Elevation of brain magnesium with Swiss chard and buckwheat extracts in an animal model of reduced magnesium dietary intake

Abstract

Objectives: Inadequate dietary magnesium (Mg) intake is a growing public health concern. Mg is critical for diverse metabolic processes including energy production, macromolecule biosynthesis, and electrolyte homeostasis. Inadequate free Mg2+ ion concentration ([Mg2+]) in the brain is associated with several neurological and behavioral disorders. Elevating [Mg2+]in the brain using oral Mg supplementation has proven to be challenging due to the tight regulation of Mg2+ transport to the brain. This study explored the effect of short-term moderate reduction in dietary Mg intake (87% of normal Mg diet for 30 days) on [Mg2+] in the cerebrospinal fluid (CSF) ([Mg2+]CSF) and red blood cells (RBCs) ([Mg2+]RBC) in adult male rats. In addition, we investigated the effectiveness of magnesium-rich blend of Swiss chard and buckwheat extracts (SC/BW extract) in increasing brain [Mg2+] compared to various Mg salts commonly used as dietary supplements. Methods: Animals were assigned to either normal or low Mg diet for 30 - 45 days. Following this, animals maintained on low Mg diet were supplemented with various Mg compounds. [Mg2+]CSF and [Mg2+]RBC were measured at baseline and following Mg administration. Anxiety-like behavior and cognitive function were also evaluated. Results: The present study showed that a short-term and moderate reduction in Mg dietary intake results in a significant decline in [Mg2+]CSF and [Mg2+]RBC and the emergence of anxiety-like behavior in comparison to animals maintained on normal Mg diet. Supplementation with SC/BW extract significantly elevated [Mg2+]CSF and improved animal performance in the novel object recognition test in comparison with animals maintained on reduced Mg intake and supplemented with various Mg compounds. Discussion: These observations indicate that brain [Mg2+] is more sensitive to a short-term and moderate reduction in Mg dietary intake than previously thought and emphasizes the importance of dietary Mg in replenishing brain Mg2+ reserves.