Synthesis and activity of the salicylic acid ester of bakuchiol in psoriasis-surrogate keratinocytes and skin substitutes

Synthesis and new skin-relevant properties of the salicylic acid ester of bakuchiol

Bakusylan (bakuchiol salicylate) is a bipartite compound obtained by merging two skin-active entities with complementary bioactivities-bakuchiol and salicylic acid-for the purpose of generating a new class of functional retinoids with enhanced skin benefits. Here, we describe its preparation process and report that pure bakusylan exhibits potential for an improved permeation through the stratum corneum, enhances type IV collagen gene expression in organotypic skin substitutes containing both epidermal and dermal layers, and upregulates this protein in adult human dermal fibroblast cultures. The mechanism of action underlying these effects appears to involve the components of the IP3K/Akt signaling pathway selectively implicated in the maintenance of skin integrity, further underlying the suitability of this ester for skin care applications requiring enhanced cutaneous permeation targeting the dermal-epidermal junction.

Bakuchiol and ethyl (linoleate/oleate) synergistically modulate endocannabinoid tone in keratinocytes and repress inflammatory pathway mRNAs

The endocannabinoid (eCB) system plays an active role in epidermal homeostasis. Phytocannabinoids such as cannabidiol modulate this system but also act through eCB-independent mechanisms. This study evaluated the effects of cannabidiol, bakuchiol (BAK), and ethyl (linoleate/oleate) (ELN) in keratinocytes and reconstituted human epidermis. Molecular docking simulations showed that each compound binds the active site of the eCB carrier FABP5. However, BAK and ethyl linoleate bound this site with the highest affinity when combined 1:1 (w/w), and in vitro assays showed that BAK + ELN most effectively inhibited FABP5 and fatty acid amide hydrolase. In TNF-stimulated keratinocytes, BAK + ELN reversed TNF-induced expression shifts and uniquely downregulated type I IFN genes and PTGS2 (COX2). BAK + ELN also repressed expression of genes linked to keratinocyte differentiation but upregulated those associated with proliferation. Finally, BAK + ELN inhibited cortisol secretion in reconstituted human epidermis skin (not observed with cannabidiol). These results support a model in which BAK and ELN synergistically interact to inhibit eCB degradation, favoring eCB mobilization and inhibition of downstream inflammatory mediators (e.g., TNF, COX-2, type I IFN). A topical combination of these ingredients may thus enhance cutaneous eCB tone or potentiate other modulators, suggesting novel ways to modulate the eCB system for innovative skincare product development.

Applications of bakuchiol in dermatology: Systematic review of the literature

BACKGROUND

Bakuchiol (BAK), a meroterpene phenol abundant in the plant Psoralea corylifolia, is an emerging cosmeceutical agent with promising anti-aging, anti-inflammatory, and antibacterial properties. The trend for "clean" skincare products and search for anti-aging retinoid alternatives have poised BAK as a "must-have" ingredient in skincare.

AIMS

Our aim was to review the data for the applications of BAK in dermatology.

METHODS

This is a systematic review of PubMed.

RESULTS

Thirty articles matched our search terms ["Bakuchiol" and "Dermatology"] or ["Bakuchiol" and "Skin"] of which one did not meet inclusion criteria, 16 were pre-clinical studies, seven clinical studies, three commentaries, two narrative reviews, and one report on adverse events. BAK has been mostly studied for its effects on photoaging, acne, and post-inflammatory hyperpigmentation (PIH), showing beneficial results comparable to those achieved by topical retinoids. While having no structural resemblance to retinoids, BAK can function as a retinol analog, through retinol-like regulation of gene expression. In in vivo studies, BAK was used alone or in combination with other products resulting in a significant reduction in photodamage, hyperpigmentation, wrinkle scores, and acne severity. Additionally, in vitro studies hinted at its anti-cancer properties by inhibiting epidermal growth factor induced neoplastic cell transformation. Also, demonstrated potential applications in psoriasis by normalizing keratinocyte activity and in pigmentary disorders through inhibition of melanogenesis. There was one adverse event case reported of contact dermatitis in the literature.

CONCLUSIONS

Bakuchiol is a retinol alternative with anti-aging, antibacterial, and anti-inflammatory properties. Additional studies are warranted to better understand its applications in dermatology.

The Efficacy and Tolerability of Turmeric and Salicylic Acid in Psoriasis Treatment

Introduction

Patients and Methods

Results

Conclusion

Bakuchiol – a natural meroterpenoid: structure, isolation, synthesis and functionalization approaches

Bakuchiol is an emblematic meroterpene class of natural product extracted from Psoralea corylifolia. It has been reported to possess a broad range of biological and pharmacological properties and is considered as a leading biomolecule. It is highly desirable to devise an efficient approach to access bakuchiol and its chemical biology applications. In this review we provided structural features, isolation methods, various chemical routes and late-stage functionalization (LSF) approaches for bakuchiol and its derivatives. Moreover, this review encompasses the structure–activity relationships (SAR), value-added contributions and future perspectives of bakuchiol

The isolation methods, various chemical routes and late-stage functionalization approaches and structure–activity relationships of bakuchiol – a meroterpene class of natural product has been discussed in detail.

A Sensitization-Free Dimethyl Fumarate Prodrug, Isosorbide Di-(Methyl Fumarate), Provides a Topical Treatment Candidate for Psoriasis

Dimethyl fumarate (DMF) is an effective oral treatment for psoriasis administered in Europe for nearly 60 years. However, its potential has been limited by contact dermatitis that prohibits topical application. This paper characterizes a DMF derivative, isosorbide DMF (IDMF), which was designed to have antipsoriatic effects without skin-sensitizing properties. We show that IDMF exhibits neither genotoxicity nor radiation sensitivity in skin fibroblasts and is nonirritating and nonsensitizing in animal models (rat, rabbit, guinea pig). Microarray analysis of cytokine-stimulated keratinocytes showed that IDMF represses the expression of genes specifically upregulated in psoriatic skin lesions but not those of other skin diseases. IDMF also downregulated genes induced by IL-17A and TNF in keratinocytes as well as predicted targets of NF-κB and the antidifferentiation noncoding RNA (i.e., ANCR). IDMF further stimulated the transcription of oxidative stress response genes (NQO1, GPX2, GSR) with stronger NRF2/ARE activation compared to DMF. Finally, IDMF reduced erythema and scaling while repressing the expression of immune response genes in psoriasiform lesions elicited by topical application of imiquimod in mice. These data show that IDMF exhibits antipsoriatic activity that is similar or improved compared with that exhibited by DMF, without the harsh skin-sensitizing effects that have prevented topical delivery of the parent molecule.