Tannins in cancer prevention and therapy

Abstract

Tannins are the heterogenous class of polyphenolic natural products with promising cancer chemopreventive and therapeutic potential. Studies undertaken over the last 30 years demonstrated their capacity to target many cellular pathways and molecules important in the development of cancer. Recently, new mechanisms which might be important in anticarcinogenic activity, such as inhibition of epithelial‐to‐mesenchymal transition, reduction of cancer stem cell creation, and modulation of cancer cells metabolism were described. Besides the mechanisms of tannins' activity, this review focuses on their possible application as chemosensitizers in adjuvant therapy and countering multidrug resistance. Furthermore, characteristic physicochemical properties of some tannins, particularly tannic acid, are found useful in the formation of nano‐vehicles for anti‐cancer drugs or the isolation of circulating cancer cells. These new potential applications of tannins deserve further studies. Well‐designed clinical trials, which are scarce, are necessary to assess the therapeutic effects of tannins themselves or as adjuvants in cancer treatment.

New Avenues and Major Achievements in Phytocompounds Research for Glioblastoma Therapy

“…Another group of compounds with high anti-GBM activity is gallotanins, for example, found in Quercus infectoria galls [102,103]. Kamarudin et al obtained the fractioned extract rich in gallotanins and showed its high cytotoxicity (IC 50 15.0 µg/mL) in the in vitro tests using the DBTRG-05MG cell line.…”

A Comprehensive Analysis of Diversity, Structure, Biosynthesis and Extraction of Biologically Active Tannins from Various Plant-Based Materials Using Deep Eutectic Solvents

“…The influence of tannins on the process of cancer formation has been monitored for the last 30 years, resulting in a comprehensive understanding of the molecular targets of tannins. Mechanisms of the anticancer action of tannins include the modulation of signaling pathways in cancer cells, the induction of apoptosis and autophagy, and the reduction of cancer stem cell population by downregulation of the expression of specific biomarkers, such as CD44 and ALDH1 [266,267]. The influence of tannin through these mechanisms has been mostly studied with compounds such as ellagic acid, tannic acid, and epigallocatechin gallate.…”

“…When using tea or extracts containing tannins, alongside numerous other bioactive components, isolating the specific effect of tannins becomes challenging. In such instances, any observed positive effects are often attributed to the synergy among the various components present [266]. This underscores the complexity of natural products and highlights the importance of considering interactions among multiple compounds in evaluating their therapeutic potential.…”