• Record Type: Journal Article
• Authors: Tumu, Hemanta C. Rao; Cuffari, Benedette J.; Pino, Maria A.; Palus, Jerzy; Piętka-Ottlik, Magdalena; Billack, Blase
• Is Part Of: Drug and chemical toxicology. Volume 43:Number 4(2020)
• Page Start: 335
• Page End: 346
• Publication Date: 2020-07-03
• Subjects: Mechlorethamine -- ebselen oxide -- mouse ear vesicant model -- MMP-9 -- dermatotoxicity; Toxicology -- Periodicals; Drugs -- Toxicology -- Periodicals; Toxicology, Experimental -- Periodicals; 615.9005
• DOI: 10.1080/01480545.2018.1488858
• Languages: English
• ISSNs: 0148-0545

Abstract

Abstract: Mechlorethamine (HN2) is an alkylating agent and sulfur mustard mimetic. Topical exposure to HN2 is associated with tissue blistering. Previous work in our laboratory has shown that ebselen (EB-1) possesses anti-vesicant, anti-inflammatory, anti-bacterial, anti-fungal, and cytoprotective properties, both in vivo and in vitro . We recently reported that ebselen oxide (EB-2), an analog of EB-1 with a tetravalent selenium atom, also possesses anti-bacterial and anti-fungal activity and confers cytoprotection against HN2 in vitro . The purpose of the present study was to determine the vesicant countermeasure potential of EB-2 using the mouse ear vesicant model (MEVM). Compared to control ears, mouse ears exposed to a single dose of HN2 (0.500 µmol/ear) showed an increase in wet weights, ear thickness, hyperplasia, vesication, and inflammatory cell infiltration after 24 h. Fluorescence microscopy of terminal deoxynucleotidyl transferase (TdT) dUTP nick end labeling (TUNEL)-stained sections showed that the occurrence of apoptosis extended from the epidermis of the HN2-treated side, all the way to the contralateral epidermis. In contrast, HN2-exposed ears treated topically with EB-2 at a test dose of 0.250 mg/ear showed a significant decrease in wet weight (12% less vs. HN2 alone), morphometric thickness (13% less vs. HN2 alone), and vesication. In addition, TUNEL staining revealed that HN2 ears treated with EB-2 (0.250 mg/ear) showed a decrease in apoptosis as compared to the HN2 group. EB-2 also reduced the abundance of matrix metalloproteinase-9 (MMP-9) in ear tissues exposed to HN2. Taken together, our study demonstrates that EB-2 is an efficacious countermeasure to HN2.