Aquaporins as Targets of Dietary Bioactive Phytocompounds

Abstract

Plant-derived bioactive compounds have protective role for plants but may also modulate several physiological processes of plant consumers. In the last years, a wide spectrum of phytochemicals have been found to be beneficial to health interacting with molecular signaling pathways underlying critical functions such as cell growth and differentiation, apoptosis, autophagy, inflammation, redox balance, cell volume regulation, metabolic homeostasis, and energy balance. Hence, a large number of biologically active phytocompounds of foods have been isolated, characterized, and eventually modified representing a natural source of novel molecules to prevent, delay or cure several human diseases. Aquaporins (AQPs), a family of membrane channel proteins involved in many body functions, are emerging among the targets of bioactive phytochemicals in imparting their beneficial actions. Here, we provide a comprehensive review of this fast growing topic focusing especially on what it is known on the modulatory effects played by several edible plant and herbal compounds on AQPs, both in health and disease. Phytochemical modulation of AQP expression may provide new medical treatment options to improve the prognosis of several diseases.

Keywords: anti-inflammatory; antioxidants; aquaporin membrane channels; chronic diseases; epigenetics; functional foods; gut microbiota; nutraceutics.

Figure 1

Mammalian aquaporins are grossly subdivided in orthodox aquaporins (AQP0, AQP1, AQP2, AQP4, AQP5, AQP6, and AQP8) and aquaglyceroporins (AQP3, AQP7, AQP9, and AQP10) depending on their ability to conduct only water or glycerol and some other small neutral solutes, in addition to water, respectively. Two of the 13 AQPs found in mammals, AQP11 and AQP12, are called unorthodox aquaporins as they show marked distinctions in terms of evolutionary pathway. Some AQPs also express conductance to gases of physiological relevance.

Figure 2

Some AQPs also allow transport of ammonia (AQP3, AQP4, AQP6, AQP7, AQP8, and AQP9), particularly AQP8, and/or hydrogen peroxide (AQP1, AQP3, AQP5, AQP8, and AQP9) and are called ammoniaporins (or aquaammoniaporins) and peroxiporins, respectively.