Anti-inflammatory effect of stevioside abates Freund's complete adjuvant (FCA)-induced adjuvant arthritis in rats

Equisetum diffusum whole plant methanol extract attenuates rheumatoid arthritis by modulating the expression of key inflammatory biomarkers in rat models

Rheumatoid arthritis (RA) is a chronic inflammatory disease associated with subsequent damage to the bone joints with a global incidence rate of 0.5-1%. To combat with RA various commercially available anti-inflammatory drugs like non-steroidal anti-inflammatory drugs (NSAIDs) are commonly practiced; however, their long-term exposure often results in eliciting gastrointestinal and renal toxicity. Given this, the scientific communities are searching for an alternative therapeutic option that seems less injurious and equally efficacious. Equisetum diffusum D. Don, from the Equisetaceae family, is a native pteridophyte species of the sub-Himalayan region of India and has been reported to have a diverse array of pharmacological properties. The decoction and macerated whole plant extract has been used by various tribal communities (like Tagin, Galo, Adi, Kukis, Meiteis, Mulam) throughout the tropical and sub-tropical Asian countries for the treatment of arthritis, bone fractures, back pain, and abrasives. The present research is focused on determining the anti-arthritic potential of E. diffusum whole plant methanol extract (EDME) in adjuvant-induced arthritic rats. Oral administration with 250 and 500 mg/kg b.w. doses of EDME significantly restored paw-edema, arthritic scoring, and normal body weight. EDME treatment also normalized the haematological, biochemical, radiological, and histological status when compared to the arthritic control rats. The methanol extract significantly (p < 0.05) attenuated arthritis progression by downregulating the gene expression of pro-inflammatory mediators, like COX-2, TNF-α, IL-6, and upregulating the expression of anti-inflammatory mediators PPAR-γ, Iκβ in the blood, in a dose-dependent manner. Significantly, EDME also reduced the serum concentration of COX-2, TNF-α, and IL-6 compared to arthritic control rats (p < 0.05). The treatment with EDME also normalized the oxidative stress level in liver by restoring the GSH level, CAT and SOD activities and reducing the elevated MDA level. HPTLC and LC-MS/MS analyses of EDME confirmed the presence of potent polyphenols (chlorogenic acid, 4-hydroxycinnamic acid) and flavonoids (kaempferol), thereby suggesting the anti-arthritic property of the plant. All our findings established the anti-arthritic potential of E. diffusum extract in chronic arthritis model on a strong ground.

Structure, Properties, and Biomedical Activity of Natural Sweeteners Steviosides: An Update

Stevioside is a natural sweetener with the characteristics of low calorie and high sweetness. It comprises a diverse range of monomers that play crucial roles in numerous biological processes. Due to these attributes, it has gained widespread application in agriculture, food, and pharmaceutical industries. As a substitute for sugar, stevioside also shows good pharmacological activities on glucose metabolism, bodyweight keeping, blood pressure maintenance, and shows anti-inflammatory, anti-oxidation, anti-tumor, antibacterial, and immune regulation activities. This review summarized the update on the food safety, sweet structure-activity relationship, pharmacological activity of stevia glycosides recently, and discussed the limitations of its application in food and medicine.

Transdermal Delivery of Tofacitinib Citrate via Mannose-Decorated Transferosomes Loaded with Tofacitinib Citrate in Arthritic Joints

Transdermal drug delivery systems are a promising option for the treatment of rheumatoid arthritis (RA) because they can lower systemic adverse effects of immunosuppressants. Janus kinase (JAK) inhibitors were found to be effective for the treatment of RA by inhibiting the JAK-STAT pathway and preventing autoimmune joint destruction. The aim of this study is to deliver tofacitinib (a JAK 1 and 3 inhibitor) through mannose-decorated transferosomes (MDTs) directly to inflamed joints. Transferosomes are composed of phospholipids, Cremophor A25, PEG400, Labrafac lipophile, and oleic acid to enhance the permeation of tofacitinib and control nanovesicle size (∼70-200 nm). Permeation through rat skin was evaluated, where the skin permeation of MDTs (Q24: 38.8 ± 9.82 μg/cm2) and flux (0.5311 ± 0.072 μg/cm2/h) were significantly greater than those of the uncoated transferosomes (Q24 of T1: 1.522 ± 0.329 μg/cm2, Q24 of T2: 3.5002 ± 0.998 μg/cm2, and Q24 of T3: 18.226 ± 5.25 μg/cm2). In addition, MDTs seem to permeate the skin intact, as shown by the transmission electron microscopy (TEM) images of the recipient buffer removed from the Franz diffusion cell. A histopathology assay was performed during the in vivo evaluation of MDTs in an arthritic rat model, in which, significantly less inflammation was observed when MDTs were applied directly to the joint compared to when applied to the dorsal skin and untreated arthritic joints. Furthermore, significantly lower tumor necrosis factor-α (TNFα), IL-6, and IL-1β levels (P < 0.05) were detected by enzyme-linked immunosorbent assay (ELISA) in homogenates of the joints treated with MDTs than in untreated arthritic joints. In conclusion, this study proposed effective MDTs that could deliver tofacitinib directly to inflamed joints possibly by targeting the macrophages circulating in the proximity of the site of inflammation.

Changes in the rumen development, rumen fermentation, and rumen microbiota community in weaned calves during steviol glycosides treatment

Early weaning leads to weaning stress in calves, which hinders healthy growth and development. As an excellent sweetener applied in food, steviol glycosides (STE) has also been shown to exhibit positive biological activity in monogastric animals. Therefore, this study aimed to evaluate the impact of incorporating STE as a dietary supplement on rumen development, fermentation, and microbiota of rumen in weaned calves. This study selected 24 healthy Holstein bull calves and randomly allocated them into two groups (CON and STE). The results indicated that supplementation STE group improved rumen development in weaned calves, as demonstrated by a marked increase in the weight of the rumen, as well as the length and surface area of the rumen papilla. Compared with the CON group, the concentrations of total volatile fatty acids (TVFA), propionate, butyrate, and valerate were higher in the STE group. Moreover, STE treatment increased the relative abundance of Firmicutes and Actinobacteria at the phylum level. At the genus level, the STE group showed a significantly increased relative abundance of Succiniclasticum, Lachnospiraceae_NK3A20_group, and Olsenella, and a decreased relative abundance of Acinetobacter compared to the CON group. Pusillimonas, Lachnospiraceae_NK3A20_group, Olsenella, and Succiniclasticum were significantly enriched in rumen chyme after supplementation with STE, as demonstrated by LEfSe analysis. Overall, our findings revealed that rumen bacterial communities altered in response to the dietary supplementation with STE, and some bacterial taxa in these communities may have positive effects on rumen development during this period.

Deciphering the therapeutic potential of trimetazidine in rheumatoid arthritis via targeting mi-RNA128a, TLR4 signaling pathway, and adenosine-induced FADD-microvesicular shedding: In vivo and in silico study

Rheumatoid arthritis (RA) is a debilitating autoimmune condition characterized by chronic synovitis, joint damage, and inflammation, leading to impaired joint functionality. Existing RA treatments, although effective to some extent, are not without side effects, prompting a search for more potent therapies. Recent research has revealed the critical role of FAS-associated death domain protein (FADD) microvesicular shedding in RA pathogenesis, expanding its scope beyond apoptosis to include inflammatory and immune pathways. This study aimed to investigate the intricate relationship between mi-RNA 128a, autoimmune and inflammatory pathways, and adenosine levels in modulating FADD expression and microvesicular shedding in a Freund's complete adjuvant (FCA) induced RA rat model and further explore the antirheumatoid potency of trimetazidine (TMZ). The FCA treated model exhibited significantly elevated levels of serum fibrogenic, inflammatory, immunological and rheumatological diagnostic markers, confirming successful RA induction. Our results revealed that the FCA-induced RA model showed a significant reduction in the expression of FADD in paw tissue and increased microvesicular FADD shedding in synovial fluid, which was attributed to the significant increase in the expression of the epigenetic miRNA 128a gene in addition to the downregulation of adenosine levels. These findings were further supported by the significant activation of the TLR4/MYD88 pathway and its downstream inflammatory IkB/NFB markers. Interestingly, TMZ administration significantly improved, with a potency similar to methotrexate (MTX), the deterioration effect of FCA treatment, as evidenced by a significant attenuation of fibrogenic, inflammatory, immunological, and rheumatological markers. Our investigations indicated that TMZ uniquely acted by targeting epigenetic miRNA128a expression and elevating adenosine levels in paw tissue, leading to increased expression of FADD of paw tissue and mitigated FADD microvesicular shedding in synovial fluid. Furthermore, the group treated with TMZ showed significant downregulation of TLR4/MYD88 and their downstream TRAF6, IRAK and NF-kB. Together, our study unveils the significant potential of TMZ as an antirheumatoid candidate, offering anti-inflammatory effects through various mechanisms, including modulation of the FADD-epigenetic regulator mi-RNA 128a, adenosine levels, and the TLR4 signaling pathway in joint tissue, but also attenuation of FADD microvesicular shedding in synovial fluid. These findings further highlight the synergistic administration of TMZ and MTX as a potential approach to reduce adverse effects of MTX while improving therapeutic efficacy.

Anti-rheumatoid arthritis potential of Halodule pinifolia: development, characterization and in vivo evaluation of H. pinifolia-based oral suspension and lipid nano-emulsion

For treating chronic diseases like rheumatoid arthritis, herbal medicines are preferred due to their evident therapeutic effects and lesser side effects as compared to the long-term used conventional drugs. In this study, the anti-rheumatoid arthritis effect of an unexplored marine grass Halodule pinifolia (HP), and a combination of it with Glycyrrhiza glabra (liquorice; LQ), prepared as a conventional suspension (C1) and a lipid nano-emulsion (C1-N) was evaluated in Freund's complete adjuvant (FCA)- and collagen-induced arthritis (CIA) models. Formulations C1 and C1-N contained standardized extract HP (100 mg/kg) as major active ingredient and liquorice LQ (50 mg/kg) as both active ingredient (anti-inflammatory and anti-ulcer) and sweetening agent. Oral administration of HP and C1 to FCA-induced Sprague-Dawley rats significantly reduced the paw oedema, spleen index, controlled the haematological parameters, cytokine levels (IL-1β, IL-6, TNF-α estimated by ELISA), mRNA expression of cytokines and osteoclast markers (RANK, TRAP and cathepsin K measured by RTPCR). Histopathology and radiological scanning demonstrated lesser joint deterioration in sample-treated rats, as evident phenotypically. The downregulation of CD51 and MMP-3 (western blot) corroborated the anti-arthritic effect of HP and C1. HP showed better results among all. Further, under the CIA model, both C1 and C1-N were found to be potentially active as evidenced by their effect on rat paw oedema, spleen index, haematological parameters, rheumatoid factor, cytokines, osteoclast markers, histology and X-rays. The results proved the anti-arthritic effect of HP and the formulations, particularly the lipid nano-emulsion that showed improved stability as well as activity.

Antiarthritic potential of ethanolic extract of Ixora coccinea leaves on complete Freund's adjuvant-induced arthritis in animal model

CONTEXT

Ixora coccinea leaves possess antioxidant, anti-inflammatory, antinociceptive, antimutagenic, and gastroprotective properties. On this background, its antiarthritic potential was evaluated.

AIMS

The objective is to evaluate the effect of Ethanolic extract of Ixora coccinea leaves (EEICL) on complete Freund's adjuvant-induced arthritis in rats.

SETTINGS AND STUDY DESIGN

PG research laboratory, Pharmacology Department, MKCG Medical College, Berhampur, Odisha.

SUBJECTS AND METHODS

Thirty-six Wistar albino rats were randomly distributed into sixgroups (n = 6) as follows: Gr 1 (normal control)-DW p.o, Gr-2 (disease control [DC] - Tween 80 p.o), Gr-3 (piroxicam 0.9 mg/kg p.o), Gr-4 (EEICL-1 g/kg, p.o, Gr 4-EEICL-1.5 g/kg p.o, Gr 5-ED50 (0.82 g/kg) + piroxicam (0.45 mg/kg) p.o. After induction of arthritis, drugs, and vehicles were administered daily from 5th to 25th day. On 0, 5th, 10th, 15th, and 25th day, parameters like body weight, rotarod fall time, paw volume displacement, and arthritis index were measured. On the last day, Erythrocyte sedimentation rate (ESR), tissue malondialdehyde (MDA), and histopathological analysis were done.

STATISTICAL ANALYSIS USED

Analysis of parametric data was done by one-way ANOVA and nonparametric data by Kruskal-Wallis test using graph pad prism 7.0. P < 0.05 was considered statistically significant.

RESULTS

EEICL (1.5 mg/kg) showed anti-arthritic effect compared with DC. Rotarod fall-off time 137.5 ± 2.5 sec and body weight (139 ± 12.74 g) were increased significantly. The percentage inhibition of paw volume was increased(52%) whereas arthritic score(0.33), ESR(3.51mm/hr), synovial tissue MDA level (0.62±0.13µmol/gm) and Mankin score(2) were reduced significantly as compared to disease control.

CONCLUSIONS

EEICL has anti-arthritic potential in rat model.

Sustained release polymer and surfactant based solid dispersion of andrographolide exhibited improved solubility, dissolution, pharmacokinetics, and pharmacological activity

Andrographolide (AD) is a potent natural product with a wide range of pharmacological activities. However, it has low oral bioavailability due to poor solubility and dissolution rate. Solid dispersion (SD) is a promising technique to improve the solubility and dissolution rate of such molecules. In this study, SD formulation of AD was prepared using Kollidon-SR (KSR) and Poloxamer-407 (P-407) as carriers. SD was prepared using the solvent evaporation method and evaluated for the modulation of solubility of AD. The developed SD formulation was characterized using scanning electron microscopy (SEM), differential scanning calorimetry (DSC), powder X-ray diffraction (PXRD), and Fourier transform infrared spectroscopy (FTIR). Further, dissolution rate, yield, drug content, stability, flowability, and pharmacokinetic profile of SD were evaluated. The compatibility of SD with the Caco-2 cells and its impact on the P-glycoprotein (P-gp) mediated efflux was also investigated. Furthermore, carrageenan-induced paw edema, and adjuvant-induced arthritic model were used to evaluate the efficacy of SD. The results showed that SD3 (AD + KSR + P-407, 1:6:8) exhibited the highest solubility and dissolution rate, and significantly improved pharmacokinetic profile compared to native AD. SD3 was found to be stable during storage and displayed excellent yield, drug content, and flowability. This formulation was found to be compatible with the Caco-2 cells and retarded the efflux of P-gp substrate. SD3 also demonstrated substantially better efficacy than native AD in terms of paw edema inhibition (carrageenan-induced paw edema, Wistar rats), and overall improvement of disease condition (in terms of paw edema, arthritic score, AST, ALT, cytokines, radiological changes, and histopathology) in arthritic Wistar rats. In conclusion, SD3 exhibited improved solubility, dissolution rate, pharmacokinetic profile, and pharmacological activity than native AD.

Ganoderma lucidum polysaccharide peptide (GLPP) attenuates rheumatic arthritis in rats through inactivating NF-κB and MAPK signaling pathways

BACKGROUND

Not many drugs with fewer side effects are available for the treatment of rheumatoid arthritis (RA). Ganoderma lucidum polysaccharide peptide (GLPP) has good immunomodulatory effects, but whether it is effective in managing RA is not clear.

PURPOSE

This study was conducted to examine the anti-RA activity and possible mechanisms of GLPP in collagen-induced arthritis (CIA) rats.

METHODS

Male Wistar rats were intradermally injected with bovine type II collagen in the tail base to establish the CIA model and were orally administered 100 or 200 mg/kg GLPP for 35 days. Paw thickness, clinical arthritis scores, gait analysis, organ index determination, blood cell counts, micro-CT imaging and pathological staining were performed on the rats. Liver and kidney function were measured by commercial kits, and antibody levels were measured by ELISA kits. RA-related protein levels were detected by Western blotting.

RESULTS

GLPP effectively alleviated CIA symptoms and reduced immune organ indexes, antibody levels and systemic organ injury. GLPP decreased the protein expression of tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, matrix metalloproteinase (MMP)2, MMP9, MMP13, BCL-2, OPN, β-Catenin, and hypoxia inducible factor (HIF)-1α and increased the protein expression of BAX in the joint tissues of CIA rats. Moreover, GLPP decreased the phosphorylation levels of p65, IκB-α and ERK1/2.

CONCLUSION

GLPP effectively alleviated RA symptoms in CIA rats by inhibiting the NF-κB and MAPK pathways. This study suggests a promising therapeutic effect of mushroom-derived polysaccharide peptides on RA.

Ccrl2-centred immune-related lncRNA-mRNA co-expression network revealed the local skin immune activation mechanism of moxibustion on adjuvant arthritis mice

BACKGROUND

Moxibustion is an important external therapy of traditional medicine that operates on some acupoints on the skin and is usually used for immune-related diseases. However, whether the immune function of the skin, especially the immune-related lncRNAs, contributes to the mechanism of moxibustion remains unclear.

METHODS

Adjuvant arthritis (AA) was induced by injection of Complete Freund's adjuvant (CFA) into the right hind paw of mice. Moxibustion was administered on the Zusanli (ST36) acupoint for 3 weeks. The alteration of foot volume and cytokine concentration in serum was used to evaluate the anti-inflammation effect of moxibustion. CD83 expression in the local skin of ST36 was measured by immunofluorescence staining. Transcriptome RNA sequencing (RNA-seq) and lncRNA-mRNA network analysis were performed to construct a moxibustion-induced Immune-related lncRNA-mRNA co-expression network. qRT-PCR was used to validate the RNA-seq data.

RESULTS

Moxibustion at ST36 relieved the foot swelling, decreased the TNF-α and IL-1β concentrations in serum, and obviously increased the CD83 expression at the local skin of ST36. A total of 548 differentially expressed lncRNAs and 520 linked mRNAs were screened out. The significantly and predominately enriched Go term was inflammatory and immune response, and the main pathways related to inflammatory and immune responses include Toll-like receptor, cytokine-cytokine receptor, and MAPK signaling. The immune-related lncRNA-mRNA co-expression network showed 88 lncRNAs and 36 mRNAs, and Ccrl2 is the central hub of this network.

CONCLUSION

Local immune activation is significantly triggered by moxibustion in ST36 of AA mice. The Ccrl2-centered immune-related lncRNA-mRNA co-expression network would be a promising target for decoding the mechanism of moxibustion for immune-related diseases.

Chitosan coated clove oil-based nanoemulsion: An attractive option for oral delivery of leflunomide in rheumatoid arthritis

Rheumatoid arthritis (RA), a distressing inflammatory autoimmune disease, is managed mainly by Disease-modifying antirheumatic drugs (DMARDs), e.g. leflunomide (LEF). LEF (BCS class II) has limited solubility and adverse effects following its systemic exposure. The appealing antirheumatic properties of both clove oil and chitosan (CS) were exploited to design oral leflunomide (LEF)-loaded nanoemulsion (NE) system to augment the therapeutic action of LEF and decrease its systemic side effects as well. Different LEF-NEs were prepared using clove oil, Tween® 20 (surfactant), and PEG 400(co-surfactant) and characterized by thermodynamic stability, percentage transmittance, cloud point, size analysis, and drug content. Optimized LEF-NE was subjected to CS coating forming LEF-CS-NE that exhibited nanometric size range, prolonged drug release, and good physical stability. In vivo anti-rheumatic activity of pure LEF, market LEF, and LEF-CS-NE was assessed utilizing a complete Freund's adjuvant (CFA) rat model. Treatment with LEF-CS-NE reduced edema rate (48.68% inhibition) and caused a marked reduction in interleukin-6 (IL-6) (510.9 ± 2.48 pg/ml), tumor necrosis factor- α (TNF-α) (397.3 ± 2.53 pg/ml), and rheumatoid factor (RF) (42.58 ± 0.49 U/ml). Furthermore, LEF-CS-NE reduced serum levels of glutamic pyruvic transaminase (GPT) to (83.19%) and glutamic oxaloacetic transaminase (GOT) to (40.68%) compared to the control + ve group. The effects of LEF-CS-NE were also superior to both pure and market LEF and showed better results in histopathological studies of paws, liver, kidney, lung, and heart. The remarkable therapeutic and safety profile of LEF-CS-NE makes it a potential oral system for the management of RA.

Stevioside reduces inflammation in periodontitis by changing the oral bacterial composition and inhibiting P. gingivalis in mice

BACKGROUND

Excessive sugar intake has become a major challenge in modern societies. Stevioside is a promising non-calorie sweetener with anti-inflammatory effects; however, its effects on the oral environment and periodontitis remain unclear. Therefore, this study explores the effect of stevioside on periodontitis in mice.

METHODS

Mice were divided into four groups, namely, control, treated with water, and periodontitis models, established using 5 - 0 silk sutures ligation around the second molar then infected the oral cavity with Porphyromonas gingivalis (P. gingivalis) viscous suspension, divided into three groups treated with 0.1% stevioside (P + S), 10% glucose (P + G), or water (P). Micro-CT scanning was used to assess alveolar bone resorption, while RT-PCR was used to evaluate the inflammatory factors expression and P. gingivalis invasion in the gingiva. The composition of the oral bacteria was analysed using 16 S rRNA sequence in the saliva. In addition, P. gingivalis was co-cultured with stevioside at different concentrations in vitro, and bacterial activity was detected via optical density values and live/dead staining. The virulence was detected using RT-PCR, while biofilm formation was detected using scanning electron microscopy.

RESULTS

Compared with 10% glucose, treatment with 0.1% stevioside reduced alveolar bone absorption and osteoclasts while decreasing IL-6, TNF-α, IL-1β, and P. gingivalis in the gingiva of periodontitis mice. The CEJ-ABC distance in the P + S group was significantly lower than that in the P and P + G groups (P < 0.05). Moreover, the composition of the oral bacteria in the P + S group was similar to that of the control. In vitro stevioside treatment also reduced the bacterial activity and toxicity of P. gingivalis in a dose-dependent manner and affected its biofilm composition.

CONCLUSION

Our results indicate that, compared with 10% glucose, 0.1% stevioside intake can reduce alveolar bone resorption and inflammation in periodontal tissues in mice; the bacterial composition following 0.1% stevioside intake was similar to that of a healthy environment. In vitro, high concentrations of stevioside reduced P. gingivalis activity, biofilm formation, and virulence expression. Therefore, stevioside is a potential alternative to glucose for patients with periodontitis.

Macrophage Polarization Towards M2 Phenotype by Curcuminoids Through NF-κB Pathway Inhibition in Adjuvant-Induced Arthritis

Macrophage polarization is decisive for homeostasis maintenance and tissue repair. Anti-inflammatory properties of curcumin (CUR) have been demonstrated in several studies. It used in the treatment of bone disorders includingrheumatoid arthritis. The present study aims to explore the potential mechanisms of curcumin on macrophage polarization, expression, activation, and cytokine secretion in adjuvant-induced arthritis as well as its possible role in enhancing the therapeutic action of methotrexate (MTX) together with minimizing MTX initiated side-effects. Rats were divided into eight groups as follows; Control group, MTX group: was weekly injected with MTX, CUR group: was treated with a daily oral dose of curcumin, MTX + CUR group: was treated with both methotrexate and curcumin, Adjuvant arthritis group (AIA): was injected with complete Freund's adjuvant for arthritis induction, AIA/MTX group: arthritic rats treated with methotrexate, AIA/CUR group: arthritic rats treated with curcumin and AIA/MTX + CUR: arthritic rats treated with both methotrexate and curcumin. Paw swelling, haematological analysis, immunological studies, histological observations and quantitative immunohistochemical investigations were performed. The present results showed that treating arthritic rats with curcumin either alone or in combination with methotrexate resulted in amelioration in paws inflammation, growth rate, absolute and relative spleen weights, and haematological analyses. Antinuclear antibodies, IL-1β, IL-8, IL-10, NF-kB levels, and CD68 + joint expression were also ameliorated. The microscopic examination of joint and spleen showed more improvement as apparently normal tissues in treated groups. It can be concluded that curcumin seems to be most promising in regulating macrophage expression, activation, cytokine secretion, and polarization, thus providing a novel insight in the application of curcumin-based treatments.

Stevioside targets the NF-κB and MAPK pathways for inhibiting inflammation and apoptosis of chondrocytes and ameliorates osteoarthritis in vivo

Osteoarthritis (OA) is a joint disease that is characterized by articular cartilage degeneration and destruction. Stevioside (SVS) is a diterpenoid glycoside extracted from Stevia rebaudiana Bertoni with some specific effects against inflammatory and apoptotic, whereas it is still unclear what function SVS has in osteoarthritis. This study focuses on the anti-inflammatory and anti-apoptosis functions of SVS on chondrocytes induced by interleukin (IL)-1beta, and the role of SVS in an osteoarthritis model for mice. We can detect the production of inflammatory factors such as nitric oxide (NO) and prostaglandin E2 (PGE2) using real-time quantitative polymerase chain reaction (RT-qPCR), the Griess reaction, and enzyme linked immunosorbent assay (ELISA). On the basis of Western blot, we have observed the protein expressions of cartilage matrix metabolism, inflammatory factors, and apoptosis of chondrocytes. Simultaneously, the pharmacological effects of SVS in mice were evaluated by hematoxylin and eosin (HE), toluidine blue, Safranin O, and immunohistochemical staining. The results show that SVS slows extracellular matrix degradation and chondrocyte apoptosis. In addition, SVS mediates its cellular effect by inhibiting the activation of mitogen-activated protein kinase (MAPK) and nuclear factor kappa B (NF-κB) signaling pathways. Meanwhile, molecular docking studies revealed that SVS has excellent binding capabilities to p65, extracellular signal-regulated kinase (ERK), p38, and c-Jun N-terminal kinase (JNK). The study suggests that SVS can be developed as a potential osteoarthritis treatment.

Zerumbone Protects Rats from Collagen-Induced Arthritis by Inhibiting Oxidative Outbursts and Inflammatory Cytokine Levels

Rheumatoid arthritis (RA) is an immunocompromised disorder characterized by a marked increase in the synthesis of inflammatory molecules that stimulates the destruction of bones and cartilage. The conventional treatment modalities for RA are associated with adverse side effects and lack sensitivity, suggesting an immediate demand for alternate beneficial therapeutic remedies. The current study sought to understand more about zerumbone's anti-inflammatory properties in diagnosing collagen-induced arthritis (CIA) in experimental animals. The current study observed that zerumbone reduced clinical severity in CIA-induced animals compared to healthy animals. Zerumbone administration significantly decreased (p < 0.001) the concentration of SOD, CAT, GR, and GSH in treatment groups. Zerumbone administration drove down significantly (p < 0.001) the concentration of inflammatory cytokine molecules. Zerumbone was effective in bringing significant changes in levels of MPO, NO, LDH, MMP-8, and ELA. The therapeutic potential of zerumbone was found to be associated with reduced joint destruction and restored normal histology in the cartilage and tissue. Adsorption, distribution, metabolism, excretion, and toxicity studies were used to determine the druglike properties of zerumbone. ProTox-II studies revealed that zerumbone did not possess toxic properties like hepatotoxicity, immunotoxicity, carcinogenicity, mutagenicity, and cytotoxicity. Therefore, the present study evaluated the therapeutic properties of zerumbone in CIA animal models.

A STUDY OF THE INFLUENCE OF JUVENILE ADJUVANT ARTHRITIS ON DENTAL HARD TISSUES CONDITION IN EXPERIMENTAL ANIMALS

OBJECTIVE

The aim: To study the intensity and depth of carious tooth lesions in rats with experimental juvenile adjuvant-induced arthritis.

PATIENTS AND METHODS

Materials and methods: An experimental study on a model of juvenile adjuvant arthritis (JAA) in 10 one-month-old rats induced by method of A.M. Bendele was carried out. 10 rats of the same age were intact. Injection of adjutant in rats of experimental group led to the development of acute local reaction and then caused generalized joint reaction of autoimmune origin. The performed basic therapy of JAA promoted transition of acute autoimmune process to chronic. Rats were withdrawn from the experiment in 58 days and the dental-jaw blocks were made, in which the intensity and depth of carious lesions of the masticatory group of teeth were determined.

RESULTS

Results: The course of JAA was accompanied by the development of dental caries in 100% of experimental animals. It was found that the intensity of carious teeth lesions in terms of the number of carious teeth and cavities is probably higher than in intact rats (respectively 4.3 ± 0.3 vs. 2.2 ± 0.6 and 4.5 ± 0.3 vs. 2.3 ± 0.7, p <0.001). In rats with JAA, mostly middle and deep carious cavities were revealed, at the same time in intact rats - superficial and middle carious cavities were observed.

CONCLUSION

Conclusions: It has been established that adjuvant arthritis is accompanied by 100% prevalence of dental caries, high intensity of carious process, presence of middle and deep carious cavities, that confirm the negative influence of autoimmune disease on the condition of the hard tooth tissues.

Stevia and Stevioside Attenuate Liver Steatosis through PPARα-Mediated Lipophagy in db/db Mice Hepatocytes

Lipophagy, a type of autophagy that breaks down lipid droplets, is essential in the regulation of intracellular lipid accumulation and intracellular free fatty acid levels in numerous organisms and metabolic conditions. We investigated the effects of Stevia rebaudiana Bertoni (S), a low-calorie sweetener, and stevioside (SS) on hepatic steatosis and autophagy in hepatocytes, as well as in db/db mice. S and SS reduced the body and liver weight and levels of serum triglyceride, total cholesterol, and hepatic lipogenic proteins. In addition, S and SS increased the levels of fatty acid oxidase, peroxisome proliferator-activated receptor alpha (PPARα), and microtubule-associated protein light chain 3 B but decreased that of sequestosome 1 (p62) in the liver of db/db mice. Additionally, Beclin 1, lysosomal associated membrane protein 1, and phosphorylated adenosine monophosphate-activated protein kinase protein expression was augmented following S and SS treatment of db/db mice. Furthermore, the knockdown of PPARα blocked lipophagy in response to SS treatment in HepG2 cells. These outcomes indicate that PPARα-dependent lipophagy is involved in hepatic steatosis in the db/db mouse model and that SS, a PPARα agonist, represents a new therapeutic option for managing associated diseases.

Targeting of Nrf2/PPARγ/NLRP3 Signaling Pathway by Stevia rebudiana Bertoni Extract Provides a Novel Insight into Its Protective Effect against Acute Gouty Arthritis-Induced Synovial Inflammation, Oxidative Stress and Apoptosis in a Rat Model

Our research work examined the potential protection of Stevia rebaudiana extract against monosodium urate crystals (MSU)-induced acute gouty arthritis in a rat model and its possible underlying mechanism. Forty rats were allocated into four groups (n = 10); a control group; an MSU group, whose rats received 0.1 of MSU single intra-articular injection in the ankle joint on the fifth day of the experiment; an MSU + Stevia group, which received 250 mg/kg/day of Stevia extract orally for seven days and MSU crystals on the fifth day; and an MSU + colchicine group, which was administered colchicine at 0.28 mg/kg daily for seven days and MSU crystals on the fifth day. Pretreatment with Stevia extract mitigated MSU-induced inflammation as evidenced by a decrease of the ankle edema and inflammatory cell infiltration and a significant downregulation of the protein level of NFκB, TNFα, IL-1β, IL6, and IL18 as well as NLRP3 gene expression. Additionally, there was a markedly increased PPARγ gene expression (p < 0.001) compared with the MSU group (p < 0.001) and alleviated oxidative stress via significant upregulating of Nrf2/HO-1. Moreover, the pretreatment attenuated apoptosis by significantly decreasing cytochrome c, Bax, Caspase-3, and by increasing Bcl-2 protein. In conclusion, Stevia extract exhibited strong anti-inflammatory, antioxidant, and antiapoptotic effects against MSU-induced gouty arthritis similar to the standard anti-inflammatory colchicine drugs.

Leurieus quinquestriatus scorpion venom ameliorates adjuvant-induced arthritis in rats: Modulating JAK/STAT/RANKL signal transduction pathway

Leurieus quinquestriatus (LQ) is a type of Egyptian scorpions. Prior studies have established the potential use of scorpion venoms in treating several autoimmune diseases. Therefore, the current study investigates the possible pharmacological effect of LQ venom in CFA-induced arthritis - through different mechanisms - by assessing different serum and tissue parameters. This study was divided into two phases: phase I was conducted to determine the lowest therapeutic dose of LQ scorpion venom, whereas phase II investigated the potential therapeutic effect of the chosen dose of LQ venom on induced arthritis through different mechanisms. The Wistar albino rats were divided equally and randomly into normal control group, LQ control group, arthritis control group, infliximab-treated group, and LQ-treated group. On day 20, blood and tissue samples were collected for further analysis of serum and tissue biomarkers as well as histopathological examination. The results revealed a potential therapeutic effect of LQ venom on arthritic-induced rats through a significant decrease in Rheumatoid Factor, Janus Kinase, Signal transducers and activators of transcription, Receptor activator of nuclear factor Kappa-B ligand, Tumor Necrosis Factor-alpha, Interleukin-6, Nuclear factor kappa-light-chain-enhancer of activated B cells and Malondialdehyde by 57%, 66%, 64%, 62%, 75%, 59%, 38%, and 69%, respectively as well as a significant increase in reduced glutathione, and Nuclear factor erythroid 2-related factor 2 by 102% and 360%, respectively. Histopathological examination of knee joint and spleen also revealed a substantial improvement, indicating the possible utilization of LQ venom in the treatment of rheumatoid arthritis.

Toxic Effects of Endocrine Disruptor Exposure on Collagen-Induced Arthritis

Endocrine disruptors (EDs) are chemical substances capable of affecting endocrine system functioning and interfering with organ morphogenesis and physiological functions. The development and regeneration of bone tissues have a complex hormonal regulation, and therefore, bone tissue cells can be considered potential targets for endocrine disruptors. In that regard, the aim of this research was to investigate the impact of ED exposure on the inflammatory response and oxidative stress in an experimental model of collagen-induced arthritis (CIA). Arthritis was induced by an emulsion of type II collagen (CII) and complete Freund’s adjuvant, which was administered intradermally on days 0 and 21. Mice from day 21 to day 35 received the following EDs by oral gavage: cypermethrin (CP), diethyl phthalate (DEP), vinclozolin (VCZ), 17α-ethinylestradiol (EE), perfluorooctanesulfonic acid (PFOS) and atrazine (ATR). ED exposure caused worsening of clinical signs (erythema and edema in the hind paws), histological and radiographic changes, as well as behavioral deficits, induced by CII injections. Furthermore, ED exposure significantly increased the degree of inflammation and oxidative damage induced by arthritis; this upregulation was more evident after exposure to ATR than to other EDs. The results from our study suggest that exposure to EDs may play a deleterious role in the progression of RA; therefore, exposure to EDs should be limited.

Butin Attenuates Arthritis in Complete Freund's Adjuvant-Treated Arthritic Rats: Possibly Mediated by Its Antioxidant and Anti-Inflammatory Actions

The present research work was planned to evaluate the antioxidant and anti-inflammatory actions of butin in preventing complete Freund’s adjuvant-induced arthritis in rats. Adult Wistar rats (200–240 g) were segregated equally into four groups: Group I (normal) and Group II complete Freund’s adjuvant (CFA control) were administered orally with 3 ml/kg of 0.5% SCMC (vehicle); Group III and Group IV were test groups and orally administered 25 and 50 mg/kg of butin. These oral treatments were administered for a total of 21 days. In the 21-day treatment schedule, on the first day, animals from group I (normal control) were injected a single dose of normal saline (0.1 ml) intradermally into one of the hind paws, and animals from Group II to IV were injected CFA (0.1 ml) intradermally into one of the hind paws. During the treatment schedule, the volume of the hind paw and body weight were recorded at every 7 days intervals, and animals were scored for severe arthritis on days 17, 19, and 21. On the 22nd day, samples of blood were withdrawn by puncturing the retro-orbital sinus for analysis of RBC, WBC, hemoglobin, ALT, AST, ALP, PGE2, and cytokines. After blood withdrawal, animals were euthanized; the paw was separated by cutting at the ankle joint and used for analysis of oxidative stress and antioxidant parameters, as well as for the histopathological study. Administration of butin to CFA-treated animals significantly attenuated the CFA-induced inflammatory response, oxidative stress, and reversed the histopathological alteration towards normal. According to the findings, butin has anti-inflammatory and anti-arthritic properties in rats with CFA-induced arthritis.

Perillyl alcohol attenuates rheumatoid arthritis via regulating TLR4/NF-κB and Keap1/Nrf2 signaling pathways: A comprehensive study onin-vitro and in-vivo experimental models

BACKGROUND

Rheumatoid arthritis is a chronic and idiopathic autoimmune disorder. Perillyl alcohol (POH) is a monoterpene which can be extracted from widely available essential oils and is known for its strong anti-inflammatory and anti-oxidant properties.

HYPOTHESIS/PURPOSE

Recent studies have been proven that inhibitors of farnesyltransferase enzyme showed significant anti-arthritic activity. POH is one such natural molecule having anti-inflammatory and anti-oxidant properties by inhibiting farnesyltransferase enzyme which further down regulates NF-κB and Nrf2 via Ras/Raf/MAPK pathway. Also, the effect of POH against rheumatoid arthritis is not known yet. Hence, the present research was intended to assess the anti-arthritic potential of POH in-vitro and in-vivo.

METHODS

The in-vitro effects of POH on RAW 264.7 cells stimulated with LPS 1 µg/ml were investigated to its potential therapeutic effects. CFA 100 µl was intradermally administered to rats for the induction of arthritis. POH 100 mg/kg and 200 mg/kg administered topically from day 1 to day 28. Paw volumes measured, radiography analysis, anti-oxidant status, Gene expression studies, western blot analysis and histological analysis were performed to check the effects of POH.

RESULTS

Our in-vitro findings suggested that POH inhibits inflammation by suppressing reactive oxygen species (ROS), NF-кB and Nrf2 signaling axis. Besides this, POH also rescinded the nitrate levels, pro-inflammatory cytokine levels like IL-1β, IL-6 and TNF-α also PGE2 and COX-2 levels induced by LPS in murine macrophages. Additionally, our in-vivo results revealed that POH conscientiously alleviated CFA induced inflammation by restoring arthritis index, body weight, nitrosative, lipid peroxidation assays. Macroscopically through measuring paw volumes and X-ray, it was evidenced that POH has decreased inflammation and bone erosion. Not only in-vitro but also in-vivo, POH has abridged cytokine levels IL-1β, IL-6, and TNF-α. Histopathological evaluation presented POH treatment alleviated joint inflammation, pannus formation, and bone erosion significantly. Moreover, POH suppressed the protein expression of NF-кB, COX-2, iNOS and improved Nrf2, and SOD2 levels in paw tissues estimated by western blotting.

CONCLUSION

POH was effective in ameliorating LPS stimulation mediated oxidative stress and pro-inflammatory cytokines in RAW 264.7 cells in-vitro and FCA induced arthritis in rats in-vivo through its anti-inflammatory effects via regulating TLR4/NF-κB and Keap1/Nrf2 signaling pathways..

Zingerone (4-(four-hydroxy-3-methylphenyl) butane-two-1) modulates adjuvant-induced rheumatoid arthritis by regulating inflammatory cytokines and antioxidants

OBJECTIVE

Ginger (Zingiber officinale Roscoe) is considered to be one of the most commonly consumed dietary condiments of the world. The present study was designed to explicate the protective role of zingerone; an active ingredient of ginger in complete Freund's adjuvant (FCA)-immunized arthritic rats.

METHODS

24 Wistar rats were divided into 4 groups with 6 rats each. Group I as control followed by group II, III and IV were treated with single intradermal injection of FCA (0.1 ml = 100 µg) to induce rheumatoid arthritis. Group III and IV were also administered with zingerone orally at 25 mg/kg b.w for 3 weeks at two different time points.

RESULTS

Adjuvant-treated rats exhibited a significant increase in lipid peroxidation and a reduction in the enzymatic antioxidants such as SOD, catalase and GPx, in the liver and joint tissues. Moreover, FCA inoculation resulted in the increase in levels of NF-κB, TGF-β, TNF-α, IL-1β, IL-6 and Hs-CRP and a decrease in IL-10 levels. Zingerone significantly reduced the levels of NF-κB, TGF-β, TNF-α, IL-1β, IL-6 and Hs-CRP and markedly increased IL-10 levels. Levels of antioxidant enzymes were also restored by zingerone treatment.

DISCUSSION

Oral administration of zingerone ameliorated inflammatory outburst and decreased oxidative stress, suggesting its role in the prevention of rheumatoid arthritis. Further mechanistic insights are necessary to study the exact mechanism involved.

Alum Pickering Emulsion as Effective Adjuvant to Improve Malaria Vaccine Efficacy

Malaria is a life-threatening global epidemic disease and has caused more than 400,000 deaths in 2019. To control and prevent malaria, the development of a vaccine is a potential method. An effective malaria vaccine should either combine antigens from all stages of the malaria parasite’s life cycle, or epitopes of multiple key antigens due to the complexity of the Plasmodium parasite. Malaria’s random constructed antigen-1 (M.RCAg-1) is one of the recombinant vaccines, which was selected from a DNA library containing thousands of diverse multi-epitope chimeric antigen genes. Moreover, besides selecting an antigen, using an adjuvant is another important procedure for most vaccine development procedures. Freund’s adjuvant is considered an effective vaccine adjuvant for malaria vaccine, but it cannot be used in clinical settings because of its serious side effects. Traditional adjuvants, such as alum adjuvant, are limited by their unsatisfactory immune effects in malaria vaccines, hence there is an urgent need to develop a novel, safe and efficient adjuvant. In recent years, Pickering emulsions have attracted increasing attention as novel adjuvant. In contrast to classical emulsions, Pickering emulsions are stabilized by solid particles instead of surfactant, having pliability and lateral mobility. In this study, we selected aluminum hydroxide gel (termed as “alum”) as a stabilizer to prepare alum-stabilized Pickering emulsions (ALPE) as a malaria vaccine adjuvant. In addition, monophosphoryl lipid A (MPLA) as an immunostimulant was incorporated into the Pickering emulsion (ALMPE) to further enhance the immune response. In vitro tests showed that, compared with alum, ALPE and ALMPE showed higher antigen load rates and could be effectively endocytosed by J774a.1 cells. In vivo studies indicated that ALMPE could induce as high antibody titers as Freund’s adjuvant. The biocompatibility study also proved ALMPE with excellent biocompatibility. These results suggest that ALMPE is a potential adjuvant for a malaria vaccine.

Maternal stevioside supplementation ameliorates intestinal mucosal damage and modulates gut microbiota in chicken offspring challenged with lipopolysaccharide

Our previous study showed that dietary stevioside supplementation could alleviate intestinal mucosal damage induced by lipopolysaccharide (LPS) through its anti-inflammatory and antioxidant effects in broiler chickens. However, it remains unknown whether feeding stevioside to breeder hens could exert similar biological functions in their offspring. The present study aimed to investigate whether maternal dietary stevioside supplementation could prevent LPS-induced intestinal mucosal damage and alteration of gut microbiota in chicken offspring. A total of 120 Jinmao yellow-feathered breeder hens were fed a basal diet (CON) or a 250 mg kg^-1 stevioside-supplemented diet (STE) for 5 weeks before collecting their eggs. After hatching, 160 male offspring (80 chickens from each group) were randomly selected and divided into four treatment groups: (1) the offspring of hens fed a basal diet (CON); (2) the offspring of hens fed a stevioside-supplemented diet (STE); (3) the CON group challenged with LPS (LPS); and (4) the STE group challenged with LPS (LSTE). The results showed that maternal stevioside supplementation increased the hatching weight and improved the intestinal morphology. LPS challenge significantly decreased the terminal body weight and the concentrations of serum triglyceride (TG) and glucose (GLU) of the chicken offspring. Maternal stevioside supplementation protected against LPS-induced morphological damage, goblet cell impairment, intestinal apoptosis, and gene expression alteration. In addition, sequence analysis of 16S rRNA gene showed that maternal stevioside supplementation could prevent the impairment of bacterial diversity in LPS-challenged chicken offspring. Moreover, the increased abundance of Lactobacillus caused by maternal stevioside supplementation had a significant negative correlation with the expression of intestinal inflammatory cytokines. In conclusion, maternal stevioside supplementation could ameliorate intestinal mucosal damage and modulate gut microbiota in chicken offspring challenged with LPS.

Stevioside Activates AMPK to Suppress Inflammation in Macrophages and Protects Mice from LPS-Induced Lethal Shock

Stevioside, a diterpenoid glycoside, is widely used as a natural sweetener; meanwhile, it has been proven to possess various pharmacological properties as well. However, until now there were no comprehensive evaluations focused on the anti-inflammatory activity of stevioside. Thus, the anti-inflammatory activities of stevioside, both in macrophages (RAW 264.7 cells, THP-1 cells, and mouse peritoneal macrophages) and in mice, were extensively investigated for the potential application of stevioside as a novel anti-inflammatory agent. The results showed that stevioside was capable of down-regulating lipopolysaccharide (LPS)-induced expression and production of pro-inflammatory cytokines and mediators in macrophages from different sources, such as IL-6, TNF-α, IL-1β, iNOS/NO, COX2, and HMGB1, whereas it up-regulated the anti-inflammatory cytokines IL-10 and TGF-β1. Further investigation showed that stevioside could activate the AMPK -mediated inhibition of IRF5 and NF-κB pathways. Similarly, in mice with LPS-induced lethal shock, stevioside inhibited release of pro-inflammatory factors, enhanced production of IL-10, and increased the survival rate of mice. More importantly, stevioside was also shown to activate AMPK in the periphery blood mononuclear cells of mice. Together, these results indicated that stevioside could significantly attenuate LPS-induced inflammatory responses both in vitro and in vivo through regulating several signaling pathways. These findings further strengthened the evidence that stevioside may be developed into a therapeutic agent against inflammatory diseases.