Chemopreventive Potential of Paddy Waste: A Promising Approach Against Benign Prostate Hyperplasia in Spontaneously Hypertensive Rats

Background: Benign prostate hyperplasia (BPH) is common in elderly men. Previously, paddy waste (both husk and straw) reportedly had chemopreventive potential. The main aim of this study was to explore the chemopreventive properties of paddy waste against prostate disease. This study determines the antiproliferative activity of the paddy waste product in spontaneously hypertensive rats (SHRs). Methods: Aqueous methanol extracts of paddy husk and straw were administered to SHRs for 17 weeks via drinking water, with no observed toxicity on dietary intake, body weight, liver, or kidney. The study used 18 male SHRs to model primary hypertension and 6 male Wistar Kyoto (WKY) rats as normotensive controls. The SHRs were divided into three groups: control (n = 6), paddy husk treated (n = 6, 15 mg/kg), and paddy straw treated (n = 6, 15 mg/kg), with treatment delivered in drinking water. Results: It managed to reduce blood pressure (72.0 mmHg; p  < 0.01) and the size of the ventral prostate to around 0.05% (p  < 0.01). Histological analysis revealed antiproliferative signs such as a reduction in the number of acini (7.50; p  < 0.01), epithelial height (10.55 µm; p  < 0.01), and epithelial acinar area (18.17%; p  < 0.01). Aqueous methanol extracts have arrested the cell cycle by downregulating (p  < 0.01) proliferative marker, Ki-67, and proliferating cell nuclear antigen (PCNA). Prostate cell growth is arrested by downregulation of androgen receptor (AR) which inhibited AR mRNA transcription (RTPCR analysis) and induced cell cycle arrest at the S phase through p27 and cyclin E2 (western blot analysis). Conclusion: In conclusion, paddy waste product especially husk is a better chemopreventive agent against prostate disease.