OBJECTIVETo observe the effects of the extract of Buddleja officinalis eye drops (EBOED) on basic tears secretory volume, tear film stability, and expressions of androgen receptors (AR) in castrated rats with dry eye, and to investigate the mechanism of EBOED on dry eye caused by decreased anti-androgen levels.

METHODSForty-five male Wistar rats were randomly divided into the blank group, the model group, and the treatment group (treated by EBOED), respectively. Rats in each group were further divided into three sub-groups (fed for one month, two months, and three months, respectively). There were totally nine groups, with five in each. The dry eye model was established with orchiectomy of rats in the model group and the treatment group. EBOED was given to rats in the treatment group for one successive month. Schirmer I test (SIT) and breakup time of tear film (BUT) were determined in all experimental rats. Expressions of AR was analyzed by flow cytometer.

RESULTSThs SIT value, BUT, and AR positive rate in the model group at the 1st, 2nd, 3rd month were lower than those in the blank group of the same time points (P < 0.01). There was statistical difference in SIT value, BUT, and AR positive rate between the model group and the treatment group at the three time points (P < 0.01). Take the three-month subgroup as an example, the SIT value in the treatment group was (12.667 +/- 5.221) mm, obviously higher than that in the model group (2.676 +/- 1.987) mm. The BUT in the treatment group was (11.758 +/- 4.415) s, obviously longer than that of the model group (4.667 +/- 2.108) s. The AR positive rate in the treatment group was 49.33% +/- 3.44%, obviously higher than that of the model group (33.32% +/- 7.12%, all P < 0.01).

CONCLUSIONSThe main components of EBOED was the flavonoids which could significantly inhibit the occurrence of dry eye in rats with decreased androgen levels. Its mechanism might possibly be similar to androgen.