Boldine as antioxidant: From farm to pharmacy

Oxidative stress plays a causative and important role in the initiation and progression of various diseases such as cancer, cardiovascular and neurodegenerative pathologies. Over the last decades, much attention has been focused on diet as a rich source of natural antioxidants such as flavonoids, carotenoids, and alkaloids. Recent studies have demonstrated that different alkaloids, derived from plants, microorganisms, and marine organisms, are effective antioxidants both under in vitro and in vivo conditions. In addition, alkaloids are known as highly scavengers of reactive oxygen and nitrogen species (such as hydroxyl radical and peroxynitrite ) and from this way, possess a wide range of health -promoting effects. Boldine is one of the most important antioxidant alkaloids, widely distributed in the Chilean medicinal plant, commonly known as boldo. There are several scientific studies about the in vitro antioxidant effects of boldine as well as in vivo protective role of this alkaloid against oxidative stress. According to its chemical structure, the phenol group bound to the aporphine ring and the benzylic amine function play important roles in the antioxidant and free radical scavenging activities of boldine. Furthermore, boldine inhibitory activity against lipid peroxidation is due to the presence of hydroxyl moieties in its chemical skeleton. The aim of the present chapter is to examine the antioxidant activity of boldine and its mechanism of action in order to explain its potential health-promoting effects. As a first step, the definitions and important aspects regarding reactive species, oxidative stress and potential role of oxidative stress have been discussed as background for next steps of this chapter. Subsequently, we provide information regarding boldo (the main source of boldine), boldine, its chemistry and toxicity. Finally we critically reviewed the available literature data on antioxidant and free radical scavenging activities of boldine and its potential mechanisms of actions.