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The incidence of colon cancer recurrence and metastasis is known to increase as an adverse effect related to postoperative infection. Lipopolysaccharide or LPS, which is derived from gram-negative bacteria, is a key inducer of inflammatory-related tumor metastasis. Although there are numerous known biological effects of purple rice extract (PRE), its protective effect on colon metastasis was unknown. This study first evaluated the effects of hexane soluble fraction (HSF) or γ-oryzanol-rich fraction of PRE on LPS-induced colon cancer adhesion and invasion, which was accomplished using adhesive and invasive assay. Gelatin zymography was also utilized for gelatinase activity and secretion. Its chelating activity was also further analyzed by reverse gelatin zymography with zinc chloride. The study findings support the synergistic effect of HSF in protection against adverse events from LPS-induced colon cancer metastasis, as shown by effects on adhesive and invasive ability as well as matrix metalloproteinase-2 secretion and activity. PRACTICAL APPLICATIONS: Bacterial infection is still one of the main adverse events following abdominal cancer surgery and is associated with an increased incidence of colon cancer metastasis. Lipopolysaccharide (LPS) is a major component of this pathogen-mediated response. This first study investigated the efficiency of a gamma-oryzanol (OR) rich fraction, collected from purple rice extract (PRE), against LPS-induced colon cancer metastasis that occurs via three main steps; adhesion to the extracellular matrix, the secretion, and activity of gelatinase and further tissue invasion. The acquired data supported the role of an OR-rich fraction from PRE as a potential inhibitor to LPS-induced colon cancer progression. This finding, related to PRE, could be further developed to create a new adjunctive treatment to reduce operative complications related to bowel cancer surgery as well as increasing the value of this crop in Thailand., (© 2020 Wiley Periodicals LLC.)

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., (© 2019 Wiley Periodicals, Inc.)