Oral Administration of Vanillin Improves Imiquimod-Induced Psoriatic Skin Inflammation in Mice

Honey Phytochemicals: Bioactive Agents With Therapeutic Potential for Dermatological Disorders

Honey has been reported to have a range of biological activities including antimicrobial, immunomodulatory, and wound healing effects. Indeed, medical-grade honey is currently used in hospitals for the clinical management of wound infections. Honey is also of scientific interest for its therapeutic effects on other dermatological disorders such as atopic dermatitis, rosacea, and skin cancer. Recent studies have uncovered that honey contains a range of phytochemicals including flavonoids, dicarboxylic acids, coumarins, and phenolic acids. In this review, PubMed was used to search the scientific literature on the biological properties of honey phytochemicals in relation to dermatological disorders and to evaluate their potential as bioactive agents, drugs, or cosmeceuticals for the treatment of skin disease. The review revealed that phytochemicals found in honey have antimicrobial, anti-inflammatory, antiaging, antioxidant, anticancer, depigmenting, photoprotective, wound healing, and skin barrier enhancing properties. Although further high-quality studies are required to establish clinical efficacy, these findings suggest that honey phytochemicals may have the potential to be used as bioactive agents for the management of a range of dermatological disorders including wounds, psoriasis, atopic dermatitis, vitiligo, rosacea, and skin cancer.

Cyclin-Dependent kinase 9 (CDK9) inhibitor Atuveciclib ameliorates Imiquimod-Induced Psoriasis-Like dermatitis in mice by inhibiting various inflammation factors via STAT3 signaling pathway

Psoriasis is a chronic, autoimmune skin disease characterized by the deregulated secretion of inflammatory factors in multiple organs. The aberrant activation of signal transducer and activator of transcription 3 (STAT3) signaling pathway mediated by cyclin-dependent kinase 9 (CDK9) is vital for the pathology of psoriasis, leading to the accumulation of inflammatory factors and the progression of skin damage. In this study, we explored the effect of CDK9 inhibition on attenuating the secretion of inflammatory factors and alleviating skin damage in psoriasis models both in vitro and in vivo. Results showed that Atuveciclib, a highly selective CDK9 inhibitor, significantly relieved skin lesions in Imiquimod (IMQ)-induced mice models by lowering the expression of CDK9 and p-RNA Pol II Ser2. Meanwhile, Atuveciclib significantly inhibited STAT3 phosphorylation in mice skin and reduced the levels of key inflammatory cytokines in mice skin, plasma and spleen. In addition to suppressing the secretion of inflammatory cytokines, Atuveciclib ablated the activation of STAT3 induced by tumor necrosis factor-α (TNF-α)/interferon-γ (IFN-γ). Overall, our findings indicated that the overexpression and hyperfunction of CDK9 promote the progression of psoriasis. Moreover, Atuveciclib interfered with the abnormal STAT3 signaling pathway through the inhibition of CDK9, which ultimately ameliorated psoriatic-like skin inflammation. These suggested that CDK9 inhibition is a potential strategy for batting psoriasis.

The effect of Medicago sativa extract and light on skin hypopigmentation disorders in C57/BL6 mice

BACKGROUND

Vitiligo is a common depigmentation skin disease that affects the quality of life in many patients.

AIMS

This study aims to investigate the effect of Medicago sativa methanol extract on the treatment of skin hypopigmentation disorders.

METHODS

Antioxidant activity and phytochemical constituents of the extract were determined using DDPH assay, Folin-Ciocalteu, AlCl_3, and HPLC-MS/MS analysis. Oil in water (o/w) creams were prepared to contain the methanolic extract, and applied to hydroquinone-induced depigmentation in vivo model and further challenged in combination with UVA light exposure. Skin and hair colors were visually scored and evaluated at different time intervals, and histopathological examinations of skin layers and hair follicles were performed.

RESULTS

A total phenolic content of 187.70 mg/g, equivalent to gallic acid, and total flavonoid content of 21.97 mg/g, equivalent to quercetin, were recorded. Extract showed 71% antioxidant activity. Moreover, the HPLC-MS/MS detection revealed the presence of 18 compounds including P-coumaric acid and antioxidants flavonoids, of those are seven compounds not previously detected in this species. The in vivo study showed a remarkable skin and hair pigmentation effect on plant extract-treated groups, compared to the reference, placebo, and control groups. Histopathological examinations showed the growth of colored hair follicles in the dermis and epidermis layers of the extract-treated mice.

CONCLUSION

The study suggests the use of M. sativa extract in enhancing the pigmentation process in hypopigmented skin and hair if combined with UVA light. Therefore, M. sativa extract can be considered a potential treatment for vitiligo.

Process optimization of vanillin production by conversion of ferulic acid by Bacillus megaterium

BACKGROUND

Vanillin is an important flavoring and aromatic ingredient found mainly in the pods of the tropical plant vanilla and is widely used in the food industry. Attempts have been made to produce vanillin from ferulic acid esters in agricultural residues of wheat bran.

RESULTS

The results showed that a strain with high tolerance to the substrate ferulic acid was isolated and screened from soil and identified as belonging to the genus Bacillus (Bacillus megaterium). The concentration of vanillin produced by this strain was 0.048 g L^-1 , and the molar conversion of vanillin was 12.25%. The production of vanillin was optimized by orthogonal experiments. Beef pastes 6.0 g L^-1 , soybean meal 5.0 g L^-1 , magnesium sulfate heptahydrate 1.0 g L^-1 , iron(II) sulfate heptahydrate 1.0 g L^-1 , calcium chloride 1.0 g L^-1 , dipotassium hydrogen phosphate trihydrate 1.0 g L^-1 ; fermentation culture conditions were pH 7.0, inoculum level 5%, loading volume 20%, ferulic acid 1.0 g L^-1 , fermentation culture temperature 35 °C. The concentration of vanillin obtained was 0.218 g L^-1 . Finally, transcriptomic analysis of the strain samples before and after the optimization of the fermentation conditions was carried out to study the effect of the optimization of the fermentation conditions on the concentration of vanillin produced by the strain.

CONCLUSION

This study provides a theoretical basis for further improving the yield of vanillin and gradually realizing efficient industrial production. © 2022 Society of Chemical Industry.

Odour hedonics and the ubiquitous appeal of vanilla

Our food choices and consumption behaviours are often influenced by odour hedonics, especially in the case of those orthonasally experienced aromas (that is, those odours that are food-related). The origins of odour hedonics remain one of the most intriguing puzzles in olfactory science and, over the years, several fundamentally different accounts have been put forwards to try and explain the varying hedonic responses that people have to a wide range of odorants. Associative learning, innate and molecular accounts of odour pleasantness have all been suggested. Here the origins of the hedonic response to vanilla, which is one of the most liked smells cross-culturally, are explored. The history of vanilla's use in food and medicine is outlined, with a focus on its neurocognitive appeal. While vanilla is one of the most widely liked aromas, it is also rated as smelling sweet to most people. Food scientists are becoming increasingly interested in the possibility that such 'sweet smells' could be used to help maintain the sweetness of commercial food products while, at the same time, reducing the use of calorific sweeteners. Such an approach is likely to be facilitated by the low cost of artificial vanilla flavouring (when compared with the high and fluctuating price of natural vanilla pods).

Rosmarinic acid ameliorated psoriatic skin inflammation in mice through the novel inhibition of the interleukin-17A/interleukin-17A receptor interaction

The interaction between interleukin-17A (IL-17A) and IL-17A receptor (IL-17RA) is a crucial target of psoriasis. Several natural compounds from foods or herbs have displayed efficacies on the amelioration of psoriasis. However, the anti-psoriatic mechanisms are mostly through the common anti-inflammatory effects and rarely via the blockage of the IL-17A/IL-17RA interaction. In this study, the IL-17A/IL-17RA-targeting effects of phenylpropanoids, a large class of secondary metabolites in plants, were analyzed. By screening 17 phenylpropanoids, we found that top four compounds with IL-17A/IL-17RA-blocking abilities were rosmarinic acid, eugenol, syringic acid, and gallic acid, with inhibitory concentrations at 50% of 2.14 ± 0.35 mM, 6.35 ± 0.1 mM, 4.79 ± 0.2 mM, and >10 mM, respectively. The oral administration of rosmarinic acid ameliorated redness and scaling on the dorsal skin of imiquimod-induced psoriatic mice in a dose-dependent manner. Rosmarinic acid suppressed the production of IL-23 and IL-17A and the infiltration of granulocyte subsets in skin tissues. Docking analysis showed that rosmarinic acid docked into IL-17A/IL-17RA interaction regions and exhibited hydrogen bonding with Arg-61, Glu-68, Arg-100, and Ser-118 of IL-17A, which are located in the epitope regions recognized by IL-17A neutralizing antibodies Fab6785 and Fab6468. In conclusion, this is the first study reporting that rosmarinic acid is an IL-17A-targeting agent that ameliorates psoriatic skin inflammation in mice via blocking the IL-17A/IL-17RA interaction.

Preparation and characterization of vanillin-chitosan Schiff base zinc complex for a novel Zn2+ sustained released system

In this work, a novel sustained released system (VCSB-Zn(II)) for zinc supplements was built by vanillin-chitosan Schiff base (VCSB) chelated with Zn²⁺ to improve the zinc trace element utilization ratio. Samples were characterized by FT-IR, ¹H NMR, XRD, SEM, and TGA. The results showed that VCSB exhibited a more excellent chelation capacity of Zn²⁺ than chitosan. The chelation capacity of VCSB was about 1.7 times more than that of chitosan, corresponding to 50.96 mg/g and 29.91 mg/g, respectively. Furthermore, VCSB-Zn(II) showed excellent sustained released performance at simulated gastric fluid because of the acid slow-dissolving ability. And the higher the CN content of VCSB, the higher the cumulative release rate (R_i) of Zn²⁺, the highest R_i reached 77.81%. The sustained released curves were described by the first-order and Korsmeyer-Peppas equation, which described the Zn²⁺ sustained released performance caused by the dissolution of VCSB-Zn(II) and Fick diffusion. This Zn²⁺ sustained released system shows great potential in the application in the field of trace elements supplements for animals.

Hydroxycinnamic Acids and Derivatives Formulations for Skin Damages and Disorders: A Review

Alterations of skin homeostasis are widely diffused in our everyday life both due to accidental injuries, such as wounds and burns, and physiological conditions, such as late-stage diabetes, dermatitis, or psoriasis. These events are locally characterized by an intense inflammatory response, a high generation of harmful free radicals, or an impairment in the immune response regulation, which can profoundly change the skin tissue' repair process, vulnerability, and functionality. Moreover, diabetes diffusion, antibiotic resistance, and abuse of aggressive soaps and disinfectants following the COVID-19 emergency could be causes for the future spreading of skin disorders. In the last years, hydroxycinnamic acids and derivatives have been investigated and applied in several research fields for their anti-oxidant, anti-inflammatory, and anti-bacterial activities. First, in this study, we give an overview of these natural molecules' current source and applications. Afterwards, we review their potential role as valid alternatives to the current therapies, supporting the management and rebalancing of skin disorders and diseases at different levels. Also, we will introduce the recent advances in the design of biomaterials loaded with these phenolic compounds, specifically suitable for skin disorders treatments. Lastly, we will suggest future perspectives for introducing hydroxycinnamic acids and derivatives in treating skin disorders.

A new functionality study of vanillin as the inhibitor for α-glucosidase and its inhibition kinetic mechanism

Vanillin is a natural phenolic compound mainly used as flavors in food industry. In this work, a new functionality of vanillin as the α-glucosidase inhibitor was studied based on the inhibition kinetic mechanism. The inhibitory effect (IC50) of vanillin against α-glucosidase was 28.34 ± 0.89 mg/mL, which belongs to mixed inhibition mechanism and its process was spontaneous. Vanillin could bind to α-glucosidase by hydrophobic interactions and hydrogen bonds with -8.42 kcal/mol intermolecular energy to form the steric hindrance. The average binding distances was calculated as 2.20 nm according to energy transfer theory. In addition, the protein secondary structure and denaturation temperature (decreasing about 10 °C) were changed significantly after vanillin binding to α-glucosidase, resulting in an inhibitory effect. The findings of this research provide insights for the development of vanillin as potential inhibitor for α-glucosidase in special dietary foods.

Hispidulin alleviates imiquimod-induced psoriasis-like skin inflammation by inhibiting splenic Th1/Th17 cell population and keratinocyte activation

Psoriasis is a chronic inflammatory skin disease characterized by hyperproliferation and abnormal differentiation of epidermal keratinocytes accompanied by increased infiltration of immune cells. Previous studies have demonstrated that hispidulin (4',5,7-trihydroxy-6-methoxyflavone, HPD) has various pharmacological benefits such as anti-fungal, anti-inflammation, and anti-allergic effects. This study investigated the effectiveness of HPD to treat psoriasis using an imiquimod (IMQ)-induced mouse model and activated keratinocytes. IMQ was topically applied to the back skin of mice for six consecutive days, and the mice were orally administered HPD. Based on the histological observation and immunological analysis, oral administration of HPD suppressed psoriatic characteristics including skin thickness, psoriasis area severity index, transepidermal water loss, and neutrophil infiltration. HPD alleviated pathologically increased levels of immunoglobulin G2a, myeloperoxidase, and tumor necrosis factor-α. Splenic Th1 and Th17 cell populations were also reduced by HPD in the murine model. In addition, in activated keratinocytes, HPD inhibited gene expression of Th1- and Th17-associated cytokines and chemokines, and phosphorylation of mitogen-activated protein kinases and nuclear factor-κB. In summary, HPD alleviates psoriasis skin inflammation in vivo and in vitro. Therefore, we suggest that HPD would be a potent therapeutic candidate for the treatment of psoriasis.

Vanillin protects lipopolysaccharide-induced acute lung injury by inhibiting ERK1/2, p38 and NF-κB pathway

Aim: Thus far, the anti-inflammatory effect of vanillin in acute lung injury (ALI) has not been studied. This study aimed to investigate the effect of vanillin in lipopolysaccharide (LPS)-induced ALI. Results & methodology: Our study detected the anti-inflammatory effects of vanillin by ELISA and western blot, respectively. Pretreatment of mice with vanillin significantly attenuated LPS-stimulated lung histopathological changes, myeloperoxidase activity and expression levels of proinflammatory cytokines by inhibiting the phosphorylation activities of ERK1/2, p38, AKT and NF-κB p65. In addition, vanillin inhibited LPS-induced TNF-α and IL-6 expression in RAW264.7 cells via ERK1/2, p38 and NF-κB signaling. Conclusion: Vanillin can inhibit macrophage activation and lung inflammation, which suggests new insights for clinical treatment of ALI.

Protective effect of vanillin on diabetic nephropathy by decreasing advanced glycation end products in rats

AIMS

Diabetic nephropathy (DN) is a common chronic microvascular complication of both types of diabetes mellitus, which leads to renal dysfunction and subsequent need of dialysis and organ transplantation. Advanced glycation end products (AGEs) are metabolic consequence of hyperglycemia and are main contributory factor in the DN pathogenesis through mediating establishment of oxidative status and chronic inflammatory milieu. This study aimed to explore the impact of vanillin on preventing the progression of DN.

MAIN METHODS

Experimental DN model was established in rats utilizing streptozotocin. Serum concentration of AGEs and Interleukin-6 (IL-6) and transforming growth factor β1 (TGFβ1) levels in kidney homogenate were assessed using ELISA technique. Also, we evaluated the expression of nuclear factor kappa B (NF-κB) using immunohistochemistry.

KEY FINDINGS

Treatment with vanillin for 8 weeks significantly ameliorated DN. Vanillin significantly decreased hyperglycemia and improved kidney function reflected by decreased serum levels of blood urea nitrogen, creatinine, and decreased proteinuria. Also, vanillin significantly decreased malondialdehyde content and elevated superoxide dismutase activity in renal tissues. Moreover, vanillin decreased renal expression of NF-κB and renal concentrations of IL-6, TGFβ1 and collagen. In addition, vanillin significantly decreased serum AGEs concentration. Also, vanillin attenuated histological abnormalities in kidney architecture.

SIGNIFICANCE

Vanillin, which is a cheap and abundant natural product, exhibited anti-AGEs, antioxidant, anti-inflammatory and anti-fibrotic activities. These activities might be helpful and potent mechanisms in preventing the progression of DN.

Ferulic acid altered IL-17A/IL-17RA interaction and protected against imiquimod-induced psoriasis-like skin injury in mice

Ferulic acid (FA), a phenolic phytochemical, is commonly found in grains, vegetables, and fruits. Interleukin-17A (IL-17A) and IL-17 receptor A (IL-17RA) interaction is one of important therapeutic targets for psoriasis. Here we analyzed the FA effects on IL-17A/IL-17RA interaction and psoriasis-like skin injury induced by imiquimod (IMQ). IL-17A-blocking assay and docking analysis showed that FA interacted with Trp-67, Gln-94, and Glu-95 residues of IL-17A via hydrogen bonds and consequently abolished the binding of IL-17RA to IL-17A. Mice were topically given with IMQ and orally given with various amounts of FA for 14 consecutive days. FA attenuated IMQ-induced psoriasis-like skin lesions in a dose-dependent manner, and the epidermal thickness of mice treated with 100 mg/kg FA was reduced by 53.48 ± 4.44% in comparison with sham. Global analysis of differentially expressed genes showed that IMQ and FA significantly affected immune response, metabolism, and mitogen-activated protein kinase signaling pathways. Immunohistochemical staining showed that FA inhibited the infiltration and the cytokine secretion of Th17 cell, dendritic cell, and granulocyte subsets in psoriatic skin tissues. In conclusion, we newly identified that oral administration of FA protected against IMQ-induced psoriatic skin injury in mice. Moreover, its protection was associated with the interference of IL-17A/IL-17RA interaction.

Effect of grape seed extract on maternal toxicity and in utero development in mice treated with zearalenone

The aims of this study were to determine the polyphone content of grape seed extract (GSE) and to assess their protective effects against zearalenone (ZEN)-induced maternal toxicity and in utero development defects in mice. Five groups of pregnant mice were treated orally during days 6-13 of gestation as follows: control group, corn oil as vehicle (0.1 ml/mice)-treated group, ZEN-treated group (25 mg/kg b.w), GSE-treated group (150 mg/kg b.w.), and ZEN plus GSE-treated group. All animals were sacrificed on the 19th day of gestation and samples of bone marrow were collected for the micronucleus assay. The maternal and developmental toxicity were carried out. The HPLC analyses revealed that GES is rich in gallic acid, syringic acid, vanillin, quercetin, and coumaric acid. ZEN administration resulted in severe maternal and developmental toxicity which included an increase of micronuclei formation in bone marrow, decreased maternal weight gain, and litter weight. It also induces fetal growth retardation, increased number of the aborted dams and resorbed fetuses, abnormality of fetal bone ossification, and number of fetuses with a hematoma. GSE showed positive effects on the pregnant mice and the developing fetuses. Moreover, it counteracted the detrimental effects of ZEN in dams and fetuses. It could be concluded that polyphenols in GSE are a promising candidate to protect against ZEN toxicity in highly endemic areas.

Vanillin Alleviates High Fat Diet-Induced Obesity and Improves the Gut Microbiota Composition

Vanillin, a simple phenolic compound, exists marginally in some plants and can be produced by microbes. This study uses high-fat-diet (HFD) induced obese mice to study the effect of vanillin on obesity and obtain positive results. First, both body and adipose tissue weight are reduced. Second, the blood properties signaling certain disorders such as ALT, LDH, glucose, cholesterol, LDL-C, TG and HDL-C are ameliorated and both insulin sensitivity, and glucose tolerance are improved. Third, vanillin reduced elevated levels of inflammatory factors including LPS, IL-6, and TNF-α in plasma and liver tissue resulting from obesity. Finally, the production of short chain fatty acids (SCFAs) is enhanced. Additionally, study results demonstrate that vanillin significantly alleviates obesity-related gut microbiota (GM) disorders including the decrease of alpha- and beta-diversity. Furthermore, vanillin reduces the abundance of Firmicutes phylum, increases the richness of Bacteroidetes and Verrucomicrobiota phyla, and inhibits the expansion of the lipopolysaccharide (LPS)-producing bacteria Bilophila genus and the H₂S-producing bacteria Desulfovibrio genus.

Vanillin-Ameliorated Development of Azoxymethane/Dextran Sodium Sulfate-Induced Murine Colorectal Cancer: The Involvement of Proteasome/Nuclear Factor-κB/Mitogen-Activated Protein Kinase Pathways

Vanillin is a natural dietary flavoring widely used in the food industry. Colorectal cancer (CRC) is one of the common malignancies in the world. Chronic intestinal inflammation is a risk factor for the development of CRC. We have previously found that vanillin improves and prevents colitis in mice. Here we evaluated the inhibitory activities of vanillin on a mouse model of colitis-induced CRC. Mice were challenged intraperitoneally with azoxymethane (AOM) and orally with dextran sodium sulfate (DSS). Various dosages of vanillin were orally administered for 13 consecutive weeks. Vanillin alleviated the development of tumors in AOM/DSS-induced mice. The total number of tumors in 100 mg/kg vanillin group was significantly reduced by 57.14 ± 7.67%, compared with sham group. Gene expression analysis showed that vanillin downregulated the expression levels of proteasome genes in colon tissues. Moreover, vanillin at 10 mM significantly suppressed proteasome activities in HCT-116 cells by 41.27 ± 0.41%. Furthermore, vanillin diminished the phosphorylation of mitogen-activated protein kinases (MAPKs) and reduced the number of p65-positive cells, proliferating cells, and granulocytes in colon tissues with statistical significance. In conclusion, our data suggested that vanillin was a bioactive compound that ameliorated the development of AOM/DSS-induced colon cancer in mice. Moreover, the amelioration of vanillin might be associated with the downregulation of proteasome, nuclear factor-κB, and MAPK pathways.