Spotlight on adapalene

Molecular docking and pharmacophore models to probe binding hypothesis of inhibitors of hypoxia inducible factor-1

Hypoxia inducible factor-1 is a heterodimeric transcription factor that regulates cellular responses to hypoxia and is involved in tumor progression and resistance to chemotherapy. Dimerization between HIF-1α and β subunits has been recognized crucial for DNA binding and transcriptional activity of HIF-1. Therefore, inhibitors of α and β dimerization subunits of HIF-1 may potentially evade HIF-1-mediated chemotherapy resistance. In the current study, ligand-based pharmacophore model was developed to determine 3 D binding features of HIF-1 inhibitors. The selected pharmacophore model comprises of one hydrogen bond donor, one hydrogen bond acceptor and one hydrophobic feature. The selected model was used for virtual screening of publically available data base by ChemBridge Corporation. Overall, six potential hits against HIF-1α and β dimerization have been identified. These include, Hit 1 (4-(4-chlorophenyl)-2,6-dimethyl-3,5-pyridinedicarboxylic acid), 3 (2-[2-(2-hydroxybenzoyl)carbonohydrazonoyl]benzoic acid) and 5 (3-(4-methoxyphenyl)-2,4-quinolinedicarboxylic acid) nicotonic acid derivatives, Hit 2 (3-[(1-adamantylamino)sulfonyl]benzoic acid), 4 (5-{[(2-fluorophenyl)amino]sulfonyl}-2-methylbenzoic acid), and 6 (4-({[2-(trifluoromethyl)phenyl]sulfonyl}amino)benzoic acid) sulfonamide derivatives. Additionally, adamantyl moiety of compound 2 shows interactions with the experimentally known hydrophobic amino acid residues (V336, C334, E245) of HIF-1α and β dimerization site. The identified hits showed lower to higher µM biological activity (IC₅₀) values and thus, after further structure optimization may serve as potential inhibitor of HIF-1 dimerization in cancer chemotherapy.Communicated by Ramaswamy H. Sarma.

Overview of all-trans-retinoic acid (ATRA) and its analogues: Structures, activities, and mechanisms in acute promyelocytic leukaemia

All-trans-retinoic acid (ATRA) is effective for preventing cancer and treating skin diseases and acute promyelocytic leukaemia (APL). These pharmacological effects of ATRA are mainly mediated by retinoid X receptors (RXRs) and retinoic acid receptors (RARs). This article provides a comprehensive overview of the clinical progress on and the molecular mechanisms of ATRA in the treatment of APL. ATRA can promote the transcriptional activation of differentiation-related genes and regulate autophagy by inhibiting mTOR, which results in anti-APL effects. In detail, the structures, pharmacological effects, and clinical studies of 68 types of ATRA analogues are described. These compounds have excellent antitumour therapeutic potential and could be used as lead compounds for further development and research.

The effectiveness of adapalene 0.1% with intense pulsed light versus benzoyl peroxide 5% with intense pulsed light in the treatment of acne vulgaris: A comparative study

Background:

Acne vulgaris (AV) is one of the most common skin diseases with major psychological impacts. Hence, selecting the best treatment modality is so important; there are different ways to treat AV such as topical and systemic agents, laser, and also photodynamic therapy. In this study, we tried to assess the difference between the efficacy of combination therapy with intense pulsed light (IPL) and benzoyl peroxide (BPO) in comparison with IPL and adapalene (AD) in the treatment of the mild to moderate AV.

Materials and Methods:

Thirty Iranian females in reproductive age with mild to moderate acne were enrolled in this study. The left and right side of the patients were randomized to receive either AD 0.1% or BPO 5% every other day plus three sessions of monthly apart IPL in the treatment of AV. Different parameters of AV such as acne severity index (ASI), total acne lesions counting (TLC), and Acne Global Severity Scale (AGSS) were measured before, during, and after the treatments.

Results:

There was a significant difference regarding AGSS, TLC, and ASI before and after treatment with AD plus IPL (P < 0.001). Furthermore, there was a significant difference regarding AGSS, TLC, and ASI before and after treatment with BP plus IPL (P < 0.001). However, no significant difference regarding AGSS, TLC, and ASI were observed between the 2 groups after treatment (P > 0.05). No significant side effects were observed in both groups.

Conclusion:

Our study shows that there was not any significant difference between combining IPL with either AD or BPO so we can use either one of these combinations to achieve similar efficacy.

Crystal structure and Hirshfeld surface analysis of a pyridiniminium bromide salt: 1-[2-(adamantan-1-yl)-2-oxoeth-yl]pyridin-4-iminium bromide

In the cation of the title salt, C17H23N2O+·Br-, the adamantyl moiety and the pyridiniminium ring are inclined to the ketone bridge by torsion angles of -78.1 (2) (C-C-C=O) and 58.3 (2)° (C-C-N-C), respectively, and the ketone bridge has a C-C-C-N torsion angle of 174.80 (15)°. In the crystal, the cations are connected into chains parallel to the c axis by C-H⋯O hydrogen bonds. The chains are further linked into layers parallel to the bc plane by N-H⋯Br and C-H⋯Br hydrogen bonds, C-H⋯π inter-actions and π-π stacking inter-actions [centroid-to-centroid distance = 3.5657 (11) Å]. A Hirshfeld surface analysis, which comprises the dnorm surface, electrostatic potential map and two-dimensional fingerprint plots, was carried out to verify the contribution of the various inter-molecular inter-actions.

Use of adapalene in alopecia areata: Efficacy and safety of mometasone furoate 0.1% cream versus combination of mometasone furoate 0.1% cream and adapalene 0.1% gel in alopecia areata

Alopecia areata (AA) is an autoimmune disease characterized by non-cicatricial hair loss. No definitive therapy currently exists for AA. To compared the efficacy and safety of the mometasone furoate 0.1% cream alone with the mometasone furoate 0.1% cream plus adapalene 0.1% gel in treatment of AA. Twenty patients with AA and with mean age of 27.4 ± 9.2 years were enrolled. Patches with a diameter of < 5 cm were treated with mometasone furate 0.1% cream (M), and patches with a diameter of ≥5 cm were treated with mometasone furate 0.1% cream plus adapalene 0.1% gel (M + D) for a period of 12 weeks. Hair regrowth was evaluated using a Re-growth score (RGS). Mean RGSs of M + D group were higher than M group for 4th week (2.60 vs. 1.45); 8th week (3.85 vs. 2.40) and 12th week (4.40 vs. 3.30). Mean percentages of hair re-growth in M + D group were statistically higher than M group for 4th (50.2% vs. 23.5%), 8th (78.5% vs. 50.7%), and 12th week (90.5% vs. 71%). Study revealed the efficacy and safety of adapalene and mometasone furoate combination in AA. Adapalene can be used as a new therapeutic modality in AA.

Cholinesterase Inhibitory Activities of Adamantyl-Based Derivatives and Their Molecular Docking Studies

Adamantyl-based compounds are clinically important for the treatments of type 2 diabetes and for their antiviral abilities, while many more are under development for other pharmaceutical uses. This study focused on the acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activities of adamantyl-based ester derivatives with various substituents on the phenyl ring using Ellman's colorimetric method. Compound 2e with a 2,4-dichloro electron-withdrawing substituent on the phenyl ring exhibited the strongest inhibition effect against AChE, with an IC₅₀ value of 77.15 µM. Overall, the adamantyl-based ester with the mono-substituent at position 3 of the phenyl ring exhibited good AChE inhibition effects with an ascending order for the substituents: Cl < NO₂ < CH₃ < OCH₃. Furthermore, compounds with electron-withdrawing groups (Cl and NO₂) substituted at position 3 on their phenyl rings demonstrated stronger AChE inhibition effects, in comparison to their respective positional isomers. On the other hand, compound 2j with a 3-methoxyphenyl ring showed the highest inhibition effect against BChE, with an IC₅₀ value of 223.30 µM. Molecular docking analyses were conducted for potential AChE and BChE inhibitors, and the results demonstrated that the peripheral anionic sites of target proteins were predominant binding sites for these compounds through hydrogen bonds and halogen interactions instead of hydrophobic interactions in the catalytic active site.

Synthesis and Crystallographic Insight into the Structural Aspects of Some Novel Adamantane-Based Ester Derivatives

Adamantyl-based compounds are commercially important in the treatments for neurological conditions and type-2 diabetes, aside from their anti-viral abilities. Their values in drug design are chronicled as multi-dimensional. In the present study, a series of 2-(adamantan-1-yl)-2-oxoethyl benzoates, 2(a-q), and 2-(adamantan-1-yl)-2-oxoethyl 2-pyridinecarboxylate, 2r, were synthesized by reacting 1-adamantyl bromomethyl ketone with various carboxylic acids using potassium carbonate in dimethylformamide medium at room temperature. Three-dimensional structures studied using X-ray diffraction suggest that the adamantyl moiety can serve as an efficient building block to synthesize 2-oxopropyl benzoate derivatives with synclinal conformation with a looser-packed crystal packing system. Compounds 2a, 2b, 2f, 2g, 2i, 2j, 2m, 2n, 2o, 2q and 2r exhibit strong antioxidant activities in the hydrogen peroxide radical scavenging test. Furthermore, three compounds, 2p, 2q and 2r, show good anti-inflammatory activities in the evaluation of albumin denaturation.

Pharmaceuticals that contain polycyclic hydrocarbon scaffolds

This review comprehensively explores approved pharmaceutical compounds that contain polycyclic scaffolds and the properties that these skeletons convey.

Treatment of capecitabine-induced hand-foot syndrome using a topical retinoid: A case report

Capecitabine is a chemotherapeutic drug used in patients with breast, colon and gastric cancer. Hand-foot syndrome (HFS) is a type of dermatitis that frequently occurs as a reaction to capecitabine. To date, no effective strategies have been found to prevent or reverse HFS. Furthermore, chemotherapy induces an elevation in the expression of heparin-binding epidermal growth factor-like growth factor (HB-EGF), and this activation represents a critical mechanism for the induction of chemotherapeutic resistance. Adapalene is a third-generation synthetic retinoid. Topical retinoids are important therapeutic anti-aging agents for managing photodamaged skin, and are known to increase HB-EGF levels, which is important for skin wound healing. Accordingly, the current report focused on the topical retinoids that increase HB-EGF expression in the skin, and we hypothesized that these topical retinoids induce local chemotherapeutic resistance in the skin of patients receiving chemotherapy and consequently, decrease the cutaneous side-effects of chemotherapy. This report presents a case of the successful treatment of refractory HFS induced by capecitabine using the topical application of adapalene. Topical adapalene was applied for 3 months and significantly reduced inflammation and pain following chemotherapy. Topical retinoids may have the potential to effectively treat capecitabine-induced HFS by increasing HB-EGF expression and decreasing cutaneous side-effects. Further studies are required to establish the therapeutic efficacy of topical retinoids on HFS.

Role of the viral hemagglutinin in the anti-influenza virus activity of newly synthesized polycyclic amine compounds

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We report on the synthesis of polycyclic amines designed as ring-rearranged analogs of amantadine.

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Only one compound inhibited A/M2 proton channel function.

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However, they showed low-micromolar activity against A/H1N1, but not A/H3N2 influenza viruses.

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A/PR/8/34 mutants selected for resistance to these compounds possessed mutation in the viral hemagglutinin.

We here report on the synthesis of new series of polycyclic amines initially designed as ring-rearranged analogs of amantadine and featuring pentacyclo, hexacyclo, and octacyclo rings. A secondary amine, 3-azahexacyclo[7.6.0.0^1,5.0^5,12.0^6,10.0^11,15]pentadeca-7,13-diene, 3, effectively inhibited A/M2 proton channel function, and, moreover, possessed dual activity against an A/H3N2 virus carrying a wild-type A/M2 proton channel, as well as an amantadine-resistant A/H1N1 virus. Among the polycyclic amines that did not inhibit influenza A/M2 proton channel function, several showed low-micromolar activity against tested A/H1N1 strains (in particular, the A/PR/8/34 strain), but not A/H3N2 influenza viruses. A/PR/8/34 mutants selected for resistance to these compounds possessed mutations in the viral hemagglutinin that markedly increased the hemolysis pH. Our data suggest that A/H1N1 viruses such as the A/PR/8/34 strain are particularly sensitive to a subtle increase in the endosomal pH, as caused by the polycyclic amine compounds.

New synthesis of 6[3-(1-adamantyl)-4-methoxyphenyl]-2-naphthoic acid and evaluation of the influence of adamantyl group on the DNA binding of a naphthoic retinoid

6[3-(1-Adamantyl)-4-methoxyphenyl]-2-naphthoic acid (Adapalene®), a synthetic aromatic retinoid specific for RARβ and RARγ receptors, has been prepared utilizing a Pd/C-mediated Suzuki coupling between 6-bromo-2-naphthoic acid and 4-methoxyphenyl boronic acid, followed by introduction of an adamantyl group in the position 3 of the formed 6-(4-methoxyphenyl)-2-naphthoic acid. The interaction of 6-(4-methoxyphenyl)-2-naphthoic acid/ethyl ester and the 3-adamantyl analogs with DNA was studied in aqueous solution at physiological conditions by UV-vis spectroscopy. The calculated binding constants K(ligand-DNA) ranged between 1.1×10(4) M(-1) and 1.1×10(5) M(-1), the higher values corresponding to those of the adamantylated compounds. Molecular modeling studies have emphasized that the intercalative binding of adapalene and its derivatives to DNA is mainly stabilized by hydrophobic interactions related to the presence of the adamantyl group.

Topical absorption and systemic toxicity

Dermal absorption of some chemicals and drugs can cause systemic toxicity. We evaluated several case reports from the past decade, which discuss the dermal absorption of a specific chemical and potential local and systemic effects. We focused on herbicide and pesticide exposure along with exposure to cutaneous medication, occupational contact, and cosmeceutical exposure. Although causality cannot be established in most cases, it is critical to be aware of the possible effects of topical absorption that may not be immediately apparent. We recommended further studies on specific chemicals to ascertain causality and determine the highest exposure level with no observed adverse affect level (NOAEL) and the reference dose (RfD). Post-marketing epidemiology data in most geographical areas are markedly limited. A weak link in public health resides in the inadequate reporting and workup of alleged chemically related adverse effects. This arena mandates a re-thinking of how to increase this reporting, and workup, as a backup to our preclinical and clinical studies. Public awareness and funding will be rewarded by increased evidence to backup pre-approval pre-marketing studies.