Preventive Effects against Retinal Degeneration by Centella asiatica Extract (CA-HE50) and Asiaticoside through Apoptosis Suppression by the Nrf2/HO-1 Signaling Pathway.

Dae-Won Park,Yong-Joon Jeong,Se-Chan Kang,Yeong-Geun Lee,Hyelin Jeon

doi:10.3390/antiox10040613

Abstract

Age-related macular degeneration (AMD) is caused by the chronic and gradual oxidative degeneration of the retina. Unfortunately, the general purpose of current treatments is to slow AMD progression, as the retina cannot be restored to its pre-AMD condition. We aimed to identify natural products that can be potential treatments that prevent AMD and can delay the development of late-AMD and selected Centella asiatica extract (CA-HE50), which shows excellent efficacy in cytoprotection. In animal experiments using N-methyl-N-nitrosourea (MNU), CA-HE50 dramatically increased the thickness of photoreceptors and the outer nuclear layer (ONL) and the number of nuclei in the ONL (p < 0.05). Using retinal epithelial ARPE-19 cells showed that CA-HE50 inhibited apoptosis through inhibition of the intrinsic apoptosis signaling pathway and cell cycle regulation (p < 0.05). The anti-apoptotic efficacy was confirmed to be due to activation of the Nrf2/HO-1 antioxidation pathway (p < 0.05). These results were also observed with asiaticoside, a functional substance of CA-HE50. In addition, the accumulation of oxidized-N-retinylidene-N-retinylethanolamine (A2E), which induces AMD, was inhibited by CA-HE50, resulting in increased ARPE-19 cell viability (p < 0.05). This study demonstrates that CA-HE50 is worth further research and human application tests, to develop it as a raw material for treatment or dietary supplement for the prevention of AMD.

Highlights

The increase in human life expectancy naturally leads to an increase in the number of patients with age-related diseases such as cancer, cardiovascular disease, diabetes, and joint, tooth, and eye diseases
We evaluated the protective effect of CA-HE50 on retinal cells in mice administered
We showed that CA-HE50 inhibited the activation of caspase-3 and PARP

Summary

Introduction

The increase in human life expectancy naturally leads to an increase in the number of patients with age-related diseases such as cancer, cardiovascular disease, diabetes, and joint, tooth, and eye diseases. Older age can lead to eye diseases such as cataracts, glaucoma, and age-related macular degeneration (AMD). AMD, which is caused by the chronic and gradual degeneration of the retina, is the third leading cause of blindness worldwide and a major cause of vision loss in Western society [1,2,3]. AMD generally include patient characteristics (age, gender, social class, and ethnic group), vascular factors (cardiovascular disease, dietary fat intake, smoking, alcohol consumption, and estrogen), oxidative processes, and genetic factors [4]. AMD can be divided into early, intermediate, and late stages

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