Recent advance in natural plant products for treatment of dry eye disease

Dry eye disease (DED), a chronic multifactorial illness of the ocular surface with itching, burning, irritation, eye fatigue and ocular inflammation, may result in potential damage, such as cornea and conjunctiva, and even decreased vision. With the global prevalence of DED on the rise, it is crucial to find treatment options with minimal side effects. Natural plant products have shown promise in alleviating DED symptoms and may serve as a potential approach for its treatment. However, their application as instilled drugs is limited by solubility, stability and biological barriers. This review summarizes recent studies (published in the last 5 years) on natural plant products and their derivatives for the treatment of DED, focusing on efficacy, mechanism, drug delivery systems. Meanwhile, their shortcomings are also discussed. By exploring these aspects, we find polyphenol, flavonoid and others natural plant products can effectively improve or treat DED by different mechanisms, and suitable delivery system and structural modification can enhance their therapeutic effect, suggesting they are likely to become candidates for the treatment of DED.