Flavonoids and
polyphenols are heterocyclic molecules that have been associated with beneficial effects on human health, such as reducing the risk of various diseases like
cancer, diabetes, and cardiovascular and
brain diseases.
Protocatechuic acid (PCA) is a type of widely distributed naturally occurring
phenolic acid. PCA has structural similarity with
gallic acid,
caffeic acid,
vanillic acid, and
syringic acid which are well-known
antioxidant compounds. More than 500 plants contain PCA as active constituents imparting various pharmacological activity and these effects are due to their
antioxidant activities, along with other possible mechanisms, such as anti-inflammatory properties and interaction with several
enzymes. Over the past two decades, there have been an increasing number of publications on
polyphenols and
flavonoids, which demonstrate the importance of understanding the chemistry behind the
antioxidant activities of both natural and synthesized compounds, considering the benefits from their dietary ingestion as well as pharmacological use. This work aims to review the pharmacological effects of PCA molecules in humans and the structural aspects that contribute to these effects.