Objective: To investigate the effect of Ruyi Jinhuang Plaster (RJP) on testosterone propionate-induced BPH in the rat model and its action mechanisms.
Methods: Forty-eight SD male rats were randomly divided into six groups of equal number: normal control, BPH model control, finasteride, and high-, medium- and low-dose RJP. The BPH model was made in the latter five groups by hypodermic injection of testosterone propionate. From the first day of modeling, the rats of the normal control and BPH model control groups were treated with blank plasters and those of the high-, medium- and low-dose RJP groups with RJPs at 42.0, 21.0 and 10.5 cm2/kg applied to the dehaired area of the back, and those of the finasteride group by gavage of finasteride at 4.5 mg/kg, all once a day for 30 successive days. Then the prostates of the animals were harvested for observation of histopathological changes by HE staining, measurement of the areas of interstitial and epithelial cells and prostatic glandular cavity, and determination of the expressions of P38, JNK2, NF-кBP65 and STAT3 proteins in the prostate tissue by Western blot.
Results: Compared with the BPH model controls, the high-dose RJP group showed significantly decreased proliferation and area proportion of prostatic epithelial cells (P < 0.05), increased area proportion of the prostatic glandular cavity (P < 0.05), and reduced expressions of P38, p-P38, NF-кBP65, P-NF-кBP65, STAT3, P-STAT3 and JNK2 in the prostate tissue (P < 0.05); the medium-dose RJP group exhibited markedly down-regulated expressions of JNK2 and NF-кBP65 (P < 0.05) but an up-regulated level of p-JNK (P < 0.05); while the low-dose RJP group displayed a remarkably reduced expression of JNK2 (P < 0.05) but an elevated level of p-JNK (P < 0.05).
Conclusions: RJP suppresses BPH in the model rat by down-regulating the expressions of P38, p-P38, NF-кBP65, P-NF-кBP65, STAT3, P-STAT3 and JNK2 or up-regulating that of p-JNK in the prostate tissue.
Keywords: P38; Ruyi Jinuang Plaster; c-Jun N-terminal kinase 2; nuclear factor кBP65; rat; signal transducer and activator of transcription 3; testosterone propionate; benign prostatic hyperplasia.