Next Article in Journal
Protective Effects of Kirenol against Lipopolysaccharide-Induced Acute Lung Injury through the Modulation of the Proinflammatory NFκB Pathway and the AMPK2-/Nrf2-Mediated HO-1/AOE Pathway
Next Article in Special Issue
Rhamnusalaternus Plant: Extraction of Bioactive Fractions and Evaluation of Their Pharmacological and Phytochemical Properties
Previous Article in Journal
From Green Technology to Functional Olive Oils: Assessing the Best Combination of Olive Tree-Related Extracts with Complementary Bioactivities
Previous Article in Special Issue
Antioxidant and Anti-Inflammatory Activity of Citrus Flavanones Mix and Its Stability after In Vitro Simulated Digestion
Open AccessArticle

Protective Effect of Pomegranate on Oxidative Stress and Inflammatory Response Induced by 5-Fluorouracil in Human Keratinocytes

1
Department of Pharmacy, University of Salerno, Via Giovanni Paolo II 132, 84084 Fisciano, SA, Italy
2
Department of Medicine, Surgery and Dentistry “Scuola Medica Salernitana”, University of Salerno, Via Salvador Allende, 84081 Baronissi, SA, Italy
*
Author to whom correspondence should be addressed.
Antioxidants 2021, 10(2), 203; https://doi.org/10.3390/antiox10020203
Received: 29 December 2020 / Revised: 25 January 2021 / Accepted: 28 January 2021 / Published: 30 January 2021

Abstract

5-Fluorouracil (5-FU) is a pyrimidine analogue used as an antineoplastic agent to treat multiple solid tumors. Despite its use and efficacy, it also has important side effects in healthy cells, including skin reactions, related to its pro-oxidant and pro-inflammatory potential. Although there are numerous remedies for chemotherapy-induced skin reactions, the efficacy of these treatments remains limited. In this study we focused on the effects of pomegranate (Punica granatum L.) juice extract (PPJE) on the oxidative and inflammatory state in 5-FU-treated human skin keratinocytes (HaCaT). The obtained results showed that PPJE significantly inhibited reactive oxygen species release and increased the cellular antioxidant response, as indicated by the increased expression of cytoprotective enzymes, such as heme oxygenase-1 and NAD(P)H dehydrogenase [quinone] 1. In these experimental conditions, PPJE also inhibited nitrotyrosine formation and 5-FU-induced inflammatory response, as indicated by the reduced cytokine level release. Moreover, PPJE inhibited nuclear translocation of p65-NF-κB, a key factor regulating the inflammatory response. In 5-FU-treated HaCaT cells PPJE also inhibited apoptosis and promoted wound repair. These results suggest a potential use of PPJE as an adjuvant in the treatment of the oxidative and inflammatory state that characterizes chemotherapy-induced skin side effects.
Keywords: 5-Fluorouracil; human keratinocytes; pomegranate juice extract; oxidative stress; inflammation; apoptosis; wound repair 5-Fluorouracil; human keratinocytes; pomegranate juice extract; oxidative stress; inflammation; apoptosis; wound repair

1. Introduction

Chemotherapeutic treatment is associated with severe toxic effects that vary with the dose and the patient, and lead sometimes to chemotherapy discontinuation which adversely affects the prognosis and eventually reduces the survival rates of patients. The therapies target specifically not only cancer cells but also normal proliferating cells, causing inhibition of cell proliferation, genomic instability, overproduction of different reactive toxic products and mediators and necrosis, leading to severe toxic effects and complications. 5-Fluorouracil (5-FU), a pyrimidine analogue, is among the most widely used drugs in the treatment of many types of cancer. Like most chemotherapeutic agents, 5-FU does not have a selective action targeting cancer cells and this leads to a number of serious side effects [1]. Different complications are associated with 5-FU therapy and among the most common complications are gastrointestinal effects and dermatitis [2,3,4,5,6,7,8]. In particular, dermatitis is a frequent side effect of chemotherapy and radiotherapy treatment in cancer patients. Dermatitis arises as the beginning of erythema, swelling, an acneiform rash, severe pruritus, xerosis cutis, skin wounds and inflammatory ulcers, which can lead to chronic inflammation, necrosis, fibrosis and increased risk of infections in patients [9,10,11]. 5-FU may rapidly harm dividing immature keratinocytes, as well as dividing stem cells [12,13,14] and the basal cell layer of epithelium can be directly damaged leading to the loss of the renewal capacity of the epithelium, which may result in ulceration [15].
Among the etiological factors that can determine the pathogenesis of toxic side effects induced by chemotherapy treatments, oxidative stress and inflammation are important [16,17]. In particular, chemotherapy drugs are responsible for an excessive production of radical oxygen species (ROS) and inflammatory mediators that trigger pathological mechanisms of cell damage, altering the normal physiological parameters of the cells [18,19]. In particular, ROS levels are also increased after 5-FU treatment and its induction is also critical to promote both inflammation and drug-mediated apoptotic cell death [20]. Therefore, inhibiting or limiting ROS production and inflammation may help in the treatment of dermatitis in cancer patients.
Although various types of therapies have been introduced for the prevention and treatment of chemotherapy-induced dermatitis, the efficacy of these treatments remains limited, and thus researchers have a great interest in finding new therapeutic strategies also in the field of natural products.
Pomegranate (Punica granatum L.) was one of the first domesticated fruits to be cultivated and has also gained considerable recognition as a functional food in the modern era. A large body of literature has highlighted the health-promoting activities of pomegranate juice and fruit extracts. Pomegranate has been used to expel parasites [21], its seeds and fruit peels to treat diarrhea [22,23], its plant flowers to manage diabetes [24], its tree barks and roots to end bleeding and heal ulcers, and its leaves to manage inflammation and handle digestive system disorders [25]. The ingredients of pomegranate also show a chemopreventive role through the inactivation and activation of different cell signaling pathways [26,27] and their effect in counteracting some chemotherapy-induced side effects, such as nephrotoxicity, hepatotoxicity and intestinal mucositis, have also been reported [28,29]. Considering the properties of the polyphenols present in pomegranate juice extract (PPJE), in this study we evaluated its effect on oxidative stress, apoptosis and cellular migration in a human keratinocyte cell line (HaCaT) treated with 5-FU.

2. Materials and Methods

2.1. Reagents

Unless stated otherwise, all reagents and compounds were purchased from Sigma Chemicals Company (Sigma, Milan, Italy).

2.2. Sample Preparation

Punica granatum L. fruits were purchased in a local store in Fisciano (SA). Fruits were manually washed and peeled, then the arils were squeezed with an electric homogenizer. The juice obtained was centrifuged and then the supernatant purified by solid phase extraction.
The polyphenolic extract (PPJE) was eluted with methanol, evaporated to dryness under vacuum at 40 °C in a rotary evaporator, and finally dissolved in methanol, filtered and then analyzed by LC × LC system coupled online to IT-TOF instrument equipped with an electrospray source (ESI). HILIC × RP-MS/MS parameters and the full list of identified polyphenolic compounds are in complete agreement with data previously reported by us [29].

2.3. Cell Culture

The immortal keratinocyte (HaCaT) cell line, derived from normal adult human skin, was purchased from CLS Cell Lines Service GmbH (Eppelheim, Germany—accession number 300493) [30]. HaCaT cells are routinely maintained in the presence of Dulbecco’s modified Eagle’s medium (DMEM) containing 10% (v/v) fetal bovine serum (FBS) and 1% (v/v) penicillin-streptomycin. Cells were grown at 37 °C in a humidified atmosphere of 5% CO2/ 95% air.

2.4. Cellular Treatment

In order to estimate the antioxidant and anti-inflammatory potential at skin level of pomegranate juice extract (PPJE) on HaCaT during chemotherapy treatment, cells were plated and, after adhesion, treated with PPJE (1.25–10 µg/mL) alone, for 1 h, and then simultaneously with 5-FU (10 µg/mL), for different times based on the mediators evaluated. Details regarding sample preparation and the qualitative and quantitative profile of the PPJE are reported above [29].

2.5. Measurement of Intracellular ROS Release

ROS levels were evaluated by means of the probe 2′,7′-dichlorofluorescin-diacetate (H2DCF-DA) [31]. HaCaT cells were plated in 24-well plates (8.0 × 103 cells/well) and, after adhesion, were treated as previously described, for 24 h. The cells were then collected, washed with phosphate buffered saline (PBS), and then incubated in PBS containing H2DCF-DA (10 μM). After 15 min at 37 °C, cell fluorescence was evaluated using a fluorescence-activated cell sorter (FACSscan; Becton Dickinson, Franklin Lakes, NJ, USA) and analyzed with Cell Quest software (version 4; Becton Dickinson, Milan, Italy).

2.6. Evaluation of HO-1, NQO1, Bax and Bcl-2 Expression and Nitrotyrosine Formation by Flow Cytometry

After the cellular treatment, HaCaT were collected, washed with PBS, then incubated in fixing solution for 20 min and then in Fix Perm solution for 30 min. Anti-heme oxygenase-1 (HO-1; Santa Cruz Biotechnologies, Dallas, TX, USA), anti-NAD(P)H Quinone Dehydrogenase 1 (NQO-1; Santa Cruz Biotechnologies), anti-Bax (Santa Cruz Biotechnologies, Dallas, TX, USA), anti-Bcl-2 (Santa Cruz Biotechnologies, Dallas, TX, USA) or anti-nitrotyrosine (Merck Millipore, Milan, Italy) antibodies were then added for 1 h. The secondary antibody was added to HaCaT cells in fixing solution and cell fluorescence was then evaluated by a fluorescence-activated cell sorter (FACSscan; Becton Dickinson, Milan, Italy) and then elaborated by Cell Quest software (version 4; Becton Dickinson, Milan, Italy) [32].

2.7. TNF-α, IL-6 and IL-1β Levels

Following the cellular treatment described above, the cytokine levels were measured in the supernatants of the treated HaCaT cells, through the use of an enzyme-linked immunosorbent assay (ELISA), according to the manufacturer’s instructions. Data were expressed as pg/mL of cytokine release [33].

2.8. Quantitative Imaging of NF-κB Nuclear Translocation

HaCat cells were seeded on glass cover slips and treated with PJJE (2.5–10 μg/mL) and 5-FU, as described above, for 4 h. Cells seeded on glass cover slips were then washed with PBS, fixed in PBS 4% paraformaldehyde (PFA) and processed for immunofluorescence as previously described [34,35]. In particular, after fixation cells were quenched with 50 mM NH4Cl. Then, cells were permeabilized 5 min with PBS 0.1% Triton and blocked for 30 min with PBS containing 0.5% bovine serum albumin (BSA) and 50 mM NH4Cl. Cells were immunostained with the primary antibody mouse monoclonal anti-NF-κB p65 (Santa Cruz Biotechnology: sc-8008). Primary antibody was detected with Alexa 488 (Jackson Immuno Research). Nuclei were counterstained with 2 μg/mL of the nuclear stain DAPI for 5 min. For each image, z-stacks centered around the plane with maximum DAPI (4′,6-Diamidino-2-phenylindole dihydrochloride) staining were acquired on a laser scanning confocal microscope (TCS SP5; Leica MicroSystems) equipped with a plan Apo 63X, NA 1.4 (Carl Zeiss, White Plains, NY 10601 United States) soil immersion objective lens taking care to use the same parameters and to remain below saturation. Quantitative analysis was performed by the Image software on a minimum of 50 cells for each sample. Automatic thresholding was applied and binary image masks were created of NF-κB and DAPI positive staining to define regions of interest (ROI) for analysis [36,37]. The DAPI staining mask was used to define the nuclear ROI. Using the image calculator, the DAPI mask was subtracted from the NF-κB mask to create a staining mask defining the cytoplasmic ROI. Each of these ROI masks were then applied to the original NF-κB staining images to separate nuclear and cytoplasmic staining within each field. Mean intensity of fluorescence was measured in the defined ROI to calculate nuclear/cytoplasmic ratio.

2.9. Propidium Iodide Assay

The percentage of hypodiploid nuclei was analyzed using propidium iodide (PI) staining by flow cytometry [38]. Briefly, HaCaT cells (8.0 × 103 cells/well) were grown in 24-well plates and allowed to adhere. Thereafter cells were exposed to PPJE (1.25–10 μg/mL) in combination with 5-FU (10 μg/mL), for a further 24 h. Subsequently, after removing the cell medium and washing the cells with PBS, the treated HaCaT cells were suspended in 500 µL of a solution consisting of 0.1% (w/v) sodium citrate and 50 µg/mL PI. At the same time, the cell medium was centrifuged and the cell pellet was added to the cell suspension in order to evaluate both live and dead cells. After incubation for 30 min, al 4 °C and in the dark, hypodiploid nuclei were analyzed with FACScan flow cytometer (Becton Dickinson, Franklin Lakes, NJ, USA) and analyzed with Cell Quest software (ver-sion 4; Becton Dickinson, Milan, Italy).

2.10. Wound Healing Assay

For the wound healing assay, HaCaT cells were plated in 24-well plates (8.0 × 103 cells/well) and allowed to adhere. Then, a wound was produced at the center of the cell monolayer, scraping the bottom with a sterile p10 pipette. The cells were washed with PBS and incubated with cell medium alone or with 5-FU alone (10 μg/mL) or with PPJE (2.5–5 μg/mL) plus 5-FU (10 μg/mL) in a balanced incubation chamber (Integrated Live Cell Workstation Leica AF-6000 LX) with a controlled environment (37 °C; 5% v/v CO2). A 10× phase contrast objective was used to record cell movements with a frequency of acquisition of 10 min. At the end of the acquisition, three different positions were considered for each wound, and the movement of ten randomly selected cells was analyzed for each wound. Cell migration distances were calculated from time 0 to the chosen time points, using the Leica ASF software. Statistical evaluation was performed with the GraphPad Prism 4 software (GraphPad, San Diego, CA, USA) [39].

2.11. Data Analysis and Statistical Evaluation

Data are shown as mean ± mean standard error (s.e.m.), of at least three independent experiments, performed in triplicate. Statistical evaluation was performed using GraphPad Prism 4 software (San Diego, CA, USA), through analysis of variance test and Bonferroni’s test for multiple comparisons A P-value lower than 0.05 was considered significant.

3. Results

3.1. PPJE Inhibited ROS Release and Increased HO-1 and NQO1 Expression in 5-FU-Treated HaCaT Cells

In order to investigate the antioxidant potential of PPJE, we evaluated its ability to reduce intracellular release of ROS, induced by 5-FU. Our results indicated that PPJE (1.25–10 µg/mL) significantly inhibited ROS release in 5-FU-treated (10 µg/mL) HaCaT cells at the three highest tested concentrations (p < 0.001 vs. 5-FU; Figure 1a).
Oxidative stress is triggered by the imbalance between the excessive production of ROS and the reduced antioxidant defense capabilities in cells. For this reason, we analyzed the expression of two antioxidant and cytoprotective enzymes, HO-1 and NQO1. Flow cytometric analysis demonstrated that PPJE (1.25–10 µg/mL) was able to significantly increase the expression of HO-1 (p < 0.05 vs. 5-FU; Figure 1b) and NQO1 at the three highest tested concentrations (p < 0.001 vs. 5-FU; Figure 1c) in HaCaT cells treated with 5-FU.

3.2. PPJE Reduced Nitrotyrosine Formation in 5-FU-Treated HaCaT Cells

Nitrotyrosine is an important biomarker of oxidative stress, formed by the nitration of the tyrosine residues of proteins from reactive peroxynitrite species. The resulting nitration of protein residues can play an important role in the pathogenesis of inflammatory skin diseases. In this work we have shown that 5-FU significantly increased nitrotyrosine formation compared to untreated cells (p < 0.001 vs. C; Figure 2), but PPJE (1.25–10 µg/mL) reduced the formation of this biomarker in 5-FU-treated keratinocytes, significantly at 2.5, 5 and 10 µg/mL (p < 0.001 vs. 5-FU; Figure 2).

3.3. PPJE Reduced Cytokine Levels

A positive correlation exists between oxidative damage and release of pro-inflammatory cytokines. Moreover, scientific evidence has reported that the release of pro-inflammatory cytokines by cutaneous keratinocytes is implicated in various inflammatory skin diseases, also caused by 5-FU [15]. Using an ELISA assay, we evaluated the ability of PPJE to reduce pro-inflammatory cytokine levels in the supernatants of 5-FU-treated HaCaT cells. Our results showed that PPJE (1.25–10 µg/mL) significantly reduced the levels of tumor necrosis factor-α (TNF- α; 2.5–10 µg/mL; p < 0.01 vs. 5-FU; Figure 3a), interleukin-6 (IL-6; p < 0.001 vs. 5-FU; Figure 3b) and interleukin-1β (IL-1 β; p < 0.001 vs. 5-FU; Figure 3c) for all the tested concentrations in 5-FU-treated HaCaT cells.

3.4. PPJE Inhibited NF-κB Translocation in 5-FU Treated HaCaT Cells

In order to analyze the effect of PPJE directly on NF-κB activation, we performed a quantitative immunofluorescence-imaging assay of the nuclear translocation of NF-κB in HaCaT cells exposed to 5-FU alone or in combination with PPJE (2.5–10 μg/mL). As expected, we found that in HaCaT cells the 5-FU treatment (10 μg/mL; 4 h) induced the cytoplasmic to nuclear translocation of NF-κB with a significant 1.7-fold increase in the nuclear/cytoplasmic ratio of NF-κB staining. Conversely, the treatment with PPJE significantly inhibited the nuclear translocation of NF-κB in response to 5-FU with a significant effect evident across the entire PPJE dose range, including the lower dose (p < 0.001 vs. 5-FU; Figure 4 a, b). These results demonstrate that PPJE, inhibiting NF-κB nuclear localization, could have a protective effect on HaCaT in the presence of 5-FU.

3.5. PPJE Reduced 5-FU-Induced Apoptosis in HaCaT Cells

5-FU induces apoptosis in human keratinocytes, which is closely related to an increase in oxidative stress markers, both as increased super anion levels and increased membrane lipid peroxidation [40]. To evaluate whether PPJE could negatively modulate apoptosis induced by 5-FU, we analyzed the percentage of hypodiploid nuclei, through the PI (propidium iodide) assay. Figure 5a shows that the tested extract (1.25–10 µg/mL) significantly reduced 5-FU-induced apoptosis in HaCaT cells (2.5–10 µg/mL; p < 0.001 vs. 5-FU; Figure 5a).
Interestingly, PPJE significantly reduced the expression of the pro-apoptotic protein Bax (p < 0.01 vs. 5-FU; Figure 5b) and increased the expression of the anti-apoptotic protein Bcl-2 (p < 0.01 vs. 5-FU; Figure 5c) at the three highest tested concentrations.

3.6. PPJE Promoted Cell Migration Following Wound

After skin damage induced by chemotherapy drugs, HaCaT keratinocytes divide and proliferate to cover the wound area. This process is known as “re-epithelialization” and is crucial for rapid wound closure. For this reason, we evaluated PPJE’s ability to promote skin regeneration processes by increasing the scratch repair and the speed of cell migration. We observed that PJJE (2.5–5 µg/mL) significantly enhanced cell migration speed compared to 5-FU-treated cells (p < 0.001 vs. 5-FU; Figure 6).

4. Discussion

Chemotherapy is the most widely used therapeutic approach for cancer treatment but its results are also associated with, sometimes, substantial adverse effects. The mechanism of action of many of these drugs, as well as radiotherapy, is the induction of tumor cells’ necrosis or apoptosis, with consequent ROS overproduction. Although oxidative stress, inflammation and apoptosis play a pivotal role as cellular mechanisms related to therapies for cancer treatment, to cause cancer cells elimination, they can also affect healthy cells. These side effects are particularly evident in tissue with a rapid turnover, such as skin, thus inducing effects that can significantly impair the quality of life in these patients. Therefore, control of oxidative stress and of the inflammatory response is of primary importance to avoid deleterious pathological conditions and to counteract anticancer treatment side effects.
Evidence has shown that many foods rich in polyphenols could be used for cancer prevention as adjuvants in chemotherapy treatments, but they could be used to also reduce cancer therapy side effects [41,42,43,44,45]. Pomegranate is a fruit rich in punicalagin, cyanidin 3,5-diglucoside and pelargonidin 3-glucoside [29], which have potent free-radical scavenging properties [46] and pomegranate has the potential to be an agent for cancer prevention related to the anti-inflammatory, pro-apoptotic and anti-proliferative activities of its constituents. In this study we focused our attention on the whole PPJE, reporting its protective effect on 5-FU-treated keratinocytes by: (i) reducing oxidative stress, (ii) reducing the inflammatory response, (iii) reducing apoptosis and (iv) promoting cell migration rate.
ROS are one of the principal mediators in tissue and cellular damage triggered by chemotherapy. In accordance with this, our data show that 5-FU induced a significant ROS release with respect to control cells and PPJE significantly inhibited ROS release in 5-FU-treated cells, at the three highest tested concentrations. This antioxidant effect of PPJE is in accordance with other evidence reporting the antioxidant effect of pomegranate on keratinocytes exposed to UV radiation [47] and in keratinocytes against H2O2-induced oxidative stress and cytotoxicity in human keratinocytes HaCaT [48]. If in normal conditions ROS production can be controlled by antioxidant mechanisms, including small-molecular-weight antioxidants and antioxidant enzyme systems protecting the organism from the damaging effects of oxidative stress, under conditions of severe oxidative stress, for example during the administration of certain drugs as chemotherapeutic agents, cellular endogenous antioxidant defense mechanisms may fail to control the excessive oxidative stress due to ROS overproduction. An oxidative stress condition is due to an imbalance between oxidant factors, such as ROS, and antioxidant factors, such as nuclear factor erythroid 2-like 2 (Nrf2). Nrf2 is a key regulator of the antioxidant response also in keratinocytes, being a redox-sensitive transcriptional regulator that controls the expression of antioxidant and detoxification enzymes such as HO-1 and NQO1 [49]. Our results indicated that PPJE significantly increased these Nrf-2-related antioxidant enzymes, in accordance with other experimental models reporting the protective effect of Nrf-2 pathway activation in keratinocytes during oxidative stress [50,51,52]. Evidence has shown that ROS activate NF-κB, thus amplifying the pro-inflammatory response [53,54]. Nitrotyrosine formation, due to the reaction between ROS and nitric oxide (NO), a pro-inflammatory mediator, is the stable product of the action of peroxynitrite on tyrosine-containing proteins. Nitrotyrosine residues can significantly impair the protein structure and alter its function, leading to potentially pathological results also in keratinocytes [55]. Our data indicated that PPJE was also able to significantly reduce nitrotyrosine formation thus also reducing the nitrosative stress response.
Proinflammatory cytokine production by epidermal keratinocytes plays a key role in skin inflammation [56]. Among these pro inflammatory cytokines, TNF-α has been implicated in the promotion of inflammatory reactions via the activation of cytokines IL-6 and IL-1β [56,57]. TNF-α released from keratinocytes would facilitate the subsequent influx of inflammatory cells on neighboring endothelial cells and it has been shown to promote the immune/inflammatory reactions via the activation and induction of other cytokines, such as IL-6 and IL-1β [58,59]. Therefore, inhibiting or limiting the production of these pro-inflammatory cytokines may help in the treatment of inflammation and dermatitis in cancer patients. PPJE treatment significantly inhibited TNF-α, IL-6 and IL-1β release, thus strongly contributing to the anti-inflammatory response. These data are in accordance with previous studies reporting the anti-inflammatory effect of pomegranate in different experimental models [60,61,62].
NF-κB is the most important transcriptional factor regulating inflammatory pathways. It also directly controls pro-inflammatory cytokine cellular production in keratinocytes suffering from 5-FU-induced dermatitis [15,55,63]. Our findings revealed that PPJE attenuated 5-FU-induced p65 NF-κB nuclear translocation, thereby reducing the expression of pro-inflammatory cytokines. Previous studies have reported that other agents, such as caffeic acid, saikosaponin A and palmitic acid, can reduce keratinocyte inflammation via NF-κB, TNF-α, IL-1β and IL-6 inhibition [55,56,64] thus highlighting the modulation of these factors as crucial in regulating 5-FU-induced skin side effects.
As a result of oxidative stress and inflammatory response onset, apoptosis occurs in 5-FU-treated keratinocytes relative to non-damaged control cells and PPJE significantly inhibited apoptosis in 5-FU-treated cells. The normal balance between pro-apoptotic members of the family (e.g., Bax) and anti-apoptotic components (e.g., Bcl-2) might also be disrupted by the administration of chemotherapy in healthy cells. PPJE was able to reduce Bax expression and to increase the anti-apoptotic protein Bcl-2, thus contributing to protecting keratinocytes from cell death. Our results are in accordance with other studies reporting the protective effect of pomegranate in protecting normal cells from various stimuli-induced toxicities and apoptosis [65].
Keratinocytes play a fundamental role in maintaining the integrity of the epidermal barrier [66], also taking part in skin repair processes and for these reasons their homeostasis is of primary importance. 5-FU treatment induced a significant reduction in cell migration rate, as assessed in wound healing assay, but PPJE induced a significant increase in cell migration speed, thus promoting the skin damage resolution. The obtained results highlight the potential use of PPJE in counteracting chemotherapy-induced side effects, also because this potential can be exerted with topical use. Thus, PPJE would not interfere in reducing the pro-oxidant, pro-inflammatory and pro-apoptotic effect of the therapy on the cancer cells.

5. Conclusions

The results of this study support the antioxidant and anti-inflammatory effects of pomegranate in a course of chemotherapeutic treatment. These effects, together with the anti-apoptotic properties and with the ability to promote wound healing, highlight the potential of using PPJE as a topic onconutraceutical treatment for 5-FU-induced skin damage. This study highlights the potential of pomegranate which appears to be a promising strategy not only in cancer prevention, but also in the management of chemotherapy side effects.

Author Contributions

S.M. conceived and designed and supervised the experiments; S.F.R., G.M. and G.A. (Giuseppina Amodio) performed the experiments; G.P., G.A. (Giuseppina Autore) and P.C. critically revised the manuscript; S.M. and S.F.R. wrote the paper. All authors have read and agreed to the published version of the manuscript.

Funding

This research was funded by: Progetto “Aloe vera gel e punica granatum in onconutraceutica ed oncocosmeceutica”— POR FESR Campania 2014–2020 O.S. 1.1 Az. 1.1.3–1.1–4. Avviso pubblico Progetti di trasferimento tecnologico e di prima industrializzazione per le imprese innovative ad alto potenziale per la lotta alle patologie oncologiche—Campania Terra del Buono-CUP: B63D18000230007 in favor of M.S.; and by: Progetto “Campania Onco Terapie—Combattere la resistenza tumorale: piattaforma integrata multidisciplinare per un approccio tecnologico innovativo alle oncoterapie”—POR Campania FESR 2014/2020 O.S. 1.2 Az. 1.2.2 Avviso per Manifestazione di interesse per la Realizzazione di Technology Platform nell’ambito della lotta alle patologie oncologiche—CUP: B61G18000470007 in favor of C.P.

Institutional Review Board Statement

Not applicable.

Informed Consent Statement

Not applicable.

Data Availability Statement

The data presented in this study are available on request from the corresponding author.

Conflicts of Interest

The authors declare no conflict of interest.

References

  1. Saba, N.F.; Mody, M.D.; Tan, E.S.; Gill, H.S.; Rinaldo, A.; Takes, R.P.; Strojan, P.; Hartl, D.M.; Vermorken, J.B.; Haigentz, M., Jr.; et al. Toxicities of systemic agents in squamous cell carcinoma of the head and neck (SCCHN); A new perspective in the era of immunotherapy. Cri. Rev. Oncol. Hematol. 2017, 115, 50–58. [Google Scholar] [CrossRef] [PubMed]
  2. Al-Asmari, A.K.; Khan, A.Q.; Al-Qasim, A.M.; Al-Yousef, Y. Ascorbic acid attenuates antineoplastic drug 5-fluorouracil induced gastrointestinal toxicity in rats by modulating the expression of inflammatory mediators. Toxicol. Rep. 2015, 2, 908–916. [Google Scholar] [CrossRef] [PubMed]
  3. Layoun, M.E.; Wickramasinghe, C.D.; Peralta, M.V.; Yang, E.H. Fluoropyrimidine-induced cardiotoxicity: Manifestations, mechanisms, and management. Curr. Oncol. Rep. 2016, 18, 35. [Google Scholar] [CrossRef] [PubMed]
  4. Ribeiro, R.A.; Wanderley, C.W.; Wong, D.V.; Mota, J.M.; Leite, C.A.; Souza, M.H.; Cunha, F.Q.; Lima-Júnior, R.C. Irinotecan- and 5-fluorouracil-induced intestinal mucositis: Insights into pathogenesis and therapeutic perspectives. Cancer. Chemother. Pharmacol. 2016, 78, 881–893. [Google Scholar] [CrossRef] [PubMed]
  5. Rashid, S.; Ali, N.; Nafees, S.; Hasan, S.K.; Sultana, S. Mitigation of 5-Fluorouracil induced renal toxicity by chrysin via targeting oxidative stress and apoptosis in wistar rats. Food Chem. Toxicol. 2014, 66, 185–193. [Google Scholar] [CrossRef]
  6. Narayana, K.; D’Souza, U.J.; Sanyal, A.K.; Rao, K.P. 5-Fluorouracil (5-FU) induces the formation of giant cells and sloughing of seminiferous epithelium in the rat testis. Indian J. Physiol. Pharmacol. 2000, 44, 317–322. [Google Scholar]
  7. Hartinger, J.; Veselý, P.; Šíma, M.; Netíková, I.; Matoušková, E.; Petruželka, L. 5-fluorouracil toxicity mechanism determination in human keratinocytes: In vitro study on HaCaT cell line. Prague Med. Rep. 2017, 118, 128–138. [Google Scholar] [CrossRef]
  8. Harada, K.; Ferdous, T.; Kobayashi, H.; Ueyama, Y. Elemental diet accelerates the recovery from oral mucositis and dermatitis induced by 5-Fluorouracil through the induction of fibroblast growth factor 2. Integr. Cancer Ther. 2018, 17, 423–430. [Google Scholar] [CrossRef]
  9. Burdelya, L.G.; Gleiberman, A.S.; Toshkov, I.; Aygun-Sunar, S.; Bapardekar, M.; Manderscheid-Kern, P.; Bellnier, D.; Krivokrysenko, V.I.; Feinstein, E.; Gudkov, A.V. Toll-like receptor 5 agonist protects mice from dermatitis and oral mucositis caused by local radiation: Implications for head-and-neck cancer radiotherapy. Int. J. Radiat. Oncol. Biol. Phys. 2012, 83, 228–234. [Google Scholar] [CrossRef] [PubMed]
  10. Imai, T.; Matsuura, K.; Asada, Y.; Sagai, S.; Katagiri, K.; Ishida, E.; Saito, D.; Sadayasu, R.; Wada, H.; Saijo, S. Effect of HMB/Arg/Gln on the prevention of radiation dermatitis in head and neck cancer patients treated with concurrent chemoradiotherapy. Jpn. J. Clin. Oncol. 2014, 44, 422–427. [Google Scholar] [CrossRef]
  11. Habl, G.; Potthoff, K.; Haefner, M.F.; Abdollahi, A.; Hassel, J.C.; Boller, E.; Indorf, M.; Debus, J. Differentiation of irradiation and cetuximab induced skin reactions in patients with locally advanced head and neck cancer undergoing radioimmunotherapy: The HICARE protocol (head and neck cancer: Immunochemo and radiotherapy with erbitux)—A multicenter phase IV trial. BMC Cancer 2013, 13, 345. [Google Scholar]
  12. Alverdy, J.C. Effects of glutamine-supplemented diets on immunology of the gut. JPEN J. Parenter. Enteral. Nutr. 1990, 14, 109S–113S. [Google Scholar] [CrossRef] [PubMed]
  13. Souba, W.W.; Klimberg, V.S.; Hautamaki, R.D.; Mendenhall, W.H.; Bova, F.C.; Howard, R.J.; Bland, K.I.; Copeland, E.M. Oral glutamine reduces bacterial translocation following abdominal radiation. J. Surg. Res. 1990, 48, 1–5. [Google Scholar] [CrossRef]
  14. Keefe, D.M.; Schubert, M.M.; Elting, L.S.; Sonis, S.T.; Epstein, J.B.; Raber-Durlacher, J.E.; Migliorati, C.A.; McGuire, D.B.; Hutchins, R.D.; Peterson, D.E. Updated clinical practice guidelines for the prevention and treatment of mucositis. Cancer 2007, 109, 820–831. [Google Scholar] [CrossRef] [PubMed]
  15. Harada, K.; Ferdous, T.; Mizukami, Y.; Mishima, K. Elemental diet inhibits pro-inflammatory cytokine production in keratinocytes through the suppression of NF-κB activation. Oncol. Rep. 2018, 40, 361–368. [Google Scholar] [CrossRef] [PubMed]
  16. Conklin, K.A. Dietary antioxidants during cancer chemotherapy: Impact on chemotherapeutic effectiveness and development of side effects. Nutr. Cancer 2000, 37, 1–18. [Google Scholar] [CrossRef]
  17. Conklin, K.A. Chemotherapy-associated oxidative stress: Impact on chemotherapeutic effectiveness. Integr. Cancer. Ther. 2004, 3, 294–300. [Google Scholar] [CrossRef]
  18. Yoshino, F.; Yoshida, A.; Nakajima, A.; Wada-Takahashi, S.; Takahashi, S.; Lee, M.C. Alteration of the redox state with reactive oxygen species for 5-fluorouracil-induced oral mucositis in hamsters. PLoS ONE 2013, 8, E82834. [Google Scholar]
  19. Chang, C.T.; Ho, T.Y.; Lin, H.; Liang, J.A.; Huang, H.C.; Li, C.C.; Lo, H.Y.; Wu, S.L.; Huang, Y.F.; Hsiang, C.Y. 5-Fluorouracil induced intestinal mucositis via nuclear factor-B activation by transcriptomic analysis and in vivo bioluminescence imaging. PLoS ONE 2012, 7, E31808. [Google Scholar] [CrossRef]
  20. Ozer, U.; Barbour, K.W.; Clinton, S.A.; Berger, F.G. Oxidative stress and response to Thymidylate Synthase-targeted antimetabolites. Mol. Pharmacol. 2015, 88, 970–981. [Google Scholar] [CrossRef]
  21. Dell’Agli, M.; Galli, G.V.; Corbett, Y.; Taramelli, D.; Lucantoni, L.; Habluetzel, A.; Maschi, O.; Caruso, D.; Giavarini, F.; Romeo, S.; et al. Antiplasmodial activity of Punica granatum L. fruit rind. J. Ethnopharmacol. 2009, 125, 279–285. [Google Scholar] [CrossRef] [PubMed]
  22. Qnais, E.Y.; Elokda, A.S.; Abu Ghalyun, Y.Y.; Abdulla, F.A. Antidiarrheal activity of the aqueous extract of Punica granatum (pomegranate) peels. Pharm. Biol. 2007, 45, 715–720. [Google Scholar] [CrossRef]
  23. Das, A.K.; Mandal, S.C.; Banerjee, S.K.; Sinha, S.; Das, J.; Saha, B.P.; Pal, M. Studies on antidiarrhoeal activity of Punica granatum seed extract in rats. J. Ethnopharmacol. 1999, 68, 205–208. [Google Scholar] [CrossRef]
  24. Banihani, S.; Swedan, S.; Alguraan, Z. Pomegranate and type 2 diabetes. Nutr. Res. 2013, 33, 341–348. [Google Scholar] [CrossRef] [PubMed]
  25. Bhowmik, D.; Gopinath, H.; Kumar, B.; Duraivel, S.; Aravind, G.; Kumar, K. Medicinal uses of Punica granatum and its health benefits. J. Pharmacogn. Phytochem. 2013, 1, 28–35. [Google Scholar]
  26. Toi, M.; Bando, H.; Ramachandran, C.; Melnick, S.J.; Imai, A.; Fife, R.S.; Carr, R.E.; Oikawa, T.; Lansky, E.P. Preliminary studies on the anti-angiogenic potential of pomegranate fractions in vitro and in vivo. Angiogenesis 2003, 6, 121–128. [Google Scholar] [CrossRef]
  27. Pantuck, A.; Leppert, J.; Zomorodian, N.; Aronson, W.; Hong, J.; Barnard, R.J.; Seeram, N.; Liker, H.; Wang, H.; Elashoff, R.; et al. Phase II study of pomegranate juice for men with rising prostate-specific antigen following surgery or radiation for prostate cancer. Clin. Cancer Res. 2006, 12, 4018–4026. [Google Scholar] [CrossRef]
  28. Cayır, K.; Karadeniz, A.; Simşek, N.; Yıldırım, S.; Karakuş, E.; Kara, A.; Akkoyun, H.T.; Sengül, E. Pomegranate seed extract attenuates chemotherapy-induced acute nephrotoxicity and hepatotoxicity in rats. J. Med. Food 2011, 14, 1254–1262. [Google Scholar] [CrossRef]
  29. Pepe, G.; Rapa, S.F.; Salviati, E.; Bertamino, A.; Auriemma, G.; Cascioferro, S.; Autore, G.; Quaroni, A.; Campiglia, P.; Marzocco, S. Bioactive polyphenols from pomegranate juice reduce 5-Fluorouracil-induced intestinal mucositis in intestinal epithelial cells. Antioxidants (Basel) 2020, 9, 699. [Google Scholar] [CrossRef]
  30. Boukamp, P.; Petrussevska, R.T.; Breitkreutz, D.; Hornung, J.; Markham, A.; Fusenig, N.E. Normal keratinization in a spontaneously immortalized aneuploid human keratinocyte cell line. J. Cell. Biol. 1988, 106, 761–771. [Google Scholar] [CrossRef]
  31. Rapa, S.F.; Waltenberger, B.; Di Paola, R.; Adesso, S.; Siracusa, R.; Peritore, A.F.; D’Amico, R.; Autore, G.; Cuzzocrea, S.; Stuppner, H.; et al. Plumericin prevents intestinal inflammation and oxidative stress in vitro and in vivo. FASEB J. 2020, 34, 1576–1590. [Google Scholar] [CrossRef] [PubMed]
  32. Adesso, S.; Autore, G.; Quaroni, A.; Popolo, A.; Severino, L.; Marzocco, S. The Food Contaminants Nivalenol and Deoxynivalenol Induce Inflammation in Intestinal Epithelial Cells by Regulating Reactive Oxygen Species Release. Nutrients 2017, 9, 1343. [Google Scholar] [CrossRef] [PubMed]
  33. Adesso, S.; Russo, R.; Quaroni, A.; Autore, G.; Marzocco, S. Astragalus membranaceus Extract Attenuates Inflammation and Oxidative Stress in Intestinal Epithelial Cells via NF-κB Activation and Nrf2 Response. Int. J. Mol. Sci. 2018, 19, 800. [Google Scholar] [CrossRef] [PubMed]
  34. Grimaldi, M.; Stillitano, I.; Amodio, G.; Santoro, A.; Buonocore, M.; Moltedo, O.; Remondelli, P.; D’Ursi, A.M. Structural basis of antiviral activity of peptides from MPER of FIV gp36. PLoS ONE 2018, 13, e0204042. [Google Scholar] [CrossRef] [PubMed]
  35. Amodio, G.; Moltedo, O.; Fasano, D.; Zerillo, L.; Oliveti, M.; Di Pietro, P.; Faraonio, R.; Barone, P.; Pellecchia, M.T.; De Rosa, A.; et al. Mediated Unfolded Protein Response Activation and Oxidative Stress in PARK20 Fibroblasts. Front. Neurosci. 2019, 3, 673. [Google Scholar] [CrossRef]
  36. Noursadeghi, M.; Tsang, J.; Haustein, T.; Miller, R.F.; Chain, B.M.; Katz, D.R. Quantitative imaging assay for NF-kappaB nuclear translocation in primary human macrophages. J. Immunol. Methods 2008, 329, 194–200. [Google Scholar] [CrossRef]
  37. Fasano, D.; Parisi, S.; Pierantoni, G.M.; De Rosa, A.; Picillo, M.; Amodio, G.; Pellecchia, M.T.; Barone, P.; Moltedo, O.; Bonifati, V.; et al. Alteration of endosomal trafficking is associated with early-onset parkinsonism caused by SYNJ1 mutations. Cell Death Dis. 2018, 9, 385. [Google Scholar] [CrossRef]
  38. Pepe, G.; Salviati, E.; Rapa, S.F.; Ostacolo, C.; Cascioferro, S.; Manfra, M.; Autore, G.; Marzocco, S.; Campiglia, P. Citrus sinensis and Vitis vinifera Protect Cardiomyocytes from Doxorubicin-Induced Oxidative Stress: Evaluation of Onconutraceutical Potential of Vegetable Smoothies. Antioxidants (Basel) 2020, 9, 378. [Google Scholar] [CrossRef]
  39. Adesso, S.; Ruocco, M.; Rapa, S.F.; Piaz, F.D.; Di Iorio, R.B.; Popolo, A.; Autore, G.; Nishijima, F.; Pinto, A.; Marzocco, S. Effect of Indoxyl Sulfate on the Repair and Intactness of Intestinal Epithelial Cells: Role of Reactive Oxygen Species’ Release. Int. J. Mol. Sci. 2019, 20, 2280. [Google Scholar] [CrossRef]
  40. Lamberti, M.; Porto, S.; Zappavigna, S.; Stiuso, P.; Tirino, V.; Desiderio, V.; Mele, L.; Caraglia, M. Levofolene modulates apoptosis induced by 5-fluorouracil through autophagy inhibition: Clinical and occupational implications. Int. J. Oncol. 2015, 46, 1893–1900. [Google Scholar] [CrossRef]
  41. Arafa, M.H.; Atteia, H.H. Protective role of epigallocatechin gallate in a rat model of cisplatin-induced cerebral inflammation and oxidative damage: Impact of modulating NF-κB and Nrf2. Neurotox. Res. 2020, 37, 380–396. [Google Scholar] [CrossRef] [PubMed]
  42. Refolo, M.G.; Lippolis, C.; Carella, N.; Cavallini, A.; Messa, C.; D’Alessandro, R. Chlorogenic acid improves the regorafenib effects in human hepatocellular carcinoma cells. Int. J. Mol. Sci. 2018, 19, 1518. [Google Scholar] [CrossRef] [PubMed]
  43. Abushouk, A.I.; Ismail, A.; Salem, A.M.A.; Afifi, A.M.; Abdel-Daim, M.M. Cardioprotective mechanisms of phytochemicals against doxorubicin-induced cardiotoxicity. Biomed. Pharm. 2017, 90, 935–946. [Google Scholar] [CrossRef] [PubMed]
  44. Hakim, L.; Alias, E.; Makpol, S.; Ngah, W.Z.; Morad, N.A.; Yusof, Y.A. Gelam honey and ginger potentiate the anti-cancer effect of 5-FU against HCT 116 colorectal cancer cells. Asian Pac. J. Cancer Prev. 2014, 15, 4651–4657. [Google Scholar] [CrossRef] [PubMed]
  45. Shakibaei, M.; Mobasheri, A.; Lueders, C.; Busch, F.; Shayan, P.; Goel, A. Curcumin enhances the effect of chemotherapy against colorectal cancer cells by inhibition of NF-kappaB and Src protein kinase signaling pathways. PLoS ONE 2013, 8, e57218. [Google Scholar] [CrossRef]
  46. Kulkarni, A.P.; Mahal, H.S.; Kapoor, S.; Aradhya, S.M. In vitro studies on the binding, antioxidant, and cytotoxic actions of punicalagin. J. Agric. Food Chem. 2007, 55, 1491–1500. [Google Scholar] [CrossRef]
  47. Zaid, M.A.; Afaq, F.; Syed, D.N.; Dreher, M.; Mukhtar, H. Inhibition of UVB-mediated oxidative stress and markers of photoaging in immortalized HaCaT keratinocytes by pomegranate polyphenol extract POMx. Photochem. Photobiol. 2007, 83, 882–888. [Google Scholar] [CrossRef]
  48. Liu, C.; Guo, H.; DaSilva, N.A.; Li, D.; Zhang, K.; Wan, Y.; Gao, X.H.; Chen, H.D.; Seeram, N.P.; Ma, H. Pomegranate (Punica granatum) phenolics ameliorate hydrogen peroxide-induced oxidative stress and cytotoxicity in human keratinocytes. J. Funct. Foods 2019, 54, 559–567. [Google Scholar] [CrossRef]
  49. Schäfer, M.; Werner, S. Nrf2-A regulator of keratinocyte redox signaling. Free Radic. Biol. Med. 2015, 88 (Pt B), 243–252. [Google Scholar] [CrossRef]
  50. Xu, X.; Li, H.; Hou, X.; Li, D.; He, S.; Wan, C.; Yin, P.; Liu, M.; Liu, F.; Xu, J. Punicalagin Induces Nrf2/HO-1 Expression via Upregulation of PI3K/AKT Pathway and Inhibits LPS-Induced Oxidative Stress in RAW264.7 Macrophages. Mediat. Inflamm. 2015, 2015, 380218. [Google Scholar] [CrossRef]
  51. Xu, L.; He, S.; Yin, P.; Li, D.; Mei, C.; Yu, X.; Shi, Y.; Jiang, L.; Liu, F. Punicalagin induces Nrf2 translocation and HO-1 expression via PI3K/Akt, protecting rat intestinal epithelial cells from oxidative stress. Int. J. Hyperth. 2016, 32, 465–473. [Google Scholar] [CrossRef] [PubMed]
  52. Ye, M.; Zhang, L.; Yan, Y.; Lin, H. Punicalagin protects H9c2 cardiomyocytes from doxorubicin-induced toxicity through activation of Nrf2/HO-1 signaling. Biosci. Rep. 2019, 39, BSR20190229. [Google Scholar] [CrossRef] [PubMed]
  53. Flohé, L.; Brigelius-Flohé, R.; Saliou, C.; Traber, M.G.; Packer, L. Redox regulation of NF-kappa B activation. Free Radic. Biol. Med. 1997, 22, 1115–1126. [Google Scholar] [CrossRef]
  54. Ranneh, Y.; Ali, F.; Akim, A.; Hamid, H.A.; Khazaai, H.; Fadel, A. Crosstalk between reactive oxygen species and pro-inflammatorymarkers in developing various chronic diseases: A review. Appl. Biol. Chem. 2017, 60, 327–338. [Google Scholar] [CrossRef]
  55. Bölck, B.; Ibrahim, M.; Steinritz, D.; Morguet, C.; Dühr, S.; Suhr, F.; Lu-Hesselmann, J.; Bloch, W. Detection of key enzymes, free radical reaction products and activated signaling molecules as biomarkers of cell damage induced by benzo[a]pyrene in human keratinocytes. Toxicol. In Vitro 2014, 28, 875–884. [Google Scholar] [CrossRef]
  56. Zhang, M.; Zhou, J.; Wang, L.; Li, B.; Guo, J.; Guan, X.; Han, Q.; Zhang, H. Caffeic acid reduces cutaneous tumor necrosis factor alpha (TNF-α), IL-6 and IL-1β levels and ameliorates skin edema in acute and chronic model of cutaneous inflammation in mice. Biol. Pharm. Bull. 2014, 37, 347–354. [Google Scholar] [CrossRef]
  57. Zhu, J.; Luo, C.; Wang, P.; He, Q.; Zhou, J.; Peng, H. Saikosaponin A mediates the inflammatory response by inhibiting the MAPK and NF-κB pathways in LPS-stimulated RAW 264.7 cells. Exp. Ther. Med. 2013, 5, 1345–1350. [Google Scholar] [CrossRef]
  58. Nickoloff, B.J.; Turka, L.A. Keratinocytes: Key immunocytes of the integument. Am. J. Pathol. 1993, 143, 325–331. [Google Scholar]
  59. Mazza, J.; Rossi, A.; Weinberg, J.M. Innovative uses of tumor necrosis factor alpha inhibitors. Dermatol. Clin. 2010, 28, 559–575. [Google Scholar] [CrossRef]
  60. Rasheed, Z.; Akhtar, N.; Anbazhagan, A.N.; Ramamurthy, S.; Shukla, M.; Haqqi, T.M. Polyphenol-rich pomegranate fruit extract (POMx) suppresses PMACI-induced expression of pro-inflammatory cytokines by inhibiting the activation of MAP Kinases and NF-κB in human KU812 cells. J. Inflamm. 2009, 6, 1. [Google Scholar] [CrossRef]
  61. Xu, J.; Zhao, Y.; Aisa, H.A. Anti-inflammatory effect of pomegranate flower in lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages. Pharm. Biol. 2017, 55, 2095–2101. [Google Scholar] [CrossRef] [PubMed]
  62. Mastrogiovanni, F.; Mukhopadhya, A.; Lacetera, N.; Ryan, M.T.; Romani, A.; Bernini, R.; Sweeney, T. Anti-Inflammatory Effects of Pomegranate Peel Extracts on In Vitro Human Intestinal Caco-2 Cells and Ex Vivo Porcine Colonic Tissue Explants. Nutrients 2019, 11, 548. [Google Scholar] [CrossRef] [PubMed]
  63. Barnes, P.J.; Karin, M. Nuclear factor-kappaB: A pivotal transcription factor in chronic inflammatory diseases. N. Engl. J. Med. 1997, 336, 1066–1071. [Google Scholar] [CrossRef] [PubMed]
  64. Zhou, B.R.; Zhang, J.A.; Zhang, Q.; Permatasari, F.; Xu, Y.; Wu, D.; Yin, Z.Q.; Luo, D. Palmitic acid induces production of proinflammatory cytokines interleukin-6, interleukin-1β, and tumor necrosis factor-α via a NF-κB-dependent mechanism in HaCaT keratinocytes. Mediat. Inflamm. 2013, 2013, 530429. [Google Scholar] [CrossRef] [PubMed]
  65. Choudhury, S.; Ghosh, S.; Mukherjee, S.; Gupta, P.; Bhattacharya, S.; Adhikary, A.; Chattopadhyay, S. Pomegranate protects against arsenic-induced p53-dependent ROS-mediated inflammation and apoptosis in liver cells. J. Nutr. Biochem. 2016, 38, 25–40. [Google Scholar] [CrossRef] [PubMed]
  66. Hänel, K.H.; Cornelissen, C.; Lüscher, B.; Baron, J.M. Cytokines and the skin barrier. Int. J. Mol. Sci. 2013, 14, 6720–6745. [Google Scholar] [CrossRef] [PubMed]
Figure 1. Effect of pomegranate juice extract (PPJE; 1.25–10 µg/mL) on intracellular ROS (reactive oxygen species) release (a), evaluated by means of the probe 2′,7′-dichlorofluorescin-diacetate (H2DCF-DA), and HO-1 (b) and NQO1 (c) expression, evaluated by cytofluorimetric technique, on HaCaT cells treated with 5-fluorouracil (5-FU; 10 µg/mL). Data are expressed as mean of fluorescence intensity. C denotes control group. ### denotes p < 0.001 vs. C; *** and * denote respectively p < 0.001 and p < 0.05 vs. 5-FU.
Figure 1. Effect of pomegranate juice extract (PPJE; 1.25–10 µg/mL) on intracellular ROS (reactive oxygen species) release (a), evaluated by means of the probe 2′,7′-dichlorofluorescin-diacetate (H2DCF-DA), and HO-1 (b) and NQO1 (c) expression, evaluated by cytofluorimetric technique, on HaCaT cells treated with 5-fluorouracil (5-FU; 10 µg/mL). Data are expressed as mean of fluorescence intensity. C denotes control group. ### denotes p < 0.001 vs. C; *** and * denote respectively p < 0.001 and p < 0.05 vs. 5-FU.
Antioxidants 10 00203 g001
Figure 2. Effect of pomegranate juice extract (PPJE; 1.25–10 µg/mL) on nitrotyrosine formation, evaluated by cytofluorimetric technique, on HaCaT cells treated with 5-fluorouracil (5-FU; 10 µg/mL). Data are expressed as mean of fluorescence intensity. C denotes control group. ### denotes p < 0.001 vs. C; *** denotes p < 0.001 vs. 5-FU.
Figure 2. Effect of pomegranate juice extract (PPJE; 1.25–10 µg/mL) on nitrotyrosine formation, evaluated by cytofluorimetric technique, on HaCaT cells treated with 5-fluorouracil (5-FU; 10 µg/mL). Data are expressed as mean of fluorescence intensity. C denotes control group. ### denotes p < 0.001 vs. C; *** denotes p < 0.001 vs. 5-FU.
Antioxidants 10 00203 g002
Figure 3. Effect of pomegranate juice extract (PPJE; 1.25–10 µg/mL) on TNF-α (tumor necrosis factor-α) (a), IL-6 (interleukin-6) (b) and IL-1β (interleukin-1β) (c), evaluated by ELISA assay, on HaCaT cells treated with 5-fluorouracil (5-FU; 10 µg/mL). Data are expressed as pg/mL of cytokine release. C denotes control group. ### denotes p < 0.001 vs. C; *** and ** denote respectively p < 0.001 and p < 0.01 vs. 5-FU.
Figure 3. Effect of pomegranate juice extract (PPJE; 1.25–10 µg/mL) on TNF-α (tumor necrosis factor-α) (a), IL-6 (interleukin-6) (b) and IL-1β (interleukin-1β) (c), evaluated by ELISA assay, on HaCaT cells treated with 5-fluorouracil (5-FU; 10 µg/mL). Data are expressed as pg/mL of cytokine release. C denotes control group. ### denotes p < 0.001 vs. C; *** and ** denote respectively p < 0.001 and p < 0.01 vs. 5-FU.
Antioxidants 10 00203 g003aAntioxidants 10 00203 g003b
Figure 4. Immunofluorescence staining of NF-κB (a) and quantification of nuclear/cytoplasmic ratios of NF-κB staining (b) in HaCaT cells treated for 4 h with 5-FU (10 μg/mL) alone or in combination with increasing concentration of PPJE (2.5–10 μg/mL). (b) Histograms represent the mean ± s.e.m. of nuclear/cytoplasmic ratios of NF-κB staining calculated as described in methods section. C denotes control group. ### denotes p < 0.01 vs. C; *** denote p < 0.001 vs. 5-FU.
Figure 4. Immunofluorescence staining of NF-κB (a) and quantification of nuclear/cytoplasmic ratios of NF-κB staining (b) in HaCaT cells treated for 4 h with 5-FU (10 μg/mL) alone or in combination with increasing concentration of PPJE (2.5–10 μg/mL). (b) Histograms represent the mean ± s.e.m. of nuclear/cytoplasmic ratios of NF-κB staining calculated as described in methods section. C denotes control group. ### denotes p < 0.01 vs. C; *** denote p < 0.001 vs. 5-FU.
Antioxidants 10 00203 g004
Figure 5. Effect of pomegranate juice extract (PPJE; 1.25–10 µg/mL) on apoptosis (a), evaluated by propidium iodide assay, and on Bax (b) and Bcl-2 (c), evaluated by cytofluorimetric technique, on HaCaT cells treated with 5-fluorouracil (5-FU; 10 µg/mL). Data are expressed as % of hypodiploid nuclei or as mean of fluorescence intensity. C denotes control group. ### denotes p < 0.001 vs. C; *** and ** denote respectively p < 0.001 and p < 0.01 vs. 5-FU.
Figure 5. Effect of pomegranate juice extract (PPJE; 1.25–10 µg/mL) on apoptosis (a), evaluated by propidium iodide assay, and on Bax (b) and Bcl-2 (c), evaluated by cytofluorimetric technique, on HaCaT cells treated with 5-fluorouracil (5-FU; 10 µg/mL). Data are expressed as % of hypodiploid nuclei or as mean of fluorescence intensity. C denotes control group. ### denotes p < 0.001 vs. C; *** and ** denote respectively p < 0.001 and p < 0.01 vs. 5-FU.
Antioxidants 10 00203 g005
Figure 6. Effect of PPJE (2.5–5 µg/mL) on wound repair after a mechanical scratch in HaCaT cells treated with 5-fluorouracil. FU; 10 µg/mL); Bar = 150 μm (a), and the quantitative analysis expressed as HaCaT migration rate after 24 h (b). C denotes control group; ### denotes p < 0.001 vs. C; *** denotes p < 0.001 vs. 5-FU.
Figure 6. Effect of PPJE (2.5–5 µg/mL) on wound repair after a mechanical scratch in HaCaT cells treated with 5-fluorouracil. FU; 10 µg/mL); Bar = 150 μm (a), and the quantitative analysis expressed as HaCaT migration rate after 24 h (b). C denotes control group; ### denotes p < 0.001 vs. C; *** denotes p < 0.001 vs. 5-FU.
Antioxidants 10 00203 g006
Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Back to TopTop