The elucidation of structure-activity and structure-permeation relationships for the cutaneous delivery of phytosterols to attenuate psoriasiform inflammation

The anti-inflammatory activity of flavonoids and alkaloids from Sophora flavescens alleviates psoriasiform lesions: Prenylation and methoxylation beneficially enhance bioactivity and skin targeting

The herb Sophora flavescens displays anti-inflammatory activity and can provide a source of antipsoriatic medications. We aimed to evaluate whether S. flavescens extracts and compounds can relieve psoriasiform inflammation. The ability of flavonoids (maackiain, sophoraflavanone G, leachianone A) and alkaloids (matrine, oxymatrine) isolated from S. flavescens to inhibit production of cytokine/chemokines was examined in keratinocytes and macrophages. Physicochemical properties and skin absorption were determined by in silico molecular modeling and the in vitro permeation test (IVPT) to establish the structure-permeation relationship (SPR). The ethyl acetate extract exhibited higher inhibition of interleukin (IL)-6, IL-8, and CXCL1 production in tumor necrosis factor-α-stimulated keratinocytes compared to the ethanol and water extracts. The flavonoids demonstrated higher cytokine/chemokine inhibition than alkaloids, with the prenylated flavanones (sophoraflavanone G, leachianone A) led to the highest suppression. Flavonoids exerted anti-inflammatory effects via the extracellular signal-regulated kinase, p38, activator protein-1, and nuclear factor-κB signaling pathways. In the IVPT, prenylation of the flavanone skeleton significantly promoted skin absorption from 0.01 to 0.22 nmol/mg (sophoraflavanone G vs. eriodictyol). Further methoxylation of a prenylated flavanone (leachianone A) elevated skin absorption to 2.65 nmol/mg. Topical leachianone A reduced the epidermal thickness in IMQ-treated mice by 47%, and inhibited cutaneous scaling and cytokine/chemokine overexpression at comparable levels to a commercial betamethasone product. Thus, prenylation and methoxylation of S. flavescens flavanones may enable the design of novel antipsoriatic agents.

Model-Informed Drug Development: In Silico Assessment of Drug Bioperformance following Oral and Percutaneous Administration

The pharmaceutical industry has faced significant changes in recent years, primarily influenced by regulatory standards, market competition, and the need to accelerate drug development. Model-informed drug development (MIDD) leverages quantitative computational models to facilitate decision-making processes. This approach sheds light on the complex interplay between the influence of a drug's performance and the resulting clinical outcomes. This comprehensive review aims to explain the mechanisms that control the dissolution and/or release of drugs and their subsequent permeation through biological membranes. Furthermore, the importance of simulating these processes through a variety of in silico models is emphasized. Advanced compartmental absorption models provide an analytical framework to understand the kinetics of transit, dissolution, and absorption associated with orally administered drugs. In contrast, for topical and transdermal drug delivery systems, the prediction of drug permeation is predominantly based on quantitative structure-permeation relationships and molecular dynamics simulations. This review describes a variety of modeling strategies, ranging from mechanistic to empirical equations, and highlights the growing importance of state-of-the-art tools such as artificial intelligence, as well as advanced imaging and spectroscopic techniques.

Skin delivery of synthetic benzoyl pterostilbenes suppresses atopic dermatitis-like inflammation through the inhibition of keratinocyte and macrophage activation

Atopic dermatitis (AD) is one of the most common skin autoimmune diseases needing continuous anti-inflammatory management. Pterostilbene is reported to exhibit anti-inflammatory activity with higher bioavailability and stability than its parent compound, resveratrol. In this study, a series of synthetic pterostilbene analogs were designed by the hybridization of pterostilbene with chalcones or benzoyl chloride. Seventeen analogs derived from pterostilbene were synthesized with differences in the positions of hydroxyl, methoxyl, or fluoro moieties. These compounds were screened by the inhibitory effect on the overexpressed Th2-associated cytokines/chemokines in the activated human keratinocytes (HaCaT). The anti-IL-5 and anti-CCL5 activity of these compounds led to the identification of three effective compounds: 3a ((E)- 4-(3,5-dimethoxystyryl)phenyl benzoate), 3d ((E)- 4-(3,5-dimethoxystyryl)phenyl 2-methoxybenzoate), and 3g ((E)- 4-(3,5-dimethoxystyryl)phenyl 2-fluorobenzoate). These benzoyl pterostilbenes also significantly decreased Th1/Th17-associated proinflammatory mediators in the activated macrophages (differentiated THP-1). The result showed that the conditioned medium of benzoyl pterostilbene-treated macrophages reduced the phosphorylated STAT3 in the keratinocytes, indicating the blockade of crosstalk between resident and immune cells. Compounds 3d and 3g generally showed greater skin absorption than 3a. The flux of 3g across barrier-defective skins mimicking the AD skin was 3-fold higher than that of across intact skin. The dinitrochlorobenzene (DNCB)-induced AD mouse model manifested that topical delivery with 3g improved the pathological signs through inhibiting cytokines/chemokines (IL-5, TNF-α, CCL17, and CCL22) and macrophage recruitment. The epidermal thickness was reduced from 76 to 55 µm after topical 3g delivery. The therapeutic activity of 3g was comparable to that of tacrolimus (TAC) used as a positive control. The benzoyl pterostilbenes attenuated the inflammation via the MAPK and c-Jun signaling. Furthermore, this study provided experimental evidence of benzoyl pterostilbene analogs for therapeutic potential on AD.

Evaluation of Plasma Concentrations of Galectins-1, 2 and 12 in Psoriasis and Their Clinical Implications

Psoriasis is a complex disease that nowadays is considered not only a dermatosis but a kind of systemic disorder associated with many accompanying diseases. Metabolic complications leading to cardiovascular incidences are the cause of increased mortality in psoriatic patients. Galectins (gal) are beta-galactoside-binding lectins that exert different functions, including engagement in metabolic processes. Our aim was to assess the concentrations of gal-1, 2 and 12 in psoriatics, to establish their potential clinical implications, including in metabolic complications. Plasma galectins were assessed by ELISA in 60 psoriatic patients and 30 controls without dermatoses and a negative family history of psoriasis. Plasma concentrations of all galectins were significantly higher in patients than controls (gal-1 with p < 0.001, gal-2 and 12 with p < 0.05). There were no correlations between galectins concentrations and psoriasis severity in PASI or disease duration (p > 0.05). Gal-1 and 12 were significantly negatively correlated with GFR (p < 0.05, p < 0.01, respectively) and gal-2 with HDL (p < 0.05). Gal-2 was significantly positively correlated with CRP (p < 0.05) and gal-12 with fasting glucose (p < 0.01). Based on the results and given the reported role of galectins in metabolic disorders we may conclude that gal-1, 2 and 12 could be potentially engaged in metabolic complications in psoriatics, most probably in atherosclerosis. Gal-2 could be perhaps further investigated as a marker of metabolically induced inflammation in psoriasis, gal-1 and gal-12 as predictors of renal impairment in psoriatics due to metabolic disorders. Potentially, gal-12 could be considered in the future as a marker of carbohydrate metabolism disorders in psoriatics.