Faculty of Medicine, Department of Biochemistry, Chiang Mai University, Chiangmai, Thailand.
Faculty of Medicine, Research Administration Section, Chiang Mai University, Chiangmai, Thailand.
J Food Biochem. 2019 Sep;43(9):e12987. doi: 10.1111/jfbc.12987. Epub 2019 Jul 24.
The preventive effects of purple rice crude ethanolic extract (PRE) were firstly investigated on testosterone-induced benign prostatic hyperplasia (BPH) in castrated rats. As compared to vehicle-treated rats, lower prostate weights were found in the BPH rats that received PRE 1 g/kg bw. In addition, the PRE treatment down-regulated the androgen receptor (AR) expression in the dorsolateral prostate of those rats. In human prostate cancer cell line, LNCaP, PRE could reduce the cell growth, down-regulate the expression of AR and suppress prostate-specific antigen (PSA) secretion. Moreover, PRE also inhibited an activity of 5α-reductase from rat liver microsomes and the mutagenicity of Salmonella Typhimurium induced by standard mutagen. These results demonstrate that PRE altered testosterone-induced BPH in rats and retarded prostate cancer cell growth by modulating AR expression. It is therefore recommended that further investigation is undertaken into the chemopreventive potential of PRE in androgen-AR mediated diseases. PRACTICAL APPLICATIONS: This study revealed the mechanisms of purple rice extract on testosterone-induced rat benign prostatic hyperplasia. Such information, purple rice components show promise as an effective chemopreventive agent for prostatic hyperplasia prevention by alternating the influence of testosterone through its receptor. Thus, purple rice might be developed as food supplement for reduction of prostatic hyperplasia or cancer in elder men.
本研究首次探讨了紫米粗醇提物（PRE）对去势大鼠睾丸酮诱导的良性前列腺增生（BPH）的预防作用。与 vehicle 处理的大鼠相比，PRE 1g/kg bw 处理的 BPH 大鼠前列腺重量较低。此外，PRE 处理下调了这些大鼠背外侧前列腺中的雄激素受体（AR）表达。在人前列腺癌细胞系 LNCaP 中，PRE 可减少细胞生长，下调 AR 的表达并抑制前列腺特异性抗原（PSA）的分泌。此外，PRE 还抑制了来自大鼠肝微粒体的 5α-还原酶的活性和标准诱变剂诱导的鼠伤寒沙门氏菌的致突变性。这些结果表明，PRE 通过调节 AR 表达改变了大鼠睾丸酮诱导的 BPH，并减缓了前列腺癌细胞的生长。因此，建议进一步研究 PRE 在雄激素-AR 介导的疾病中的化学预防潜力。
本研究揭示了紫米提取物对睾丸酮诱导的大鼠良性前列腺增生的作用机制。这些信息表明，紫米成分有望通过其受体改变睾丸酮的影响，成为预防前列腺增生的有效化学预防剂。因此，紫米可能被开发为老年男性前列腺增生或癌症的减少的膳食补充剂。
