OBJECTIVETo investigate the effects of the combination of musk and olibanum on the tight junction protein expressions in prostatic epithelial cells of normal and chronic prostatitis (CP) rats.

METHODSEighty male SD rats were randomly divided into 8 groups of equal number: normal control, normal musk, normal olibanum, normal musk + olibanum, CP model control, CP model musk, CP model olibanum, and CP model musk + olibanum. At 60 days after modeling, the rats in the control, musk, olibanum, and musk + olibanum groups were treated intragastrically with normal saline, musk (0.021 g per kg body weight per day), olibanum (1.05 g per kg body weight per day), or musk + olibanum respectively, all for 3 days. Then, all the rats were sacrificed and their prostate tissues harvested for detection of the expressions of the tight junction proteins Claudin-1, Claudin-3, Occludin, and ZO-1 in the prostatic epithelial cells by immunohistochemical staining.

RESULTSIn the CP models, only the expression of Claudin-1 was significantly increased. In the normal rats, the expression of Claudin-1 was remarkably upregulated after treated with musk (824.6 ± 393.3, P < 0.05), olibanum (982.0 ± 334.0, P < 0.05), and musk + olibanum (1088.1 ± 640.2, P < 0.01); that of Claudin-3 was elevated markedly by olibanum (1 009.5 ± 243.6, P < 0.05) and insignificantly by musk (597.5 ± 80.7), but the increasing effect of olibanum was reduced by musk + olibanum (678.4 ± 255.1). No statistically significant differences were found in the expression of Occludin among the rats treated with musk (693.0 ± 424.8), olibanum (732.1 ± 302.0), and musk + olibanum (560.2 ± 202.3), or in that of ZO-1 in the animals treated with musk (290.0 ± 166.8) and olibanum (419.7 ± 108.1), but the latter was markedly decreased in the musk + olibanum group (197.7 ± 98.2, P < 0.05). In the CP rat models, both the expressions of Claudin-1 (823.0 ± 100.1, P < 0.01) and Occludin (1160.0 ± 32.2, P < 0.05) were significantly increased. The expression of Claudin-1 was remarkably down-regulated by musk (764.9 ± 179.0), olibanum (468.4 ± 220.4), and musk + olibanum (335.1 ± 204.0) (all P < 0.05), but that of Claudin-3 up-regulated by musk (744.6 ± 94.5) and olibanum (700.1 ± 223.7) (both P < 0.05). The expression of Occludin was reduced by musk (615.0 ± 221.0), olibanum (749.6 ± 321.7), and musk + olibanum (505.8 ± 523.7), while that of ZO-1 increased by olibaum (443.2 ± 44.9) and decreased by musk + olibanum (213.5 ± 24.9, P < 0.05).

CONCLUSIONIn physiological and pathological conditions, the combination of musk and olibanum acts on the expressions of tight junction proteins in prostate epithelial cells in a selective and dual-targeting manner, promoting their permeability by down-regulating the expression of ZO-1 and maintaining their structural stability by regulating the expressions of Claudin-1, Claudin-3, and Occludin.