TNF-α: The shape of small molecules to come?

Impact of photobiomodulation therapy on pro-inflammation functionality of human peripheral blood mononuclear cells - a preliminary study

Research into the efficacy of photobiomodulation therapy (PBMT) in reducing inflammation has been ongoing for years, but standards for irradiation methodology still need to be developed. This study aimed to test whether PBMT stimulates in vitro human peripheral blood mononuclear cells (PBMCs) to synthesize pro-inflammatory cytokines, including chemokines. PBMCs were irradiated with laser radiation at two wavelengths simultaneously (λ = 808 nm in continuous emission and λ = 905 nm in pulsed emission). The laser radiation energy was dosed in one dose as a whole (5 J, 15 J, 20 J) or in a fractionated way (5 J + 15 J and 15 J + 5 J) with a frequency of 500, 1,500 and 2,000 Hz. The surface power densities were 177, 214 and 230 mW/cm2, respectively. A pro-inflammatory effect was observed at both the transcript and protein levels for IL-1β after PBMT at the energy doses 5 J and 20 J (ƒ=500 Hz) and only at the transcript level after application of PBMT at energy doses of 20 J (ƒ= 1,500; ƒ=2,000 Hz) and 5 + 15 J (ƒ=500 Hz). An increase in CCL2 and CCL3 mRNA expression was observed after PBMT at 5 + 15 J (ƒ=1,500 Hz) and 15 + 5 J (ƒ=2,000 Hz) and CCL3 concentration after application of an energy dose of 15 J (frequency of 500 Hz). Even though PBMT can induce mRNA synthesis and stimulate PBMCs to produce selected pro-inflammatory cytokines and chemokines, it is necessary to elucidate the impact of the simultaneous emission of two wavelengths on the inflammatory response mechanisms.

Forsythiaside A alleviates acute lung injury by inhibiting inflammation and epithelial barrier damages in lung and colon through PPAR-γ/RXR-α complex

INTRODUCTION

Acute lung injury (ALI) is a lung disease characterized by inflammation and still requires further drug development. Forsythiaside A as the active compound of Forsythiae Fructus has the therapeutic potential for ALI.

OBJECTIVE

To investigate the mechanism of forsythiaside A in treating ALI through PPAR-γ and its conjugate RXR-α based on gut-lung axis.

METHODS

This study constructed in vitro and in vivo injury models using LPS and TNF-α. Forsythiaside A was used for the drug treatment, and RXR-α inhibitor UVI3003 was used to interfere with PPAR-γ/RXR-α complexes in the cells. HE staining was used for histopathological examination. Serum endotoxin contents were determined using limulus lysate kit. IHC staining and Western blot were conducted to assess the protein expressions. ELISA was applied to examine the content of pro-inflammatory cytokines in the cell supernatants. The protein interactions were analyzed via CO-IP.

RESULTS

In vivo results showed that forsythiaside A regulated PPAR-γ/RXR-α and inhibited TLR4/MAPK/NF-κB and MLCK/MLC2 signal pathways, thus inhibiting inflammation and epithelial barrier damages of lung and colon in ALI mice induced by intratracheal LPS. PPAR-γ/RXR-α were promoted by forsythiaside A in lungs, whereas inhibited by forsythiaside A in colons. Additionally, in vitro results showed that forsythiaside A suppressed inflammation and epithelial barrier damages in macrophages and lung/colon epithelial cells, by manipulating PPAR-γ/RXR-α to suppress the LPS- and TNF-α-induced activation of TLR4/MAPK/NF-κB and NF-κB/MLCK/MLC2 signal pathways. Moreover, further mechanism study indicated that forsythiaside A showed a cell-specific regulatory effect on PPAR-γ/RXR-α complex. Specifically, the PPAR-γ/RXR-α protein interactions were promoted by forsythiaside A in LPS-induced macrophages RAW264.7 and TNF-α-induced lung epithelial cells A549, but inhibited by forsythiaside A in TNF-α-induced colon epithelial cells SW620.

CONCLUSION

In the treatment of ALI, Forsythiaside A inhibited inflammation and epithelial barrier damages of lung and colon through its regulation on PPAR-γ/RXR-α complex.

Photoaffinity labeling coupled with proteomics identify PDI-ADAM17 module is targeted by (-)-vinigrol to induce TNFR1 shedding and ameliorate rheumatoid arthritis in mice

Various biological agents have been developed to target tumor necrosis factor alpha (TNF-α) and its receptor TNFR1 for the rheumatoid arthritis (RA) treatment, whereas small molecules modulating such cytokine receptors are rarely reported in comparison to the biologicals. Here, by revealing the mechanism of action of vinigrol, a diterpenoid natural product, we show that inhibition of the protein disulfide isomerase (PDI, PDIA1) by small molecules activates A disintegrin and metalloprotease 17 (ADAM17) and then leads to the TNFR1 shedding on mouse and human cell membranes. This small-molecule-induced receptor shedding not only effectively blocks the inflammatory response caused by TNF-α in cells, but also reduces the arthritic score and joint damage in the collagen-induced arthritis mouse model. Our study indicates that targeting the PDI-ADAM17 signaling module to regulate the shedding of cytokine receptors by the chemical approach constitutes a promising strategy for alleviating RA.

Corydalis tomentella Franch. Exerts anti-inflammatory and analgesic effects by regulating the calcium signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Corydalis tomentella Franch. is a perennial cespitose plant commonly used to treat stomachaches as a folk medicine. The C. tomentella total alkaloids have good protective effects against acute liver injury and potential anti-hepatoma and anti-Alzheimer's disease activities.

AIM OF THE STUDY

To establish an effective purification process for total alkaloids from C. tomentella and investigate the mechanism of their anti-inflammatory effects.

MATERIALS AND METHODS

Corydalis tomentella were purified using macroporous resin. Then the crude and purified C. tomentella extracts (cCTE and pCTE) were qualitatively analyzed using UPLC-Triple-TOF-MS/MS. The cCTE and pCTE were used to investigate and compare their anti-inflammatory effects on lipopolysaccharide (LPS)-induced RAW264.7 cells. Doses at 100, 200 and 400 mg/kg/d of pCTE were used to study their anti-inflammatory and analgesic activities in mice with xylene-induced ear swelling and acetic acid-induced writhing tests. Content of nitric oxide (NO), interleukin-6 (IL-6), interleukin-1β (IL-1β), and tumor necrosis factor-α (TNF-α) were determined both in RAW264.7 cells and mice. Network pharmacology was used to predict the anti-inflammatory mechanism of C. tomentella, and the key enzymes were validated using qPCR and Western Blot analysis. Concentration of intracellular Ca2+ was detected using flow cytometric analysis.

RESULTS

The C. tomentella total alkaloid purity increased from 6.29% to 47.34% under optimal purification conditions. A total of 54 alkaloids were identified from CTE. Both cCTE and pCTE could suppress the LPS-induced production of NO, IL-6, IL-1β, and TNF-α in RAW264.7 cells. The pCTE exhibited a more potent anti-inflammatory effect; it also inhibited pain induced by xylene and acetic acid in mice. The calcium signaling pathway is associated with the anti-inflammatory and analgesic activities of C. tomentella. The mRNA expression of nitric oxide synthase (NOS) 2, NOS3 and calmodulin1 (CALM1) was regulated by C. tomentella through the reduction of inflammation-induced Ca2+ influx, and it also exhibited a more pronounced effect than the positive control (L-NG-nitro arginine methyl ester).

CONCLUSIONS

Purified C. tomentella extract shows anti-inflammatory effect both in vitro and in vivo. It exerts anti-inflammatory and analgesic effects through the calcium signaling pathway by down-regulating NOS2 and CALM1 expression and up-regulating NOS3 expression in LPS-induced RAW264.7 cells, and decreasing intracellular Ca2+ concentration.

New and Emerging Oral/Topical Small-Molecule Treatments for Psoriasis

The introduction of biologic therapies has led to dramatic improvements in the management of moderate-to-severe psoriasis. Even though the efficacy and safety of the newer biologic agents are difficult to match, oral administration is considered an important advantage by many patients. Current research is focused on the development of oral therapies with improved efficacy and safety compared with available alternatives, as exemplified by deucravacitinib, the first oral allosteric Tyk2 inhibitor approved for the treatment of moderate to severe psoriasis in adults. Recent advances in our knowledge of psoriasis pathogenesis have also led to the development of targeted topical molecules, mostly focused on intracellular signaling pathways such as AhR, PDE-4, and Jak-STAT. Tapinarof (an AhR modulator) and roflumilast (a PDE-4 inhibitor) have exhibited favorable efficacy and safety outcomes and have been approved by the FDA for the topical treatment of plaque psoriasis. This revision focuses on the most recent oral and topical therapies available for psoriasis, especially those that are currently under evaluation and development for the treatment of psoriasis.

Study on Cloning and Expression of TNF-α Variants in E. coli: Production, Purification, and Interaction with Anti-TNF-α Inhibitors

BACKGROUND

TNF-α is a proinflammatory cytokine and plays a role in cell proliferation, differentiation, survival, and death pathways. When administered at high doses, it may cause damage to the tumor vasculature, thereby increasing the permeability of the blood vessels. Therefore, monitoring the dose and the response of the TNF-α molecule is essential for patients' health.

OBJECTIVES

This study aimed to clone, express, and purify the active form of the TNF-α protein, which can interact with various anti-TNF-α inhibitors with high efficiency.

METHODS

Recombinant DNA technology was used to clone three different versions of codon-optimized human TNF-α sequences to E. coli. Colony PCR protocol was used for verification and produced proteins were analyzed through SDS-PAGE and western blot. Size exclusion chromatography was used to purify sTNF-α. ELISA techniques were used to analyze and compare binding efficiency of sTNF-α against three different standards.

RESULTS

Under native condition (25°C), interaction between sTNF-α and anti-TNF-α antibody was 3,970, compared to positive control. The interaction was 0,587, whereas it was 0,535 for TNF- α and anti-TNF-α antibodies under denaturing conditions (37°C). F7 of sTNF-α (920 μg/mL) had the same/higher binding efficiency to adalimumab, etanercept, and infliximab, compared to commercial TNF-α.

CONCLUSION

This study was the first to analyze binding efficiency of homemade sTNF-α protein against three major TNF-α inhibitors (adalimumab, etanercept, and infliximab) in a single study. The high binding efficiency of sTNF-α with adalimumab, etanercept, and infliximab, evidenced in this study supports the feasibility of its use in therapeutic applications, contributing to more sustainable, cost-effective, and independent healthcare system.

Evaluation of the anti-inflammatory effects of PI3Kδ/γ inhibitors for treating acute lung injury

Phosphatidylinositol 3-kinase delta (PI3Kδ) and gamma (PI3Kγ) are predominantly located in immune and hematopoietic cells. It is well-established that PI3Kδ/γ plays important roles in the immune system and participates in inflammation; hence, it could be a potential target for anti-inflammatory therapy. Currently, several PI3K inhibitors are used clinically to treat cancers with aberrant PI3K signaling; however, their role in treating acute respiratory inflammatory diseases has rarely been explored. Herein, we investigated the potential anti-inflammatory activities of several pharmacological PI3K inhibitors, including marketed drugs idelalisib (PI3Kδ), duvelisib (PI3Kδ/γ), and copanlisib (pan-PI3K with preferential α/δ) and the clinical drug eganelisib (PI3Kγ), for treating acute lung injury (ALI). In the lipopolysaccharide-induced RAW264.7 macrophage inflammatory model, the four inhibitors significantly suppressed proinflammatory cytokine expression by inhibiting the PI3K signaling pathway. Oral administration of PI3K inhibitors markedly improved lung injury in a murine model of ALI. PI3K pathway inhibition decreased inflammatory cell infiltration and totalprotein levels, as well as reduced the expression of associated lung inflammatory factors. Collectively, all four representative PI3K inhibitors exerted prominent anti-inflammatory properties, indicating that PI3K δ and/or γ inhibition could be ideal targets to treat respiratory inflammatory diseases by reducing the inflammatory response. The findings of the current study provide a new basis for utilizing PI3K inhibitors to treat acute respiratory inflammatory diseases.

Psoriasis: a focus on upcoming oral formulations

INTRODUCTION

Targeted therapies have greatly improved the quality of life of patients with psoriasis. Despite the extensive list of treatments available, multiple new drugs are being developed, especially oral therapies with potential advantages as regards comfort of administration. However, the efficacy and safety of these new oral therapies need to be improved to match those of novel biologics.

AREAS COVERED

We provide a narrative review of the oral therapies for psoriasis that are currently under development, from Jak inhibitors to oral IL-17 and IL-23 inhibitors, among others. A literature search was performed for articles published from 1 January 2020, to 6 June 2023.

EXPERT OPINION

The approval of deucravacitinib, the first Jak inhibitor for the treatment of moderate-to-severe plaque psoriasis, heralds a bright therapeutic future with multiple new oral formulations. A great number of oral treatments with singular mechanism of action, like A3AR agonists, HSP90 inhibitors, ROCK-2 inhibitors, oral TNF inhibitors, oral IL-23 inhibitors, oral IL-17 inhibitors, PD4 inhibitors (orismilast) and several Tyk2 inhibitors, are currently being evaluated in clinical trials and could be suitable for approval in the future. Growing variation in treatment modes of administration will allow dermatologists to better integrate patient preferences in the therapeutic decision process.

Characterisation of IL-23 receptor antagonists and disease relevant mutants using fluorescent probes

Association of single nucleotide polymorphisms in the IL-23 receptor with several auto-inflammatory diseases, led to the heterodimeric receptor and its cytokine-ligand IL-23, becoming important drug targets. Successful antibody-based therapies directed against the cytokine have been licenced and a class of small peptide antagonists of the receptor have entered clinical trials. These peptide antagonists may offer therapeutic advantages over existing anti-IL-23 therapies, but little is known about their molecular pharmacology. In this study, we use a fluorescent version of IL-23 to characterise antagonists of the full-length receptor expressed by living cells using a NanoBRET competition assay. We then develop a cyclic peptide fluorescent probe, specific to the IL23p19:IL23R interface and use this molecule to characterise further receptor antagonists. Finally, we use the assays to study the immunocompromising C115Y IL23R mutation, demonstrating that the mechanism of action is a disruption of the binding epitope for IL23p19.

Apigenin suppresses mycoplasma-induced alveolar macrophages necroptosis via enhancing the methylation of TNF-α promoter by PPARγ-Uhrf1 axis

BACKGROUND

Mycoplasma-associated pneumonia is characterized by severe lung inflammation and immunological dysfunction. However, current anti-mycoplasma agents used in clinical practice do not prevent dysfunction of alveolar macrophages caused by the high level of the cytokine tumor necrosis factor-α (TNF-α) after mycoplasma infection. Apigenin inhibits the production of TNF-α in variet inflammation associated disease.

PURPOSE

This study aimed to investigate apigenin's effect on mycoplasma-induced alveolar immune cell injury and the mechanism by which it inhibits TNF-α transcription.

METHODS

In this study, we performed a mouse model of Mycoplasma hyopneumoniae infection to evaluate the effect of apigenin on reducing mycoplasma-induced alveolar immune cell injury. Furthermore, we carried out transcriptome analysis, RNA interference assay, methylated DNA bisulfite sequencing assay, and chromatin immunoprecipitation assay to explore the mechanism of action for apigenin in reducing TNF-α.

RESULTS

We discovered that M. hyopneumoniae infection-induced necroptosis in alveolar macrophages MH-S cells and primary mouse alveolar macrophages, which was activated by TNF-α autocrine. Apigenin inhibited M. hyopneumoniae-induced elevation of TNF-α and necroptosis in alveolar macrophages. Apigenin inhibited TNF-a mRNA production via increasing ubiquitin-like with PHD and RING finger domains 1 (Uhrf1)-dependent DNA methylation of the TNF-a promotor. Finally, we demonstrated that apigenin regulated Uhrf1 transcription via peroxisome proliferator activated receptor gamma (PPARγ) activation, which acts as a transcription factor binding to the Uhrf1 promoter and protected infected mice's lungs, and promoted alveolar macrophage survival.

CONCLUTSION

This study identified a novel mechanism of action for apigenin in reducing alveolar macrophage necroptosis via the PPARγ/ Uhrf1/TNF-α pathway, which may have implications for the treatment of Mycoplasma pneumonia.

Native Top-Down Mass Spectrometry Reveals a Role for Interfacial Glycans on Therapeutic Cytokine and Hormone Assemblies

Oligomerization and glycosylation modulate therapeutic glycoprotein stability and efficacy. The interplay between these two critical attributes on therapeutic glycoproteins, is however often hard to define. Here, we present a native top-down mass spectrometry (MS) approach to assess the glycosylation status of therapeutic cytokine and hormone assemblies and relate interfacial glycan occupancy to complex stability. We found that interfacial O-glycan stabilizes tumor necrosis factor-α trimer. On the contrary, interferon-β1a dimerization is independent of glycosylation. Moreover, we discovered a unique distribution of N-glycans on the follicle-stimulating hormone α subunit. We found that the interfacial N-glycan, at Asn52 of the α subunit, interacts extensively with the β subunit to regulate the dimer assembly. Overall, we have exemplified a method to link glycosylation with assembly status, for cytokines and hormones, critical for informing optimal stability and bioavailability.

Native Top-Down Mass Spectrometry Reveals a Role for Interfacial Glycans on Therapeutic Cytokine and Hormone Assemblies

Oligomerization and glycosylation modulate therapeutic glycoprotein stability and efficacy. The interplay between these two critical attributes on therapeutic glycoproteins, is however often hard to define. Here, we present a native top-down mass spectrometry (MS) approach to assess the glycosylation status of therapeutic cytokine and hormone assemblies and relate interfacial glycan occupancy to complex stability. We found that interfacial O-glycan stabilizes tumor necrosis factor-α trimer. On the contrary, interferon-β1a dimerization is independent of glycosylation. Moreover, we discovered a unique distribution of N-glycans on the follicle-stimulating hormone α subunit. We found that the interfacial N-glycan, at Asn52 of the α subunit, interacts extensively with the β subunit to regulate the dimer assembly. Overall, we have exemplified a method to link glycosylation with assembly status, for cytokines and hormones, critical for informing optimal stability and bioavailability.

An orally available small molecule that targets soluble TNF to deliver anti-TNF biologic-like efficacy in rheumatoid arthritis

Tumor necrosis factor (TNF) is a pleiotropic cytokine belonging to a family of trimeric proteins with both proinflammatory and immunoregulatory functions. TNF is a key mediator in autoimmune diseases and during the last couple of decades several biologic drugs have delivered new therapeutic options for patients suffering from chronic autoimmune diseases such as rheumatoid arthritis and chronic inflammatory bowel disease. Attempts to design small molecule therapies directed to this cytokine have not led to approved products yet. Here we report the discovery and development of a potent small molecule inhibitor of TNF that was recently moved into phase 1 clinical trials. The molecule, SAR441566, stabilizes an asymmetrical form of the soluble TNF trimer, compromises downstream signaling and inhibits the functions of TNF in vitro and in vivo. With SAR441566 being studied in healthy volunteers we hope to deliver a more convenient orally bioavailable and effective treatment option for patients suffering with chronic autoimmune diseases compared to established biologic drugs targeting TNF.

An orally active, small-molecule TNF inhibitor that disrupts the homotrimerization interface improves inflammatory arthritis in mice

Excessive signaling by the proinflammatory cytokine TNF is involved in several autoimmune diseases, including rheumatoid arthritis (RA). However, unlike the approved biologics currently used to treat this and other conditions, commercially available small-molecule inhibitors of TNF trimerization are cytotoxic or exhibit low potency. Here, we report a TNF-inhibitory molecule (TIM) that reduced TNF signaling in vitro and was an effective treatment in a mouse model of RA. The initial lead compound, TIM1, attenuated TNF-induced apoptosis of human and mouse cells by delaying the induction of proinflammatory NF-κB and MAPK signaling and caspase 3– and caspase 8–dependent apoptosis. TIM1 inhibited the secretion of the proinflammatory cytokines IL-6 and IL-8 by disrupting TNF homotrimerization, thereby preventing its association with the TNF receptor. In a mouse model of collagen-induced polyarthritis, the more potent TIM1 analog TIM1c was orally bioavailable and reduced paw swelling, histological indicators of knee joint pathology, inflammatory infiltration of the joint, and the overall arthritis index. Orally delivered TIM1c showed immunological effects similar to those elicited by intraperitoneal injection of the FDA-approved TNF receptor decoy etanercept. Thus, TIM1c is a promising lead compound for the development of small-molecule therapies for the treatment of RA and other TNF-dependent systemic inflammation disorders.

Actuators for Implantable Devices: A Broad View

The choice of actuators dictates how an implantable biomedical device moves. Specifically, the concept of implantable robots consists of the three pillars: actuators, sensors, and powering. Robotic devices that require active motion are driven by a biocompatible actuator. Depending on the actuating mechanism, different types of actuators vary remarkably in strain/stress output, frequency, power consumption, and durability. Most reviews to date focus on specific type of actuating mechanism (electric, photonic, electrothermal, etc.) for biomedical applications. With a rapidly expanding library of novel actuators, however, the granular boundaries between subcategories turns the selection of actuators a laborious task, which can be particularly time-consuming to those unfamiliar with actuation. To offer a broad view, this study (1) showcases the recent advances in various types of actuating technologies that can be potentially implemented in vivo, (2) outlines technical advantages and the limitations of each type, and (3) provides use-specific suggestions on actuator choice for applications such as drug delivery, cardiovascular, and endoscopy implants.

Multicomponent Macrocyclic IL-17a Modifier

IL-17a is a major inflammation target, with several approved antibodies in clinical use. Small-molecule IL-17a antagonists are an emerging hot topic, with the recent advancement of three compounds into clinical trials. Here, we describe the design, discovery, synthesis, and screening of macrocyclic compounds that bind to IL-17a. We found that all currently described IL-17a modifiers belong to the same pharmacophore model, likely resulting in a similar receptor binding mode on IL-17a. A pipeline of pharmacophore analysis, virtual screening, resynthesis, and protein biophysics resulted in a potent IL-17a macrocyclic modifier.

Phytochemical Analysis of the Methanolic Extract and Essential Oil from Leaves of Industrial Hemp Futura 75 Cultivar: Isolation of a New Cannabinoid Derivative and Biological Profile Using Computational Approaches

Cannabis sativa L. is a plant belonging to the Cannabaceae family, cultivated for its psychoactive cannabinoid (Δ⁹-THC) concentration or for its fiber and nutrient content in industrial use. Industrial hemp shows a low Δ⁹-THC level and is a valuable source of phytochemicals, mainly represented by cannabinoids, flavones, terpenes, and alkaloids, with health-promoting effects. In the present study, we investigated the phytochemical composition of leaves of the industrial hemp cultivar Futura 75, a monoecious cultivar commercially used for food preparations or cosmetic purposes. Leaves are generally discarded, and represent waste products. We analyzed the methanol extract of Futura 75 leaves by HPLC and NMR spectroscopy and the essential oil by GC-MS. In addition, in order to compare the chemical constituents, we prepared the water infusion. One new cannabinoid derivative (1) and seven known components, namely, cannabidiol (2), cannabidiolic acid (3), β-cannabispirol (4), β-cannabispirol (5), canniprene (6), cannabiripsol (7), and cannflavin B (8) were identified. The content of CBD was highest in all preparations. In addition, we present the outcomes of a computational study focused on elucidating the role of 2α-hydroxy-Δ^3,7-cannabitriol (1), CBD (2), and CBDA (3) in inflammation and thrombogenesis.

Characteristic of Streptozotocin-Nicotinamide-Induced Inflammation in A Rat Model of Diabetes-Associated Renal Injury

Background: Chemical agents such as streptozotocin (STZ) and nicotinamide (NAD) are used in animal models of diabetes mellitus and their related consequences in the kidneys. Several studies have been conducted to determine the modeling, however, the results are still unclear. Moreover, diabetic nephropathy is considered to begin with an inflammatory reaction in the kidneys.  Objectives: This study aims to investigate the metabolic profile STZ and NAD induce inflammation in the kidney.  Methods: The male Wistar rats used were divided into control and STZ-induced diabetes. Half of the diabetes group received a single dose of nicotinamide (230 mg/Kg) 15 minutes after STZ injection and all groups were monitored for 6 weeks. Furthermore, the profiles of creatinine, urea, and uric acid from serum and urine were observed and the kidney inflammation was tested by immunohistochemistry (IHC) with IL-6 and TNF-α parameters.  Results: The result shows that the administration of a single dose of 230 mg/kg NAD in diabetic rats induced with 50 mg/kg and 65 mg/kg STZ affects body weight and kidney organ index. For 6 weeks of testing, both doses of STZ were enhanced several parameters of kidney damage in diabetic rats in blood and urine chemical parameters. Furthermore, the use of NAD to promote inflammation in STZ-induced diabetic rats gave no significant difference. However, NAD can help mice live longer and avoid problems throughout the test.  Conclusions: The use of NAD leads to inflammation in Streptozotocin-induced diabetic rats. Therefore, the administration of Nicotinamide is recommended since it helps the rats live longer during the experiment.