Standardized Pluchea Indica Leaf Extract Exhibited Antiproliferative Activity Against TGF-β-induced Prostate Stromal Cells (WPMY-1) Through G 1 Phase Cell Cycle Arrest via SMAD2/3 and ERK1/2 Signaling Pathways.

Background/aim: Benign prostatic hyperplasia (BPH) is characterized by the abnormal proliferation of prostate stromal cells, resulting in the enlargement of the prostate gland and the manifestation of troublesome symptoms, such as nocturia, urinary retention, and urinary incontinence. Dihydrotestosterone (DHT) and interleukin-17 (IL-17) are known to be key factors in promoting the overproduction of transforming growth factor-beta (TGF-β) in prostate stromal cells, contributing to their excessive proliferation, leading to BPH.

Materials and methods: In this study, selected plant extracts traditionally used to alleviate urinary symptoms were subjected to primary screening for their anti-proliferative activity by evaluating DHT- and IL-17-induced proliferation in WPMY-1 prostate stromal cells. This was followed by a secondary screening using TGF-β induction.

Results: The extract that significantly inhibited cell proliferation was standardized and further investigated for its anti-proliferative effects through the TGF-β signaling pathway. Results showed that the leaf extract of P. indica significantly inhibited cell proliferation induced by DHT, IL-17, and TGF-β. It was demonstrated that P. indica has anti-proliferative properties via the TGF-β signaling pathways by inhibiting PCNA protein expression and inducing cell accumulation at the G₀/G₁ phase, while reducing the cell population at the S phase. Additionally, it down-regulated the expression of both canonical (p-SMAD2/3) and non-canonical (p-ERK1/2) proteins in TGF-β-induced WPMY-1 cells.

Conclusion: The standardized leaf extract of P. indica showed notable anti-proliferative activity against TGF-β-induced WPMY-1 cells by arresting the cell cycle at the G₀/G₁ phase through the SMAD2/3 and ERK1/2 signaling pathways.