Study On The Effects Of 5α-Reductase Inhibitors And Photodynamic Therapy On Benign Prostatic Hyperplasia

Benign prostatic hyperplasia (BPH) is common and frequently occurs among elder men. BPH is the main reason of urinary obstruction. Therefore, the treatment for BPH has attracted the wide concerns, and it has an important significance for the investigation of treating BPH. In this paper, the base information of BPH, Photodynamic therapy (PDT), photosencitizers and 5α-reductatse inhibitors are introduced firstly. Then, following three studies have been executed.In first section of the studies, the extraction efficiency of ethanol extract from seeds of Brassica alba has been studied. A number of factors, including extraction temperature and time, the ratio of seeds of Brassica alba and solvent, as well as the concentration of the solvent, have been discussed. The optimal conditions for the extraction of ethanol extract were found: seeds of Brassica alba (50g) was extracted twice with 80% ethanol (300mL) at 80 for 8 hours. Under these conditions, the yield of ethanol extract was 9.52%. Then, the therapeutical efficacy of ethanol extract from seeds of Brassica alba on the benign prostatic hyperplasia rats was investigated. Rats were administered with testosterone propionate 5 mg/(kg·d) subcutaneously for 15 days, and then administered with the ethanol extract from seeds of Brassica alba 30, 60, 120 mg/(kgd) orally respectively for 15 days. The results showed that ethanol extract from seeds of Brassica alba could significantly suppress BPH caused by testosterone propionate in rats, decrease the wet-weight of prostate remarkably, and the serum acid phosphatase (ACP) was observably decreased compared with the model group. It is indicated that ethanol extract from seeds of Brassica alba has positive effect on BPH caused by testosterone propionate.In the second section of the studies, a HPLC model screening and evaluating the steroid 5α-reductatse inhibitors was proposed. Proper HPLC operating conditions were investigated, which could determine the activity of the steroid 5α-reductatse. These conditions include column, temperature, solvent, mobile phase, flow rate, and detectionwavelength. The analysis of testosterone and other compounds investigated required no longer than 15 minutes. Suitable chromatographic condition: the column was RPC 18 column, the column temperature was ambient; the mobile phase was mixture of methanol and water (70/30, v/v) maintained at a flow rate of 0.7mL/min, and the UV detector was used at a wavelength of 254nm. Under these conditions, it can separate and analyze testosterone and other compounds. The precision is 0.9%~1.5% and recoveries are 89.70%~95.52%. Under the proper HPLC operating conditions, the activity of the steroid 5α-reductatse was determined. The activity of the enzymatic is defined as the descending rate of the concentration of testosterone. And inhibition constant (Ki) of the steroid 5α-reductatse inhibitors could be calculated according to the Lineweaver-Burk plots. The inhibition constants (Ki) of ethanol extract from seeds of Brassica alba, Finasteride and Epristeride were 3.68±0.31μmol/L, 1.14±0.23μmol/L and 4.32±0.38μmol/L, respectively. And the inhibit efficacy of ethanol extract from seeds of Brassica alba increased with the increase of concentration of ethanol extract. The results were consistent with those of the studies in first section. It is indicated that this method of HPLC is simple, rapid and reproducible well to screen and evaluate steroid 5α-reductatse inhibitors. In the third section of the studies, the effects of HMME-PDT, ZnPcS2P2-PDT and Chlorin e6-PDT on BPH, using the rat model of benign prostatic hyperplasia as the object, were firstly investigated. Rats were divided into seven groups: the normal control, the rat model of BPH, the photosensitizer alone, laser irradiation alone, and HMME(3mg/kg)-PDT, ZnPcS2P2(3mg/kg)-PDT, Chlorin e6(3mg/kg)-PDT. The results of this study demonstrated that the photosensitizer alone and laser irradiation alone could be not efficacious for treatment of BPH. However, the cooperation between the photosensitizer and PDT could kill the prostate cells remarkably (P<0.05). And the photodynamic activity of HMME is considerably better than those of ZnPcS2P2 and Chlorin e6. This indicated that HMME-PDT can be used to treat BPH of rats more effective. Then, using HMME as the photosensitizer, the rats received HMME-PDT treatment with 1mg/kg,3mg/kg,5mg/kg HMME and application of 45J/cm2,90 J/cm2,135 J/cm2,180J/cm2 light at 670nm, respectively. The results showed that the efficacy of HMME-PDT increased significantly with the increase of concentration of HMME. HMME-PDT was almost no efficacy with low energy density of light (<45J/cm2), and with the increase of the energy density of light the photodynamic activity increased. However, Photodynamic activity decreased when the energy density of light exceeded 135 J/cm2. And the pathology change of prostate also proved the conclusions mentioned above. Then the pathology change prostate of the rats was observed and analyzed to explore the mechanism of photodynamic therapy, affordtheoretic basis for PDT of BPH in the clinic. Finally, the effects of cooperation between ethanol extract from seeds of Brassica alba and PDT on BPH caused by testosterone propionate in rats were investigated. The results indicated that the cooperation between ethanol extract from seeds of Brassica alba and PDT could treat BPH more effective than ethanol extract from seeds of Brassica alba or PDT alone.