Kjellmaniella crassifolia for the Prevention of Ultraviolet B-Induced Oxidative Stress in HaCaT Keratinocytes

This work aimed to evaluate the skin anti-photoaging properties of ginsenoside Rb3 (Rb3), one of the main protopanaxdiol-type ginsenosides from ginseng, in HaCaT keratinocytes. The skin anti-photoaging activity was assessed by analyzing the levels of reactive oxygen species (ROS), pro-matrix metalloproteinase-2 (proMMP-2), pro-matrix metalloproteinase-9 (proMMP-9), total glutathione (GSH), and superoxide dismutase (SOD) activity as well as cell viability in HaCaT keratinocytes under UV-B irradiation. When HaCaT keratinocytes were exposed to Rb3 prior to UV-B irradiation, Rb3 exhibited suppressive activities on UV-B-induced ROS, proMMP-2, and proMMP-9 enhancements. On the contrary, Rb3 displayed enhancing activities on UV-B-reduced total GSH and SOD activity levels. Rb3 could not interfere with cell viabilities in UV-B-irradiated HaCaT keratinocytes. Rb3 plays a protective role against UV-B-induced oxidative stress in human HaCaT keratinocytes, proposing its potential skin anti-photoaging properties.

Reactive oxygen species (ROS) promote oxidative stress, which directly causes molecular damage and disrupts cellular homeostasis, leading to skin aging. Baicalein, a flavonoid compound isolated from the root of Scutellaria baicalensis Georgi has antioxidant, anticancer, anti-inflammatory, and other medicinal properties. We aimed to investigate the protective effect of baicalein on the disruption of tight junctions and mitochondrial dysfunction caused by H2O2-induced oxidative stress in HaCaT keratinocytes. The cells were pretreated with 20 and 40 µM baicalein followed by treatment with 500 µM H2O2. The results revealed that baicalein exerted antioxidant effects by reducing intracellular ROS production. Baicalein attenuated the degradation of the ECM (MMP-1 and Col1A1) and the disruption of tight junctions (ZO-1, occludin, and claudin-4). In addition, baicalein prevented mitochondrial dysfunction (PGC-1α, PINK1, and Parkin) and restored mitochondrial respiration. Furthermore, baicalein regulated the expression of antioxidant enzymes, including NQO-1 and HO-1, via the Nrf2 signaling pathway. Our data suggest that the cytoprotective effects of baicalein against H2O2-induced oxidative stress may be mediated through the Nrf2/NQO-1/HO-1 signaling pathway. In conclusion, baicalein exerts potent antioxidant effects against H2O2-induced oxidative stress in HaCaT keratinocytes by maintaining mitochondrial homeostasis and cellular tight junctions.

Five compounds including a new bisbibenzyl named dendropachol (1) and four known compounds (2–5) comprising 4,5-dihydroxy-2,3-dimethoxy-9,10-dihydrophenanthrene (2), gigantol (3), moscatilin (4) and 4,5,4′-trihydroxy-3,3′-dimethoxybibenzyl (5) were isolated from a methanolic extract of Dendrobium pachyglossum (Orchidaceae). The chemical structures of the isolated compounds were characterized by spectroscopic methods. Dendropachol (1) was investigated for its protective effects on hydrogen peroxide (H2O2)-induced oxidative stress in HaCaT keratinocytes. Compound 1 showed strong free radical scavenging compared to the positive control. For the cytoprotective effect, compound 1 increased the activities of GPx and CAT and the level of GSH but reduced intracellular reactive oxygen species (ROS) generation and accumulation. In addition, compound 1 significantly diminished the expression of p53, Bax, and cytochrome C proteins, decreased the activities of caspase-3 and caspase-9, and increased Bcl-2 protein. The results suggested that compound 1 exhibited antioxidant activities and protective effects in keratinocytes against oxidative stress induced by H2O2.

This study was designed to investigate the cytoprotective effect of rosmarinic acid (RA) on ultraviolet B (UVB)-induced oxidative stress in HaCaT keratinocytes. RA exerted a significant cytoprotective effect by scavenging intracellular ROS induced by UVB. RA also attenuated UVB-induced oxidative macromolecular damage, including protein carbonyl content, DNA strand breaks, and the level of 8-isoprostane. Furthermore, RA increased the expression and activity of superoxide dismutase, catalase, heme oxygenase-1, and their transcription factor Nrf2, which are decreased by UVB radiation. Collectively, these data indicate that RA can provide substantial cytoprotection against the adverse effects of UVB radiation by modulating cellular antioxidant systems, and has potential to be developed as a medical agent for ROS-induced skin diseases.

Exposure to UVA radiation is known to cause many adverse biological effects by inducing the stricken cells to produce reactive oxygen species (ROS). In recent years the use of botanicals has received considerable interest in the skin protection. Bilberry (Vaccinium myrtillus L.) fruit contains several polyphenols with strong antioxidant and anti-inflammatory properties. In this study we evaluated potential UVA preventive effect of V. myrtillus fruit extract (VME; anthocyanins, 25% w/w) in HaCaT keratinocytes. Pre-treatment (1 h) or post-treatment (4 h) of HaCaT with VME resulted in attenuation of UVA-caused damage. Application of the extract significantly reduced UVA-stimulated ROS formation in keratinocytes. VME also prevented/reduced UVA-caused peroxidation of membrane lipids and depletion of intracellular GSH. The observed cytoprotective effect may be linked to the antioxidant activity of the plant constituents, namely anthocyanins.

Recent studies have revealed that marine brown seaweeds contain numerous bioactive compounds which exhibit various bioactivities. The present study investigated the effect of low molecular weight fucoidan (SCF) isolated from Sargassum confusum, a brown alga, on inflammatory responses and oxidative stress in HaCaT keratinocytes stimulated by tumor necrosis factor (TNF)-α/interferon (IFN)-γ. SCF significantly increased the cell viability while decreasing the intracellular reactive oxygen species (ROS) production in TNF-α/IFN-γ-stimulated HaCaT keratinocytes. In addition, SCF effectively reduced inflammatory cytokines (interleukin (IL)-1β, IL-6, IL-8, IL-13, TNF-α, and IFN-γ) and chemokines (Eotaxin, macrophage-derived chemokine (MDC), regulated on activation, normal T cell expressed and secreted (RANTES), and thymus and activation-regulated chemokine (TARC)) expression, by down-regulating the expression of epithelial and epidermal innate cytokines (IL-25, IL-33, and thymic stromal lymphopoietin (TSLP)). Furthermore, SCF suppressed the activation of TNF-α/IFN-γ-stimulated mitogen-activated protein kinase (MAPK) and nuclear factor-κB (NF-κB) signaling pathways, while activating the nuclear factor erythroid 2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) signaling pathway. The cytoprotective effect of SCF against TNF-α/IFN-γ stimulation was considerably reduced upon inhibition of HO-1 activity by ZnPP. Overall, these results suggest that SCF effectively suppressed inflammatory responses and oxidative stress in TNF-α/IFN-γ-stimulated HaCaT keratinocytes via activating the Nrf2/HO-1 signaling pathway.

The present study was designed to investigate the protective effect of ethanol extracts from Lindera coreana leaves (LCE) on UVB-induced oxidative stress in HaCaT keratinocytes. The HaCaT cells were pretreated with LCE for 24 h and then exposed to UVB (20 mJ/cm2) for 2 h. UVB significantly decreased the cell viability (p<0.05). LCE did not exhibit significantly cytotoxic effects and increased the viability of the HaCaT cells in a concentration-dependent manner. To further investigate the protective effects of LCE on UVB-induced oxidative stress in HaCaT cells, the cellular levels of reactive oxygen species (ROS), lipid peroxidation and endogenous antioxidant enzymes, including catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GSH-px), were analyzed. LCE decreased the intracellular levels of ROS and lipid peroxidation and increased the activity of antioxidant enzymes. These results suggest that LCE exerted cytoprotective activity against UVB-induced oxidative stress in HaCaT cells through the inhibition of lipid peroxidation, reduction of ROS levels and stimulation of antioxidant enzymes activities. In addition, LCE also decreased the TNF-α, IL-1β and IL-6 levels in UVB-irradiated HaCaT cells.

Ultraviolet B (UVB) radiation is part of the spectrum of light produced by the sun. This form of radiation has been implicated as one of the potential etiological factors causing age-related macular degeneration (AMD). Oxidative injury to the retinal pigment epithelium (RPE) has also been thought to play a key role in AMD. The aim of the present study was to determine the mechanism by which UVB causes damage to the RPE cells, whether it occurs through oxidative stress and the mitogen-activated protein kinase (MAPK) pathway and whether the green tea extract, (-)-epigallocatechin gallate (EGCG), has a protective role. Cell viability assays were used to determine the viability of the cells under different conditions. Cell death caused by apoptosis was determined using fluorescein isothiocyanate conjugated-annexin V/PI labeling, followed by flow cytometry. Intracellular reactive oxygen species (ROS) levels were measured by flow cytometry. Western blot analysis was used to detect UVB-induced MAPK signaling pathways. The findings showed that UVB induced apoptosis, which increased intracellular ROS in ARPE19 cells. Inhibition of c-Jun NH2-terminal kinase (JNK) with a specific inhibitor augmented this apoptosis, and anisomycin (an activator of JNK) attenuated this apoptosis. In addition, UVB decreased the phosphorylation of JNK1 and c-Jun. Finally, EGCG reduced the ROS generation and apoptosis, and also partially blocked the decreased phosphorylation of JNK1 and c-Jun by UVB irradiation. The findings show that UVB irradiation is able to induce apoptosis in ARPE19 cells through oxidative stress, but EGCG treatment attenuates this damage. In this situation, the JNK pathway plays an anti-apoptotic role. The use of selective activators or antioxidants may be useful in reducing the oxidative damage occurring in AMD.

Role of Phagocyte Oxidase in UVA-Induced Oxidative Stress and Apoptosis in Keratinocytes

We investigated the protective effects of chlorogenic acid (CGA), a polyphenol compound, on oxidative damage induced by UVB exposure on human HaCaT cells. In a cell-free system, CGA scavenged 1,1-diphenyl-2-picrylhydrazyl radicals, superoxide anions, hydroxyl radicals, and intracellular reactive oxygen species (ROS) generated by hydrogen peroxide and ultraviolet B (UVB). Furthermore, CGA absorbed electromagnetic radiation in the UVB range (280–320 nm). UVB exposure resulted in damage to cellular DNA, as demonstrated in a comet assay; pre-treatment of cells with CGA prior to UVB irradiation prevented DNA damage and increased cell viability. Furthermore, CGA pre-treatment prevented or ameliorated apoptosis-related changes in UVB-exposed cells, including the formation of apoptotic bodies, disruption of mitochondrial membrane potential, and alterations in the levels of the apoptosis-related proteins Bcl-2, Bax, and caspase-3. Our findings suggest that CGA protects cells from oxidative stress induced by UVB radiation.

Objectives : Lonicerae japonicae Flos(LJF) has been reported to exhibit anti-oxidant, anti-infl ammatory, anti-viral, anti-rheumatoid properties. However, it is still largely unknown whether LJF inhibits the ultraviolet(UV)B-induced oxidative damage in human HaCaT keratinocytes. Therefore in thi s paper, we investigated the anti-oxidative capacity and protective effect of LJF against UVB-induced oxida tive demage in human HaCaT keratinocytes.Methods : To evaluate the anti-oxidative activity of LJF extracts, we measured total phenolic contents, total flavonoid contents, antioxidant capacity, and superoxide scavenging activity. To give an oxidative stress to HaCaT cells, UVB was irradiated with 200 mJ/㎠ to HaCaT cells. To detect the protective effect of LJF against UVB, we measured cell viability, DNA fragmentation and reactive oxygen species (ROS) production. In addition, we performed high-performance liquid chromatography (HPLC) analysi s to find a major component of LJF.Results : LJF contained phenolic and flavonoid contents, and showed the anti-oxidant and superoxide scavenging activity. The UVB-induced oxidative conditions led to the cell death, DNA fragmentation and reactive oxygen species (ROS) production. However, pretreatment with LJF reduce d oxidative conditions, including inhibition of cell death, DNA fragmentation and ROS production. In addition, we found out chlorogenic acid as major component of LJF.Conclusions : These results could suggest that LJF contained anti-oxidative contents and exhibited protective effects against UVB on human HaCaT keratinocytes. And the effective com pound of LJF which could show protective activities against UVB is chlorogenic acid. Thus, LJF and chlor ogenic acid would be useful for the development of drug or cosmetics treating skin troubles.Key words : HaCaT keratinocytes, Lonicerae japonicae Flos, UVB(ultravioletB), Reactive Oxygen Species (ROS), chlorogenic acid

Skin, our first interface to the external environment, is subjected to oxidative stress caused by a variety of factors such as solar ultraviolet, infrared and visible light, environmental pollution, including ozone and particulate matters, and psychological stress. Excessive reactive species, including reactive oxygen species and reactive nitrogen species, exacerbate skin pigmentation and aging, which further lead to skin tone unevenness, pigmentary disorder, skin roughness and wrinkles. Besides these, skin microbiota are also a very important factor ensuring the proper functions of skin. While environmental factors such as UV and pollutants impact skin microbiota compositions, skin dysbiosis results in various skin conditions. In this review, we summarize the generation of oxidative stress from exogenous and endogenous sources. We further introduce current knowledge on the possible roles of oxidative stress in skin pigmentation and aging, specifically with emphasis on oxidative stress and skin pigmentation. Meanwhile, we summarize the science and rationale of using three well-known antioxidants, namely vitamin C, resveratrol and ferulic acid, in the treatment of hyperpigmentation. Finally, we discuss the strategy for preventing oxidative stress-induced skin pigmentation and aging.

This study aims to investigate the photoprotective properties of a Lomentaria hakodatensis ethanol extract (LHE) against ultraviolet B (UVB) radiation-induced cellular damage in human HaCaT keratinocytes. LHE exhibited scavenging activity against intracellular reactive oxygen species (ROS), which were generated by either hydrogen peroxide (H2O2) or UVB radiation. Moreover, LHE scavenged superoxide anion generated by the xanthine/xanthine oxidase system and hydroxyl radical generated by the Fenton reaction (FeSO4 + H2O2). Furthermore, LHE exhibited UVB absorptive properties and attenuated injury to cellular components (e.g., lipids, proteins and DNA), resulting from UVB-induced oxidative stress. In addition, LHE reduced apoptosis in response to UVB, as shown by decreased DNA fragmentation and the formation of apoptotic bodies. These results suggest that LHE protects human keratinocytes against UVB-induced oxidative stress by scavenging ROS and absorbing UVB rays; thereby reducing damage to biological components.

Oxidative stress plays a critical role in skin aging and in various dermatological disorders by promoting inflammation, apoptosis, and cellular dysfunction. Among reactive oxygen species (ROS), hydrogen peroxide (H2O2) readily penetrates cell membranes, triggering oxidative damage. This study investigated the protective effects of the Dendranthema boreale (Makino) Ling ex Kitam. flower extract (DBE) against H2O2-induced oxidative stress in HaCaT keratinocytes and explored the underlying molecular mechanisms. DBE (30-80 μg/ml) significantly attenuated H2O2-induced cytotoxicity by reducing cleaved caspase-3 activation and lowering the Bax/Bcl-2 ratio, thereby inhibiting apoptosis. Furthermore, DBE selectively suppressed JNK and ERK phosphorylation while having no effect on p38 MAPK activation. Inflammatory responses were also modulated, as DBE inhibited NF-κB p65 phosphorylation and downregulated COX-2 expression, a key mediator of oxidative stress-induced inflammation. These findings indicate that DBE protects HaCaT keratinocytes from oxidative stress-induced cellular damage by promoting cell survival, suppressing apoptosis, and modulating the key signaling pathways involved in oxidative stress and inflammation. This study provides foundational insights into the potential therapeutic and cosmetic applications of DBE for the prevention of oxidative stress-related skin disorders.

Environmental contaminants have recently attracted attention because of their severe atmospheric concentration and long-term negative health consequences, such as inflammatory and carcinogenic effects. This study investigated the adverse effects of daily environmental exposures including particulate matter (PM) and ultraviolet B (UVB), individually and in combination, on HaCaT keratinocytes, focusing on cell viability and oxidative stress under acute and chronic conditions. Keratinocytes were treated with various doses of PM and UVB reflective of real-world exposure: 12.5, 25, 50, 100, 200 µg/mL for PM and 25, 50, 75, 100, 200 mJ/cm2 for UVB irradiation. Cytotoxicity was investigated using cell viability assay and reactive oxygen species (ROS) generation was observed by using 2′,7′-Dichlorodihydrofluorescein Diacetate staining prior to flow cytometry analysis. Treatment with PM or UVB individually demonstrated dose-dependent and significantly decline in cell viability. In addition, the additive effects were exhibited in PM and UVB co-treatment conditions. Flow cytometry analysis of co-treatments revealed the strong effects on cellular damages, indicative of programmed cell death. The mechanistic studies showed that co-exposure slightly elevated ROS levels upon chronic exposure, suggesting adverse complications in oxidative damage. These findings underscore the harmful effects of PM and UVB on keratinocytes, emphasizing the need to address combined environmental stressors.