Photoprotection against UV-induced damage by skin-derived precursors in hairless mice

Innovative snail-mucus-extract (SME)-coated nanoparticles exhibit anti-inflammatory and anti-proliferative effects for potential skin cancer prevention and treatment

Nowadays, several studies have highlighted the ability of snail mucus in maintaining healthy skin conditions due to its emollient, regenerative and protective properties. In particular, mucus derived from H. aspersa muller has been reported to have beneficial effects such as antioxidant, antimicrobial activity and wound repair capacity. To enhance antioxidant activity of snail mucus, it was extracted in a hydroalcoholic solution and consequently freeze-dried. The obtained snail mucus extract (SME) was indeed endowed with higher antioxidant activity observed in cell-free models, however it was not possible to test its effects in cellular models as it creates a thick film on the cell surface. Therefore, in order to enhance beneficial effects of snail mucus and extend its potential use, SME was used to develop snail mucus extract-coated gold nanoparticles (AuNPs-SME) which exhibited anti-inflammatory properties on non-tumorigenic cells. LPS-induced inflammation in human NCTC keratinocytes was used as model to investigate the in vitro cytoprotective effects of nanoparticles. Co-treatment with LPS and AuNPs-SME significantly reduced pro-inflammatory cytokine transcription. Moreover, we demonstrated that AuNPs-SME not only can be used for anti-inflammatory treatments, but also as a sunscreen and antioxidant for potential cosmetic applications. Furthermore, AuNPs-SME's ability to selectively inhibit the growth of two human melanoma cell lines without affecting immortalized human keratinocyte viability in the same conditions was assessed. Thus, we demonstrated that snail mucus is suitable for creating innovative formulations and it can be considered a valid candidate for cosmeceutical applications to enrich the snail mucus based anti-age and sunscreen products already present on the market. Moreover, innovative formulations containing snail mucus can be potentially used for the treatment of specific skin neoplasms.

Modified Qing’e Formula protects against UV-induced skin oxidative damage via the activation of Nrf2/ARE defensive pathway

Exposure to ultraviolet (UV) light triggers the rapid generation and accumulation of reactive oxygen species (ROS) in skin cells, which increases oxidative stress damage and leads to photoaging. Nuclear factor E2-related factor 2 (Nrf2) modulates the antioxidant defense of skin cells against environmental factors, especially ultraviolet radiation. Natural products that target Nrf2-regulated antioxidant reactions are promising candidates for anti-photoaging. The aim of this study was to investigate the protective effect of Modified Qing’e Formula (MQEF) on UV-induced skin oxidative damage and its molecular mechanisms. In this study, the photoaging models of human keratinocytes (HaCaT) and ICR mice were established by UV irradiation. In vitro models showed that MQEF displayed potent antioxidant activity, significantly increased cell viability and reduced apoptosis and excess ROS levels. Meanwhile, the knockdown of Nrf2 reversed the antioxidant and anti-apoptotic effects of MQEF. In vivo experiments indicated that MQEF could protect the skin against UV-exposed injury which manifested by water loss, sensitivity, tanning, wrinkling, and breakage of collagen and elastic fibers. The application of MQEF effectively increased the activity of antioxidant enzymes and reduced the content of malondialdehyde (MDA) in mice. In addition, MQEF was able to activate Nrf2 nuclear translocation in mouse skin tissue. In summary, MQEF may attenuate UV-induced photoaging by upregulating Nrf2 expression and enhancing antioxidant damage capacity. MQEF may be a potential candidate to prevent UV-induced photoaging by restoring redox homeostasis.

NRF2 in dermatological disorders: Pharmacological activation for protection against cutaneous photodamage and photodermatosis

The skin barrier and its endogenous protective mechanisms cope daily with exogenous stressors, of which ultraviolet radiation (UVR) poses an imminent danger. Although the skin is able to reduce the potential damage, there is a need for comprehensive strategies for protection. This is particularly important when developing pharmacological approaches to protect against photocarcinogenesis. Activation of NRF2 has the potential to provide comprehensive and long-lasting protection due to the upregulation of numerous cytoprotective downstream effector proteins that can counteract the damaging effects of UVR. This is also applicable to photodermatosis conditions that exacerbate the damage caused by UVR. This review describes the alterations caused by UVR in normal skin and photosensitive disorders, and provides evidence to support the development of NRF2 activators as pharmacological treatments. Key natural and synthetic activators with photoprotective properties are summarized. Lastly, the gap in knowledge in research associated with photodermatosis conditions is highlighted.

The “End Life” of the Grape Pomace Waste Become the New Beginning: The Development of a Virtuous Cycle for the Green Synthesis of Gold Nanoparticles and Removal of Emerging Contaminants from Water

During the last decades, the demand for processes developed according to the Circular Economy Principles has increased, searching for an alternative life for wastes. For this purpose, a one-pot green approach is exploited during this work to synthesize gold nanoparticles (AuNPs) by using grape pomace waste from Vitis vinifera. A raw aqueous extract of grape seeds, skin, and stems is used for AuNPs synthesis. UV-Vis, XPS, SEM, and ATR-FTIR spectroscopies demonstrate the main role of the extract’s polyphenolic components in stabilizing nanoparticles. XRD, DLS, and Zeta Potential analyses were used to characterize AuNPs. Moreover, the ionic strength, pH, and temperature role was investigated through the Surface Plasmon Resonance (SPR) band observation to assess AuNPs’ stability and photostability. For foreseeing the as-synthesized AuNPs’ potential use in cosmetic and biomedical fields as multifunctional platforms, their antioxidant, and skin-lightening properties were tested, together with their sunscreen ability. A preliminary in-vitro evaluation is reported about the AuNPs’ cytoprotective effects against H₂O₂ oxidative stress-induced in normal human dermal fibroblasts. Briefly, the possibility of reusing the grape pomace waste after the AuNPs synthesis as an adsorbent for the efficient removal of emergent contaminants is preliminarily discussed in the paper, further valorizing the use of waste according to a bio circular approach.

Protective effect of oligosaccharides isolated from Panax ginseng C. A. Meyer against UVB-induced skin barrier damage in BALB/c hairless mice and human keratinocytes

ETHNOPHARMACOLOGICAL RELEVANCE

Skin barrier dysfunction can lead to water and electrolyte loss, triggering homeostatic imbalances that can trigger atopic dermatitis and anaphylaxis. Panax ginseng C.A. Meyer is a traditional Chinese medicinal herb with known therapeutic benefits for the treatment of skin diseases, including photodamage repair effects and reduction of pigmentation. However, few reports exist that describe effectiveness of ginseng active components for repair of skin barrier damage.

MATERIALS AND METHODS

Ginseng oligosaccharide extract (GSO) was prepared from P. ginseng via water extraction followed by ethanol precipitation and resin and gel purification. GSO composition and structural characteristics were determined using LC-MS, HPLC, FT-IR, and NMR. To evaluate GSO as a skin barrier repair-promoting treatment, skin of UVB-irradiated BALB/c hairless mice was treated with or without GSO then skin samples were evaluated for epidermal thickness, transepidermal water loss (TEWL), and stratum corneum water content. In addition, UVB-exposed skin samples and HaCaT cells were analyzed to assess GSO treatment effects on levels of epidermal cornified envelope (CE) protein and other skin barrier proteins, such as filaggrin (FLG), involucrin (IVL), and aquaporin-3 (AQP3). Meanwhile, GSO treatment was also evaluated for effects on UVB-irradiated hairless mouse skin and HaCaT cells based on levels of serine protease inhibitor Kazal type-5 (SPINK5), trypsin-like kallikrein-related peptidase 5 (KLK5), chymotrypsin-like KLK7, and desmoglein 1 (DSG1). These proteins are associated with UVB-induced skin barrier damage manifesting as dryness and desquamation.

RESULTS

GSO was shown to consist of oligosaccharides comprised of seven distinct types of monosaccharides with molecular weights of approximately 1 kDa that were covalently linked together via β-glycosidic bonds. In vivo, GSO applied to dorsal skin of BALB/c hairless mice attenuated UVB-induced epidermal thickening and moisture loss. Furthermore, GSO ameliorated UVB-induced reductions of levels of FLG, IVL, and AQP3 proteins. Additionally, GSO treatment led to increased DSG1 protein levels due to decreased expression of KLK7. In vitro, GSO treatment of UVB-irradiated HaCaT cells led to increases of FLG, IVL, and AQP3 mRNA levels and corresponding proteins, while mRNA levels of desquamation-related proteins SPINK5, KLK5, KLK7, and DSG1 and associated protein levels were restored to normal levels.

CONCLUSION

A P. ginseng oligosaccharide preparation repaired UVB-induced skin barrier damage by alleviating skin dryness and desquamation symptoms, highlighting its potential as a natural cosmetic additive that can promote skin barrier repair after UVB exposure.

Snail slime-based gold nanoparticles: An interesting potential ingredient in cosmetics as an antioxidant, sunscreen, and tyrosinase inhibitor

Due to their properties, snail slime-based products have been appreciated and used worldwide. So, as an alternative and innovative use of snail slime, it was adopted to induce gold nanoparticles' formation, conferring them interesting properties. By a simple, one-pot, and eco-friendly approach, 14 ± 6 nm wide hybrid gold nanoparticles, having an inorganic metallic core decorated by the slime's main components, were obtained. Among their several properties, their antioxidant and tyrosinase inhibition activity were investigated through the DPPH and ABTS and the tyrosinase assays, respectively. After assessing their non-cytotoxicity in our previous work, the results revealed positive responses, enabling their use as a potential novel multifunctional ingredient in cosmetics. Interestingly, the gold nanoparticle photostability, investigated by means of a solar simulator lamp, suggests using them in commercial cosmetic sunscreen products as a potential alternative to the commonly used inorganic sunscreen ingredients. The theoretical Sun Protection Factor was evaluated, obtaining values in the range 0-12. The proposed environmentally friendly and cost-effective protocol for nanoparticle synthesis, following the principles of Green Chemistry, opens a hugely attractive space toward the study of snail slime-based gold nanoparticles as a potential multipurpose platform in cosmetics.

Therapeutic Effects of Dipterocarpus tuberculatus with High Antioxidative Activity Against UV-Induced Photoaging of NHDF Cells and Nude Mice

To investigate the therapeutic effects of methanol extracts of Dipterocarpus tuberculatus Roxb. (MED) against UV-induced photoaging, we assessed for alterations in the antioxidant activity, anti-apoptotic effects, ECM modulation, skin appearances, and anti-inflammatory response in normal human dermal fibroblast (NHDF) cells and nude mice orally treated with MED. High levels of tannin content and high free radical scavenging activity to DPPH were determined in MED, while seven active components, namely, gallic acid, bergenin, ellagic acid, ε-viniferin, asiatic acid, oleanolic acid, and 2α-hydroxyursolic acid, were identified using LC–MS analyses. UV-induced alterations in the NO concentration, SOD activity, and Nrf2 expression were remarkably recovered in MED-treated NHDF cells. Moreover, the decreased number of apoptotic cells and G2/M phase arrest were observed in the UV + MED-treated groups. Similar recoveries were detected for β-galactosidase, MMP-2/9 expression, and intracellular elastase activity. Furthermore, MED treatment induced suppression of the COX-2-induced iNOS mediated pathway, expression of inflammatory cytokines, and inflammasome activation in UV-radiated NHDF cells. The anti-photoaging effects observed in NHDF cells were subsequently evaluated and validated in UV + MED-treated nude mice through skin phenotypes and histopathological structure analyses. Taken together, these results indicate that MED exerts therapeutic effects against UV-induced photoaging and has the potential for future development as a treatment for photoaging.

Mouse skin-derived precursors alleviates ultraviolet B irradiation damage via early activation of TGF-β/Smad pathway by thrombospondin1

Our previous research implied mouse skin-derived precursors (mSKPs) possessed the capacity of anti-ultraviolet B (UVB) irradiation damage, and the mechanisms might be associated with transforming growth factor-β (TGF-β) signaling pathway activation. In this study, we investigated and compared the response to UVB irradiation between mSKPs and dermal mesenchymal stem cells (dMSCs), and explored the underlying mechanisms. Irradiation damage such as decreased cell viability, cell senescence, and cell death was observed in both mSKPs and dMSCs at 24 h after UVB exposure. In mSKPs, change in cell morphology, viability, cell senescence and death at the following time points implied the recovery of UVB irradiation damage. Additionally, thrombospondin1 (TSP1) and TGF-β1 increased significantly in mSKPs' supernatant after UVB irradiation. The gene expression of TSP1, TGF-β1, metalloproteinase 1 (MMP1), and Collagen I elevated shortly after the UVB exposure. The protein expression of TSP1, TGF-β1, MMP1, Collagen I, smad2/3, and p-smad2/3 at multiple time points after the UVB exposure was consistent with the gene expression results. In dMSCs, no obvious recovery was noticed. Together, these results revealed that in mSKPs, one of the mechanisms to attenuate the UVB irradiation damage might be the early activation of TGF-β/Smad pathway by TSP1. Given that mSKPs could differentiate into fibroblast-like SKP-derived fibroblasts (SFBs) in vivo or with the presence of serum, mSKPs might serve as a therapeutic potential for fibroblasts supplement and UVB irradiation damage treatment.Abbreviations: SKPs: skin-derived precursors; mSKPs: mouse SKPs; UVB: ultraviolet B; TGF-β/Smad: transforming growth factor-β/Smad; TSP1: thrombospondin 1; MMP 13: metalloproteinases 13; TβRII: TGF-β receptor II; SFBs: SKP-derived fibroblasts; KEGG: Kyoto encyclopedia of genes and genomes; DEGs: differentially expressed genes; dMSCs: dermal mesenchymal stem cells; LM: light microscope; CCK-8: cell counting kit 8; ELISA: Enzyme-linked immuno sorbent assay; qRT-PCR: quantitative real-time polymerase chain reaction; TSPs: thrombospondins; ECM: extracellular matrix; R-smads: receptor-regulated smads.

Andrographolide sodium bisulfate attenuates UV‑induced photo‑damage by activating the keap1/Nrf2 pathway and downregulating the NF‑κB pathway in HaCaT keratinocytes

Oxidative and inflammatory damage has been suggested to play important roles in the pathogenesis of skin photoaging. Andrographolide sodium bisulfate (ASB) is a soluble derivative of andrographolide and has known antioxidant and anti‑inflammatory properties. In the present study, cellular experiments were designed to investigate the molecular mechanisms underlying the effect of ASB in relieving ultraviolet (UV)‑induced photo‑damage. Following ASB pretreatment and UV irradiation, the apoptosis and necrosis of HaCaT cells were investigated by Hoechst 33342/propidium iodide staining. Reactive oxygen species (ROS) production was investigated using a DCFH‑DA fluorescence probe. Furthermore, the protein expression levels of p65, NF‑κB inhibitor‑α, nuclear factor E2‑related factor 2 (Nrf2) and kelch‑like ECH‑associated protein 1 (keap1) were measured via western blotting and immunofluorescence analyses. Furthermore, NF‑κB‑mediated cytokines were assessed by ELISA, and Nrf2‑mediated genes were detected by reverse transcription‑quantitative PCR. Pretreatment with ASB markedly increased cell viability, decreased cell apoptosis and decreased UV‑induced excess ROS levels. In addition, ASB activated the production of Nrf2 and increased the mRNA expression levels of glutamate‑cysteine ligase catalytic subunit and NAD(P)H quinone oxidoreductase 1, while ASB downregulated the protein expression of p65 and decreased the production of interleukin (IL)‑1β, IL‑6 and tumor necrosis factor‑α. These results suggested that ASB attenuates UV‑induced photo‑damage by activating the keap1/Nrf2 pathway and downregulating the NF‑κB pathway in HaCaT keratinocytes.

Nrf2 Overexpression for the Protective Effect of Skin-Derived Precursors against UV-Induced Damage: Evidence from a Three-Dimensional Skin Model

Background

Skin photodamage is associated with ultraviolet- (UV-) induced reactive oxygen species (ROS) overproduction and nuclear factor erythroid 2-related factor 2 (Nrf2) inactivation. In our previous study, skin-derived precursors (SKPs) were shown to ameliorate a UV-induced damage in mice, probably through Nrf2 activation and ROS scavenging.

Objective

To clarify the mechanism underlying the photoprotective effect of SKPs against UV-induced damage in a three-dimensional (3D) skin model.

Methods

The Nrf2 gene in SKPs was modified using lentiviral infection, and 3D skin models were reconstructed with keratinocytes and fibroblasts on the basis of type I collagen. Subsequently, these models were divided into the following six groups: normal, model, overexpressed, control, silenced, and negative control groups. Prior to irradiation, respective SKPs were injected into the last four groups. Next, all groups except the normal group were exposed to UVA+UVB. Lastly, the pathological and molecular-biological techniques were employed to determine the parameters. Additionally, LY294002, a PI3K inhibitor, was used to investigate the roles of PI3K/Akt and Nrf2/hemeoxygenase-1 (HO-1) in SKP photoprotection.

Results

Normal 3D skin models appeared as milky-white analogs with a clear, well-arranged histological structure. After the skin was exposed to irradiation, it exhibited cell swelling and a disorganized structure and developed nuclear condensation with numerous apoptotic cells. The expressions of cellular protective genes and Nrf2/HO-1/PI3K/Akt proteins remarkably decreased, which were accompanied by increased oxidative stress and decreased antioxidants (P < 0.05). However, these phenomena were reversed by nrf2-overexpressing SKPs. The 3D skin in the overexpressed group showed mild swelling, neatly arranged cells, and few apoptotic cells. Cellular protective genes and Nrf2/HO-1/PI3K/Akt proteins were highly expressed, and the oxidative biomarkers were remarkably ameliorated (P < 0.05). Nevertheless, the expression of these proteins decreased after LY294002 pretreatment regardless of SKP treatment or not. Meanwhile, there were increases in both UV-induced apoptotic cells and ROS level accompanied with SOD and GPX decrease in the presence of LY294002.

Conclusions

Evidence from the 3D skin model demonstrates that the protection of SKPs against UV-mediated damage is primarily via the PI3K/Akt-mediated activation of the Nrf2/HO-1 pathway, indicating that SKPs may be a promising candidate for the treatment of photodermatoses.

Protective Effects of Kuding Tea (Ilex kudingcha C. J. Tseng) Polyphenols on UVB-Induced Skin Aging in SKH1 Hairless Mice

In this study, the protective effects of Kuding tea polyphenols (KTPs) on ultraviolet B (UVB)-induced skin injury of SKH1 hairless mice were studied. The ion precipitation method was used for extraction of polyphenols from Kuding tea. High-performance liquid chromatography showed that KTPs contains chlorogenic acid, cryptochlorogenic acid, isochlorogenic acid B, isochlorogenic acid A, and isochlorogenic acid C. SKH1 hairless mice were induced skin aging using 2.0 mW/s intensity of 90 mJ/cm² UV light once a day for seven weeks. The 2.5% and 5% KTPs solution was smeared on 2 cm² of back skin of skin aging mice twice a day. Mouse experiments showed that KTP strongly increased the serum levels of total superoxide dismutase (T-SOD) and catalase (CAT) and reduced those of malondialdehyde, interleukin 6 (IL-6), IL-1β, and tumor necrosis factor alpha (TNF-α) in mice with UVB-induced skin damage. KTP also increased the levels of type 1 collagen (Col I), hydroxyproline, and hyaluronic acid and reduced those of Col III and hydrogen peroxide in the damaged skin tissues of mice. Pathological observations of tissues stained with H & E, Masson’s trichrome, Verhoeff, and toluidine blue showed that KTPs could protect skin cells, collagen, and elastin and decrease the number of mast cells, thus inhibiting skin damage. Quantitative PCR and western blot assays showed that KTP upregulated the mRNA and protein expression of tissue inhibitor of metalloproteinase 1 (TIMP-1), TIMP-2, copper/zinc-SOD, manganese-SOD, CAT, and glutathione peroxidase and downregulated the expression of matrix metalloproteinase 2 (MMP-2) and MMP-9. In addition, the same concentration of KTP had stronger protective effects than vitamin C. The results of this study demonstrate that KTPs have good skin protective effects, as they are able to inhibit UVB-induced skin damage.

Protective effect of pre- and post-vitamin C treatments on UVB-irradiation-induced skin damage

Several studies have reported the effects of vitamin C (L-ascorbic acid, AA) on ultraviolet B (UVB)-induced cell damage using cultured keratinocytes. However, the epidermis consists of multiple cell layers, and the effect of AA on UVB-induced damage to the human epidermis remains unclear. Therefore, we investigated the effect of AA on UVB-induced skin damage using reconstituted human epidermis. The reconstituted human epidermal surface was treated with 100 and 500 mM AA and cultured for 3 h before (pre-AA treatment) or after (post-AA treatment) 120 mJ/cm² UVB irradiation. Pre- and post-AA treatments of the epidermal surface suppressed UVB-induced cell death, apoptosis, DNA damage, reactive oxygen species (ROS) production, and the inflammatory response by downregulating tumour necrosis factor-α (TNF-α) expression and release. Moreover, the pre-AA treatment was more effective at preventing UVB-induced skin damage than the post-AA treatment. In summary, pre- and post-AA treatments of the epidermis prevent UVB-induced damage.

One pot environmental friendly synthesis of gold nanoparticles using Punica Granatum Juice: A novel antioxidant agent for future dermatological and cosmetic applications

HYPOTHESIS

The interesting properties of Gold Nanoparticles (AuNPs) make them attractive for different application fields such as cosmetology, medicine and clinical nanotechnologies. In this work a fast, easy and eco-friendly method for the AuNPs synthesis is proposed by using the Punica Granatum Juice (PGJ) with potential dermatological and cosmetic applications. The AuNPs antioxidant activity, due to the presence of phenols from the juice, and their use as booster for improving the Sun Protection Factor (SPF) in commercial sunscreen formulations, are thus expounded.

EXPERIMENTS

By using appropriate amounts of PGJ and HAuCl₄, under mild work conditions, AuNPs with a mean size of 100 ± 40 nm are observed and carefully characterized. Solution pH, temperature, and volume were also changed for optimizing the AuNPs formation and features. The antioxidant activity was studied, by evaluating the AuNP ability of scavenging the radical 2,2-diphenyl-1-picrylhydrazylhydrate (DPPH). This finding was confirmed performing special experiments focused on the reaction between AuNPs and H₂O₂, by using suitable probes, such as 4-thiothymidine (S⁴TdR) and Cytochrome-c (Cyt-c). The SPF value was also calculated.

FINDINGS

The synthetized AuNPs showed a surface plasmon in visible range at 577 nm and resulted stable for long time in aqueous medium, also changing the pH values in the range 2-12. The studied antioxidant activity, confirmed also by performing special experiments with suitable probes, demonstrated the high performance of AuNPs. The AuNP photostability under sun irradiation is also shown. The calculated SPF values were in the range 3-18, related to AuNPs concentration in the range 1.80 × 10^-12-1.00 × 10^-11 M. The same AuNPs concentrations were used for cellular experiments. Indeed, since the AuNPs-PGJ mediated will be potentially introduced by dermal contact, dermal fibroblasts (Human Dermal Fibroblasts, HDF) and Human Microvascular Endothelial Cells (HMVEC) were used to evaluate the possible effects of these nanoparticles as a preliminary step. The results indicated that an AuNP concentrations in the range 1.80 × 10^-12-3.60 × 10^-12 M could be adopted since they do not appeared cyctotoxic.