Terpene compounds in nature: a review of their potential antioxidant activity

Reactive Oxygen Species are involved in the pathological development of many important human diseases such as neurodegenerative diseases, cardiovascular processes, diabetes and many others. The most promising strategy to prevent from the oxidative damage caused by these reactive species is the use of antioxidant molecules. These compounds can act as direct antioxidants through free radical scavenging mechanisms and/or as indirect antioxidants by enhancing the antioxidant status (enzymatic and non-enzymatic). Terpenes, one of the most extensive and varied structural compounds occurring in nature, display a wide range of biological and pharmacological activities. Here we highlight their antioxidant properties. Due to their antioxidant behaviour terpenes have been shown to provide relevant protection under oxidative stress conditions in different diseases including liver, renal, neurodegenerative and cardiovascular diseases, cancer, diabetes as well as in ageing processes. Evidence for this comes from the increasing number of publications on this issue in recent years. This review provides a complete overview of the natural terpenes with potential antioxidant properties, focusing on their source, structures, antioxidant mechanisms through which they exert their pharmacological and possible therapeutic activities.