The Potential Toxic Side Effects of Flavonoids

Zhimei Tang,Qiang Zhang

doi:10.32604/biocell.2022.015958

Abstract

Flavonoids are a class of phytochemical molecules abundant in many plants, fruits, vegetables, and leaves. Flavonoids possess a series of significant biological activities, including anticancer, antioxidant, antiviral, and antiinflammatory properties. They become an important source of dietary supplements and natural health products. Though many studies confirmed the safety of flavonoids, the potential toxicity of flavonoids is still a remarkable field of research to be explored. The enthusiasm for flavonoids expressed by the public has sometimes overlooked their toxicity and also consumed the flavonoids exceeding the body requirements. The current review focused on the potential toxicity of flavonoids to make the public consume flavonoids with caution. This review summarizes the current toxicity which has been reported in vivo and in vitro experiments. The toxicity involves carcinogenicity and mutation, liver and kidney toxicity, and the influence on the thyroid and reproductive function and intestinal flora disorders. The mechanism of toxicity is fully complicated, and current evidence indicates that natural flavonoid glycosides act on different targets with different doses in vivo and in vitro experiments. Though most kinds of flavonoids are considered safe, flavonoids proposed as food supplements need to be assessed their tolerable upper intake level as there have been reports of toxic flavonoids.

Highlights

Flavonoids are a large number of small molecules abundant in fruits, vegetables, and legumes
It has been widely known for centuries that derivatives of plant origin have a broad spectrum of biological activity (Jin, 2019; Martins et al, 2019)
Many studies proved that low doses of these compounds have the potential for adverse effects. In this condition many biological effects published in a great number of scientific studies based on in vitro experiments, as well as animal and human studies declared the safety of the flavonoids, the potential toxicity found among the safety evaluation of flavonoids should be paid with caution

Summary

Introduction

Flavonoids are a large number of small molecules abundant in fruits, vegetables, and legumes. In this condition many biological effects published in a great number of scientific studies based on in vitro experiments, as well as animal and human studies declared the safety of the flavonoids, the potential toxicity found among the safety evaluation of flavonoids should be paid with caution.

Results

Conclusion