Urtica dioica Whole Vegetable as a Functional Food Targeting Fat Accumulation and Insulin Resistance-a Preliminary Study in a Mouse Pre-Diabetic Model

Abstract

The shoot of Urtica dioica is used in several cultures as a vegetable or herb. However, not much has been studied about the potential of this plant when consumed as a whole food/vegetable rather than an extract for dietary supplements. In a 12-week dietary intervention study, we tested the effect of U. dioica vegetable on high fat diet induced obesity and insulin resistance in C57BL/6J mice. Mice were fed ad libitum with isocaloric diets containing 10% fat or 45% fat with or without U. dioica. The diet supplemented with U. dioica attenuated high fat diet induced weight gain (p < 0.005; n = 9), fat accumulation in adipose tissue (p < 0.005; n = 9), and whole-body insulin resistance (HOMA-IR index) (p < 0.001; n = 9). Analysis of gene expression in skeletal muscle showed no effect on the constituents of the insulin signaling pathway (AKT, IRS proteins, PI3K, GLUT4, and insulin receptor). Notable genes that impact lipid or glucose metabolism and whose expression was changed by U. dioica include fasting induced adipocyte factor (FIAF) in adipose and skeletal muscle, peroxisome proliferator-activated receptor-α (Ppar-α) and forkhead box protein (FOXO1) in muscle and liver, and Carnitine palmitoyltransferase I (Cpt1) in liver (p < 0.01). We conclude that U. dioica vegetable protects against diet induced obesity through mechanisms involving lipid accumulation and glucose metabolism in skeletal muscle, liver, and adipose tissue.

Combined Effects of Exercise and Phytoanabolic Extracts in Castrated Male and Female Mice

“…In addition, some studies have described benefits for U. dioica extract for management of diabetes complications [ 34 , 57 , 89 ]. More recently, it was demonstrated that supplementation with plain U. dioica led to body weight loss in mice that received a high-fat diet, via modulation of genes related to lipid and glucose metabolism [ 33 ]. In our study, the association of exercise with U. dioica extract significantly reduced the final body weight in OVX mice, and also improved the travelled distance and speed in an open arena.…”

“…The compounds present in U. dioica extract include fatty acids, phenylpropanes, lignans, coumarins, triterpenes, ceramides, sterols, and lecithins [ 31 , 32 ]. Animals supplemented with U. dioica showed a reduction of adipose tissue accumulation, lower levels of fasting glucose and insulin, a decrease in HOMA-IR, and a reduction of liver triglycerides [ 33 ]. Compelling pre-clinical evidence revealed a hypoglycemic activity for the plant, and a meta-analysis carried out by Ziaie and collaborators (2019) corroborated the beneficial effects of U. dioica on glycemic levels.…”

Kale supplementation during high fat feeding improves metabolic health in a mouse model of obesity and insulin resistance

“…The sample was subjected to nutrient composition analysis before incorporation into the diets. The dietary preparation, animal study procedures, and analytical procedures for tissues were as previously shown [ 17 ] and are briefly described in the following sections. Results of nutrient analysis by the Association of Analytical Chemists (AOAC) methods for calorific value and proximate analysis: moisture, ash, lipid, protein, carbohydrate, soluble fiber, insoluble fiber and fatty acid profile are shown in S1 and S2 Tables.…”

Activation of Insulin Signaling by Botanical Products

“…Thus, U. dioica inhibited PP2A via a ceramide-independent mechanism. In support of the effects of U. dioica extract on activation of insulin signaling, leaf extract of U. dioica had hypoglycemic effects in normoglycemic rats [ 90 ] and attenuated glucose intolerance and improved insulin sensitivity in HFD-fed mice [ 89 , 91 ]. The active components mediating the anti-diabetic effects of this botanical preparation have not yet been determined.…”