Biological Evaluation of a Novel Red Maple Leaf Extract for Nutraceutical Applications

Abstract

The red maple (Acer rubrum) and sugar maple (Acer saccharum) species, which are endemic to eastern North America, are widely known for their sap which is used produce the natural sweetener, maple syrup. Interestingly, various parts of the red maple tree have been used as traditional medicines by the indigenous people of North America and our laboratory has identified a series of glucitol‐core containing gallotannins (GCGs) from its aerial parts. These GCGs show a wide range of biological activities including antioxidant, anti‐diabetic, anti‐glycation, and anti‐proliferative effects. Herein, we report the biological evaluation of a red maple leaf extract (MLX) for functional food/nutraceutical applications. The MLX was evaluated in a panel of in vitro assays antioxidant, anti‐glycation, and anti‐acetylcholinesterase effects. At concentrations ranging from 20 to 500 μg/mL, MLX scavenged free radicals in the DPPH assay, as well as displayed ferric reducing antioxidant power in the FRAP assay. MLX showed inhibitory effects against the formation of advanced glycation endproducts and acetylcholinesterase enzyme with IC50 values of 157.6 and 327.3 μg/mL, respectively. In summary, this study suggests that MLX should be further investigated for functional food/beverage applications given its GCGs content and biological activities. Future studies in our laboratory will include the evaluation of MLX in animal models.