Levosimendan and Dobutamin Attenuate LPS-Induced Inflammation in Microglia by Inhibiting the NF-κB Pathway and NLRP3 Inflammasome Activation via Nrf2/HO-1 Signalling.

Hypovolemic shock is a circulatory failure, due to a loss in the effective circulating blood volume, that causes tissue hypoperfusion and hypoxia. This condition stimulates reactive oxygen species (ROS) and pro-inflammatory cytokine production in different organs and also in the central nervous system (CNS). Levosimendan, a cardioprotective inodilator, and dobutamine, a ß1-adrenergic agonist, are commonly used for the treatment of hypovolemic shock, thanks to their anti-inflammatory and antioxidant effects. For this reason, we aimed at investigating levosimendan and dobutamine's neuroprotective effects in an "in vitro" model of lipopolysaccharide (LPS)-induced neuroinflammation. Human microglial cells (HMC3) were challenged with LPS (0.1 µg/mL) to induce an inflammatory phenotype and then treated with levosimendan (10 µM) or dobutamine (50 µM) for 24 h. Levosimendan and dobutamine significantly reduced the ROS levels and markedly increased Nrf2 and HO-1 protein expression in LPS-challenged cells. Levosimendan and dobutamine also decreased p-NF-κB expression and turned off the NLRP3 inflammasome together with its downstream signals, caspase-1 and IL-1ß. Moreover, a reduction in TNF-α and IL-6 expression and an increase in IL-10 levels in LPS-stimulated HMC3 cells was observed following treatment. In conclusion, levosimendan and dobutamine attenuated LPS-induced neuroinflammation through NF-κB pathway inhibition and NLRP3 inflammasome activation via Nrf2/HO-1 signalling, suggesting that these drugs could represent a promising therapeutic approach for the treatment of neuroinflammation consequent to hypovolemic shock.

Attention Deficit Hyperactivity Disorder (ADHD) and Polyphenols: A Systematic Review.

Polyphenols are natural compounds also contained in daily consumed foods that show their efficacy in different clinical fields. Both pre-clinical and clinical studies demonstrated that polyphenols may manage neuroinflammation and oxidative stress processes tightly connected to neurodegenerative diseases and mental disorders. Thus, a neuroinflammatory state may influence the neurotransmitters pathways, such as the noradrenergic, glutamatergic, serotoninergic, and, in particular, dopaminergic ones, whose impairment is strongly associated with attention deficit hyperactivity disorder (ADHD). Therefore, the aim of the present systematic review is to provide an overview of the clinical outcomes' changes following ADHD treatment with polyphenols alone and in combination with the traditional drugs. This review was conducted according to PRISMA guidelines and recorded on PROSPERO with the number CRD42023438491; PubMed, Scopus, and Web of Science were used as search-engines to lead our research until June 2023. The inclusion criteria were articles written in English, including clinical, placebo-controlled, and case-control trials. We excluded reviews, metanalyses, background articles, and papers published in other languages. To avoid any bias, Rayyan software (COPYRIGHT © 2022 RAYYAN) was used to organize the work and manage the literature review. After screening, 10 studies were included, with a total of 556 patients that met the established inclusion criteria. The data obtained from these studies showed that polyphenols rebalanced oxidative stress pathways through different mechanisms, are effective for the treatment of ADHD both alone and in combination with traditional drugs, and are able to reduce symptoms as well as the side effects related to the use of conventional therapies. Finally, a positive effect of using polyphenols for ADHD prevention could be hypothesized.

Steady state plasma and tissue distribution of low molecular weight hyaluronic acid after oral administration in mice.

The oral administration is probably the most used and largely applicable method, even if absorption across the intestinal epithelium is a limiting factor that can invalidate the achievement of a therapy. The aim of this study was to assess the steady state bioavailability of very low molecular weight hyaluronic acid (vLMW-HA) and its distribution in different districts of mice. Adult female C57BL6/J mice (n = 26) were divided in three groups and orally treated for 7 days with: saline solution (SHAM-HA), high dose of vLMW-HA (5 kDa; 500 mg/kg/day; HD-vLMW-HA), and low dose of vLMW-HA (5 kDa; 100 mg/kg/day; LD-vLMW-HA). HA content was quantified in plasma, skin, bladder, gut, rectum, vagina, and eyes with ELISA assay at the end of treatment. HA level significantly increased after treatment with HD-vLMW-HA in all analyzed tissues and plasma. Therefore, vLMW-HA easy absorption and distribution after the oral intake opens new possibilities for future biomedical applications.

Insights into the antiosteoporotic mechanism of the soy-derived isoflavone genistein: Modulation of the Wnt/beta-catenin signaling.

Bone remodeling is a process that involves osteoblasts, osteoclasts, and osteocytes, and different intracellular signaling, such as the canonical Wnt/ß-catenin pathway. Dysregulations of this pathway may also occur during secondary osteoporosis, as in the case of glucocorticoid-induced osteoporosis (GIO), which accelerates osteoblast and osteocyte apoptosis by reducing bone formation, osteoblast differentiation and function, accelerates in turn osteoblast, and osteocyte apoptosis. Genistein is a soy-derived nutrient belonging to the class of isoflavones that reduces bone loss in osteopenic menopausal women, inhibiting bone resorption; however, genistein may also favor bone formation. The aim of this study was to investigate whether estrogen receptor stimulation by genistein might promote osteoblast and osteocyte function during glucocorticoid challenge. Primary osteoblasts, collected from C57BL6/J mice, and MLO-A5 osteocyte cell line were used to reproduce an in vitro model of GIO by adding dexamethasone (1 µM) for 24 h. Cells were then treated with genistein for 24 h and quantitative Polymerase Chain Reaction (qPCR) and western blot were performed to study whether genistein activated the Wnt/ß-catenin pathway. Dexamethasone challenge reduced bone formation in primary osteoblasts and bone mineralization in osteocytes; moreover, canonical Wnt/ß-catenin pathway was reduced following incubation with dexamethasone in both osteoblasts and osteocytes. Genistein reverted these changes and this effect was mediated by both estrogen receptors α and ß. These data suggest that genistein could induce bone remodeling through Wnt/ß-catenin pathway activation.

Correction: Mannino et al. Beta-Caryophyllene Exhibits Anti-Proliferative Effects through Apoptosis Induction and Cell Cycle Modulation in Multiple Myeloma Cells. Cancers 2021, 13, 5741.

In the original publication [...].

Beta-Caryophyllene, a Plant-Derived CB2 Receptor Agonist, Protects SH-SY5Y Cells from Cadmium-Induced Toxicity.

Cadmium (Cd) is a transition heavy metal that is able to accumulate in the central nervous system and may induce cell death through reactive oxygen species (ROS)-mediated mechanisms and inactivating the antioxidant processes, becoming an important risk factor for neurodegenerative diseases. The antioxidant effects of cannabinoid receptor modulation have been extensively described, and, in particular, ß-Caryophyllene (BCP), a plant-derived cannabinoid 2 receptor (CB2R) agonist, not only showed significant antioxidant properties but also anti-inflammatory, analgesic, and neuroprotective effects. Therefore, the aim of the present study was to evaluate BCP effects in a model of Cd-induced toxicity in the neuroblastoma SH-SY5Y cell line used to reproduce Cd intoxication in humans. SH-SY5Y cells were pre-treated with BCP (25, 50, and 100 µM) for 24 h. The day after, cells were challenged with cadmium chloride (CdCl2; 10 µM) for 24 h to induce neuronal toxicity. CdCl2 increased ROS accumulation, and BCP treatment significantly reduced ROS production at concentrations of 50 and 100 µM. In addition, CdCl2 significantly decreased the protein level of nuclear factor erythroid 2-related factor 2 (Nrf2) compared to unstimulated cells; the treatment with BCP at a concentration of 50 µM markedly increased Nrf2 expression, thus confirming the BCP anti-oxidant effect. Moreover, BCP treatment preserved cells from death, regulated the apoptosis pathway, and showed a significant anti-inflammatory effect, thus reducing the pro-inflammatory cytokines increased by the CdCl2 challenge. The results indicated that BCP preserved neuronal damage induced by Cd and might represent a future candidate for protection in neurotoxic conditions.

Positive Effects of the Nutraceutical Association of Lycopene and Selenium in Experimental Varicocele.

Many natural substances commonly found in healthy diets have been studied for their potential to reduce male infertility associated with varicocele. A positive role of selenium (Se) or lycopene alone was demonstrated in experimental varicocele, while no data are available on their association. One group of male Sprague-Dawley rats was sham operated and daily treated with Se (3 mg/kg, i.p.), lycopene (1 mg/kg, i.p.), or their association. A second group underwent surgery to induce varicocele. Sham and half of the varicocele animals were sacrificed after twenty-eight days, while the residual animals were treated for one more month and then sacrificed. In varicocele animals, testosterone levels and testes weight were reduced, Hypoxia Inducible Factor-1α (HIF-1α) expression was absent in the tubules and increased in Leydig cells, caspare-3 was increased, seminiferous epithelium showed evident structural changes, and many apoptotic germ cells were demonstrated with TUNEL assay. The treatment with lycopene or Se alone significantly increased testis weight and testosterone levels, reduced apoptosis and caspase-3 expression, improved the tubular organization, decreased HIF-1α positivity of Leydig cells, and restored its tubular positivity. Lycopene or Se association showed a better influence on all biochemical and morphological parameters. Therefore, the nutraceutical association of lycopene plus Se might be considered a possible therapeutic tool, together with surgery, in the treatment of male infertility. However, long-term experimental and clinical studies are necessary to evaluate sperm quantity and quality.

Blunting Neuroinflammation by Targeting the Immunoproteasome with Novel Amide Derivatives.

Neuroinflammation is an inflammatory response of the nervous tissue mediated by the production of cytokines, chemokines, and reactive oxygen species. Recent studies have shown that an upregulation of immunoproteasome is highly associated with various diseases and its inhibition attenuates neuroinflammation. In this context, the development of non-covalent immunoproteasome-selective inhibitors could represent a promising strategy for treating inflammatory diseases. Novel amide derivatives, KJ3 and KJ9, inhibit the ß5 subunit of immunoproteasome and were used to evaluate their possible anti-inflammatory effects in an in vitro model of TNF-α induced neuroinflammation. Differentiated SH-SY5Y and microglial cells were challenged with 10 ng/mL TNF-α for 24 h and treated with KJ3 (1 µM) and KJ9 (1 µM) for 24 h. The amide derivatives showed a significant reduction of oxidative stress and the inflammatory cascade triggered by TNF-α reducing p-ERK expression in treated cells. Moreover, the key action of these compounds on the immunoproteasome was further confirmed by halting the IkB-α phosphorylation and the consequent inhibition of NF-kB. As downstream targets, IL-1ß and IL-6 expression resulted also blunted by either KJ3 and KJ9. These preliminary results suggest that the effects of these two compounds during neuroinflammatory response relies on the reduced expression of pro-inflammatory targets.

Effects of genistein aglycone in glucocorticoid induced osteoporosis: A randomized clinical trial in comparison with alendronate.

Glucocorticoid-induced osteoporosis (GIO) complicates the clinical management of patients subjected to long-term glucocorticoid use. This study explored the effects of genistein on bone loss in a randomized double-blind alendronate-controlled trial in postmenopausal women with GIO. 200 postmenopausal women (taking at least 5 mg of prednisone equivalents) since 3 months, or more, and expected to continue for at least other 12 months, were randomized to receive genistein (54 mg/day daily) or alendronate (70 mg once a week) for 24 months. Both groups received also Calcium and Vitamin D3 supplementation. Median bone mineral density (BMD) at the antero-posterior lumbar spine significantly increased from 0.75 g/cm2 at baseline to 0.77 g/cm2 at 1 year and 0.79 g/cm2 at 2 years in alendronate-treated patients and from 0.77 g/cm2 at baseline to 0.79 g/cm2 at 12 months and to 0.80 g/cm2 at 24 months in genistein recipients. No difference was observed between the two treatments. Median BMD at the femoral neck increased from 0.67 g/cm2 at baseline to 0.68 g/cm2 at 1 year and 0.69 g/cm2 at 2 years in alendronate-treated patients and from 0.68 g/cm2 at baseline to 0.70 g/cm2 at 12 months and to 0.71 g/cm2 at 24 months in genistein recipients. No difference was observed between alendronate and genistein groups in BMD. Regarding bone markers genistein and alendronate statistically decreased c-terminal telopeptide, while osteocalcin, bone-ALP, and sclerostin showed greater changes in genistein treated patients. This randomized clinical trial suggests that genistein aglycone represents an additional therapeutic option for patients with GIO.

Anti-oxidant and anti-inflammatory effects of ellagic and punicic acid in an in vitro model of cardiac fibrosis.

Cardiac fibrosis is a pathological process characterized by an excessive deposition of extracellular matrix (ECM) and an increased production of fibrillar collagen in the cardiac interstitium, mainly caused by the activation of cardiac fibroblasts and their transition into myofibroblasts. Oxidative stress is deeply implicated in the pathogenesis of cardiac fibrosis both directly and via its involvement in the tumor growth factor ß1 (TGF-ß1) signaling. Ellagic acid (EA) and punicic acid (PA) are the main components of the Punica granatum L (pomegranate) fruit and seed oil respectively, whose antioxidant, anti-inflammatory and anti-fibrotic effects have been previously described. Therefore, the aim of this study was to investigate the effects of EA or PA or EA+PA in an in vitro model of cardiac fibrosis. Immortalized Human Cardiac Fibroblasts (IM-HCF) were stimulated with 10 ng/ml of TGF-ß1 for 24 h to induce a fibrotic damage. Cells were then treated with EA (1 µM), PA (1 µM) or EA+PA for additional 24 h. Both EA and PA reduced the pro-fibrotic proteins expressions and the intracellular reactive oxygen species (ROS) accumulation. The anti-oxidant activity was also observed by Nrf2 activation with the consequent TGF-ß1-Smad2/3-MMP2/9 and Wnt/ß-catenin signaling inhibition, thus reducing collagen production. EA and PA significantly inhibit NF-κB pathway and, consequently, TNF-α, IL-1ß and IL-6 levels: the greater effect was observed when EA and PA were used in combination. These results suggest that EA, PA and in particular EA+PA might be effective in reducing fibrosis through their antioxidant and anti-inflammatory properties by the modulation of different molecular pathways.

Toxic and Potentially Toxic Mineral Elements of Edible Gastropods Land Snails (Mediterranean Escargot).

The meat of snails can be considered a high-quality food for the human diet and demand is already increasing across Europe. Due to the bioaccumulation of trace elements in their tissues, land snails can be a significant tool also for environmental pollution evaluation. In this study, 28 mineral elements (Ag, Al, As, B, Ba, Be, Bi, Cd, Co, Cr, Cu, Fe, Hg, K, Li, Na, Mg, Mn, Mo, Ni, Pb, Sb, Se, Sr, Ti, Tl, V, Zn) in both the edible part and the shell of edible land snails commercially available in Southern Italy belonging to Cernuella virgata, Helix aperta, Theba pisana species were investigated by ICP-MS and direct mercury analyser. The concentration of trace elements was variable among the samples. The variability demonstrates the close connection among the type of snail, the geographical origin, and the habitat in which the species grows. The edible part of the snails analysed in this study was found to be a good source of macro-nutrients. Toxic elements were detected in some samples, especially in shells; nevertheless, the values fell within the safety limits. Further investigations and monitoring of mineral contents in edible land snails are suggested both for human health and environmental pollution evaluation.

Anti-Inflammatory, Antioxidant, and WAT/BAT-Conversion Stimulation Induced by Novel PPAR Ligands: Results from Ex Vivo and In Vitro Studies.

Activation of peroxisome proliferator-activated receptors (PPARs) not only regulates multiple metabolic pathways, but mediates various biological effects related to inflammation and oxidative stress. We investigated the effects of four new PPAR ligands containing a fibrate scaffold-the PPAR agonists (1a (αEC50 1.0 µM) and 1b (γEC50 0.012 µM)) and antagonists (2a (αIC50 6.5 µM) and 2b (αIC50 0.98 µM, with a weak antagonist activity on γ isoform))-on proinflammatory and oxidative stress biomarkers. The PPAR ligands 1a-b and 2a-b (0.1-10 µM) were tested on isolated liver specimens treated with lipopolysaccharide (LPS), and the levels of lactate dehydrogenase (LDH), prostaglandin (PG) E2, and 8-iso-PGF2α were measured. The effects of these compounds on the gene expression of the adipose tissue markers of browning, PPARα, and PPARγ, in white adipocytes, were evaluated as well. We found a significant reduction in LPS-induced LDH, PGE2, and 8-iso-PGF2α levels after 1a treatment. On the other hand, 1b decreased LPS-induced LDH activity. Compared to the control, 1a stimulated uncoupling protein 1 (UCP1), PR-(PRD1-BF1-RIZ1 homologous) domain containing 16 (PRDM16), deiodinase type II (DIO2), and PPARα and PPARγ gene expression, in 3T3-L1 cells. Similarly, 1b increased UCP1, DIO2, and PPARγ gene expression. 2a-b caused a reduction in the gene expression of UCP1, PRDM16, and DIO2 when tested at 10 µM. In addition, 2a-b significantly decreased PPARα gene expression. A significant reduction in PPARγ gene expression was also found after 2b treatment. The novel PPARα agonist 1a might be a promising lead compound and represents a valuable pharmacological tool for further assessment. The PPARγ agonist 1b could play a minor role in the regulation of inflammatory pathways.

Biglycan Involvement in Heart Fibrosis: Modulation of Adenosine 2A Receptor Improves Damage in Immortalized Cardiac Fibroblasts.

Cardiac fibrosis is a common pathological feature of different cardiovascular diseases, characterized by the aberrant deposition of extracellular matrix (ECM) proteins in the cardiac interstitium, myofibroblast differentiation and increased fibrillar collagen deposition stimulated by transforming growth factor (TGF)-ß activation. Biglycan (BGN), a small leucine-rich proteoglycan (SLRPG) integrated within the ECM, plays a key role in matrix assembly and the phenotypic control of cardiac fibroblasts. Moreover, BGN is critically involved in pathological cardiac remodeling through TGF-ß binding, thus causing myofibroblast differentiation and proliferation. Adenosine receptors (ARs), and in particular A2AR, may play a key role in stimulating fibrotic damage through collagen production/deposition, as a consequence of cyclic AMP (cAMP) and AKT activation. For this reason, A2AR modulation could be a useful tool to manage cardiac fibrosis in order to reduce fibrotic scar deposition in heart tissue. Therefore, the aim of the present study was to investigate the possible crosstalk between A2AR and BGN modulation in an in vitro model of TGF-ß-induced fibrosis. Immortalized human cardiac fibroblasts (IM-HCF) were stimulated with TGF-ß at the concentration of 10 ng/mL for 24 h to induce a fibrotic phenotype. After applying the TGF-ß stimulus, cells were treated with two different A2AR antagonists, Istradefylline and ZM241385, for an additional 24 h, at the concentration of 10 µM and 1 µM, respectively. Both A2AR antagonists were able to regulate the oxidative stress induced by TGF-ß through intracellular reactive oxygen species (ROS) reduction in IM-HCFs. Moreover, collagen1a1, MMPs 3/9, BGN, caspase-1 and IL-1ß gene expression was markedly decreased following A2AR antagonist treatment in TGF-ß-challenged human fibroblasts. The results obtained for collagen1a1, SMAD3, α-SMA and BGN were also confirmed when protein expression was evaluated; phospho-Akt protein levels were also reduced following Istradefylline and ZM241385 use, thus suggesting that collagen production involves AKT recruited by the A2AR. These results suggest that A2AR modulation might be an effective therapeutic option to reduce the fibrotic processes involved in heart pathological remodeling.

Corrigendum: Adenosine receptor stimulation improves glucocorticoid-induced osteoporosis in a rat model.

[This corrects the article DOI: 10.3389/fphar.2017.00558.].

Corrigendum: Activation of A2A receptor by PDRN reduces neuronal damage and stimulates WNT/ß-catenin driven neurogenesis in spinal cord injury.

[This corrects the article DOI: 10.3389/fphar.2018.00506.].

Corrigendum: Exploiting curcumin synergy with natural products using quantitative analysis of dose-effect relationships in an experimental in vitro model of osteoarthritis.

[This corrects the article DOI: 10.3389/fphar.2019.01347.].

The Nutraceutical Genistein-Lycopene Combination Improves Bone Damage Induced by Glucocorticoids by Stimulating the Osteoblast Formation Process.

Chronic glucocorticoid (GC) therapy is the most common cause of iatrogenic osteoporosis and represents an important risk factor for osteoporosis and bone fractures. New therapeutic approaches are required in order to treat osteoporosis and reduce the side effects related to the use of anti-osteoporotic drugs. In this context, previous studies reported the efficacy of some isoflavones and carotenoids, such as lycopene and genistein, on the reduction of the risk of fracture related to osteoporosis. The aim of this study was to investigate the effects of a combined oral treatment, consisting of genistein and lycopene, in an experimental model of glucocorticoid-induced osteoporosis (GIO). GIO was induced by subcutaneous injection of methylprednisolone (MP, 30 mg/kg) for 60 days, whereas the control group (Sham) received saline solution only. Following induction, MP animals randomly were assigned to receive alendronate, genistein, lycopene, or the association of genistein and lycopene or saline solution for additional 60 days together with MP. Femurs obtained from the Sham group were used for osteoblasts extraction; they were then incubated with dexamethasone (DEX) for 24 h to be then treated with lycopene or genistein or the association of lycopene and genistein for an additional 24 h. Treatments with lycopene and genistein restored the impaired mineralization of cells observed following DEX treatment and stimulated osteoblast differentiation by increasing the depressed expression of bALP and RUNX2 (p < 0.0001). Wnt5a, ß-catenin, and Nrf-2 expression were significantly increased following genistein and lycopene treatment (p < 0.0001), thus confirming their antioxidant activity as well as their ability in stimulating osteoblast function, mostly when genistein and lycopene were used in association. The combined treatment of genistein and lycopene improved the bone damage induced by glucocorticoids and significantly restored the normal architecture of bones as well as adequate interconnectivity of bone trabeculae, thus increasing bone mineral density parameters. The obtained data demonstrated that genistein and lycopene but in particular their association might prevent GC's adverse effects, thus stimulating bone formation and reducing bone resorption, improving bone structure and microarchitecture, through different molecular pathways, such as the Wnt/ß-catenin and the Nrf-2 signaling.

Atherosclerosis Plaque Reduction by Lycopene Is Mediated by Increased Energy Expenditure through AMPK and PPARα in ApoE KO Mice Fed with a High Fat Diet.

Lycopene is a carotenoid found in tomatoes that has potent antioxidant activity. The Mediterranean diet is particularly rich in lycopene, which has well-known beneficial effects on cardiovascular health. We tested the effects of lycopene extract in a group of 20 ApoE knockout mice, fed with a high fat western diet for 14 weeks. Starting from week 3 and up to week 14, the mice were randomly divided into two groups that received lycopene (n = 10) by oral suspension every day at the human equivalent dose of 60 mg/day (0.246 mg/mouse/day), or the vehicle solution (n = 10). The lycopene administration reduced triglycerides and cholesterol blood levels starting from week 6 and continuing through to the end of the experiment (p < 0.001). This reduction was mediated by an enhanced liver expression of PPAR-α and AMPK-α and reduced SREBP levels (p < 0.0001). As a histological red-out, the extent of atherosclerotic plaques and the intima−media thickness in the aorta were significantly reduced by lycopene. In this context, lycopene augmented the Nrf-2 positivity staining in the endothelium, thereby confirming that its antioxidant activity was mediated by this nuclear factor. The positive results obtained in this pre-clinical model further support the use of lycopene extracts to reduce atherosclerosis.

Beneficial Effects of Polydeoxyribonucleotide (PDRN) in an In Vitro Model of Fuchs Endothelial Corneal Dystrophy.

Fuchs endothelial corneal dystrophy (FECD) is a bilateral, hereditary syndrome characterized by progressive irreversible injury in the corneal endothelium; it is the most frequent cause for corneal transplantation worldwide. Oxidative stress induces the apoptosis of corneal endothelial cells (CECs), and has a crucial function in FECD pathogenesis. The stimulation of the adenosine A2A receptor (A2Ar) inhibits oxidative stress, reduces inflammation and modulates apoptosis. Polydeoxyribonucleotide (PDRN) is a registered drug that acts through adenosine A2Ar. Thus, the goal of this study was to assess the effect of PDRN in an in vitro FECD model. Human Corneal Endothelial Cells (IHCE) were challenged with H2O2 (200 µM) alone or in combination with PDRN (100 µg/mL), PDRN plus ZM241385 (1 µM) as an A2Ar antagonist, and CGS21680 (1 µM) as a well-known A2Ar agonist. H2O2 reduced the cells' viability and increased the expression of the pro-inflammatory markers NF-κB, IL-6, IL-1ß, and TNF-α; by contrast, it decreased the expression of the anti-inflammatory IL-10. Moreover, the pro-apoptotic genes Bax, Caspase-3 and Caspase-8 were concurrently upregulated with a decrease of Bcl-2 expression. PDRN and CGS21680 reverted the negative effects of H2O2. Co-incubation with ZM241385 abolished the effects of PDRN, indicating that A2Ar is involved in the mode of action of PDRN. These data suggest that PDRN defends IHCE cells against H2O2-induced damage, potentially as a result of its antioxidant, anti-inflammatory and antiapoptotic properties, suggesting that PDRN could be used as an FECD therapy.

Reduction of oxidative stress blunts the NLRP3 inflammatory cascade in LPS stimulated human gingival fibroblasts and oral mucosal epithelial cells.

The therapeutic armamentarium for the treatment of oral mucositis is very poor. Catechin and baicalin are two natural flavonoids that have been individually reported to have a curative potential. Flavocoxid is a mixed extract containing baicalin and catechin showing antioxidant effects and anti-inflammatory activity mainly due to a dual inhibition of inducible cyclooxygenase (COX-2), 5-lipoxygenase (5-LOX) and NLRP3 pathway. The aim of this study was to evaluate the anti-inflammatory and anti-oxidant effects of flavocoxid in an "in vitro" model of oral mucositis induced by triggering an inflammatory phenotype in human gingival fibroblasts (GF) and human oral mucosal epithelial cells (EC). GF and EC were challenged with lipopolysaccharide (LPS 2 µg/ml) alone or in combination with flavocoxid (32 µg/ml). Flavocoxid increased Nrf2, prompted a marked reduction in malondialdehyde levels and reduced the expression of COX-2 and 5-LOX together with PGE2, and LTB4 levels. Flavocoxid caused also a great decrease in the expression of NF-κB and turned off NLRP3 inflammasome and its downstream effectors signal, as caspase-1, IL-1ß and IL-18 in both GF and EC cells stimulated with LPS. These results suggest a correlation between oxidative stress and NLRP3 activation and indicate that flavocoxid suppresses the inflammatory storm that accompanies oral mucositis. This preclinical evidence deserves to be confirmed in a clinical setting.