With an enormous potential in immunology and vaccinology, lipopolysaccharides (LPSs) are among the most extensively studied bacteria-derived molecules. LPS centered studies are countless, and their results reverberate in all areas of the life sciences, including chemistry, biology, genetics, biophysics, and medicine. Most of these research activities are focused on the LPS-induced immune response activation by means of Myeloid Differentiation protein-2/Toll Like Receptor 4 (MD-2/TLR4) complex, which currently is the most largely explored LPS sensing pathway. However, the enormous structural variability of LPS allows interactions with numerous other receptors involved in a wide range of equally important immunological scenarios. In this review, we explore these additional LPS recognition systems, which operate within interconnected signaling cascades, highlighting their role in maintaining physiological homeostasis and their involvement in the development of severe human diseases. Understanding these pathways, their interconnections, and the crosstalk between them and TLR4/MD-2 is essential for guiding the development of pharmacologically active molecules that could specifically modulate the inflammatory response, paving the way to new strategies for combating immune-mediated diseases and resistant infections.

Lipopolysaccharides (LPS) decorating the cell surface of Gram-negative bacteria exhibit nuanced functionalities linked to their precise structural composition. However, despite their critical role in health and disease, information on the structure and function of LPS from members of the human gut microbiota is still limited. Here, we deciphered the complete structure of the LPS isolated from the human gut bacterium Bacteroides eggerthii 1_2_48FAA. We showed that B. eggerthii 1_2_48FAA produces an R-type LPS (or lipooligosaccharide, LOS) composed of a heterogeneous mixture of tetra- and penta-acylated lipid A species with different degree of phosphorylation, and a compact galactofuranose-containing core oligosaccharide. Using in vitro human cell lines, we showed that B. eggerthii 1_2_48FAA LOS acts as a weak activator of TLR4-mediated signaling. Moreover, we observed that expression of maturation markers CD40, CD80 and CD86 on monocytes-derived dendritic cells upon B. eggerthii 1_2_48FAA LOS exposure was significantly lower compared to pro-inflammatory Escherichia coli LPS. Taken together, these data provide new structural and biological insights into LPS from gut bacteria, underscoring the importance of structural features in modulating host immunity.

Veillonella parvula, prototypical member of the oral and gut microbiota, is at times commensal yet also potentially pathogenic. The definition of the molecular basis tailoring this contrasting behavior is key for broadening our understanding of the microbiota-driven pathogenic and/or tolerogenic mechanisms that take place within our body. In this study, we focused on the chemistry of the main constituent of the outer membrane of V. parvula, the lipopolysaccharide (LPS). LPS molecules indeed elicit pro-inflammatory and immunomodulatory responses depending on their chemical structures. Herein we report the structural elucidation of the LPS from two strains of V. parvula and show important and unprecedented differences in both the lipid and carbohydrate moieties, including the identification of a novel galactofuranose and mannitol-containing O-antigen repeating unit for one of the two strains. Furthermore, by harnessing computational studies, in vitro human cell models, as well as lectin binding solid-phase assays, we discovered that the two chemically diverse LPS immunologically behave differently and have attempted to identify the molecular determinant(s) governing this phenomenon. Whereas pro-inflammatory potential has been evidenced for the lipid A moiety, by contrast a plausible "immune modulating" action has been proposed for the peculiar O-antigen portion.

Gram-negative bacteria living in marine waters have evolved peculiar adaptation strategies to deal with the numerous stress conditions that characterize aquatic environments. Among the multiple mechanisms for efficient adaptation, these bacteria typically exhibit chemical modifications in the structure of the lipopolysaccharide (LPS), which is a fundamental component of their outer membrane. In particular, the glycolipid anchor to the membrane of marine bacteria LPSs, i.e. the lipid A, frequently shows unusual chemical structures, which are reflected in equally singular immunological properties with potential applications as immune adjuvants or anti-sepsis drugs. In this work, we determined the chemical structure of the lipid A from Cellulophaga pacifica KMM 3664T isolated from the Sea of Japan. This bacterium showed to produce a heterogeneous mixture of lipid A molecules that mainly display five acyl chains and carry a single phosphate and a D-mannose disaccharide on the glucosamine backbone. Furthermore, we proved that C. pacifica KMM 3664T LPS acts as a weaker activator of Toll-like receptor 4 (TLR4) compared to the prototypical enterobacterial Salmonella typhimurium LPS. Our results are relevant to the future development of novel vaccine adjuvants and immunomodulators inspired by marine LPS chemistry.

Background/Objectives: Mesothelioma is an aggressive cancer with limited treatment options. Mesothelioma therapy often involves a multimodal approach including surgery, radiotherapy and chemotherapy. However, the prognosis for patients remains poor. Difficult diagnosis, late symptoms when the tumor is in an advanced stage and the onset of chemotherapy resistance make mesothelioma difficult to treat. For this reason, it is essential to discover new pharmacological approaches. Capsaicin (CAPS) is the active compound of chili peppers. Based on CAPS’s anticancer properties on various tumor lines and its chemo-sensitizing action on resistant cells, in this study, we evaluated the effects of CAPS on mesothelioma cells to assess its potential use in mesothelioma therapy. Methods: To evaluate antiproliferative effects of CAPS, we performed MTS assays on various mesothelioma cells, representative of all major mesothelioma subtypes. Transwell migration and wound-healing assays were used to examine the effect of CAPS on mesothelioma cell migration. We also determined the effects of CAPS on oncogenic signaling pathways by assessing the levels of AKT and MAPK activation. Results: In this study, we show that CAPS significantly reduces proliferation of both parental and cisplatin-resistant mesothelioma cells. CAPS promotes S-phase cell cycle arrest and inhibits lateral motility and migration of mesothelioma cells. Accordingly, CAPS suppresses AKT and ERK1/2 activation in MSTO-211H and NCI-H2052 cells. Our results support an antitumor effect of CAPS on cisplatin-resistant mesothelioma cells, suggesting that it may reduce resistance to cisplatin. Conclusions: Our results could pave the way for further studies to evaluate the use of CAPS for mesothelioma treatment.

Cardiotoxicity has emerged as a serious outcome catalyzed by various therapeutic targets in the field of cancer treatment, which includes chemotherapy, radiation, and targeted therapies. The growing significance of cancer drug–induced cardiotoxicity (CDIC) and radiation-induced cardiotoxicity (CRIC) necessitates immediate attention. This article intricately unveils how cancer treatments cause cardiotoxicity, which is exacerbated by patient-specific risks. In particular, drugs like anthracyclines, alkylating agents, and tyrosine kinase inhibitors pose a risk, along with factors such as hypertension and diabetes. Mechanistic insights into oxidative stress and topoisomerase-II-B inhibition are crucial, while cardiac biomarkers show early damage. Timely intervention and prompt treatment, especially with specific agents like dexrazoxane and beta-blockers, are pivotal in the proactive management of CDIC.

The problem of residues of toxic contaminants in food products has assumed considerable importance in terms of food safety. Naturally occurring contaminants, such as mycotoxins, are monitored routinely in the agricultural and food industries. Unfortunately, the consequences of the presence of mycotoxins in foodstuffs are evident in livestock farms, where both subacute and chronic effects on animal health are observed and could have non-negligible effects on human health. Ochratoxin A (OTA) is a common mycotoxin that contaminates food and feeds. Due to its thermal stability, the eradication of OTA from the food chain is very difficult. Consequently, humans and animals are frequently exposed to OTA in daily life. In this review article, we will devote time to highlighting the redox-based nephrotoxicity that occurs during OTA intoxication. In the past few decades, the literature has improved on the main molecules and enzymes involved in the redox signaling pathway as well as on some new antioxidant compounds as therapeutic strategies to counteract oxidative stress. The knowledge shown in this work will address the use of nutraceutical substances as dietary supplements, which would in turn improve the prophylactic and pharmacological treatment of redox-associated kidney diseases during OTA exposure, and will attempt to promote animal feed supplementation.

Chronic myeloid leukemia (CML) is a myeloproliferative disease that activates multiple signaling pathways, causing cells to produce higher levels of reactive oxygen species (ROS). Nicotinamide adenine dinucleotide phosphate (NADPH) oxidases (NOXs) are a major generator of ROS in leukemia, and marine natural products have shown promising activities for the treatment of hematopoietic malignancies. In the present study, we investigated the effect of the marine microalga Skeletonema marinoi (S.M.), a ubiquitous diatom that forms massive blooms in the oceans, on the human leukemia cell line K562. The effects of S.M. extract on cell viability, production of ROS, nitric oxide (NO), and apoptosis were examined. In this preliminary work, S.M. was able to decrease cell viability (p < 0.05) and increase apoptosis levels (p < 0.05) in K562 cells after 48 h of treatment. In addition, the levels of NOX, NO, and malondialdehyde (MDA) were reduced in K562-treated cells (p < 0.05), whereas the levels of SOD, CAT, and GPx increased during treatment (p < 0.05). Finally, analyzing Bax and Bcl-2 expression, we found a significant increase in the proapoptotic protein Bax and a sustained decrease in the antiapoptotic protein Bcl-2 (p < 0.05) in the K562-treated cells.

Aflatoxin B1 (AFB1) causes hepatotoxicity, immunotoxicity, and kidney damage, and it is included in group I of human carcinogens. The European Commission has established maximum limits of AFB1 in feed, ranging from 5 to 20 μg/kg. Chicken is moderately sensitive to AFB1, which results in reduced growth performance and economic losses. Oxidative stress triggered by AFB1 plays a crucial role in kidney damage and the antioxidant activity of Curcumin (CURC) could help in preventing such adverse effect. Twenty-days-old broilers were treated for 10 days with AFB1 (0.02 mg/kg feed), alone or in combination with CURC (400 mg/kg feed), to explore the effects on the renal tissue. Animals exposed to AFB1 alone displayed alterations of the oxidative stress parameters compared with controls: serum antioxidant capacity, and enzymatic activity of kidney superoxide dismutase, catalase and glutathione peroxidase were decreased, while renal malondialdehyde levels and NADPH oxidase complex expression were increased. The administration of CURC attenuates all the oxidative stress parameters modified by AFB1 in the chicken kidney, opening new perspectives in the management of aflatoxicosis.

Ochratoxin A (OTA) is a powerful mycotoxin found in various foods and feedstuff, responsible for subchronic and chronic toxicity, such as nephrotoxicity, hepatotoxicity, teratogenicity, and immunotoxicity to both humans and several animal species. The severity of the liver damage caused depends on both dose and duration of exposure. Several studies have suggested that oxidative stress might contribute to increasing the hepatotoxicity of OTA, and several antioxidants, including curcumin (CURC), have been tested to counteract the toxic hepatic action of OTA in various classes of animals. Therefore, the present study was designed to evaluate the protective effect of CURC, a bioactive compound with different therapeutic properties on hepatic injuries caused by OTA in rat animal models. CURC effects were examined in Sprague Dawley rats treated with CURC (100 mg/kg), alone or in combination with OTA (0.5 mg/kg), by gavage daily for 14 days. At the end of the experiment, rats treated with OTA showed alterations in biochemical parameters and oxidative stress in the liver. CURC dosing significantly attenuated oxidative stress and lipid peroxidation versus the OTA group. Furthermore, liver histological tests showed that CURC reduced the multifocal lymphoplasmacellular hepatitis, the periportal fibrosis, and the necrosis observed in the OTA group. This study provides evidence that CURC can preserve OTA-induced oxidative damage in the liver of rats.

Tyrosine kinase inhibitors (TKIs) have revolutionized the treatment of patients with chronic myeloid leukemia (CML). However, continued use of these inhibitors has contributed to the increase in clinical resistance and the persistence of resistant leukemic stem cells (LSCs). So, there is an urgent need to introduce additional targeted and selective therapies to eradicate quiescent LSCs, and to avoid the relapse and disease progression. Here, we focused on emerging BCR-ABL targeted and non-BCR-ABL targeted drugs employed in clinical trials and on alternative CML treatments, including antioxidants, oncolytic virus, engineered exosomes, and natural products obtained from marine organisms that could pave the way for new therapeutic approaches for CML patients.

Ochratoxin A (OTA) is a fungal toxin of critical concern for food safety both for human health and several animal species, also representing a cancer threat to humans. Curcumin (CURC) is a natural polyphenol that has anti-apoptotic, anti-inflammatory, and antioxidant effects. The aim of this study was to investigate the cytoprotective effect of CURC against OTA-induced nephrotoxicity and hepatotoxicity through the study of the nitrosative stress, pro-inflammatory cytokines, and deoxyribonucleic acid (DNA) damage. Sprague Dawley rats were daily treated with CURC (100 mg/kg b.w.), OTA (0.5 mg/kg b.w), or CURC with OTA by oral gavage for 14 days. Our results demonstrated that OTA exposure was associated with significant increase of pro-inflammatory and DNA oxidative-damage biomarkers. Moreover, OTA induced the inducible nitric oxide synthase, (iNOS) resulting in increased nitric oxide (NO) levels both in kidney and liver. The co-treatment OTA + CURC counteracted the harmful effects of chronic OTA treatment by regulating inflammation, reducing NO levels and oxidative DNA damage in kidney and liver tissues. Histology revealed that OTA + CURC treatment determinates mainly an Iba1+ macrophagic infiltration with fewer CD3+ T-lymphocytes in the tissues. In conclusion, we evidenced that CURC exerted cytoprotective and antioxidant activities against OTA-induced toxicity in rats.

Ochratoxin A (OTA) is a mycotoxin which represents an emerging problem for both animal and human health, due to its high presence in feed and foods. Exposure to OTA is associated with oxidative stress-induced nephrotoxicity. Therefore, the identification of new antioxidant or adsorbent substances with protective action constitutes one of the main challenges to reduce the negative effects induced by mycotoxins. For this purpose, we investigated the effect of two innovative feed additives, a bio-organoclay (CHS) and a mixture of a tri-octahedral Na-smectite with a ligno-cellulose based material (MIX) alone or in combination with OTA in kidneys of treated chickens. Real-Time PCR analyses for NADPH oxidase 4 (NOX) and p47-phox were performed to evaluate oxidative stress. Our results demonstrated an increase in NOX and p47-phox levels in OTA-treated chickens. Moreover, CHS, more than MIX, was able to reduce OTA-induced toxicity, restoring NOX levels. Taken together, these findings highlight the potential beneficial role of CHS in reverting OTA-induced nephrotoxicity in chickens and could lead to the production of healthier foods with beneficial consequences for human and animal health.

Aflatoxin B1 (AFB1), the mainly Aspergillus fungi derived mycotoxin, is well known for its carcinogenic effects on liver, and frequently occurs in food supplies, leading to fatal consequences in both farm animals and humans. Poultry, one of the most important segments of agro-industry, has been demonstrated to be extremely sensitive to AFB1 intake, which results in chickens’ low performance, decreased quality of both eggs and meat and a negative economic feedback. Oxidative stress caused by AFB1 plays a crucial role in chickens’ kidney damage by generating lipid peroxidation accompanied by a concomitant increase in the antioxidant enzymes involved in ROS metabolism (NADPH oxidase isoform 4 (NOX4) and its regulatory subunit p47-phox). The aim of the present work was to investigate the benefits of dietary supplementation, in chickens affected by AFB1 mycotoxicosis, using a new Feed additive (FA) containing a mixture of a tri-octahedral Na-smectite with a ligno-cellulose-based material an antioxidant adjuvant. Exposure of AFB1-treated chickens to the feed additive induced a significant down-regulation of both NOX4 and p47-phox genes expression levels. This trend was confirmed by their protein expression, demonstrating the great potential of the FA to counteract oxidative stress. To conclude, these results could open new perspectives in the methods of feeding chickens, using eco-friendly dietary supplements able to reduce AFB1-induced mycotoxicosis and to ameliorate poultry performances.

Ochratoxin A (OTA) is a powerful nephrotoxin and the severity of its damage to kidneys depends on both the dose and duration of exposure. According to the scientific data currently available, the mechanism of action still is not completely clarified, but it is supposed that oxidative stress is responsible for OTA-induced nephrotoxicity. Bioactive compound use has emerged as a potential approach to reduce chronic renal failure. Therefore, curcumin (CURC), due to its therapeutic effects, has been chosen for our study to reduce the toxic renal effects induced by OTA. CURC effects are examined in Sprague Dawley rats treated with CURC (100 mg/kg), alone or in combination with OTA (0.5 mg/kg), by gavage daily for 14 days. The end result of the experiment finds rats treated with OTA show alterations in biochemical and oxidative stress parameters in the kidney, related to a decrease in the Glomerular Filtration Rate (GFR). Conversely, the administration of CURC attenuates oxidative stress and prevents glomerular hyperfiltration versus the OTA group. Furthermore, kidney histological tests show a reduction in glomerular and tubular damage, inflammation and tubulointerstitial fibrosis. This study shows that CURC can mitigate OTA–induced oxidative damage in the kidneys of rats.

Diabetic nephropathy (DN) is the primary cause of end-stage renal disease, worldwide, and oxidative stress has been recognized as a key factor in the pathogenesis and progression of DN. Nicotinamide adenine dinucleotide phosphate (NADPH) oxidase has the most important contribution to reactive oxygen species generation during the development of DN. Bioactive compound use has emerged as a potential approach to reduce chronic renal failure. Therefore, a red orange and lemon extract (RLE) rich in anthocyanins was chosen in our study, to reduce the toxic renal effects during the development of DN in Zucker diabetic fatty rat (ZDF). RLE effects were examined daily for 24 weeks, through gavage, in ZDF rats treated with RLE (90 mg/kg). At the end of the experiment, ZDF rats treated with RLE showed a reduction of the diabetes-associated up-regulation of both NOX4 and the p47-phox and p22-phox subunits, and restored the BAX/BCL-2 ratio respect to ZDF rats. Furthermore, RLE was able to reduce the oxidative DNA damage measured in urine samples in ZDF rats. This study showed that RLE could prevent the renal damage induced by DN through its capacity to inhibit NOX4 and apoptosis mechanisms.

Type 2 diabetes mellitus is a pathological and chronical condition that induce a rearrangement in carbohydrate metabolism (Kaneto H et al. Antioxid Redox Signal. 2007). Even if the pathological mechanism of DN is not yet clear, NADPH oxidase (NOX) has been demonstrated to be involved in kidney ROS (Reactive Oxygen Species) generation during diabetic state (Palicz A. et al. J Biol Chem. 2001). Therefore, NOX-4, whose p22-phox subunit have shown a pivotal role in diabetes development, has been considered a potential pharmacological target in DN (Gill PS and Wilcox CS. Antioxid Redox Signal. 2006). In previous experiments performed on diabetic rat animal model with DN, we have found a beneficial effect of an extract rich in anthocyanins (ANT), members of flavonoids group (Shih PH. J Agric Food Chem. 2007). The aim of the present work was to investigate the molecular mechanisms involved in the DN and the protective effects of the new extract particularly abundant in ANT, the Red orange and Lemon Extract (RLE). Zucker diabetic fatty rats were divided into three groups and treated by gavage daily until 30 weeks of age, as follows: control group (ZF rats) received 1 mL of normal saline; ZDF Group (ZDF rats) received 1mL of normal saline; ZDF + RLE group (ZDF rats) treated with 90 mg/ kg of RLE dissolved in 1mL of normal saline. We examined the gene and protein expression of NOX4 catalytic subunit and its regulatory subunit p22-phox through Real Time PCR and western blot analysis. The expression gene levels of NOX4 significantly increased in diabetic rats ZDF, compared to control ZF (***p<0.001). Exposure of ZDF rats with RLE induces a decreased expression of NOX4 (Figure 1) compared to ZDF. On the contrary, there were not significant expression levels variations for regulatory subunit p22-phox. Western blot results are in agreement with Real Time PCR data, in fact an increase in NOX4 protein levels (*p<0.05) is evident, but no significant increase in p22-phox subunit was observed. In conclusion, we hypothesize that the protective effect of RLE on the development of DN is related to its ability to inhibit NADPH oxidase activity and opens new perspectives for the treatment of DN.