A Review on Bioactive Iridoids in Edible Fruits–from Garden to Food and Pharmaceutical Products

Abstract

Iridoids are natural monoterpenoids, widely distributed in ornamental plants, herbs, and medicinal plants, but particularly in the green parts of plants. Their significance arises from diverse biological activities (anti-inflammatory, antioxidative, anti-cancer, anti-atherogenic, antidiabetic, neuroprotective, etc.) which have been well-documented and point out to the natural-origin, non-toxic compounds for the use in disease prevention and treatment. Nonetheless, iridoids are scarce in edible fruits and are not perceived as important phytocompounds of dietary fruits and food products. However, they do occur in some common edible fruits–olive, noni, berries, and a few less-common, but unique fruits–Japanese cornel, cornelian cherry, kousa dogwood, haskap berry, and guelder rose. In this review, we present the current state of knowledge regarding the identification and content of iridoids in edible fruits, their predominant activities, and above all, the possibilities and effects of iridoids’ application in foods, drinks, and pharmaceuticals. The consulted literature shows that iridoids or iridoid-rich fruits can be successfully applied to broaden the variety of foods, as functional additives, and possibly as future pharmaceuticals of natural origin. Therefore, iridoids deserve an important role in a healthy diet and disease prevention.