Chitosan-based nanoformulated (–)-epigallocatechin-3-gallate (EGCG) modulates human keratinocyte-induced responses and alleviates imiquimod-induced murine psoriasiform dermatitis

Abstract

BackgroundPsoriasis is a chronic and currently incurable inflammatory skin disease characterized by hyperproliferation, aberrant differentiation, and inflammation, leading to disrupted skin barrier function. The use of natural agents that can abrogate these effects could be useful for the treatment of psoriasis. Earlier studies have shown that treatment of keratinocytes and mouse skin with the green tea polyphenol (−)-epigallocatechin-3-gallate (EGCG) mitigated inflammation and increased the expression of caspase-14 while promoting epidermal differentiation and cornification. However, bioavailability issues have restricted the development of EGCG for the treatment of psoriasis.Materials and methodsTo overcome these limitations, we employed a chitosan-based polymeric nanoparticle formulation of EGCG (CHI-EGCG-NPs, hereafter termed nanoEGCG) suitable for topical delivery for treating psoriasis. We investigated and compared the efficacy of nanoEGCG versus native or free EGCG in vitro and in an in vivo imiquimod (IMQ)-induced murine psoriasis-like dermatitis model. The in vivo relevance and efficacy of nanoEGCG formulation (48 µg/mouse) were assessed in an IMQ-induced mouse psoriasis-like skin lesion model compared to free EGCG (1 mg/mouse).ResultsLike free EGCG, nanoEGCG treatment induced differentiation, and decreased proliferation and inflammatory responses in cultured keratinocytes, but with a 4-fold dose advantage. Topically applied nanoEGCG elicited a significant (p<0.01) amelioration of psoriasiform pathological markers in IMQ-induced mouse skin lesions, including reductions in ear and skin thickness, erythema and scales, proliferation (Ki-67), infiltratory immune cells (mast cells, neutrophils, macrophages, and CD4+ T cells), and angiogenesis (CD31). We also observed increases in the protein expression of caspase-14, early (keratin-10) and late (filaggrin and loricrin) markers of differentiation, and the activator protein-1 factor (JunB). Importantly, a significant modulation of several psoriasis-related inflammatory cytokines and chemokines was observed compared to the high dose of free EGCG (p<0.05). Taken together, topically applied nanoEGCG displayed a >20-fold dose advantage over free EGCG.ConclusionBased on these observations, our nanoEGCG formulation represents a promising drug-delivery strategy for treating psoriasis and possibly other inflammatory skin diseases.

Fisetin, a 3,7,3′,4′-Tetrahydroxyflavone Inhibits the PI3K/Akt/mTOR and MAPK Pathways and Ameliorates Psoriasis Pathology in 2D and 3D Organotypic Human Inflammatory Skin Models

“…Moreover, the overexpression of the components of mTOR/PI3K/Akt and associated signaling has been associated with psoriatic disease [30,31,76]. In this study, fisetin (1‒40 µM) treatment of NHEKs significantly increased TGase enzyme activity by 13–120%, as well as the protein expressions of TGase-1 and other differentiation markers often observed to be downregulated in lesioned psoriatic skin [38,44]. Therefore, the antiproliferative and prodifferentiative effects of fisetin on keratinocytes suggest that fisetin may correct the proliferative and differentiation imbalances observed in psoriatic keratinocytes.…”

“…Formalin-fixed, paraffin-embedded (FFPE) 5-μM cross sections were de-paraffinized by incubation in xylene (soaking twice for 10 min each), rehydrated with ethanol (twice in 100% ethanol for 10 min, twice in 95% ethanol for 10 min and then in 70% ethanol for 10 min), and finally placed in distilled water for 10 min. Antigen retrieval was performed by treatment with fresh sodium citrate buffer with 0.05% Tween 20 at pH 6.0, for 30 min at 100 °C, and sections were stained with H&E and evaluated for gross morphology, epidermal, and horny layer thickness and immunostained for the specified markers as previously described [37,44,45]. Briefly, endogenous peroxidase was blocked with 3% H 2 O 2 in methanol and incubated with a blocking solution containing 3% bovine serum albumin ( BSA)/3% normal goat serum (NGS)/0.4% Triton X-100 in PBS for 60 min at RT, followed by overnight incubation at 4°C with monoclonal antibodies (mouse cytokeratin 10 (RKSE 60) (1:75, sc-23877), mouse anti-Desmoglein-1 (1:75, Invitrogen #326000), rabbit anti-filaggrin (1:100; ab34584); rabbit anti-involucrin (1:75; 2215)).…”

Flavonoids: Broad Spectrum Agents on Chronic Inflammation

“…Especially, topical application through skin is one of plausible routes of flavonoid administration in human. Flavonoids may be efficiently used for skin inflammatory disorders topically if proper formulation such as nanoparticle or lipid nanocapsule is used (Chuang et al ., 2017; Chamcheu et al ., 2018; Hatahet et al ., 2018). As noted above, applicable disorders by using flavonoid therapy are expanding.…”

A Double-Blind, Randomized Trial Shows the Role of Zonal Priming and Direct Topical Application of Epigallocatechin-3-Gallate in the Modulation of Cutaneous Scarring in Human Skin

“…There is, however, a lack of relevant studies investigating the effects of EGCG on macrophages in vivo. There have been animal studies, including a study by Chamcheu et al (2018), showing that EGCG reduced infiltratory immune cells (MCs, neutrophils, macrophages, and CD4 þ T cells). Another study found that EGCG targets Notch to regulate the inflammatory response in the immediate early stage of healing (Wang et al, 2017).…”