Danshensu Decreases UVB-Induced Corneal Inflammation in an Experimental Mouse Model via Oral Administration

Background: Danshensu is a bioactive constituent of Salvia miltiorrhiza, a plant commonly used in traditional Chinese medicine. In this study, we investigated the pharmacological efficacy of sodium danshensu, or named salvianic acid A sodium (SAS) on ultraviolet B (UVB)-mediated corneal inflammatory injury in mice. Methods: Albino mice were divided into one blank control group, and three UVB radiation groups, i.e. SAS-untreated group, and prophylactic treatment groups with SAS at 1 and 10 mg/kg via oral administration. The structure integrity and inflammatory changes of cornea were assessed by surface evaluation of smoothness, topographic distortion, opacity, lissamine green staining, and histologic tissue staining. The inflammatory cytokines was measured by bead-based ELISA assays. Results: Prophylactic treatment of SAS significantly inhibited pathologic changes, improved tissue structural integrity, and reduced inflammatory injury in the cornea after UVB exposure. Dosing with SAS treatment attenuated the incidence rate of leukocyte influx by inhibit increase of interleukin (IL)-1β, IL-6, monocyte chemoattractant protein-1, and tumor necrosis factor-α. Treatment with 10 mg/kg SAS was more effective in preventing the onset of corneal damage than that with 1 mg/kg SAS. Conclusions: These results indicate that SAS exhibit the pharmacological efficacy on corneal protection through its inhibition of UVB induced photodamage and subsequently inflammatory injury in vivo.