Retinal safety and toxicity study of artesunate in vitro and in vivo

Bing-Wen Lu; Yu-Xiang Liang; Jin-Feng Liu; Zhong-Qing Sun; Kwok-Fai So; Kin Chiu

doi:10.1016/j.aopr.2022.11.003

Retinal safety and toxicity study of artesunate in vitro and in vivo

Adv Ophthalmol Pract Res. 2022 Dec 10;3(2):47-54. doi: 10.1016/j.aopr.2022.11.003. eCollection 2023 May-Jun.

Authors

Bing-Wen Lu¹, Yu-Xiang Liang^{2

3}, Jin-Feng Liu¹, Zhong-Qing Sun¹, Kwok-Fai So^{1

2

3

4}, Kin Chiu^{1

2

3}

Affiliations

¹ Department of Ophthalmology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China.
² State Key Laboratory of Brain and Cognitive Sciences, The University of Hong Kong, Hong Kong, China.
³ Department of Psychology, Faculty of Social Sciences, The University of Hong Kong, Hong Kong, China.
⁴ Guangdong-Hongkong-Macau (GHM) Institute of CNS Regeneration, Ministry of Education, CNS Regeneration Collaborative Joint Laboratory, Jinan University, Guangzhou, China.

Abstract

Background: Artesunate (ART), a member of the artemisinin family, possesses multi-properties, including anti-inflammation, anti-oxidation, and anti-tumor. ART was recently reported to show anti-neovascularization effect on the cornea, iris, and retina. Compared to the expensive anti-VEGF treatment, this versatile, economical treatment option is attractive in the ophthalmic field. The safety and toxicity profile of ART intravitreal application are in utmost need.

Methods: In this study, immortalized microglial (IMG) cells were treated with ART to determine the safe concentrations without inducing overt inflammatory reactions. Reverse transcription-polymerase chain reaction analysis was used to detect the cytokine expressions in IMG cells in response to ART stimulation. Various doses of ART were intravitreally injected into the right eyes of C57BL/6 mice. Retinal function was tested by electroretinogram, and retinal ganglion cell (RGC) survival was evaluated by counting Brn3a stained cells in flat-mounted retinas at 7 days after ART injection.

Results: ART below 5μM was safe for IMG cells in vitro. Both 2.5 and 5 μM ART treatment increased IL-10 gene expression in IMG cells while not changing IL-1β, IL-6, TNF-α, and Arg-1. In the in vivo study, intravitreal injection of ART below 100 μM did not cause deterioration in the retinal function and RGC survival of the mouse eyes, while 1 mM ART treatment significantly attenuated both the scotopic and photopic b-wave amplitudes and impaired RGC survival. In addition, treatment with ART of 25, 50, and 100 μM significantly decreased TNF-α gene expression while ART of 100 μM significantly increased IL-10 in the mouse retina.

Conclusions: Intravitreal injection of 100 μM ART could downregulate TNF-α while upregulate IL-10 in the mouse retina without causing retinal functional deterioration and RGC loss. ART might be used as anti-inflammatory agent for retinal disorders.

Keywords: Artesunate; Microglia; Retina; Safety.