Abstract
Purpose :
To investigate the anti-oxidative and anti-inflammatory effects of chamaecyparis obtusa (CO) on human corneal epithelial (HCE) cells and in a mouse model of experimental dry eye (EDE).
Methods :
CO extracts were used to treat HCE, and then cell viability and production of thioredoxin (TRX)-1, TRX-3, sirtuin-1 (SIRT1), phosphorylated AMP kinase (pAMPK) and total malondialdehyde (MDA) were assessed. Eye drops containing 0.001%, 0.01% and 0.1% CO extracts, or balanced salt solution were applied in EDE. Tear volume, tear film break-up time (TBUT) and corneal fluorescein staining scores were measured at 7 days after treatment. Levels of interferon (IFN)-g, interleukin (IL)-6, IL-17, tumor necrosis factor (TNF)-a, interferon gamma-induced protein (IP)-10, and monokine induced by interferon-g (MIG) were measured in the conjunctiva using a multiplex immunobead assay. Production of reactive oxygen species (ROS) was analyzed using dichloro-dihydro-fluorescein diacetate (DCFH-DA) assay.
Results :
The viability of HCE and the ratio of TRX-1, 3, SIRT1, and pAMPK showed a significant improvement after treating with 0.01 mg/mL CO extracts. The expression of MDA decreased in the CO treatment group. Mice treated with 0.1% CO showed significant improvement in tear volume, TBUT and corneal fluorescein staining scores compared with the EDE control and other treatment groups. A significant decrease in the levels of IFN-g and IP-10 was observed in the 0.1% CO group. The level of DCFH-DA significantly decreased in the 0.01% and 0.1% CO groups.
Conclusions :
CO could promote the anti-oxidative protein, improve clinical signs of dry eye, and reduce the production of inflammatory markers and oxidative stress, suggesting that CO eye drops may be useful for the treatment of dry eye disease.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.