Ocular Health Maintenance Effects of Cordyceps cicadae Mycelium Extracts on UVB-induced Dry Eye Symptoms in a Mouse Model

Dry eye is a common and often chronic problem, particularly in older adults, in which a person does not have enough quality tears to lubricate and nourish the eye. The hallmarks of this disease are considered to be ocular inflammation and hyperosmolarity of tear film. Cordyceps cicadae (Cc), a traditional Chinese medicine, has a long history of use and is known for its pharmacological effects. Previous studies have shown that Cc mycelial extracts could increase the tear break-up time (TBUT) in animal models. Further understanding of the efficacy of Cc mycelial extracts on UVB-induced dry eye symptoms were therefore examined. In this study, female Institute of Cancer Research (ICR) mice were divided into 3 groups (n = 3 per group), including (1) blank control without UVB exposure, (2) vehicle with UVB exposure, and (3) with UVB exposure and Cc extract administration. Tear volume, TBUT, and ocular surface photography (OSP) measurements, as well as histopathological analysis on the cornea, meibomian glands, and extraorbital glands were performed. The results showed that Cc extract effectively contributes to ocular health by increasing TBUT and maintaining corneal p63+ basal cells. Moreover, it lowers the expression of COX-2 and NF-kB inflammatory markers while maintaining mucin-secreting cells in density and size. Additionally, the Cc extract group demonstrated a lower expression of oxidative damage biomarkers compared to the vehicle group. These findings suggest that Cc extract is a promising alternative for treating UVB-induced dry eye symptoms.