Cannabidiol induces antioxidant pathways in keratinocytes by targeting BACH1.

Cannabidiol (CBD) is a major non-psychotropic phytocannabinoid that attracted a great attention for its therapeutic potential against different pathologies including skin diseases. However, although the efficacy in preclinical models and the clinical benefits of CBD in humans have been extensively demonstrated, the molecular mechanism(s) and targets responsible for these effects are as yet unknown. Herein we characterized at the molecular level the effects of CBD on primary human keratinocytes using a combination of RNA sequencing (RNA-Seq) and sequential window acquisition of all theoretical mass spectrometry (SWATH-MS). Functional analysis revealed that CBD regulated pathways involved in keratinocyte differentiation, skin development and epidermal cell differentiation among other processes. In addition, CBD induced the expression of several NRF2 target genes, with heme oxygenase 1 (HMOX1) being the gene and the protein most upregulated by CBD. CRISPR/Cas9-mediated genome editing, RNA interference and biochemical studies demonstrated that the induction of HMOX1 mediated by CBD, involved nuclear export and proteasomal degradation of the transcriptional repressor BACH1. Notably, we showed that the effect of BACH1 on HMOX1 expression in keratinocytes is independent of NRF2. In vivo studies showed that topical CBD increased the levels of HMOX1 and of the proliferation and wound-repair associated keratins 16 and 17 in the skin of mice. Altogether, our study identifies BACH1 as a molecular target for CBD in keratinocytes and sets the basis for the use of topical CBD for the treatment of different skin diseases including atopic dermatitis and keratin disorders.

Identification of a Strigoterpenoid with Dual Nrf2 and Nf-κB Modulatory Activity.

The sesquiterpene-coumarin ether samarcandone provided a suitable framework to replace the apocarotenoid A-C ring system of strigol (1), replicating, after linking to a butenolide moiety, the activity of the natural phytohormone on Nrf2 and also showing potent NF-kB inhibitory activity, overall modulating two critical pathways of inflammation and cancer.

The endocannabinoid system of the skin. A potential approach for the treatment of skin disorders.

The skin is the largest organ of the body and has a complex and very active structure that contributes to homeostasis and provides the first line defense against injury and infection. In the past few years it has become evident that the endocannabinoid system (ECS) plays a relevant role in healthy and diseased skin. Specifically, we review how the dysregulation of ECS has been associated to dermatological disorders such as atopic dermatitis, psoriasis, scleroderma and skin cancer. Therefore, the druggability of the ECS could open new research avenues for the treatment of the pathologies mentioned. Numerous studies have reported that phytocannabinoids and their biological analogues modulate a complex network pharmacology involved in the modulation of ECS, focusing on classical cannabinoid receptors, transient receptor potential channels (TRPs), and peroxisome proliferator-activated receptors (PPARs). The combined targeting of several end-points seems critical to provide better chances of therapeutically success, in sharp contrast to the one-disease-one-target dogma that permeates current drug discovery campaigns.

Effect of natural and semi-synthetic cadinanes from Heterotheca inuloides on NF-κB, Nrf2 and STAT3 signaling pathways and evaluation of their in vitro cytotoxicity in human cancer cell lines.

The effects of ten natural cadinane sesquiterpenoids isolated from Heterotheca inuloides on the pathways of the NF-κB, Nrf2 and STAT3 transcription factors were studied for the first time. The main constituent in this species, 7-hydroxy-3,4-dihydrocadalene (1), showed anti-NF-κB activity and activated the antioxidant Nrf2 pathway, which may explain the properties reported for the traditional use of the plant. In addition to the main metabolite, a structurally similar compound, 7-hydroxy-cadalene (2), also displayed anti-NF-κB activity. Thus, both natural compounds were used as templates for the preparation of a novel semi-synthetic derivative set, including esters and carbamates, which were evaluated for their potential in vitro antiproliferative activities against six human cancer cell lines. Carbamate derivatives 32 and 33 were found to exhibit potent activity against human colorectal adenocarcinoma and showed important selectivity in cancer cells. Among ester derivatives, compound 13 was determined to be a more potent NF-κB inhibitor and Nrf2 activator than its parent, 7-hydroxy-3,4-dihydrocadalene (1). Furthermore, this compound decreases levels of phospho-IκBα, a protein complex involved in the NF-κB activation pathway. Molecular simulations suggest that all active compounds interact with the activation loop of the IKKß subunit in the IKK complex, which is the responsible of IκBα phosphorylation. Thus, we identified two natural, and one semi-synthetic, NF-κB and Nrf2 modulators and two new promising cytotoxic compounds.

Anti-inflammatory sesquiterpene lactones from Onopordum illyricum L. (Asteraceae), an Italian medicinal plant.

Onopordum illyricum L. is a medicinal plant used in the Mediterranean area as antipyretic for the treatment of respiratory and urinary inflammations and to treat skin ulcers. Repeated chromatographic purification of O. illyricum aerial parts led to the isolation of six known sesquiterpenes, which were evaluated for the inhibition of the pro-inflammatory transcription factors NF-κB and STAT3 and for the activation of the transcription factor Nrf2, which regulates the cellular antioxidant response. Structure-activity relationships were interpreted by the NMR-based cysteamine assay. The sesquiterpene lactone vernomelitensin significantly inhibited NF-κB and STAT3, showing also a significant Nrf2 activation. Accordingly, the cysteamine assay selected vernomelitensin as the most reactive of the isolated sesquiterpenes, identifying the α,ß-unsaturated aldehyde moiety as responsible for the higher (re)activity.

Turmeric Sesquiterpenoids: Expeditious Resolution, Comparative Bioactivity, and a New Bicyclic Turmeronoid.

An expeditious strategy to resolve turmerone, the lipophilic anti-inflammatory principle of turmeric (Curcuma longa), into its individual bisabolane constituents (ar-, α-, and ß-turmerones, 2-4, respectively) was developed. The comparative evaluation of these compounds against a series of anti-inflammatory targets (NF-κB, STAT3, Nrf2, HIF-1α) evidenced surprising differences, providing a possible explanation for the contrasting data on the activity of turmeric oil. Differences were also evidenced in the profile of more polar bisabolanes between the Indian and the Javanese samples used to obtain turmerone, and a novel hydroxylated bicyclobisabolane ketol (bicycloturmeronol, 8) was obtained from a Javanese sample of turmeric. Taken together, these data support the view that bisabolane sesquiterpenes represent an important taxonomic marker for turmeric and an interesting class of anti-inflammatory agents, whose strict structure-activity relationships are worth a systematic evaluation.

Poly-Electrophilic Sesquiterpene Lactones from Vernonia amygdalina: New Members and Differences in Their Mechanism of Thiol Trapping and in Bioactivity.

In addition to known compounds, the leaves of Vernonia amygdalina afforded the new sesquiterpene lactones 14-O-methylvernolide (2), 3'-deoxyvernodalol (6), and vernomygdalin (8). These and related compounds were evaluated for modulation of a series of thiol trapping-sensitive transcription factors (NF-κB, STAT3, and Nrf2), involved in the maintenance of the chronic inflammatory condition typical of human degenerative diseases. Vernolide (1) emerged as a potent inhibitor of STAT3 and NF-κB and showed cytostatic activity toward the prostate cancer cell line DU45, arresting the cell cycle at the S phase. The exomethylene lactones are characterized by multiple Michael acceptor sites, as exemplified by vernolide (1) and vernodalol (5). By using the nuclear magnetic resonance-based cysteamine assay, the most reactive thiophilic site could be identified in both compounds, and competitive experiments qualified vernolide (1) as being more thiophilic than vernodalol (5), in agreement with the results of the pharmacological assays.

Chokeberry (Aronia melanocarpa (Michx.) Elliot) concentrate inhibits NF-κB and synergizes with selenium to inhibit the release of pro-inflammatory mediators in macrophages.

Black chokeberry has been known to play a protective role in human health due to its high polyphenolic content including anthocyanins and caffeic acid derivatives. In the present study, we first characterized the polyphenolic content of a commercial chokeberry concentrate and investigated its effect on LPS-induced NF-κB activation and release of pro-inflammatory mediators in macrophages in the presence or the absence of sodium selenite. Examination of the phytochemical profile of the juice concentrate revealed high content of polyphenols (3.3%), including anthocyanins, proanthocyanidins, phenolic acids, and flavonoids. Among them, cyanidin-3-O-galactoside and caffeoylquinic acids were identified as the major compounds. Data indicated that chokeberry concentrate inhibited both the release of TNFα, IL-6 and IL-8 in human peripheral monocytes and the activation of the NF-κB pathway in RAW 264.7 macrophage cells. Furthermore, chokeberry synergizes with sodium selenite to inhibit NF-κB activation, cytokine release and PGE2 synthesis. These findings suggest that selenium added to chokeberry juice enhances significantly its anti-inflammatory activity, thus revealing a sound approach in order to tune the use of traditional herbals by combining them with micronutrients.