Protective effect of neferine against UV-B-mediated oxidative damage in human epidermal keratinocytes

Two new bibenzyl methylglucosides as SIRT3 activators obtained through microbial transformation

Microbial transformation of dihydroresveratrol (DHRSV) using Beauveria bassiana has produced two new methylglucosylated derivatives of DHRSV (1 and 2), whose structures were characterized as 4'-O-(4″-O-methyl-β-D-glucopyranosyl)-dihydroresveratrol (4'-O-MG DHRSV, 1) and 3-O-(4″-O-methyl-β-D-glucopyranosyl)-dihydroresveratrol (3-O-MG DHRSV, 2) on the basis of spectroscopic methods. They showed moderate SIRT3 agonistic activity, and compound 2 exhibited the best deacetylation of 406.63% at 10 μM. The activity of 2 increased by 3.12-fold compared with that of DHRSV, since 2 performed better in molecular docking assay (GScore -8.445).

A Curcumin-Based Oral Gel Has Potential Protective Efficacy against Oral Mucositis: In Vitro Study

Oral mucositis is a common distressing complication of cancer therapy, characterised by painful sores within the oral cavity. Current management options offer limited symptomatic relief. Curcumin, a natural polyphenolic compound with recognised anti-inflammatory and antioxidant properties, has emerged as a potential protective agent against oral mucositis. This study explores the therapeutic potential of curcumin in mitigating the impact of oral mucositis by investigating a commercially available curcumin-based oral gel, PerioGold®. Liquid chromatography-tandem mass spectrometry was used to characterise the main constituents of PerioGold®. The cytotoxicity of curcumin constituent was investigated in four cell lines: primary oral keratinocytes (HOKs), immortalised oral keratinocytes (OKF6), dysplastic oral keratinocytes (DOKs), and oral squamous cell carcinoma cells (PE/CA-PJ15). Concentrations of hydrogen peroxide were optimised to develop in vitro models that mimic oral mucositis. The inhibitory effects of PerioGold® against the production of reactive oxygen species were assessed using a designated kit. OKF6 cells were the most sensitive to oxidative stress, while PE/CA-PJ15 cells showed the highest resistance. Pretreatment of the investigated cells for 24 h with PerioGold® demonstrated a significant antioxidative effect in all cells based on a dose-response pattern. PerioGold® exhibits clinical potential for protecting against oxidative stress, warranting further individualised clinical investigations.

The landscape of photoaging: From bench to bedside in a bibliometric analysis

Background

Bibliometric software exists as a platform providing multiple algorithms to process the data to suffice diverse goals. Interpretation of the result must be based on insight into the meaning of the original data and the algorithm used. Medical Subject Headings (MeSH) terms represent the macro-level meaning of topics, keywords that commonly reflect the micro-level aspects.

Objective

This study attempts to investigate the landscape of photoaging in the recent two decades by using bibliometric analysis.

Methods

Published studies of photoaging were obtained from PubMed and Web of Science Core Collection (WoSCC) from 2000 to 2020. Basic bibliometric information was generated by WoSCC. Major MeSH terms were performed in cluster analysis and displayed as a hierarchical form to induce knowledge structure, detection algorithm on keywords was presented as a timeline form to obtain hotspots, and institutional clusters were labeled with keywords to achieve institutional characteristics.

Results

A total of 2,727 and 2,705 studies were identified in PubMed and WoSCC, respectively. The number of photoaging-related studies at 3-year intervals grew steadily. The studies were performed in about 80 countries/regions. The highly frequent major MeSH terms were distributed in seven clusters, reflecting the etiology, pathophysiology, treatment, and prevention of photoaging. The hotspots changed as time went on, and the hotspots in recent 5 years were mitogen-activated protein kinase (MAPK), nuclear factor erythroid-derived 2-like 2 (Nrf2), and antioxidant activity. The highly productive institutions labeling in the top four clusters were Seoul National University, University of Michigan, China Medical University, and Harvard University, with corresponding keywords of UVB, retinoic acid, Nrf2, and rejuvenation.

Conclusions

This study built a knowledge structure of pathophysiology, treatment and prevention of photoaging, and identified recent hotspots of MAPK, Nrf2, and antioxidant activity. We provide a landscape of photoaging, from the bench (pathophysiology) to bedside (treatment, prevention), and pave the way for future research.

The bibenzyl derivatives of Dendrobium officinale prevent UV-B irradiation induced photoaging via SIRT3

Dendrobium officinale is a valuable medicinal herb that is widely used in traditional Chinese medicine. The chemical constituents of D. officinale have attracted much attention and a large number of compounds have been reported including many bibenzyl derivatives. 13 bibenzyl derivatives from D. officinale were sent for molecular docking, surface plasmon resonance (SPR) assay and after detection of Mn-SOD and SIRT3 activities in or not in HaCaT cells, it was concluded that bibenzyl derivatives did not directly activate Mn-SOD but promoted SIRT3 proteins. In addition, HaCaT cells were irradiated with UV-B to induce an oxidative stress model in vitro to further verify the effect of bibenzyl derivatives. The results show that bibenzyl derivatives could directly bind to SIRT3, enhance the deacetylation and then activate Mn-SOD, so as to protect UV-B induced skin photoaging.

Alkaloids from lotus (Nelumbo nucifera): recent advances in biosynthesis, pharmacokinetics, bioactivity, safety, and industrial applications

Different parts of lotus (Nelumbo nucifera Gaertn.) including the seeds, rhizomes, leaves, and flowers, are used for medicinal purposes with health promoting and illness preventing benefits. The presence of active chemicals such as alkaloids, phenolic acids, flavonoids, and terpenoids (particularly alkaloids) may account for this plant's pharmacological effects. In this review, we provide a comprehensive overview and summarize up-to-date research on the biosynthesis, pharmacokinetics, and bioactivity of lotus alkaloids as well as their safety. Moreover, the potential uses of lotus alkaloids in the food, pharmaceutical, and cosmetic sectors are explored. Current evidence shows that alkaloids, mainly consisting of aporphines, 1-benzylisoquinolines, and bisbenzylisoquinolines, are present in different parts of lotus. The bioavailability of these alkaloids is relatively low in vivo but can be enhanced by technological modification using nanoliposomes, liposomes, microcapsules, and emulsions. Available data highlights their therapeutic and preventive effects on obesity, diabetes, neurodegeneration, cancer, cardiovascular disease, etc. Additionally, industrial applications of lotus alkaloids include their use as food, medical, and cosmetic ingredients in tea, other beverages, and healthcare products; as lipid-lowering, anticancer, and antipsychotic drugs; and in facial masks, toothpastes, and shower gels. However, their clinical efficacy and safety remains unclear; hence, larger and longer human trials are needed to achieve their safe and effective use with minimal side effects.

Anti-Allergic and Anti-Inflammatory Effects of Neferine on RBL-2H3 Cells

Mast cells play a very important role in skin allergy and inflammation, including atopic dermatitis and psoriasis. In the past, it was found that neferine has anti-inflammatory and anti-aging effects on the skin, but its effect on mast cells has not yet been studied in detail. In this study, we used mast cells (RBL-2H3 cells) and mouse models to study the anti-allergic and inflammatory effects of neferine. First, we found that neferine inhibits the degranulation of mast cells and the expression of cytokines. In addition, we observed that when mast cells were stimulated by A23187/phorbol 12-myristate-13-acetate (PMA), the elevation of intracellular calcium was inhibited by neferine. The phosphorylation of the MAPK/NF-κB pathway is also reduced by pretreatment of neferine. The results of in vivo studies show that neferine can improve the appearance of dermatitis and mast cell infiltration caused by dinitrochlorobenzene (DNCB). Moreover, the expressions of barrier proteins in the skin are also restored. Finally, it was found that neferine can reduce the scratching behavior caused by compound 48/80. Taken together, our results indicate that neferine is a very good anti-allergic and anti-inflammatory natural product. Its effect on mast cells contributes to its pharmacological mechanism.

Effect of Neferine on DNCB-Induced Atopic Dermatitis in HaCaT Cells and BALB/c Mice

Atopic dermatitis (AD) is a chronic and persistent inflammatory skin disease characterized by eczematous lesions and itching, and it has become a serious health problem. However, the common clinical treatments provide limited relief and are accompanied by adverse effects. Therefore, there is a need to develop novel and effective therapies to treat AD. Neferine is a small molecule compound isolated from the green embryo of the mature seeds of lotus (Nelumbo nucifera). It has a bisbenzylisoquinoline alkaloid structure. Relevant studies have shown that neferine has many pharmacological and biological activities, including anti-inflammatory, anti-thrombotic, and anti-diabetic activities. However, there are very few studies on neferine in the skin, especially the related effects on inflammatory skin diseases. In this study, we proved that it has the potential to be used in the treatment of atopic dermatitis. Through in vitro studies, we found that neferine inhibited the expression of cytokines and chemokines in TNF-α/IFN-γ-stimulated human keratinocyte (HaCaT) cells, and it reduced the phosphorylation of MAPK and the NF-κB signaling pathway. Through in vivo experiments, we used 2,4-dinitrochlorobenzene (DNCB) to induce atopic dermatitis-like skin inflammation in a mouse model. Our results show that neferine significantly decreased the skin barrier damage, scratching responses, and epidermal hyperplasia induced by DNCB. It significantly decreased transepidermal water loss (TEWL), erythema, blood flow, and ear thickness and increased surface skin hydration. Moreover, it also inhibited the expression of cytokines and the activation of signaling pathways. These results indicate that neferine has good potential as an alternative medicine for the treatment of atopic dermatitis or other skin-related inflammatory diseases.

Neferine suppresses vascular endothelial inflammation by inhibiting the NF-κB signaling pathway

The vascular endothelium, as the interface between the blood and the surrounding tissues, plays a pivotal role in inflammation. Neferine, which was isolated from Lotus Plumule, has many biological roles, such as antifibrotic, antioxidative, anti-inflammatory, and antineoplastic activities. We demonstrated the role of neferine in the inhibition of pro-adhesion and pro-inflammatory responses of endothelial cells in vitro. We found that neferine could significantly inhibit the adhesion of Tohoku Hospital Pediatrics-1 (THP-1) cells to primary human umbilical vein endothelial cells (HUVECs). At the molecular level, neferine could significantly alleviate the interleukin 1β (IL-1β)-induced mRNA and protein expression of intercellular adhesion molecule 1 (ICAM1) and vascular cell adhesion molecule 1 (VCAM1). Our data showed that neferine suppressed nuclear factor-κB (NF-κB) nuclear translocation and inhibited the NF-κB-p65-induced transcriptional activity of ICAM1 and VCAM1. Therefore, we concluded that neferine suppressed the inflammatory response in endothelial cells in vitro, which could be mainly due to inhibition of NF-κB signaling activation. Moreover, we found that neferine alleviated LPS-induced acute inflammation injury in vivo. Thus, neferine may serve as an effective regulator during the pathogenesis of vascular inflammatory diseases.

Melaleuca leucadendron (L.) L. flower extract exhibits antioxidant and photoprotective activities in human keratinocytes exposed to ultraviolet B radiation

Recently, there has been a demand for the replacement of chemical sunscreens with natural compounds that could prevent or restore UV-induced skin damage. Here, we investigated the photoprotective influence of the Melaleuca leucadendron ethanolic flower extract (EEMec) on factors involved in cellular and molecular UVB-induced oxidative stress in human skin keratinocytes (HaCaT). The phytochemical constituents, antioxidant potential by DPPH assay, content of total phenolic and flavonoid compounds in EEMec were evaluated. HaCaT cells were treated with EEMec followed by irradiation with UVB. CAT activity; GSH and ROS levels; and SOD1, GPx, CAT and COX-2 expression assays were employed to verify the oxidative stress, as well as EEMec effect on transmembrane transport, and pro-inflammatory and pro-apoptotic protein expression. EEMec reverted the viability loss of HaCaT cells after irradiation with UVB, exhibited significant antioxidant capacity and free radical scavenging activity in vitro, inhibited COX-2 expression and ensure protection of DNA-damage. EEMec shown a great photoprotective property to prevent keratinocytes damage induced by UV radiation and, thus a candidate potential to application as an adjuvant in sunscreen formulations as a strategy to reduce risk of sunburn and prevent skin diseases associated with UV-induced inflammation and cancer.

Skin photo-protection with phytochemicals against photo-oxidative stress, photo-carcinogenesis, signal transduction pathways and extracellular matrix remodeling-An overview

Excessive exposure of skin to UV radiation triggers the generation of oxidative stress, inflammation, immunosuppression, apoptosis, matrix-metalloproteases production, and DNA mutations leading to the onset of photo ageing and photo-carcinogenesis. At the molecular level, these changes occur via activation of several protein kinases as well as transcription pathways, formation of reactive oxygen species, and release of cytokines, interleukins and prostaglandins together. Current therapies available on the market only provide limited solutions and exhibit several side effects. The present paper provides insight into scientific studies that have elucidated the positive role of phytochemicals in counteracting the UV-induced depletion of antioxidant enzymes, increased lipid peroxidation, inflammation, DNA mutations, increased senescence, dysfunctional apoptosis and immune suppression. The contribution of phytochemicals to the downregulation of expression of oxidative-stress sensitive transcription factors (Nrf2, NF-Kb, AP-1 and p53) and protein kinases (MSK, ERK, JNK, p38 MAPK, p90RSK2 and CaMKs) involved in inflammation, apoptosis, immune suppression, extracellular matrix remodelling, senescence, photo ageing and photo-carcinogenesis, is also discussed. Conclusively, several phytochemicals hold potential for the development of a viable solution against UV irradiation-mediated photo ageing, photo-carcinogenesis and related manifestations.

Neferine prevents ultraviolet radiation-induced skin photoaging

The aim of the present study was to evaluate the anti-photoaging effect of neferine upon exposure of mice to ultraviolet (UV) radiation. An in vivo photoaging model was established by repeatedly exposing mouse dorsal skin to UV-A and UV-B radiation for 12 weeks. Through skin photographs, hematoxylin and eosin staining, Masson's trichrome staining, and scanning and transmission electron microscopy, skin wrinkles, epidermal thickness and dermal collagen were analyzed in the UV-irradiated mouse skin. Furthermore, the levels of endogenous antioxidants, namely superoxide dismutase (SOD) and glutathione peroxidase (GPx), were measured to determine the extent of UV-induced oxidative stress that was associated with photoaging. The results demonstrated that the topical application of neferine following UV irradiation reduced oxidative stress by increasing SOD and GPx activities, and attenuated the photoaging process. Histological and ultrastructural examination revealed that neferine delayed skin wrinkle formation by inhibiting epidermal hypertrophy and collagen loss and degradation. In conclusion, the results of the present study indicated that neferine effectively prevents UV-induced skin photoaging and photodamage.