Mangiferin Represses Inflammation in Macrophages Under a Hyperglycemic Environment Through Nrf2 Signaling

Int J Mol Sci. 2024 Oct 18;25(20):11197. doi: 10.3390/ijms252011197.

Abstract

Inflammation in macrophages is exacerbated under hyperglycemic conditions, contributing to chronic inflammation and impaired wound healing in diabetes. This study investigates the potential of mangiferin, a natural polyphenol, to alleviate this inflammatory response by targeting a redox-sensitive transcription factor, nuclear factor erythroid 2-related factor 2 (Nrf2). Mangiferin, a known Nrf2 activator, was evaluated for its ability to counteract the hyperglycemia-induced inhibition of Nrf2 and enhance antioxidant defenses. The protective effects of mangiferin on macrophages in a hyperglycemic environment were assessed by examining the expression of Nrf2, NF-κB, NLRP3, HO-1, CAT, COX-2, IL-6, and IL-10 through gene and protein expression analyses using qPCR and immunoblotting, respectively. The mangiferin-mediated nuclear translocation of Nrf2 was evidenced, leading to a robust antioxidant response in macrophages exposed to a hyperglycemic microenvironment. This activation suppressed NF-κB signaling, reducing the expression of pro-inflammatory mediators such as COX-2 and IL-6. Additionally, mangiferin decreased NLRP3 inflammasome activation and reactive oxygen species accumulation in hyperglycemia exposed macrophages. Our findings revealed that mangiferin alleviated hyperglycemia-induced reductions in AKT phosphorylation, highlighting its potential role in modulating key signaling pathways. Furthermore, mangiferin significantly enhanced the invasiveness and migration of macrophages in a hyperglycemic environment, indicating its potential to improve wound healing. In conclusion, this study suggests that mangiferin may offer a promising therapeutic approach for managing inflammation and promoting wound healing in diabetic patients by regulating Nrf2 activity in hyperglycemia-induced macrophages.

Keywords: Nrf2 activation; antioxidant response; inflammation; macrophages; mangiferin.

MeSH terms

  • Animals
  • Antioxidants / pharmacology
  • Hyperglycemia* / drug therapy
  • Hyperglycemia* / metabolism
  • Inflammasomes / drug effects
  • Inflammasomes / metabolism
  • Inflammation* / drug therapy
  • Inflammation* / metabolism
  • Inflammation* / pathology
  • Macrophages* / drug effects
  • Macrophages* / metabolism
  • Mice
  • NF-E2-Related Factor 2* / metabolism
  • NF-kappa B / metabolism
  • NLR Family, Pyrin Domain-Containing 3 Protein / metabolism
  • RAW 264.7 Cells
  • Reactive Oxygen Species / metabolism
  • Signal Transduction* / drug effects
  • Xanthones* / pharmacology

Substances

  • mangiferin
  • NF-E2-Related Factor 2
  • Xanthones
  • NF-kappa B
  • NLR Family, Pyrin Domain-Containing 3 Protein
  • Nfe2l2 protein, mouse
  • Reactive Oxygen Species
  • Inflammasomes
  • Antioxidants