Cancer Stem Cells and Medicinal Plants, A Comprehensive Review of their Potential in Tumor Suppression and Recurrence Prevention.

Introduction: Cancer Stem Cells (CSCs) drive tumor initiation, progression, and recurrence due to their self-renewal and differentiation capacities. Herbal medicines offer potential for targeting CSCs by disrupting key pathways, inducing apoptosis, and enhancing the efficacy of conventional therapy. This review evaluates the effectiveness of plant-based compounds in suppressing CSCs across various cancers. Methods: A systematic search was conducted across databases (ISI Web of Science, PubMed, ScienceDirect, Scopus, Biological Abstracts, Chemical Abstracts) up to March 2025, using keywords such as "cancer stem cells and plant extracts." Inclusion criteria were English-language original articles or reviews on plant-based compounds targeting CSCs (in vitro, in vivo, or clinical studies) with full-text availability. Duplicates, non-relevant, non-English, or abstract-only studies were excluded, yielding 43 studies. Results: Herbal medicines derived from plants such as Pao Pereira, Rauwolfia vomitoria, and Celastrus orbiculatus inhibit CSC proliferation, self-renewal, and chemoresistance across breast, colon, pancreatic, gastric, ovarian, prostate, glioblastoma, hepatic, and lung cancers. Mechanisms include disruption of the TGF-β/Smad pathway, induction of apoptosis via caspase activation, and ROS-mediated oxidative stress, with compounds such as curcumin and resveratrol targeting Wnt, Notch, and Hedgehog pathways. Discussion: Plant-derived compounds show promise in targeting CSCs, enhancing chemotherapy sensitivity, and reducing tumor recurrence. However, inconsistent potency, limited clinical data, and bioavailability challenges limit translation. Standardized extracts and rigorous clinical trials are needed to validate efficacy and safety. Conclusion: Herbal medicines offer a promising complementary approach to CSC-targeted cancer therapy, but further research is essential to overcome current limitations and enable clinical integration.