Cataract Preventive Role of Isolated Phytoconstituents: Findings from a Decade of Research.

Vuanghao Lim,Hongli Wu,Edward Schneider,Iok-Hou Pang

doi:10.3390/nu10111580

Abstract

Cataract is an eye disease with clouding of the eye lens leading to disrupted vision, which often develops slowly and causes blurriness of the eyesight. Although the restoration of the vision in people with cataract is conducted through surgery, the costs and risks remain an issue. Botanical drugs have been evaluated for their potential efficacies in reducing cataract formation decades ago and major active phytoconstituents were isolated from the plant extracts. The aim of this review is to find effective phytoconstituents in cataract treatments in vitro, ex vivo, and in vivo. A literature search was synthesized from the databases of Pubmed, Science Direct, Google Scholar, Web of Science, and Scopus using different combinations of keywords. Selection of all manuscripts were based on inclusion and exclusion criteria together with analysis of publication year, plant species, isolated phytoconstituents, and evaluated cataract activities. Scientists have focused their attention not only for anti-cataract activity in vitro, but also in ex vivo and in vivo from the review of active phytoconstituents in medicinal plants. In our present review, we identified 58 active phytoconstituents with strong anti-cataract effects at in vitro and ex vivo with lack of in vivo studies. Considering the benefits of anti-cataract activities require critical evaluation, more in vivo and clinical trials need to be conducted to increase our understanding on the possible mechanisms of action and the therapeutic effects.

Highlights

The ocular lens is located at the anterior segment of the eye that, together with the cornea, provides the refractive power of the eye
The mature lens is composed of a core of primary lens fiber cells, layers of secondary lens fiber cells, and one layer of anterior lens epithelial cells, which covers the anterior surface of the lens [1]
The delicate balance required for lens transparency can be disturbed by oxidative stress, aging, and UV radiation, and cataracts develop as a result [1]

Summary

Introduction

The ocular lens is located at the anterior segment of the eye that, together with the cornea, provides the refractive power of the eye. The major function of the lens is to maintain transparency so that the light can be properly focused on the retina. The delicate balance required for lens transparency can be disturbed by oxidative stress, aging, and UV radiation, and cataracts develop as a result [1]. Cataracts are the most common cause of vision loss in people over the age of 40 and are the leading cause of blindness in the world [2]. Cataracts are defined as lens opacification that prevents a Nutrients 2018, 10, 1580; doi:10.3390/nu10111580 www.mdpi.com/journal/nutrients

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