Nicotinamide is a potent inhibitor of proinflammatory cytokines

Mechanistic Insights into the Multiple Functions of Niacinamide: Therapeutic Implications and Cosmeceutical Applications in Functional Skincare Products

Niacinamide (or nicotinamide) is a small-molecule hydrosoluble vitamin with essential metabolic functions in mammalian cells. Niacinamide has become a key functional ingredient in diverse skincare products and cosmetics. This vitamin plays a pivotal role in NAD+ synthesis, notably contributing to redox reactions and energy production in cutaneous cells. Via diversified biochemical mechanisms, niacinamide is also known to influence human DNA repair and cellular stress responses. Based on decades of safe use in cosmetics, niacinamide recently gained widespread popularity as an active ingredient which aligns with the "Kligman standards" in skincare. From a therapeutic standpoint, the intrinsic properties of niacinamide may be applied to managing acne vulgaris, melasma, and psoriasis. From a cosmeceutical standpoint, niacinamide has been widely leveraged as a multipurpose antiaging ingredient. Therein, it was shown to significantly reduce cutaneous oxidative stress, inflammation, and pigmentation. Overall, through multimodal mechanisms, niacinamide may be considered to partially prevent and/or reverse several biophysical changes associated with skin aging. The present narrative review provides multifactorial insights into the mechanisms of niacinamide's therapeutic and cosmeceutical functions. The ingredient's evolving role in skincare was critically appraised, with a strong focus on the biochemical mechanisms at play. Finally, novel indications and potential applications of niacinamide in dermal fillers and alternative injectable formulations were prospectively explored.

Significance of Vitamin Supplementation in Reducing the Severity of COVID-19

Coronavirus disease-19 (COVID-19), a serious pandemic due to the SARS-CoV-2 virus infection, caused significant lockdowns, healthcare shortages, and deaths worldwide. The infection leads to an uncontrolled systemic inflammatory response causing severe respiratory distress and multiple-organ failure. Quick development of several vaccines efficiently controlled the spread of COVID-19. However, the rise of various new subvariants of COVID-19 demonstrated some concerns over the efficacy of existing vaccines. Currently, better vaccines to control these variants are still under development as several new subvariants of COVID-19, such as omicron BA-4, BA-5, and BF-7 are still impacting the world. Few antiviral treatments have been shown to control COVID-19 symptoms. Further, control of COVID-19 symptoms has been explored with many natural and synthetic adjuvant compounds in hopes of treating the deadly and contagious disease. Vitamins have been shown to modulate the immune system, function as antioxidants, and reduce the inflammatory response. Recent studies have investigated the potential role of vitamins, specifically vitamins A, B, C, D, and E, in reducing the immune and inflammatory responses and severity of the complication. In this brief article, we discussed our current understanding of the role of vitamins in controlling COVID-19 symptoms and their potential use as adjuvant therapy.

New Perspectives for Antihypertensive Sartans as Components of Co-crystals and Co-amorphous Solids with Improved Properties and Multipurpose Activity

Sartans (angiotensin II receptor blockers, ARBs), drugs used in the treatment of hypertension, play a principal role in addressing the global health challenge of hypertension. In the past three years, their potential use has expanded to include the possibility of their application in the treatment of COVID-19 and neurodegenerative diseases (80 clinical studies worldwide). However, their therapeutic efficacy is limited by their poor solubility and bioavailability, prompting the need for innovative approaches to improve their pharmaceutical properties. This review discusses methods of co-crystallization and co-amorphization of sartans with nonpolymeric, low molecular, and stabilizing co-formers, as a promising strategy to synthesize new multipurpose drugs with enhanced pharmaceutical properties. The solid-state forms have demonstrated the potential to address the poor solubility limitations of conventional sartan formulations and offer new opportunities to develop dual-active drugs with broader therapeutic applications. The review includes an in-depth analysis of the co-crystal and co-amorphous forms of sartans, including their properties, possible applications, and the impact of synthetic methods on their pharmacokinetic properties. By shedding light on the solid forms of sartans, this article provides valuable insights into their potential as improved drug formulations. Moreover, this review may serve as a valuable resource for designing similar solid forms of sartans and other drugs, fostering further advances in pharmaceutical research and drug development.

Inhibition of host PARP1 contributes to the anti-inflammatory and antitubercular activity of pyrazinamide

The antibiotic pyrazinamide (PZA) is a cornerstone of tuberculosis (TB) therapy that shortens treatment durations by several months despite being only weakly bactericidal. Intriguingly, PZA is also an anti-inflammatory molecule shown to specifically reduce inflammatory cytokine signaling and lesion activity in TB patients. However, the target and clinical importance of PZA's host-directed activity during TB therapy remain unclear. Here, we identify the host enzyme Poly(ADP-ribose) Polymerase 1 (PARP1), a pro-inflammatory master regulator strongly activated in TB, as a functionally relevant host target of PZA. We show that PZA inhibits PARP1 enzymatic activity in macrophages and in mice where it reverses TB-induced PARP1 activity in lungs to uninfected levels. Utilizing a PZA-resistant mutant, we demonstrate that PZA's immune-modulatory effects are PARP1-dependent but independent of its bactericidal activity. Importantly, PZA's bactericidal efficacy is impaired in PARP1-deficient mice, suggesting that immune modulation may be an integral component of PZA's antitubercular activity. In addition, adjunctive PARP1 inhibition dramatically reduces inflammation and lesion size in mice and may be a means to reduce lung damage and shorten TB treatment duration. Together, these findings provide insight into PZA's mechanism of action and the therapeutic potential of PARP1 inhibition in the treatment of TB.

Exploring the anticancer properties of a new nicotinamide analogue: Investigations into in silico analysis, antiproliferative effects, selectivity, VEGFR-2 inhibition, apoptosis induction, and migration suppression

BACKGROUND

This study focuses on the development and evaluation of (E)-N-(3-(1-(2-(4-bromobenzoyl)hydrazono)ethyl)phenyl)nicotinamide (BHEPN) as a potential inhibitor of Vascular Endothelial Growth Factor Receptor-2 (VEGFR-2).

METHODS

Computational investigations as density function theory (DFT), docking, molecular dynamics (MD) simulations, and ADMET) in addition to in vitro (VEGFR-2 inhibition, cytotoxicity against HepG2 and MCF-7 cancer cell lines, selectivity index, cells cycle analysis, apoptosis investigation, and cells migration assay) studies were conducted.

RESULTS

DFT calculations determined the three-dimensional structure and indicated the reactivity of BHEPN. Molecular docking, and MD simulations analysis showed the BHEPN's binding affinity and its potential as a VEGFR-2 inhibitor. ADMET assessments predicted BHEPN's safety and drug-like characteristics. In vitro investigations confirmed the inhibition of VEGFR-2 with an IC50 value of 0.320 ± 0.012 µM. BHEPN also exhibited remarkable cytotoxic effects against HepG2 and MCF-7 cancer cell lines, with IC50 values of 0.19 ± 0.01 µM and 1.18 ± 0.01 µM, respectively, outperforming Sorafenib's IC50 values (2.24 ± 0.06 µM and 3.17 ± 0.01 µM), respectively. Notably, BHEPN displayed a higher IC50 value of 4.11 ± 0 µM against the non-carcinogenic Vero cell lines, indicating selectivity index values of 21.6 and 3.4 against the tested cancer cell lines, respectively. In a flow cytometry assay, BHEPN induced HepG2 cell cycle arrest at the G1/S phase. Moreover, BHEPN increased the incidence of early and late apoptosis in HepG2 cell lines (from 1.38% and 0.22%) in control cells to (4.11-26.02%) in the treated cells, respectively. Additionally, the percentage of necrosis raised to 13.39%, in contrast to 0.62% in control cells. Finally, BHEPN was able to reduce the migration and wound healing abilities in HepG2 cells to 38.89% compared to 87.92% in untreated cells after 48 h. These in vitro results aligned with the computational predictions, providing strong evidence of BHEPN's efficacy and safety in anticancer applications.

CONCLUSIONS

BHEPN is a promising candidate for the development of novel anticancer agents through further in vitro and in vivo investigations.

Modulatory role of vitamins A, B3, C, D, and E on skin health, immunity, microbiome, and diseases

Disruption of the skin barrier and immunity has been associated with several skin diseases, namely atopic dermatitis (AD), psoriasis, and acne. Resident and non-resident immune cells and the barrier system of the skin are integral to innate immunity. Recent advances in understanding skin microbiota have opened the scope of further understanding the various communications between these microbiota and skin immune cells. Vitamins, being one of the important micronutrients, have been reported to exert antioxidant, anti-inflammatory, and anti-microbial effects. The immunomodulatory action of vitamins can halt the progression of skin diseases, and thus, understanding the immuno-pharmacology of these vitamins, especially for skin diseases can pave the way for their therapeutic potential. At the same time, molecular and cellular markers modulated with these vitamins and their derivatives need to be explored. The present review is focused on significant vitamins (vitamins A, B3, C, D, and E) consumed as nutritional supplements to discuss the outcomes and scope of studies related to skin immunity, health, and diseases.

Preclinical Characterization of Pharmacologic NAD+ Boosting as a Promising Therapeutic Approach in Rheumatoid Arthritis

OBJECTIVE

We analyzed NAD+ metabolism in patients with rheumatoid arthritis (RA), its association with disease activity and clinical outcomes of RA, and the therapeutic potential of pharmacologic NAD+ boosting.

METHODS

Our study included 253 participants. In the first cohort, comprising 153 RA patients and 56 healthy donors, we assessed NAD+ levels and NAD+ -related gene pathways. We analyzed 92 inflammatory molecules by proximity extension assay. In the second cohort, comprising 44 RA patients starting anti-tumor necrosis factor (anti-TNF) drugs, we evaluated changes in NAD+ levels and their association with clinical response after 3 months. Mechanistic studies were performed ex vivo on peripheral blood mononuclear cells (PBMCs) from patients with RA to test the beneficial effects of NAD+ boosters, such as nicotinamide and nicotinamide riboside.

RESULTS

Reduced NAD+ levels were found in RA samples, in line with altered activity and expression of genes involved in NAD+ consumption (sirtuins, poly[ADP-ribose] polymerase, CD38), transport (connexin 43), and biosynthesis (NAMPT, NMNATs). Unsupervised clustering analysis identified a group of RA patients with the highest inflammatory profile, the lowest NAD+ levels, and the highest disease activity (as shown by the Disease Activity Score in 28 joints). NAD+ levels were modulated by anti-TNF therapy in parallel with the clinical response. In vitro studies using PBMCs from RA patients showed that nicotinamide riboside and nicotinamide increased NAD+ levels via NAMPT and NMNAT and reduced their prooxidative, proapoptotic, and proinflammatory status.

CONCLUSION

RA patients display altered NAD+ metabolism, directly linked to their inflammatory and disease activity status, which was reverted by anti-TNF therapy. The preclinical beneficial effects of NAD+ boosters, as shown in leukocytes from RA patients, along with their proven clinical safety, might pave the way for the development of clinical trials using these compounds.

Nicotinamide Deteriorates Post-Stroke Immunodepression Following Cerebral Ischemia-Reperfusion Injury in Mice

(1) Background: Inducing experimental stroke leads to biphasic immune responses, where the early activation of immune functions is followed by severe immunosuppression accompanied by spleen and thymus atrophy. Nicotinamide, a water-soluble B-group vitamin, is a known neuroprotectant against brain ischemia in animal models. We examined the effect of nicotinamide on the central and peripheral immune response in experimental stroke models. (2) Methods: Nicotinamide (500 mg/kg) or saline was intravenously administered to C57BL/6 mice during reperfusion after transiently occluding the middle cerebral artery or after LPS injection. On day 3, the animals were examined for behavioral performance and were then sacrificed to assess brain infarction, blood-brain barrier (BBB) integrity, and the composition of immune cells in the brain, thymus, spleen, and blood using flow cytometry. (3) Results: Nicotinamide reduced brain infarction and microglia/macrophage activation following MCAo (p < 0.05). Similarly, in LPS-injected mice, microglia/macrophage activation was decreased upon treatment with nicotinamide (p < 0.05), suggesting a direct inhibitory effect of nicotinamide on microglia/macrophage activation. Nicotinamide decreased the infiltration of neutrophils into the brain parenchyma and ameliorated Evans blue leakage (p < 0.05), suggesting that a decreased infiltration of neutrophils could, at least partially, be the result of a more integrated BBB structure following nicotinamide treatment. Our studies also revealed that administering nicotinamide led to retarded B-cell maturation in the spleen and subsequently decreased circulating B cells in the thymus and bloodstream (p < 0.05). (4) Conclusions: Cumulatively, nicotinamide decreased brain inflammation caused by ischemia-reperfusion injury, which was mediated by a direct anti-inflammatory effect of nicotinamide and an indirect protective effect on BBB integrity. Administering nicotinamide following brain ischemia resulted in a decrease in circulating B cells. This warrants attention with respect to future clinical applications.

Novel Gastroprotective and Thermostable Cocrystal of Dimethyl Fumarate: Its Preparation, Characterization, and In Vitro and In Vivo Evaluation

Crystallization has revolutionized the field of solid-state formulations by modulating the physiochemical and release profile of active pharmaceutical ingredients (APIs). Dimethyl fumarate (DF), an FDA-approved first-line drug for relapsing-remitting multiple sclerosis, has a sublimation problem, leading to loss of the drug during its processing. To tackle this problem, DF cocrystal has been prepared by using solvent evaporation technique using nicotinamide as a coformer, which has been chosen based on in silico predictions and their ability to participate in hydrogen bonding. Fourier transform infrared (FT-IR), powder X-ray diffraction (PXRD), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and sublimation analysis have characterized the cocrystal and its thermostability. Comparative analysis of the release profile has been done by the dissolution and pharmacokinetic study of DF and its cocrystal. Formulated cocrystal is noncytotoxic, antioxidant and inhibits interleukin-6 and tissue necrosis factor-α in peripheral blood mononuclear cells induced by lipopolysaccharide. We have obtained a thermostable cocrystal of DF with a similar physicochemical and release profile to that of DF. The formulated cocrystal also provides a gastroprotective effect which helps counterbalance the adverse effects of DF by reducing lipid peroxidation and total nitrite levels.

Nicotinamide Prevents Diabetic Brain Inflammation via NAD+-Dependent Deacetylation Mechanisms

This study investigated the effect of nicotinamide (NAM) supplementation on the development of brain inflammation and microglial activation in a mouse model of type 1 diabetes mellitus. C57BL/6J male mice, which were made diabetic with five consecutive, low-dose (55 mg/kg i.p.) streptozotocin (STZ) injections. Diabetic mice were randomly distributed in different experimental groups and challenged to different doses of NAM (untreated, NAM low-dose, LD, 0.1%; NAM high-dose, HD, 0.25%) for 25 days. A control, non-diabetic group of mice was used as a reference. The NAD+ content was increased in the brains of NAM-treated mice compared with untreated diabetic mice (NAM LD: 3-fold; NAM HD: 3-fold, p-value < 0.05). Immunohistochemical staining revealed that markers of inflammation (TNFα: NAM LD: -35%; NAM HD: -46%; p-value < 0.05) and microglial activation (IBA-1: NAM LD: -29%; NAM HD: -50%; p-value < 0.05; BDKRB1: NAM LD: -36%; NAM HD: -37%; p-value < 0.05) in brains from NAM-treated diabetic mice were significantly decreased compared with non-treated T1D mice. This finding was accompanied by a concomitant alleviation of nuclear NFκB (p65) signaling in treated diabetic mice (NFκB (p65): NAM LD: -38%; NAM HD: -53%, p-value < 0.05). Notably, the acetylated form of the nuclear NFκB (p65) was significantly decreased in the brains of NAM-treated, diabetic mice (NAM LD: -48%; NAM HD: -63%, p-value < 0.05) and inversely correlated with NAD+ content (r = -0.50, p-value = 0.03), suggesting increased activity of NAD+-dependent deacetylases in the brains of treated mice. Thus, dietary NAM supplementation in diabetic T1D mice prevented brain inflammation via NAD+-dependent deacetylation mechanisms, suggesting an increased action of sirtuin signaling.

1-Methylnicotinamide (1-MNA) inhibits the activation of the NLRP3 inflammasome in human macrophages

The NLRP3 inflammasome is among the most potent intracellular sensors of danger and disturbances of cellular homeostasis that can lead to the release of IL-1β and cell death, or pyroptosis. Despite its protective role, this mechanism is involved in the pathogenesis of numerous inflammatory diseases; therefore, it is seen as a potential therapeutic target. 1-methylnicotinamide (1-MNA) is a direct metabolite of nicotinamide and was previously shown to display several immunomodulatory properties, including a reduction in the reactive oxygen species (ROS). Here, we investigated whether 1-MNA could influence the activation of the NLRP3 inflammasome in human macrophages. In differentiated human macrophages we observed that 1-MNA specifically reduced the activation of the NLRP3 inflammasome. This effect was related to the scavenging of ROS, as exogenous H₂O₂ was able to restore NLRP3 activation. Additionally, 1-MNA increased the mitochondrial membrane potential, indicating that it did not inhibit oxidative phosphorylation. Moreover, at high but not low concentrations, 1-MNA decreased NF-κB activation and the level of pro-IL-1β. Interestingly, 1-MNA did not reduce the secretion of IL-6 upon endotoxin stimulation, confirming that its primary immunomodulatory effect on human macrophages is dependent on the NLRP3 inflammasome. Taken together, we have shown for the first time that 1-MNA reduced the activation of the NLRP3 inflammasome in human macrophages via an ROS-dependent pathway. Our results indicate a novel potential use of 1-MNA in NLRP3-related disorders.

Evidence-base for the beneficial effect of nutraceuticals in canine dermatological immune-mediated inflammatory diseases - A literature review

BACKGROUND

Immune-mediated inflammatory diseases (IMIDs) are associated with an abnormal immune response, resulting in a disturbed homeostasis and chronic inflammation. Most canine dermatological IMIDs (cDIMIDs), such as allergies, autoimmune and immune-mediated diseases, require long-term treatment with immunosuppressive drugs with potential adverse effects. In general, nutraceuticals are thought to be safe. As a result, there is a tendency for the more frequent use of nutraceuticals in veterinary medicine.

OBJECTIVES

The aim of this review was to present evidence-based proof for the use of various nutraceuticals in the treatment of cDIMIDs and, where possible, to provide conclusions to guide their use in veterinary dermatological practice.

METHODS

A comprehensive literature search on common cDIMIDs and nutraceuticals was performed. Only peer-reviewed articles published in English and related to the study topic were included. A total of 64 eligible publications were classified in five categories based on study design and substantively assessed on additional criteria such as standardisation of diets and number of included animals. For final appraisal, classification of major, minor or no evidence was used whereby efficacy was based on clinical outcome measurements.

CONCLUSIONS

Minor evidence for the beneficial use of several nutraceuticals, including essential fatty acids, niacinamide and probiotics, was found for treatment of specific cDIMIDs. These nutraceuticals may improve clinical signs or reduce the required dose of concurrent medication (e.g. drug-sparing effect) in some dogs. Some nutraceuticals also may be used for long-term maintenance therapy. Despite some promising findings, major evidence for the use of nutraceuticals in cDIMIDs is lacking, warranting further research.

Benefits of the Dermocosmetic Mineral 89 Probiotic Fractions Adjunct to Topical Retinoids for Anti-Aging Benefits

Purpose

Tretinoin is a topical gold standard for photoaging treatment. However, patient adherence can be impaired by local tolerability in the first 1-2 weeks of treatment. Mineral 89 Probiotic Fractions^® (M89PF) containing Vichy volcanic mineralizing water^®, probiotic fractions, hyaluronic acid, niacinamide and tocopherol was developed to fulfill the need for adjunctive products that can reinforce skin barrier and manage retinoid induced irritation.

Patients and Methods

The study included 38 women, aged 44-60 years, phototype II-VI, applying 0.025% tretinoin gel once nightly for 84 days. For 28 days, one hemi face was treated with M89PF and sunscreen SPF 50+ while other hemi face received sunscreen only. Then, M89PF application was changed to full face. Evaluations were performed at days 0, 7, 28 and 84. Erythema, dryness, fine lines, skin tone, radiance and pore appearance were assessed by a dermatologist. Tolerability was evaluated through self-assessment questionnaire. Skin hydration levels, inflammatory and oxidative stress biomarkers were analyzed by immunological assay: Interleukin(IL)-8, IL1-alpha, IL1-Receptor Antagonist (IL-1Ra), Prostaglandin E2 (PGE2), Catalase and Superoxide Dismutase (SOD).

Results

Hemiface analysis showed that erythema, fine lines, skin tone, radiance, pore appearance, hydration, tightness, dryness, burning, itching and stinging sensations were improved (p<0.05) on the M89PF side. At full face analysis on D84, erythema, fine lines, skin tone, radiance and pore appearance were improved compared to D0 (p<0.001). Tightness, dryness, burning, itching and stinging were reduced when compared to D7 (p<0.05). Dermatology Life Quality Index (DLQI) and Skindex 16 showed improvement in quality of life (p<0.05). IL-1RA increased at D28 (p=0.003) and PGE2 decreased at D28 and D84 compared to D0 (p<0.01).

Conclusion

M89PF reduced retinoid induced irritation with a good tolerability profile and, used as an adjunct to topical tretinoin, significantly improved skin hydration, erythema, fine lines, skin tone, radiance and pore appearance.

Topical niacinamide (Nicotinamide) treatment for discoid lupus erythematosus (DLE): A prospective pilot study

BACKGROUND

Cutaneous lupus erythematosus is an umbrella term for a group of autoimmune connective tissue disorders affecting the skin. Discoid lupus erythematosus (DLE) is the chronic condition and most common form of cutaneous lupus erythematosus.

AIMS

Current therapies of DLE are challenging and not completely satisfactory, highly expensive, off-label, or poorly available (like antimalarials due to COVID-19 outbreaks). Nicotinamide, also called niacinamide, is a water-soluble form of vitamin B3 (niacin). Its multiple effects let us think that nicotinamide could be a therapy for lupus-associated skin lesions.

METHODS

We performed a prospective randomized double-blind clinical trial on 60 subjects diagnosed with Discoid lupus erythematosus using topical Nicotinamide 2% and 4% preparations in form of cream and gel on skin and scalp lesions. Control group was included using only cream/gel base as placebo control.

RESULTS

Obtained data showed that topical Nicotinamide can be used for the treatment of DLE as adjuvant to other treatment regimens with good cosmetic results and minimal side effects. Topical 4% Nicotinamide is superior to 2% preparation in response but associated with a higher incidence of irritation.

CONCLUSION

Topical Nicotinamide can be used for the treatment of DLE as an adjuvant to other treatment regimens with good cosmetic results and minimal side effects. Further trials with long-term therapy, follow-up period, and bigger sample sizes are required.

The Effect of Ascorbic Acid and Nicotinamide on Panton-Valentine Leukocidin Cytotoxicity: An Ex Vivo Study

Background: Panton−Valentine Leukocidin sustains a strong cytotoxic activity, targeting immune cells and, consequently, perforating the plasma membrane and inducing cell death. The present study is aimed to examine the individual effect of ascorbic acid and nicotinamide on PVL cytotoxicity ex vivo, as well as their effect on granulocytes viability when treated with PVL. Materials and Methods: The PVL cytotoxicity assay was performed in triplicates using the commercial Cytotoxicity Detection Kit PLUS (LDH). LDH release was measured to determine cell damage and cell viability was measured via flow cytometry. Results and discussion: A clear reduction in PVL cytotoxicity was demonstrated (p < 0.001). Treatment with ascorbic acid at 5 mg/mL has shown a 3-fold reduction in PVL cytotoxicity; likewise, nicotinamide illustrated a 4-fold reduction in PVL cytotoxicity. Moreover, granulocytes’ viability after PVL treatment was maintained when incubated with 5 mg/mL of ascorbic acid and nicotinamide. Conclusions: our findings illustrated that ascorbic acid and nicotinamide exhibit an inhibitory effect on PVL cytotoxicity and promote cell viability, as the cytotoxic effect of the toxin is postulated to be neutralized by antioxidant incubation. Further investigations are needed to assess whether these antioxidants may be viable options in PVL cytotoxicity attenuation in PVL-associated diseases.

Immunomodulators for Non-Melanoma Skin Cancers: Updated Perspectives

Non-melanoma skin cancers (NMSCs) are the most common cancers worldwide and may be associated with significant morbidity and mortality, especially in immunosuppressed populations. Successful management of NMSC must take primary, secondary and tertiary prevention strategies into consideration. In response to an improved understanding of the pathophysiology of NMSC and associated risk factors, multiple systemic and topical immunomodulatory drugs have been developed and integrated into clinical practice. Many of these drugs are efficacious in the prevention and treatment of precursor lesions (actinic keratoses; AKs), low-risk NMSC, and advanced disease. The identification of patients at high risk for the development of NMSC is critical in reducing disease morbidity. Understanding the various treatment options available and their comparative effectiveness is paramount for developing a personalized treatment regimen for such patients. This review article provides an updated overview of the various topical and systemic immunomodulatory drugs available for the prevention and treatment of NMSC, and the published data supporting their use in clinical practice.

Anti-cancer and immunomodulatory evaluation of new nicotinamide derivatives as potential VEGFR-2 inhibitors and apoptosis inducers: in vitro and in silico studies

New nicotinamide derivatives 6, 7, 10, and 11 were designed and synthesised based on the essential features of the VEGFR-2 inhibitors. Compound 10 revealed the highest anti-proliferative activities with IC₅₀ values of 15.4 and 9.8 µM against HCT-116 and HepG2, respectively compared to sorafenib (IC₅₀ = 9.30 and 7.40 µM). Compound 7 owned promising cytotoxic activities with IC₅₀ values of 15.7 and 15.5 µM against the same cell lines, respectively. Subsequently, the VEGFR-2 inhibitory activities were assessed for the titled compounds to exhibit VEGFR-2 inhibition with sub-micromolar IC₅₀ values. Moreover, compound 7 induced the cell cycle cessation at the cycle at %G2-M and G0-G1phases, and induced apoptosis in the HCT-116. Compounds 7 and 10 reduced the levels of TNF-α by 81.6 and 84.5% as well as IL-6 by 88.4 and 60.9%, respectively, compared to dexamethasone (82.4 and 93.1%). In silico docking, molecular dynamics simulations, ADMET, and toxicity studies were carried out.

Neuroprotective Effects of Nicotinamide against MPTP-Induced Parkinson's Disease in Mice: Impact on Oxidative Stress, Neuroinflammation, Nrf2/HO-1 and TLR4 Signaling Pathways

Nicotinamide (NAM) is the amide form of niacin and an important precursor of nicotinamide adenine dinucleotide (NAD), which is needed for energy metabolism and cellular functions. Additionally, it has shown neuroprotective properties in several neurodegenerative diseases. Herein, we sought to investigate the potential protective mechanisms of NAM in an intraperitoneal (i.p) 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced Parkinson's disease (PD) mouse model (wild-type mice (C57BL/6N), eight weeks old, average body weight 25-30 g). The study had four groups (n = 10 per group): control, MPTP (30 mg/kg i.p. for 5 days), MPTP treated with NAM (500 mg/kg, i.p for 10 days) and control treated with NAM. Our study showed that MPTP increased the expression of α-synuclein 2.5-fold, decreased tyrosine hydroxylase (TH) 0.5-fold and dopamine transporters (DAT) levels up to 0.5-fold in the striatum and substantia nigra pars compacta (SNpc), and impaired motor function. However, NAM treatment significantly reversed these PD-like pathologies. Furthermore, NAM treatment reduced oxidative stress by increasing the expression of nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) between 0.5- and 1.0-fold. Lastly, NAM treatment regulated neuroinflammation by reducing Toll-like receptor 4 (TLR-4), phosphorylated nuclear factor-κB, tumor (p-NFκB), and cyclooxygenase-2 (COX-2) levels by 0.5- to 2-fold in the PD mouse brain. Overall, these findings suggest that NAM exhibits neuroprotective properties and may be an effective therapeutic agent for PD.

Endogenous metabolism in endothelial and immune cells generates most of the tissue vitamin B3 (nicotinamide)

In mammals, nicotinamide (NAM) is the primary NAD precursor available in circulation, a signaling molecule, and a precursor for methyl-nicotinamide (M-NAM) synthesis. However, our knowledge about how the body regulates tissue NAM levels is still limited. Here we demonstrate that dietary vitamin B₃ partially regulates plasma NAM and NAM-derived metabolites, but not their tissue levels. We found that NAD de novo synthesis from tryptophan contributes to plasma and tissue NAM, likely by providing substrates for NAD-degrading enzymes. We also demonstrate that tissue NAM is mainly generated by endogenous metabolism and that the NADase CD38 is the main enzyme that produces tissue NAM. Tissue-specific CD38-floxed mice revealed that CD38 activity on endothelial and immune cells is the major contributor to tissue steady-state levels of NAM in tissues like spleen and heart. Our findings uncover the presence of different pools of NAM in the body and a central role for CD38 in regulating tissue NAM levels.

Gut-brain communication in COVID-19: molecular mechanisms, mediators, biomarkers, and therapeutics

INTRODUCTION

Infection with COVID-19 results in acute respiratory symptoms followed by long COVID multi-organ effects presenting with neurological, cardiovascular, musculoskeletal, and gastrointestinal (GI) manifestations. Temporal relationship between gastrointestinal and neurological symptoms is unclear but warranted for exploring better clinical care for COVID-19 patients.

AREAS COVERED

We critically reviewed the temporal relationship between gut-brain axis after SARS-CoV-2 infection and the molecular mechanisms involved in neuroinvasion following GI infection. Mediators are identified that could serve as biomarkers and therapeutic targets in SARS-CoV-2. We discussed the potential therapeutic approaches to mitigate the effects of GI infection with SARS-CoV-2.

EXPERT OPINION

Altered gut microbiota cause increased expression of various mediators, including zonulin causing disruption of tight junction. This stimulates enteric nervous system and signals to CNS precipitating neurological sequalae. Published reports suggest potential role of cytokines, immune cells, B(0)AT1 (SLC6A19), ACE2, TMRSS2, TMPRSS4, IFN-γ, IL-17A, zonulin, and altered gut microbiome in gut-brain axis and associated neurological sequalae. Targeting these mediators and gut microbiome to improve immunity will be of therapeutic significance. In-depth research and well-designed large-scale population-based clinical trials with multidisciplinary and collaborative approaches are warranted. Investigating the temporal relationship between organs involved in long-term sequalae is critical due to evolving variants of SARS-CoV-2.

Deletion C-terminal thioesterase abolishes melanin biosynthesis, affects metabolism and reduces the pathogenesis of Fonsecaea monophora

Dematiaceous Fonsecaea monophora is one of the major pathogens of chromoblastomycosis. It has been well established that melanization is catalyzed by the type I polyketide synthase (PKS) in F. monophora. Multidomain protein Type I PKS is encoded by six genes, in which the last enzyme thioesterase (TE) catalyzes the cyclization and releases polyketide. Two PKS genes AYO21_03016 (pks1) and AYO21_10638 have been found in F. monophora and both PKS loci have the same gene arrangement but the TE domain in AYO21_10638 is truncated at 3’- end. TE may be the key enzyme to maintain the function of pks1. To test this hypothesis, we constructed a 3’-end 500 bp deletion mutant of AYO21_03016 (Δpks1-TE-C500) and its complemented strain. We profiled metabolome of this mutant and analyzed the consequences of impaired metabolism in this mutant by fungal growth in vitro and by pathogenesis in vivo. Compared with wild-type strain, we found that the mutant repressed pks1 expression and other 5 genes expression levels were reduced by more than 50%, perhaps leading to a corresponding melanin loss. The mutant also reduced sporulation and delayed germination, became vulnerable to various environmental stresses and was less resistance to macrophage or neutrophil killings in vitro, and less virulence in mice footpad model. Metabolomic analysis indicated that many metabolites were remarkably affected in Δpks1-TE-C500, in particular, an increased nicotinamide and antioxidant glutathione. In conclusion, we confirmed the crucial role of C-terminal TE in maintaining fully function of pks1 in F. monophora. Deletion of TE negatively impacts on the synthesis of melanin and metabolites that eventually affect growth and virulence of F. monophora. Any potential inhibitor of TE then could be a novel antifungal target for drug development.

F. monophora is a fungal pathogen that causes chromoblastomycosis. Melanin of F. monophora was synthesized through PKS in which TE is the last enzyme to catalyze the cyclization and release polyketide. Few studies have investigated the effect of TE on the metabolism and pathogenesis of F. monophora. In this study, TE deletion leads to albino phenotype, decreases the expression of other domains of the pks1, and reduces biosynthesis of metabolites. The Δpks1-TE-C500 strain exhibits a changed morphogenesis and becomes less resistant to various environmental stresses. In vitro study, the Δpks1-TE-C500 strain is avirulent and less resistant to macrophages and neutrophils. In conclusion, we demonstrate that the 500 bp C-terminal of TE is essential for the function of pks1, perhaps through its effects on melanin and metabolites to regulate the growth and virulence of F. monophora. Data from this study could inspire an exploration in development of clinical therapy for CBM.

Significantly Altered Serum Levels of NAD, AGE, RAGE, CRP, and Elastin as Potential Biomarkers of Psoriasis and Aging—A Case-Control Study

Background: This study aims to investigate potential markers of psoriasis and aging, and to elucidate possible connections between these two processes. Methods: The serum samples of 60 psoriatic patients and 100 controls were analysed, and the levels of four selected parameters (AGEs, RAGE, NAD, and elastin) were determined using commercial ELISA kits. Serum C-reactive protein was assayed using an immune-nephelometry method. Findings: Among the patients, the levels of CRP, AGEs, and RAGE were all increased, while the levels of NAD were reduced when compared to the control group. A negative correlation between the levels of AGEs and NAD was found. A negative correlation between age and the NAD levels among the control group was observed, however among the patients the relationship was diminished. While there was no difference in the levels of native elastin between the patients and the controls, a positive correlation between the levels of native elastin and age and a negative correlation between the levels of native elastin and the severity of psoriasis were found. Conclusions: The results of our study support the notion of psoriasis and possibly other immune-mediated diseases accelerating the aging process through sustained systemic damage. The serum levels of CRP, NAD, AGEs, and RAGE appear to be promising potential biomarkers of psoriasis. The decrease in the serum levels of NAD is associated with (pro)inflammatory states. Our analysis indicates that the levels of native elastin might strongly reflect both the severity of psoriasis and the aging process.

Anti-inflammatory effects of B vitamins protect against tau hyperphosphorylation and cognitive impairment induced by 1,2 diacetyl benzene: An in vitro and in silico study

1,2 diacetyl benzene (DAB) penetrates the blood-brain barrier, causing neuroinflammation, tau hyperphosphorylation, and cognitive impairment. Converging evidence supports the anti-inflammatory effects of B vitamins on cognitive impairment, but the effects of B vitamins on cognitive impairment induced by DAB remain unclear. Here, we investigated the anti-inflammatory properties of B vitamins in DAB-stimulated human neuroblastoma SH-SY5Y cells. In this in-silico analysis, we investigated the genes, transcription factors, miRNAs, and sponges linked with DAB, B vitamins and the pathogenesis of cognitive impairment. We found vitamins B1, B2, and B3 had anti-inflammatory properties in DAB-stimulated SH-SY5Y cells, possibly via inhibiting NF-κB activation. Furthermore, vitamins B1, B2, and B3 inhibited GSK-3β, β-amyloid, and tau hyperphosphorylation in SH-SY5Y cells. These vitamins can also modulate genes induced by DAB (IL1B, IL6, IL10, iNOS, COX2, NFκB, GSK3B, TNF, and APP) in SH-SY5Y cells. In silico analyses, inflammatory response related pathways, "Alzheimer's disease", "pathways of neurodegeneration-multiple disease", and "prolactin signaling pathway", were highlighted. Additionally, we explored a network-based approach to identify key genes, transcription factors, miRNAs, and pathways in cognitive impairment. The transcription factors NFKB2 and BATF3 were shown to be the most important in regulating genes. We also found eight significant miRNAs related to cognitive impairment, and these miRNAs were also validated by qPCR. Finally, we developed and tested in silico miRNA sponge sequences for these miRNAs.

A dermocosmetic formulation containing Vichy volcanic mineralizing water, Vitreoscilla filiformis extract, niacinamide, hyaluronic acid, and vitamin E regenerates and repairs acutely stressed skin

The exposome has an impact on skin from life-long exposure. Acute short-term exposure to exposome stressors can also alter skin functions such as skin physical barrier and immune defenses, leading to skin dryness, sensitivity, flares of inflammatory skin conditions, or viral reactivations. Probiotics are defined as live microorganisms, which, when administered in adequate amounts, confer a health benefit on the host. An extract produced by lysing Vitreoscilla filiformis (VfeV) cultured in Vichy volcanic mineralizing water (VVMW) has properties of probiotic fractions. In this review, we present in vivo and ex vivo studies with a dermocosmetic formulation containing 80% VVMW, 5% VfeV, 4% niacinamide (vitamin B3), 0.4% hyaluronic acid, and 0.2% vitamin E (M89PF) to evaluate the clinical efficacy in preventing and repairing stressed skin. Skin barrier benefits of M89PF were shown in studies after the skin was exposed to sudden thermal changes, after skin irritation by tape stripping, and in sleep-deprived women. M89PF significantly accelerated skin renewal compared to untreated skin. Skin antioxidant defense activity of M89PF was shown after exposure to stress from UVA plus cigarette smoke aggression. Skin microbiome recovery after acute stress from a harsh cleanser was significantly better in M89PF-treated skin compared to bare skin. Clinical benefits of M89PF on correcting clinical signs of stressed skin were shown in both Caucasian and Asian women exposed to a stressful lifestyle and various external (pollution, tobacco smoking, solar radiation) and internal (poor sleep, stressful work, unbalanced diet, and alcohol consumption) exposome factors. M89PF also showed depigmenting properties on dark spots in Asian women. Further clinical studies are now warranted to evaluate the efficacy of M89PF as adjuvant care to prevent and repair skin barrier disruption and reinforce skin defenses in skin exposed to acute stresses.

The impact of external factors on psoriasis

Psoriasis is one of the most common chronic inflammatory skin diseases, constituting a significant health and socioeconomic problem. Despite numerous therapeutic options, the results of treatment very often remain insufficient. It is extremely important to remember that many external factors impact the effectiveness of therapy. This article discusses the importance of emollients in therapy and the influence of infectious agents and injuries on the course of psoriasis. Understanding the above-mentioned factors in the treatment of psoriasis is critical to achieve satisfactory therapeutic effects.

In vitro biological activity of copper(II) complexes with NSAIDs and nicotinamide: Characterization, DNA- and BSA-interaction study and anticancer activity

Through the reaction of copper(II) acetate with nicotinamide (pyridine-3-carboxylic acid amide, niacinamide) and some derivatives of N-phenylanthranilic acid (fenamates), seven new mixed-ligand copper(II) compounds were isolated: [Cu(tolf-O)(tolf-O,O')nia-N)₂(EtOH)] (1), [Cu(tolf-O)(tolf-O,O')(nia-N)₂(MeOH)] (2), [Cu(meclf-O)(meclf-O,O')(nia-N)₂(EtOH)] (3), [Cu(meclf-O)(meclf-O,O')(nia-N)₂(MeOH)] (4), [Cu(meclf-O)(meclf-O,O')(nia-N)₂(ACN)] (5), [Cu(mef-O)(mef-O,O')(nia-N)₂(EtOH)] (6) and [Cu(mef-O)(mef-O,O')(nia-N)₂(ACN)] (7) containing a molecule of relevant solvent as ligand in their primary crystal structure (tolf = tolfenamate, meclf = meclofenamate, mef = mefenamate, nia = nicotinamide, EtOH = ethanol, MeOH = methanol, ACN = acetonitrile). The structures of the complexes were determined by single-crystal X-ray analysis. The intermolecular interactions were studied by Hirshfeld surface analysis. The complexes were characterized by IR, UV-vis and EPR spectroscopy and their redox properties were determined by cyclic voltammetry. The interaction of the complexes with bovine serum albumin was studied by fluorescence emission spectroscopy and the albumin-binding constants of the compounds were calculated. The interaction of the complexes with calf-thymus DNA was monitored by diverse techniques (UV-vis spectroscopy, cyclic voltammetry, viscosity measurements) suggesting intercalation as the most possible mode of binding. DNA-competitive studies of the complexes with ethidium bromide were monitored by fluorescence emission spectroscopy. The cytotoxic effects of copper(II) complexes on lung carcinoma cells and healthy cells were determined by the MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] colorimetric technique.

Therapeutic Potential of Emerging NAD+-Increasing Strategies for Cardiovascular Diseases

Cardiovascular diseases are the leading cause of death worldwide. Aging and/or metabolic stress directly impact the cardiovascular system. Over the last few years, the contributions of altered nicotinamide adenine dinucleotide (NAD+) metabolism to aging and other pathological conditions closely related to cardiovascular diseases have been intensively investigated. NAD+ bioavailability decreases with age and cardiometabolic conditions in several mammalian tissues. Compelling data suggest that declining tissue NAD+ is commonly related to mitochondrial dysfunction and might be considered as a therapeutic target. Thus, NAD+ replenishment by either genetic or natural dietary NAD+-increasing strategies has been recently demonstrated to be effective for improving the pathophysiology of cardiac and vascular health in different experimental models, as well as human health, to a lesser extent. Here, we review and discuss recent experimental evidence illustrating that increasing NAD+ bioavailability, particularly by the use of natural NAD+ precursors, may offer hope for new therapeutic strategies to prevent and treat cardiovascular diseases.

Nicotinamide promotes cardiomyocyte derivation and survival through kinase inhibition in human pluripotent stem cells

Nicotinamide, the amide form of Vitamin B3, is a common nutrient supplement that plays important role in human fetal development. Nicotinamide has been widely used in clinical treatments, including the treatment of diseases during pregnancy. However, its impacts during embryogenesis have not been fully understood. In this study, we show that nicotinamide plays multiplex roles in mesoderm differentiation of human embryonic stem cells (hESCs). Nicotinamide promotes cardiomyocyte fate from mesoderm progenitor cells, and suppresses the emergence of other cell types. Independent of its functions in PARP and Sirtuin pathways, nicotinamide modulates differentiation through kinase inhibition. A KINOMEscan assay identifies 14 novel nicotinamide targets among 468 kinase candidates. We demonstrate that nicotinamide promotes cardiomyocyte differentiation through p38 MAP kinase inhibition. Furthermore, we show that nicotinamide enhances cardiomyocyte survival as a Rho-associated protein kinase (ROCK) inhibitor. This study reveals nicotinamide as a pleiotropic molecule that promotes the derivation and survival of cardiomyocytes, and it could become a useful tool for cardiomyocyte production for regenerative medicine. It also provides a theoretical foundation for physicians when nicotinamide is considered for treatments for pregnant women.

Sensitive skin: Active ingredients on the spotlight

OBJECTIVE

Sensitive skin is characterized by self-reported sensory perceptions in response to stimuli that should not provoke unpleasant sensations. Cosmetic products for sensitive skin are designed to minimize these symptoms. This study aimed to unveil the most used active ingredients for sensitive skin in facial care products from the pharmacy and parapharmacy channel.

METHODS

A pool of products from the pharmacy and parapharmacy channel whose label included the expressions 'sensitive skin', 'reactive skin' or 'intolerant skin' were analysed. The active ingredients were identified from product compositions and ranked in descending order of occurrence. The scientific evidence regarding the mechanism of action and efficacy of each ingredient was also compiled.

RESULTS

Eighty-eight products from 19 multinational brands were included. Niacinamide leads the top, followed by Avena sativa, allantoin, glycyrrhetinic acid and derivatives and Laminaria ochroleuca. Ingredients that can reduce skin inflammation and act on the skin barrier were used in more than half of the products analysed. The clinical studies regarding the active ingredients used in these products remain sparse and lack methodological quality. Among the top ingredients, niacinamide, panthenol and acetyl dipeptide-1 cetyl ester were the only ones studied on volunteers having sensitive skin, while acetyl dipeptide-1 cetyl ester and palmitoyl tripeptide-8 were designed to act on the molecular targets involved in this condition.

CONCLUSION

This study reveals the most used active ingredients in cosmetic products for sensitive skin, as well as the scientific evidence supporting their efficacy and the mechanisms of action. This insight is meaningful for dermatologists and other health professionals to provide customized advice based on the symptomatology of individuals with sensitive skin, and for the formulation of cosmetic products and design of new active ingredients.

The Use of Induced Pluripotent Stem Cells to Study the Effects of Adenosine Deaminase Deficiency on Human Neutrophil Development

Inherited defects that abrogate the function of the adenosine deaminase (ADA) enzyme and consequently lead to the accumulation of toxic purine metabolites cause profound lymphopenia and severe combined immune deficiency. Additionally, neutropenia and impaired neutrophil function have been reported among ADA-deficient patients. However, due to the rarity of the disorder, the neutrophil developmental abnormalities and the mechanisms contributing to them have not been characterized. Induced pluripotent stem cells (iPSC) generated from two unrelated ADA-deficient patients and from healthy controls were differentiated through embryoid bodies into neutrophils. ADA deficiency led to a significant reduction in the number of all early multipotent hematopoietic progenitors. At later stages of differentiation, ADA deficiency impeded the formation of granulocyte colonies in methylcellulose cultures, leading to a significant decrease in the number of neutrophils generated from ADA-deficient iPSCs. The viability and apoptosis of ADA-deficient neutrophils isolated from methylcellulose cultures were unaffected, suggesting that the abnormal purine homeostasis in this condition interferes with differentiation or proliferation. Additionally, there was a significant increase in the percentage of hyperlobular ADA-deficient neutrophils, and these neutrophils demonstrated significantly reduced ability to phagocytize fluorescent microspheres. Supplementing iPSCs and methylcellulose cultures with exogenous ADA, which can correct adenosine metabolism, reversed all abnormalities, cementing the critical role of ADA in neutrophil development. Moreover, chemical inhibition of the ribonucleotide reductase (RNR) enzyme, using hydroxyurea or a combination of nicotinamide and trichostatin A in iPSCs from healthy controls, led to abnormal neutrophil differentiation similar to that observed in ADA deficiency, implicating RNR inhibition as a potential mechanism for the neutrophil abnormalities. In conclusion, the findings presented here demonstrate the important role of ADA in the development and function of neutrophils while clarifying the mechanisms responsible for the neutrophil abnormalities in ADA-deficient patients.

Natural Bioactive Compounds Targeting Epigenetic Pathways in Cancer: A Review on Alkaloids, Terpenoids, Quinones, and Isothiocyanates

Cancer is one of the most complex and systemic diseases affecting the health of mankind, causing major deaths with a significant increase. This pathology is caused by several risk factors, of which genetic disturbances constitute the major elements, which not only initiate tumor transformation but also epigenetic disturbances which are linked to it and which can induce transcriptional instability. Indeed, the involvement of epigenetic disturbances in cancer has been the subject of correlations today, in addition to the use of drugs that operate specifically on different epigenetic pathways. Natural molecules, especially those isolated from medicinal plants, have shown anticancer effects linked to mechanisms of action. The objective of this review is to explore the anticancer effects of alkaloids, terpenoids, quinones, and isothiocyanates.

An unusual nicotinamide derivative, 4-pyridone-3-carboxamide ribonucleoside (4PYR), is a novel endothelial toxin and oncometabolite

Our recent studies identified a novel pathway of nicotinamide metabolism that involves 4-pyridone-3-carboxamide-1-β-D-ribonucleoside (4PYR) and demonstrated its endothelial cytotoxic effect. This study tested the effects of 4PYR and its metabolites in experimental models of breast cancer. Mice were divided into groups: 4T1 (injected with mammary 4T1 cancer cells), 4T1 + 4PYR (4PYR-treated 4T1 mice), and control, maintained for 2 or 21 days. Lung metastasis and endothelial function were analyzed together with blood nucleotides (including 4PYR), plasma amino acids, nicotinamide metabolites, and vascular ectoenzymes of nucleotide catabolism. 4PYR metabolism was also evaluated in cultured 4T1, MDA-MB-231, MCF-7, and T47D cells. An increase in blood 4PYR in 4T1 mice was observed at 2 days. 4PYR and its metabolites were noticed after 21 days in 4T1 only. Higher blood 4PYR was linked with more lung metastases in 4T1 + 4PYR vs. 4T1. Decreased L-arginine, higher asymmetric dimethyl-L-arginine, and higher vascular ecto-adenosine deaminase were observed in 4T1 + 4PYR vs. 4T1 and control. Vascular relaxation caused by flow-dependent endothelial activation in 4PYR-treated mice was significantly lower than in control. The permeability of 4PYR-treated endothelial cells was increased. Decreased nicotinamide but enhanced nicotinamide metabolites were noticed in 4T1 vs. control. Reduced N-methylnicotinamide and a further increase in Met2PY were observed in 4T1 + 4PYR vs. 4T1 and control. In cultured breast cancer cells, estrogen and progesterone receptor antagonists inhibited the production of 4PYR metabolites. 4PYR formation is accelerated in cancer and induces metabolic disturbances that may affect cancer progression and, especially, metastasis, probably through impaired endothelial homeostasis. 4PYR may be considered a new oncometabolite.

Levels of a metabolite of nicotinamide, a form of vitamin B₃, found in the blood and urine of cancer patients may provide a useful biomarker indicating the likelihood of metastasis. Disruption to the lining of blood vessels (endothelium) enables cancer cells to infiltrate the bloodstream and migrate to other organs. Research suggests that increased levels of 4PYR, a derivative of nicotinamide metabolism, may induce metabolic disturbances that favor cancer progression. Ewa Slominska and co-workers at the Medical University of Gdansk, Poland, examined 4PYR in mouse models injected with breast cancer cells and found increased levels in the blood only two days after injection. Mice with the highest 4PYR levels had enhanced lung metastases after three weeks. The team believes 4PYR activity may increase the permeability of the endothelium, but further investigation is needed.

Nicotinamide promotes pancreatic differentiation through the dual inhibition of CK1 and ROCK kinases in human embryonic stem cells

Background

Vitamin B3 (nicotinamide) plays important roles in metabolism as well as in SIRT and PARP pathways. It is also recently reported as a novel kinase inhibitor with multiple targets. Nicotinamide promotes pancreatic cell differentiation from human embryonic stem cells (hESCs). However, its molecular mechanism is still unclear. In order to understand the molecular mechanism involved in pancreatic cell fate determination, we analyzed the downstream pathways of nicotinamide in the derivation of NKX6.1⁺ pancreatic progenitors from hESCs.

Methods

We applied downstream modulators of nicotinamide during the induction from posterior foregut to pancreatic progenitors, including niacin, PARP inhibitor, SIRT inhibitor, CK1 inhibitor and ROCK inhibitor. The impact of those treatments was evaluated by quantitative real-time PCR, flow cytometry and immunostaining of pancreatic markers. Furthermore, CK1 isoforms were knocked down to validate CK1 function in the induction of pancreatic progenitors. Finally, RNA-seq was used to demonstrate pancreatic induction on the transcriptomic level.

Results

First, we demonstrated that nicotinamide promoted pancreatic progenitor differentiation in chemically defined conditions, but it did not act through either niacin-associated metabolism or the inhibition of PARP and SIRT pathways. In contrast, nicotinamide modulated differentiation through CK1 and ROCK inhibition. We demonstrated that CK1 inhibitors promoted the generation of PDX1/NKX6.1 double-positive pancreatic progenitor cells. shRNA knockdown revealed that the inhibition of CK1α and CK1ε promoted pancreatic progenitor differentiation. We then showed that nicotinamide also improved pancreatic progenitor differentiation through ROCK inhibition. Finally, RNA-seq data showed that CK1 and ROCK inhibition led to pancreatic gene expression, similar to nicotinamide treatment.

Conclusions

In this report, we revealed that nicotinamide promotes generation of pancreatic progenitors from hESCs through CK1 and ROCK inhibition. Furthermore, we discovered the novel role of CK1 in pancreatic cell fate determination.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-021-02426-2.

Co-delivery of methotrexate and nicotinamide by cerosomes for topical psoriasis treatment with enhanced efficacy

Psoriasis is an immune-mediated skin disorder that affects populations worldwide. Methotrexate (MTX) is a cytotoxic drug with powerful anti-proliferative and anti-inflammatory effects that has gained prominence in treating inflammatory diseases including psoriasis. However, low solubility and side effects through oral administration hinder its systemic application. In this study, we developed a novel niosomes based on ceramide (cerosomes) to co-deliver MTX and nicotinamide (NIC), i.e., MTX/NIC cerosomes, for topically treating psoriasis with the aim to enhancing the efficacy and reducing the toxicity. NIC significantly solublized MTX by forming hydrogen bonds with MTX. In vitro and in vivo permeation studies showed that the cerosomes significantly promoted drug permeation through and retention in the skin, and the enhancing mechanism was clarified by Fourier transform infraredand Raman spectroscopy. MTX/NIC cerosomes exhibited strong anti-proliferation effect on lipopolysaccharide- irritated HaCaT cells by arresting the cell cycle at S phase and inducing apoptosis. Importantly, compared to MTX oral administration, topical application of MTX/NIC cerosomes on imiquimod (IMQ)-induced psoriatic mouse model exhibited a superior performance in ameliorating skin lesions, reducing spleen index and epidermal thickness, and downregulating the mRNA expression levels of proinflammatory cytokines including TNFα, IL-23, IL-17A, IL-6, IL-1β, and IL-22. Taken together, MTX/NIC cerosomes is a promising approach for psoriasis topical treatment.

Clinical Comparison of Topical 2.5% Benzoyl Peroxide plus 5% Niacinamide to 2.5% Benzoyl Peroxide Alone in the Treatment of Mild to Moderate Facial Acne Vulgaris

BACKGROUND

The combination of benzoyl peroxide and a new topical therapy, such as topical niacinamide, reduces facial sebum production and also has a skin-lightening effect. This combined treatment might lead to improved efficacy in the treatment of facial acne vulgaris while also promoting the resolution of postacne erythema and postinflammatory hyperpigmentation.

OBJECTIVE

The primary objective was to evaluate and compare the clinical efficacy of topical 2.5% benzoyl peroxide plus 5% niacinamide and 2.5% benzoyl peroxide with cream base for mild to moderate facial acne vulgaris. Secondary objectives were to evaluate and compare clinical efficacy regarding postinflammatory hyperpigmentation, postacne erythema, reduction of facial sebum production, and side effects. METHODS: Patients with mild to moderate facial acne vulgaris and aged 18 to 40 years were enrolled. Treatment was randomly assigned to the left or right side of the face for 12 weeks. Both inflammatory and noninflammatory acne lesions were counted by a physician, and the postinflammatory hyperpigmentation score and postacne erythema score were calculated using an Antera 3D^® camera (Miravex, Dublin, Ireland). Sebum casual level was measured using a Sebumeter^® (Courage+Khazaka Electronic, Köln, Germany) every two weeks. Physician improvement score, patient satisfaction index, and side effects were assessed by evaluation forms every two weeks.

RESULTS

At Week 12, the niacinamide group (5% niacinamide+2.5% benzoyl peroxide) showed significant reduction in both the acne lesion count and sebum casual levels from baseline (p=0.000 and p=0.001, respectively). The reduction in noninflammatory lesion count in the niacinamide group was better than that in the cream base group (2.5% benzoyl peroxide+cream base), with a statistically significant difference (p=0.004). However, the reduction in inflammatory lesions was not significantly different between the two groups. The sebum casual level in the niacinamide group was reduced faster than that in the cream base group. The postacne erythema score was reduced from baseline in both groups, with no statistically significant difference within or between the two groups. The postinflammatory hyperpigmentation score showed increases in both groups above the baseline, with a statistically significant difference in the cream base group (p=0.000) but no such difference in the niacinamide group (p=0.58). There was no statistically significant difference between the two groups. Furthermore, no statistically significant differences were found between the two groups at every follow-up visit in terms of physician improvement scale, patient satisfaction index, or side effects.

CONCLUSION

The combination of 2.5% benzoyl peroxide and 5% niacinamide is more effective than 2.5% benzoyl peroxide alone for mild to moderate facial acne vulgaris.

Comparative study on beneficial effects of vitamins B and D in attenuating doxorubicin induced cardiotoxicity in rats: Emphasis on calcium homeostasis

The use of doxorubicin (DOX) to treat various tumors is limited by its cardiotoxicity. This study aimed to investigate and compare the cardioprotective effects of nicotinamide (NAM) and alfacalcidol (1α(OH)D₃), against DOX-induced cardiotoxicity. Sprague Dawley male rats received DOX (5 mg/kg, i.p.) once/week for four consecutive weeks. Treated groups received either NAM (600 mg/kg, p.o.) for 28 consecutive days or 1α(OH)D₃ (0.5 ug/kg, i.p.) once/week for four consecutive weeks. DOX elicited marked cardiac tissue injury manifested by elevated serum cardiotoxicity indices, conduction and histopathological abnormalities. Both NAM and 1α(OH)D₃ successfully reversed all these changes. From the mechanistic point of view, DOX provoked intense cytosolic and mitochondrial calcium (Ca²⁺) overload hence switching on calpain1 (CPN1) and mitochondrial-mediated apoptotic cascades as confirmed by upregulating Bax and caspase-3 while downregulating Bcl-2 expression. DOX also disrupted cardiac bioenergetics as evidenced by adenosine triphosphate (ATP) depletion and a declined ATP/ADP ratio. Moreover, DOX upregulated the Ca²⁺ sensor; calmodulin kinase II gamma (CaMKII-δ) which further contributed to cardiac damage. Interestingly, co-treatment with either NAM or 1α(OH)D₃ reversed all DOX associated abnormalities by preserving Ca²⁺ homeostasis, replenishing ATP stores and obstructing apoptotic events. Additionally, DOX prompted nuclear factor kappa B (NF-κB) dependent inflammatory responses and subsequently upregulated interleukin-6 (IL-6) expression. Co-treatment with NAM or 1α(OH)D₃ effectively obstructed these inflammatory signals. Remarkably, NAM showed superior beneficial cardioprotective properties over 1α(OH)D₃. Both NAM and 1α(OH)D₃ efficiently attenuated DOX-cardiomyopathy mainly via preserving Ca²⁺ homeostasis and diminishing apoptotic and inflammatory pathways. NAM definitely exhibited effective cardioprotective capabilities over 1α(OH)D₃.

Nicotinamide Ameliorates Dextran Sulfate Sodium-Induced Chronic Colitis in Mice through Its Anti-Inflammatory Properties and Modulates the Gut Microbiota

Vitamin B (nicotinamide (NAM)), one of the most important nutritional components for humans, exerts anti-inflammatory activity. This study was aimed at investigating the effect of NAM on the gut microbiota and short-chain fatty acids (SCFAs) in mice with chronic colitis. Colitis was induced in C57BL/6 male mice by administration of 1.5% dextran sulfate sodium (DSS), and the mice were intraperitoneally injected with normal saline (NS) or NAM. NAM treatment ameliorated weight loss and changes in colon length, disease activity index (DAI) score, and histologic scores. Moreover, enzyme-linked immunosorbent assay (ELISA) analysis of LPL cells revealed that the level of interleukin- (IL-) 6, IL-12p70, IL-1β, tumor necrosis factor- (TNF-) α, interferon- (IFN-) γ, IL-21, and IL-17A was increased, while IL-10 was reduced, in the chronic colitis group compared to the control group, but the levels of all these factors were restored after NAM treatment. Then, 16S rRNA sequencing of the large intestinal content was performed, and analysis of alpha diversity and beta diversity showed that the richness of the gut microbiota was decreased in the DSS group compared to the control group and restored after NAM treatment. In addition, NAM modulated specific bacteria, including Odoribacter, Flexispira, and Bifidobacterium, in the NAM+chronic colitis group. Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt) analysis indicated that NAM treatment restored disruptions in the functions of the gut microbiota (replication and repair, cell motility) in mice with DSS-induced colitis. Furthermore, NAM also restored the reduction in valeric acid in mice with DSS-induced chronic colitis. Our results suggest that NAM treatment could alleviate DSS-induced chronic colitis in mice by inhibiting inflammation and regulating the composition and function of gut microbiota.

Intracellular Group A Streptococcus Induces Golgi Fragmentation To Impair Host Defenses through Streptolysin O and NAD-Glycohydrolase

Group A Streptococcus (GAS; Streptococcus pyogenes) is a major human pathogen that causes streptococcal pharyngitis, skin and soft tissue infections, and life-threatening conditions such as streptococcal toxic-shock syndrome. During infection, GAS not only invades diverse host cells but also injects effector proteins such as NAD-glycohydrolase (Nga) into the host cells through a streptolysin O (SLO)-dependent mechanism without invading the cells; Nga and SLO are two major virulence factors that are associated with increased bacterial virulence. Here, we have shown that the invading GAS induces fragmentation of the Golgi complex and inhibits anterograde transport in the infected host cells through the secreted toxins SLO and Nga. GAS infection-induced Golgi fragmentation required both bacterial invasion and SLO-mediated Nga translocation into the host cytosol. The cellular Golgi network is critical for the sorting of surface molecules and is thus essential for the integrity of the epithelial barrier and for the immune response of macrophages to pathogens. In epithelial cells, inhibition of anterograde trafficking by invading GAS and Nga resulted in the redistribution of E-cadherin to the cytosol and an increase in bacterial translocation across the epithelial barrier. Moreover, in macrophages, interleukin-8 secretion in response to GAS infection was found to be suppressed by intracellular GAS and Nga. Our findings reveal a previously undescribed bacterial invasion-dependent function of Nga as well as a previously unrecognized GAS-host interaction that is associated with GAS pathogenesis.IMPORTANCE Two prominent virulence factors of group A Streptococcus (GAS), streptolysin O (SLO) and NAD-glycohydrolase (Nga), are linked to enhanced pathogenicity of the prevalent GAS strains. Recent advances show that SLO and Nga are important for intracellular survival of GAS in epithelial cells and macrophages. Here, we found that invading GAS disrupts the Golgi complex in host cells through SLO and Nga. We show that GAS-induced Golgi fragmentation requires bacterial invasion into host cells, SLO pore formation activity, and Nga NADase activity. GAS-induced Golgi fragmentation results in the impairment of the epithelial barrier and chemokine secretion in macrophages. This immune inhibition property of SLO and Nga by intracellular GAS indicates that the invasion of GAS is associated with virulence exerted by SLO and Nga.

Serum Metabolomic Profiling of Patients with Non-Infectious Uveitis

The activities of various metabolic pathways can influence the pathogeneses of autoimmune diseases, and intrinsic metabolites can potentially be used to diagnose diseases. However, the metabolomic analysis of patients with uveitis has not yet been conducted. Here, we profiled the serum metabolomes of patients with three major forms of uveitis (Behҫet's disease (BD), sarcoidosis, and Vogt-Koyanagi-Harada disease (VKH)) to identify potential biomarkers. This study included 19 BD, 20 sarcoidosis, and 15 VKH patients alongside 16 healthy control subjects. The metabolite concentrations in their sera were quantified using liquid chromatography with time-of-flight mass spectrometry. The discriminative abilities of quantified metabolites were evaluated by four comparisons: control vs. three diseases, and each disease vs. the other two diseases (such as sarcoidosis vs. BD + VKH). Among 78 quantified metabolites, 24 kinds of metabolites showed significant differences in these comparisons. Four multiple logistic regression models were developed and validated. The area under the receiver operating characteristic (ROC) curve (AUC) in the model to discriminate disease groups from control was 0.72. The AUC of the other models to discriminate sarcoidosis, BD, and VKH from the other two diseases were 0.84, 0.83, and 0.73, respectively. This study provides potential diagnostic abilities of sarcoidosis, BD, and VKH using routinely available serum samples that can be collected with minimal invasiveness.

Cosmeceuticals: The Principles and Practice of Skin Rejuvenation by Nonprescription Topical Therapy

Background

Aesthetic practice relies on a harmonious relationship between medicine and commerce. Bridging the gap is a large number of skincare products that make therapeutic claims while avoiding the regulatory framework of pharmaceuticals. In this gray area, clinicians find themselves poorly disposed to counsel patients wisely as the industry is expanding faster than empirical evidence of efficacy and safety can be acquired. To serve our patients and engage with industry, we must understand the theoretical principles and evaluate the clinical evidence in practice.

Objectives

The purpose of this paper is to classify cosmeceuticals by method of action, explain how they work in principle with reference to skin aging, and evaluate the clinical evidence for them.

Methods

A literature and cosmetic clinic website search was conducted to establish a list of the most commonly advertised cosmeceuticals, and a peer-reviewed literature search was then conducted to establish the clinical evidence for them.

Results

A huge number of cosmeceuticals are marketed for skin rejuvenation but almost invariably they fall into 1 of 4 categories. These include the induction of tissue repair mechanisms, inflammatory modulation, scavenging of reactive oxygen species, or a combination of the 3. With the exception of retinol derivatives and hydroxy acids, the clinical evidence is limited, despite promising preclinical evidence for several cosmeceuticals.

Conclusions

Cosmeceuticals reside within a highly competitive ecosystem and are often brought to market based on preclinical, not clinical evidence. Success and failure will largely be governed by the establishment of clinical evidence in retrospect.

Nicotinamide Limits Replication of Mycobacterium tuberculosis and Bacille Calmette-Guérin Within Macrophages

Novel antimicrobials for treatment of Mycobacterium tuberculosis are needed. We hypothesized that nicotinamide (NAM) and nicotinic acid (NA) modulate macrophage function to restrict M. tuberculosis replication in addition to their direct antimicrobial properties. Both compounds had modest activity in 7H9 broth, but only NAM inhibited replication in macrophages. Surprisingly, in macrophages NAM and the related compound pyrazinamide restricted growth of bacille Calmette-Guérin but not wild-type Mycobacterium bovis, which both lack a functional nicotinamidase/pyrazinamidase (PncA) rendering each strain resistant to these drugs in broth culture. Interestingly, NAM was not active in macrophages infected with a virulent M. tuberculosis mutant encoding a deletion in pncA. We conclude that the differential activity of NAM and nicotinic acid on infected macrophages suggests host-specific NAM targets rather than PncA-dependent direct antimicrobial properties. These activities are sufficient to restrict attenuated BCG, but not virulent wild-type M. bovis or M. tuberculosis.

Nicotinamide Prevents Apolipoprotein B-Containing Lipoprotein Oxidation, Inflammation and Atherosclerosis in Apolipoprotein E-Deficient Mice

The potential of nicotinamide (NAM) to prevent atherosclerosis has not yet been examined. This study investigated the effect of NAM supplementation on the development of atherosclerosis in a mouse model of the disease. The development of aortic atherosclerosis was significantly reduced (NAM low dose: 45%; NAM high dose: 55%) in NAM-treated, apolipoprotein (Apo)E-deficient mice challenged with a Western diet for 4 weeks. NAM administration significantly increased (1.8-fold) the plasma concentration of proatherogenic ApoB-containing lipoproteins in NAM high-dose (HD)-treated mice compared with untreated mice. However, isolated ApoB-containing lipoproteins from NAM HD mice were less prone to oxidation than those of untreated mice. This result was consistent with the decreased (1.5-fold) concentration of oxidized low-density lipoproteins in this group. Immunohistochemical staining of aortas from NAM-treated mice showed significantly increased levels of IL-10 (NAM low-dose (LD): 1.3-fold; NAM HD: 1.2-fold), concomitant with a significant decrease in the relative expression of TNFα (NAM LD: −44%; NAM HD: −57%). An improved anti-inflammatory pattern was reproduced in macrophages cultured in the presence of NAM. Thus, dietary NAM supplementation in ApoE-deficient mice prevented the development of atherosclerosis and improved protection against ApoB-containing lipoprotein oxidation and aortic inflammation.

Immunotherapy of COVID-19 with poly (ADP-ribose) polymerase inhibitors: starting with nicotinamide

COVID-19 induces a proinflammatory environment that is stronger in patients requiring intensive care. The cytokine components of this environment may determine efficacy or otherwise of glucocorticoid therapy. The immunity modulators, the aryl hydrocarbon receptor (AhR) and the nuclear NAD+-consuming enzyme poly (ADP-ribose) polymerase 1 (PARP 1) may play a critical role in COVID-19 pathophysiology. The AhR is overexpressed in coronaviruses, including COVID-19 and, as it regulates PARP gene expression, the latter is likely to be activated in COVID-19. PARP 1 activation leads to cell death mainly by depletion of NAD+ and adenosine triphosphate (ATP), especially when availability of these energy mediators is compromised. PARP expression is enhanced in other lung conditions: the pneumovirus respiratory syncytial virus (RSV) and chronic obstructive pulmonary disease (COPD). I propose that PARP 1 activation is the terminal point in a sequence of events culminating in patient mortality and should be the focus of COVID-19 immunotherapy. Potent PARP 1 inhibitors are undergoing trials in cancer, but a readily available inhibitor, nicotinamide (NAM), which possesses a highly desirable biochemical and activity profile, merits exploration. It conserves NAD+ and prevents ATP depletion by PARP 1 and Sirtuin 1 (silent mating type information regulation 2 homologue 1) inhibition, enhances NAD+ synthesis, and hence that of NADP+ which is a stronger PARP inhibitor, reverses lung injury caused by ischaemia/reperfusion, inhibits proinflammatory cytokines and is effective against HIV infection. These properties qualify NAM for therapeutic use initially in conjunction with standard clinical care or combined with other agents, and subsequently as an adjunct to stronger PARP 1 inhibitors or other drugs.

Night Cream Containing Melatonin, Carnosine and Helichrysum italicum Extract Helps Reduce Skin Reactivity and Signs of Photodamage: Ex Vivo and Clinical Studies

Introduction

Extrinsic factors, such as solar radiation and urban pollution, cause damage that alters the structure, function and appearance of skin. The aim of this study was to determine the ability of a night cream containing melatonin, carnosine and Helichrysum italicum extract (referred to here as Night Cream) to reduce extrinsic skin damage, and to evaluate the efficacy of this Night Cream to reduce clinical signs of age and photodamage under normal conditions of use.

Methods

Recovery from extrinsic damage was assessed by exposing human skin explants to ultraviolet (UV) A, infrared light, blue light or pollution and then treating the stress-exposed explants with Night Cream. Markers of oxidative stress were examined by immunohistochemistry. Anti-aging and calming properties were determined in four single-center, open-label trials involving 117 individuals. Subjects applied Night Cream to their face once nightly for up to 12 weeks. Improvements in clinical signs of age and photodamage, and reduction of lactic acid-induced stinging were evaluated by investigator assessment and subject self-assessment.

Results

Night Cream significantly reduced oxidative stress in human skin ex vivo. Clinically, hydration (+ 64.4%; p < 0.05) and transepidermal water loss (TEWL) values (− 10.0%; p < 0.05) were improved within 1 h of use. Wrinkle counts were reduced by up to 18.9% (p < 0.05), and brown and UV spot numbers by 5.5% (p < 0.05) and 13.2% (p < 0.05), respectively. Lactic acid-induced stinging was significantly reduced within 7 days of use, with 86.7% of subjects reporting that their skin felt calmer.

Conclusion

These findings suggest that Night Cream reduces skin damage caused by environmental factors and that its nightly use can improve clinical signs of aging with additional skin calming benefits.

Protective effect of nicotinamide and L-arginine against monocrotaline-induced pulmonary hypertension in rats: gender dependence

Background

The purpose of this paper was to examine the effects of nicotinamide (ND) and l-arginine (l-ARG) on pulmonary vascular and heart changes induced by pulmonary hypertension in rats in a gender-dependent way.

Methods

Experiments were performed on male (M) and female (F) rats. PAH was induced via monocrotaline injection (sc, 60/kg B.W.) on day one of the 23-day observational period. After that, the animals were sacrificed, hearts removed and weighed and the papillary muscles isolated to measure force of contraction (F_c). Morphological changes of pulmonary vessels were also examined.

Results

Mixed diet supplementation with l-ARG + ND prevented highly significant right ventricle enlargement induced by PAH in both, male and female rats. Weight ratios between the right ventricle (RV) on one side and the left ventricle with septum on the other (LV + S) decreased from 0.46 ± 0.016 g to 0.29 ± 0.006 g in males and from 0.63 ± 0.03 g to 0.24 ± 0.008 g in females, n = 6, p < 0.001. Additionally, PAH increased basal contractility in female groups, and each of the diet allocations (l-ARG, ND, and mixed) were found to restore contractility to control values. All diet protocols in male and female restored decreased responsiveness of the myocardium to norepinephrine in hearts obtained from rats with PAH and prevented vascular changes observed in pulmonary hypertension (thickness of blood vessels and cell infiltration).

Conclusion

Our study suggests that l-arginine, nicotinamide or both play a positive role in right ventricle function or the process reducing pulmonary vascular remodeling especially in a gender-independent way.

The potential role of nicotinamide on Leishmania tropica: An assessment of inhibitory effect, cytokines gene expression and arginase profiling

Leishmaniasis represents a major health concern worldwide which has no effective treatment modality. Nicotinamide (NAm) has been used for a wide range of applications from anticancer to antimicrobial usage. This study aimed to assess the effect of NAm combination on Leishmania tropica Inhibition, as well as on cytokines gene expression and arginase (ARG) activity in L. tropica-infected macrophages in an in vitro model. The leishmanicidal effects of NAm and Glucantime (meglumine antimoniate, MA) alone and in combination (NAm/MA) were evaluated using a colorimetric assay and macrophage model. Additionally, immunomodulatory effects and enzymatic activity were assessed by analyzing Th1 and Th2 cytokines gene expression and ARG level, respectively, in infected macrophages treated with NAm and MA, alone and in combination. Findings indicated that the NAm/MA combination demonstrated greater inhibitory effects on L. tropica promastigotes and amastigotes compared with each drug individually. Docking results proved the affinity of NAm to IFN-γ, which can affirm the increased levels of IFN-γ, IL-12p40 and TNF-α as well as reductions in IL-10 secretion with a dose-response effect, especially in the combination group. The NAm/MA combination also showed a significant reduction in the level of ARG activity at all concentrations used compared to each drug individually. These findings indicate higher effectiveness of NAm plus MA in reducing parasite growth, promoting immune response and inhibiting ARG level. This combination should be considered as a potential therapeutic regimen for treatment of volunteer patients with anthroponotic cutaneous leishmaniasis (ACL) in future control programs.

Poly (ADP-Ribose) polymerase-1 (PARP-1) overactivity plays a pathogenic role in bile acids-induced nephrotoxicity in cholestatic rats

Cholestatic liver disease is a clinical complication with a wide range of etiologies. The liver is the primary organ influenced by cholestasis. Other organs, rather than the liver (e.g., kidneys), could also be affected by cholestatic liver disease. Cholestasis-induced renal injury is known as cholemic nephropathy (CN). Although the structural and functional alterations of the kidney in cholestasis have been well described, the cellular and molecular mechanisms of CN are not well understood. Some studies mentioned the role of oxidative stress and mitochondrial impairment in CN. Several cellular targets, including proteins, lipids, and DNA, could be affected by oxidative stress. Poly (ADP-Ribose) polymerase-1 (PARP-1) is an enzyme that its physiological activity plays a fundamental role in DNA repair. However, PARP-1 overexpression is associated with enhanced oxidative stress and cell death. The current study was designed to evaluate the role of PARP-1 activity in the pathogenesis of CN. Bile duct ligated (BDL) rats were treated with nicotinamide (NA) as a PARP-1 inhibitor. Kidney, urine, and plasma samples were collected at scheduled time intervals (3, 7, 14, and 28 days after BDL surgery). Serum and urine biomarkers of kidney injury, markers of oxidative stress and DNA damage, PARP-1 expression and activity in the kidney tissue, inflammatory response, renal fibrosis markers, and kidney histopathological alterations were assessed. Significant changes in the serum and urine biomarkers of kidney injury were evident in the BDL rats. Markers of oxidative stress were increased, and tissue ATP levels and antioxidant capacity were decreased in the kidney of cholestatic animals. A significant increase in PARP-1 expression and activity was evident in BDL rats (3, 7, 14, and 28 days after BDL). Moreover, inflammatory response (IL-1β and TNF-α expression; and myeloperoxidase activity), renal tissue histopathological alterations, and kidney fibrosis (α-SMA and TGF-β expression, as well as collagen deposition) were detected in cholestatic animals. It was found that the PARP-1 inhibitor, NA (50 and 100 mg/kg, i.p), significantly mitigated cholestasis-induced renal injury. The positive effects of NA were more significant at a lower dose and the early stage of CN. These data indicate a pathogenic role for PARP-1 overexpression in CN.