Therapeutic potential of plant-derived tannic acid on pulmonary disorders in experimental models

A wide variety of acute and chronic respiratory diseases pose a significant disability and mortality worldwide. To date, very few classes of safe and effective therapy are available to effectively manage disease conditions. In recent years, phytochemicals derived from food plants are getting high attention due to their diverse beneficial effects with minimal toxicity. Tannic acid (TA), a water-soluble gallotannin, is present in many plant-based food products. Accumulating experimental evidences indicate that TA possesses numerous health benefits. However, there is no comprehensive review that addresses the beneficial effects of TA on various respiratory diseases. This review provides an overview of the chemical structure, natural sources, bioavailability, toxicity, and beneficial effects of TA against a wide range of respiratory diseases. We have also discussed the mechanistic pathways through which TA offers its beneficial effects. In cancerous cells, it has been reported that TA can help to overcome multidrug resistance by increasing the sensitivity to anti-cancer drugs. Researchers have found that TA-based nanoparticles showed promising results in cancer treatment. Further, as a novel drug nanocarrier, TA has significant potential for the effective delivery of pharmaceutical drugs to lung cancer cells. Yet, clinical applications of TA against respiratory diseases have not been performed. Currently, pharmacokinetic studies of TA are very limited, which may be the reason for the lack of clinical usage. Nevertheless, further studies aimed at implementing appropriate risk and benefit assessment would accelerate the clinical usage of TA for treating common respiratory diseases.