Green tea extract enhances retinal ganglion cell survival and axonal regeneration in rats with optic nerve injury

Xiang-Ling Yuan; Shao-Lang Chen; Yanxuan Xu; Yao Yao; Jia-Jian Liang; Xi Zhuang; Eric S Hald; Tsz Kin Ng

doi:10.1016/j.jnutbio.2023.109333

Green tea extract enhances retinal ganglion cell survival and axonal regeneration in rats with optic nerve injury

J Nutr Biochem. 2023 Jul:117:109333. doi: 10.1016/j.jnutbio.2023.109333. Epub 2023 Mar 24.

Authors

Xiang-Ling Yuan¹, Shao-Lang Chen², Yanxuan Xu², Yao Yao¹, Jia-Jian Liang², Xi Zhuang², Eric S Hald³, Tsz Kin Ng⁴

Affiliations

¹ Joint Shantou International Eye Center of Shantou University and The Chinese University of Hong Kong, Shantou, Guangdong, China; Shantou University Medical College, Shantou, Guangdong, China.
² Joint Shantou International Eye Center of Shantou University and The Chinese University of Hong Kong, Shantou, Guangdong, China.
³ Department of Biomedical Engineering, Shantou University, Shantou, Guangdong, China.
⁴ Joint Shantou International Eye Center of Shantou University and The Chinese University of Hong Kong, Shantou, Guangdong, China; Shantou University Medical College, Shantou, Guangdong, China; Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong. Electronic address: micntk@hotmail.com.

PMID: 36965783
DOI: 10.1016/j.jnutbio.2023.109333

Abstract

Current clinical treatments have not yet effectively cured progressive retinal ganglion cell (RGC) death and axonal degeneration after optic nerve (ON) injury. We previously demonstrated green tea extract (GTE) can reduce RGC death in rats after ischemic injury. Here, we aim to determine the prophylactic and therapeutic effects and mechanisms of GTE on RGC survival and axonal regeneration in rats with ON injury. GTE (275 or 550 mg/kg) was administered intragastrically for 7 d before or 14 d post-ON crush surgery in adult Fischer 344 rats. Rats with pre- or post-operative treatment of 275 mg/kg GTE showed significantly higher numbers of RGCs and regenerated axons post-ON injury with improved pupillary light reflex as compared to saline-treated rats. Akt and Erk p42/44 activation was higher in the retina of rats given 275 mg/kg GTE pre-surgery, whereas Stat3 activation was higher in those with 275 mg/kg GTE post-operation. Less activated microglia were observed in rats with pre-treatment of 275 or 550 mg/kg GTE. RNA sequencing analysis identified the downregulation of inflammation, apoptosis, and microglia activation genes in the retina of rats with pre- or post-treatment with 275 mg/kg GTE as compared to the saline-treated rats. In summary, this study revealed the prophylactic and therapeutic treatment effects of GTE on RGC survival and axonal regeneration in rats with ON injury, indicating a potential alternative treatment for traumatic optic neuropathy.

Keywords: Green tea extract; anti-inflammation; neuroprotection; optic nerve injury; retinal ganglion cells.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Animals
Cell Survival
Nerve Regeneration / physiology
Optic Nerve Injuries* / drug therapy
Optic Nerve Injuries* / metabolism
Rats
Rats, Inbred F344
Retinal Ganglion Cells* / metabolism
Tea

Substances

Tea