Amauroderma rugosum Extract Suppresses Inflammatory Responses in Tumor Necrosis Factor Alpha/Interferon Gamma-Induced HaCaT Keratinocytes

Abstract

Keratinocytes form the physical barrier of the skin and play an important role in the inflammatory process. Amauroderma rugosum is an edible mushroom; however, its pharmacological properties have seldom been studied. Although the anti-inflammatory effect of the organic solvent extract of Amauroderma rugosum has been previously reported, it is not known whether the aqueous extract has a similar effect. In addition, the effect of Amauorderma rugosum extract on skin has never been explored. Therefore, the objectives of the present study were to evaluate the anti-inflammatory effects of the aqueous extract of Amauroderma rugosum on HaCaT keratinocytes, to explore its mechanisms of action, and to study the possible active ingredients involved. The results showed that the aqueous extract of Amauroderm rugosum at a concentration of 1.5 mg/mL was non-toxic to HaCaT cells and inhibited the release of cytokine interleukin-1β, and chemokines interleukin-8 and monocyte chemoattractant protein-1 in tumor necrosis factor (TNF)-α- and interferon (IFN)-γ-stimulated HaCaT cells. Amauroderma rugosum extract reduced the intracellular levels of reactive oxygen species. In addition, Amauroderma rugosum extract reduced the total protein expression of nuclear factor-kappa B (NF-κB) and B-cells inhibitor alpha in HaCaT keratinocytes and inhibited the phosphorylation of mitogen-activated protein kinase kinase (MEK) 1/2, extracellular signal-regulated kinase (ERK) 1/2, protein kinase B (Akt), and mammalian target of rapamycin (mTOR) in TNF-α- and INF-γ-stimulated HaCaT keratinocytes. Chemical analysis revealed that the aqueous extract of Amauroderma rugosum contains polysaccharides, triterpenes, and phenolic compounds. Anti-inflammatory compounds, such as gallic acid, guanosine, and uridine, were also present. The anti-inflammatory effect of Amauroderma rugosum could be mimicked by a combination of gallic acid, guanosine, and uridine. In conclusion, our study suggests that the aqueous extract of Amauroderma rugosum exerts anti-inflammatory effects on keratinocytes through its antioxidant and inhibitory effects on MEK/ERK-, Akt/mTOR-, and NF-κB-dependent signaling pathways.

Neuroprotective Effects of Polysaccharides and Gallic Acid from Amauroderma rugosum against 6-OHDA-Induced Toxicity in SH-SY5Y Cells

“…To determine the active ingredient responsible for the antioxidant effects of ARW, DPPH assays were performed on the chemical components of ARW, as described in a previous study [ 8 ]. Of the components examined, only gallic acid demonstrated a scavenging effect on the DPPH• free radicals, with an SC 50 value of 7.429 µM.).…”

“…The chemical composition of AR was determined using analytical methods, indicating the presence of sterols, flavonoids, fatty acids, esters, aromatic acids, esters, phenols, polysaccharides, and triterpenes [ 15 ]. An earlier investigation conducted using liquid chromatography-mass spectrometry (LC-MS) showed that ARW contains several major compounds, namely, ganoderic acid A, ganoderic acid D, ganoderic acid J, oleamide, (9Z, 12Z)-octadeca-9,12-dienamide, uridine, guanosine, cytosine, uracil, adenosine, adenine, gallic acid, dextrose, and l -arabinopyranose [ 8 ]. The administration of oleamide effectively mitigated the detrimental effects of 3-NP on mitochondrial function and cell survival in rat cortical sections.…”

Potentials of Natural Antioxidants in Reducing Inflammation and Oxidative Stress in Chronic Kidney Disease

“…Similarly, another study conducted by Chan et al confirmed AR’s ability to scavenge DPPH and ABTS radicals in the LPS-treated murine macrophage RAW264.7 cells [ 254 ]. Meanwhile, Shiu et al demonstrated that AR reduced intracellular ROS levels and inhibited the release of oxidant-stress-related cytokines and chemokines like IL-1β and IL-8 in TNF-α- and IFN-γ-stimulated HaCaT keratinocytes [ 257 ]. The study also identified that AR can downregulate key signalling pathways related to oxidant stress, including NF-κB, MEK1/2, ERK1/2, and Akt/mTOR.…”

Whole-genome sequencing and comparative genomic analyses of the medicinal fungus Sanguinoderma infundibulare in Ganodermataceae

“…Sanguinoderma species have been found to contain a large number of secondary metabolites, such as polysaccharides, sterols and unsaturated fatty acids, that are extremely effective against tumor progression ( Shiu et al . 2022 ), cardiovascular disease ( Li et al .…”