The Effect of the Aqueous Extract of Bidens Pilosa L. on Androgen Deficiency Dry Eye in Rats.

BACKGROUND/AIMS: Bidens pilosa L. (Bp) is widely distributed in China and has been widely used as a traditional Chinese medicine. The aim of this study was to examine the effect of the extract of Bp on androgen deficiency dry eye and determine its possible mechanisms.

METHODS: Twenty-four rats were randomly divided into four groups: Group Con (control), Group Sal (physiological saline), Group Fin (oral finasteride), and Group Bp (oral finasteride and Bp). The dry eye model was established in group Fin and group Bp. Aqueous tear quantity was measured with phenol red-impregnated cotton threads with anesthesia. Tear film breakup time (BUT) and corneal epithelial damage were evaluated by fluorescein staining. Animals were sacrificed at 28 days, and ocular tissues (lacrimal gland and cornea) were evaluated with light microscopy; gene microarray analysis for inflammatory cytokines and Western blot were also performed.

RESULTS: Finasteride administration effectively induced dry eye in rats by 14 days after administration. Group Fin rats had significantly higher fluorescein staining scores and lower aqueous tear quantity and BUT than the group Con rats, and notable inflammatory cell infiltrates were observed in the lacrimal gland of group Fin rats. The fluorescein staining score, aqueous tear quantity and BUT significantly improved with Bp treatment in the group Bp rats, and the structures of the lacrimal gland were well maintained without significant lymphocyte infiltration. Cytokine antibody array data identified the cytokines B7-2/Cd86, IL-1β, IL-4, IL-6, IL-10, MMP-8, FasL, TNF-α and TIMP-1 as candidates for validation by Western blot. Expression levels of pro-inflammatory cytokines, including IL-1β, IL-6, and TNF-α, in group Fin were upregulated compared with group Con. Levels of anti-inflammatory cytokines, such as IL-4 and IL-10, in group Fin were also upregulated compared with those in group Con. Compared with group Fin, IL-1β, FasL, and TNF-α were significantly decreased in group Bp.

CONCLUSION: The extract of Bp appears to be effective for the treatment of androgen deficiency dry eye in rats by improving aqueous tear quantity, maintaining tear film stability, and inhibiting the inflammation of the lacrimal gland.