Anthocyanins: Potential Therapeutic Approaches towards Obesity and Diabetes Mellitus Type 2

Abstract

Overweight and obesity are present in about three-quarters of the adult population in Mexico. The inflammatory mechanisms subjacent to visceral white adipose tissue are accountable for the initiation and development of cardiometabolic alterations, including type 2 diabetes. Lifestyle changes are pillars within its therapeutics and, thus, current dietary modifications should include not only hypocaloric prescriptions with balanced macronutrient intake, preferably by increasing the amount of whole grains, fruits, vegetables, nuts and legumes, but in concomitance, bioactive substances, such as anthocyanins, have been correlated with lower incidence of this disease.

Keywords: anthocyanins; diabetes; functional foods; inflammation; phytochemicals.

Figure 1

Biosynthesis pathway of anthocyanins in plants. PAL: Phenylalanine Ammonia Lyase, C4H: Cinnamate 4-hydroxylase, CPR: cyto-chrome P450 reductase, 4-CL: 4-coumaroyl-CoA ligase, CHS: Chalcone Synthase, CHI: Chalcone Isomerase, F3H: Flavanone-3-Hydroxylase, F3′H: flavonoid 3′-hydroxylase, F3′5′H:Flavonoid 3′,5′-hydroxylase, DFR: Dihydroflavonol 4-reductase, ANS: Anthocya-nidin Synthase, FGT: Flavonoid Glucosyltransferase, OMT: O-Methyltransferase, ACT: Anthocyanin Acyltransferase.

Figure 2

Anthocyanidin structures.

Figure 3

Anthocyanins effects on diabetes by regulation of incretin levels and dysbiosis, reduction in hyperglycemia and inhibition of digestive enzymes (1); cytoprotecting of pancreatic cells and regulation of insulin levels (2); and decreasing diabetes complications by reducing insulin resistance, inflammation, and oxidative stress (3). Created with BioRender.com.

Figure 4

Molecular mechanisms of anti-obesity effects of anthocyanins. (1) Various anthocyanins are strong pancreatic lipase inhibitors; (2) These pigments can up-regulate AMPK expression which increases the expression of PGC1α and UCP’s, and the excretion of adipocytokines; (3) Anthocyanins inhibit fatty acid synthesis by down-regulating the expression of ACC, FAS, and SREBP’s and by up-regulation of fatty acid oxidation by increasing the expression of PPAR´s and CPT-1; (4) Pigments, such as anthocyanins, suppress food intake by reducing the expression of NPY, GABAB1R, PKA-α, and p-CREB; (5) Anthocyanins can inhibit growth of Enterococcus spp. and Clostridium perfringens, pathogens, and exert prebiotic effects enhancing the growth of beneficial strains, such as Lactobacillus spp. and/or Bifidobacterium spp.; (6) These pigments can ameliorate oxidative stress by reducing ROS production, inhibit expression of NADPH oxidase and GPx, as well as reducing the expression of CYP2E1, and also can resolve inflammation by decreasing levels of hs-CRP, MCP-1, TNF-α, and IL6.