Effects of grape skin extract, anthocyanin oligomer, on a murine dry eye model

This study was conducted to investigate the effects of anthocyanin oligomers on dry eye disease through animal experiments. To accomplish this, 80 eyes of 40 mice were used, and dry eyes were induced by administration of 0.02% benzalkonium chloride (BAC). Anthocyanin oligomers of two doses (10 mg/kg and 50 mg/kg) were administered once a day for 2 weeks, while the control group received 0.1% cyclosporine A (CA) eye drops twice a day. Under a slit lamp microscope, the degree of corneal erosion (NEI grading system), tear break up time (TBUT) and phenol red test were observed. Moreover, histopathologic analysis of the lacrimal gland and corneal tissue was also performed. In the anthocyanin oligomer group (50 mg/kg), NEI score was significantly lower than that of the BAC treated group, while the TBUT and the wet length of phenol red thread were significantly higher than in the BAC group (P<0.01). Analysis of corneal tissue by hematoxylin and eosin (H&E) staining showed that keratinization and thickening of the cornea epithelial layer was not more prominent than those of eyes treated with anthocyanin oligomer (50 mg/kg) and CA eye drops. Overall, our results demonstrated that this natural compound has potential positive effects on the clinical index of dry eyes in the murine dry eye model.