Abstract
Purpose :
Dendrobium nobile contains specific phytochemicals that may be beneficial for vision protection. Nevertheless, the effects remain not elucidated and the underlying mechanism is largely unknown. This study investigated the water extracts of a specific Dendrobium, Jin Tong, coded as STK, for protection against UVB-induced corneal and lacrimal gland damages and underlying mechanisms.
Methods :
The mice were divided into 6 groups including: blank control (tube feeding with 0.9% NaCl), UVB damage (UVB exposure and tube feeding with 0.9% NaCl), 3 test groups (UVB exposure and tube feeding with STK extracts at 3 different doses), artificial tear control (UVB exposure and tube feeding with 0.9% NaCl, and treated with artificial tears). For the test groups, the mice were given STK extracts for 3 days (Days -2 - 0) before consecutive exposure to UVB irradiation (0.72 J/cm2) (Days 1 - 7). On Days 0, 4 and 7, tear volume (TV) and tear film break up time (TBUT) were assessed. On Day 8, cornea smoothness, opacity, topography and lissamine green stain were performed and recorded, followed by sacrifice with eye samples and lacrimal glands collected for analyses.
Results :
The results showed dose-dependent effects, with suitable doses ranging between 50 -100 mg/Kg of body weight. Both TV and TBUT were significantly increased with STK treatment, along with mitigation of cornea epithelial exfoliation and thickness reduction. Conjunctival goblet cells were maintained. Furthermore, NF-kB and Cox2 elevation in both the cornea epithelium and lacrimal gland were inhibited by oral intake of STK extracts.
Conclusions :
In conclusion, the STK Dendrobium water extracts are helpful in soothing photokeratitis symptoms similar to those commonly observed under a dry eye status. The effective ingredients remain to be further investigated.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.