Evaluation of antiarthritic activity of nimbolide against Freund’s adjuvant induced arthritis in rats

Strategic development of aceclofenac loaded organosomes for topical application: An explorative ex-vivo and in-vivo investigation for arthritis

Present study intends to develop aceclofenac-encapsulated organosomes (OS), which consist of phospholipids coupled with a combination of organic solvents, for the management of arthritis. The formulation was characterized and tested for efficacy using formalin-induced hyperalgesia, air pouch, and CFA-induced arthritic rat models. OS system exhibited spherical dimension, nanometric size with low PDI (278.3 ± 12.21 nm; 0.145), zeta potential (-24.56 ± 7.53 mV), drug entrapment (85.62 ± 7.2 %) and vesicles count (4.2x104 mm3). The gelled OS formulation demonstrated increased drug permeability and accumulation rate (51.77 ± 7.1 % and 396.19 ± 59.21 µg/cm2) compared to the MKT product (102.93 ± 13.78 µg/cm2 and 16.14 ± 4.3 %). Dermatokinetic assessments exhibited significantly higher drug levels in dermal layers compared to MKT product (p < 0.001), and CLSM studies further supported the OS system's deeper penetration. The results of arthritic index significantly better (9 times) in the OS-treated group than the MKT product. OS system treatment significantly reduced biochemicals and cytokines levels, such as CRP, ESR, TLC, lymphocytes, TNF-α, IL-6, and IL-1β to levels of the control group (p < 0.001). Pseudoplastic behaviour of the developed product was indicated by the rheological results, and it also demonstrated biocompatibility through skin compliance studies. Based on the current findings, it appears that OS may be a better choice for managing arthritis and related inflammations.

Astaxanthin, Compared to Other Carotenoids, Increases the Efficacy of Methotrexate in Rat Adjuvant Arthritis

This in vivo study performed in rat adjuvant arthritis aims to advance the understanding of astaxanthin's therapeutic properties for the possible treatment of rheumatoid arthritis (RA) in monotherapy and along with the standard RA treatment, methotrexate (MTX), in combination therapy. The main goal was to elucidate astaxanthin's full therapeutic potential, evaluate its dose dependency, and compare its effects in monotherapy with other carotenoids such as β-carotene and β-cryptoxanthin (KXAN). Moreover, potential differences in therapeutic activity caused by using different sources of astaxanthin, synthetic (ASYN) versus isolated from Blakeslea trispora (ASTAP), were evaluated using one-way ANOVA (Tukey-Kramer post hoc test). KXAN was the most effective in reducing plasma MMP-9 levels in monotherapy, significantly better than MTX, and in reducing hind paw swelling. The differences in the action of ASTAP and ASYN have been observed across various biometric, anti-inflammatory, and antioxidative parameters. In combined therapy with MTX, the ASYN + MTX combination proved to be better. These findings, especially the significant anti-arthritic effect of KXAN and ASYN + MTX, could be the basis for further preclinical studies.

Synthesized pyrrole ester ameliorates adjuvant‑induced arthritis in Wistar rats by alleviating inflammation and downregulating the pro‑inflammatory cytokines

Piperine is an amide alkaloid responsible for producing the pungent smell that comes from black pepper. Piperine has been explained to exhibit significant properties such as anti-rheumatic, anti-inflammatory, and antihypertensive effects. The aim of the study was to synthesize pyrrole ester from piperine and evaluate its anti-arthritis effects in adjuvant-induced arthritis female Wistar rats. In this study, pyrrole ester (AU-5) was designed, synthesized and evaluated for ant-arthritic activity in adjuvant-induced arthritis Wistar rats. The synthesized pyrrole ester (AU-5) was administered in three selected doses (20, 10 and 5 mg/kg) to the arthritic-induced model. The administered ester significantly inhibited the increase in arthritis index, paw and ankle joint swelling compared to the arthritic control group. Similarly, the treated rats exhibited a remarkable increase in body weight increase, improved haematological, biochemical, histopathological and radiological parameters. Moreover, the excess production of rheumatoid factor (RF), C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) was noticeably attenuated in all AU-5-treated rats. However, the spleen index, tumour necrosis factor (TNF-α) and interleukin-6 (IL-6) were distinctly lowered compared to arthritic control rats. Moreover, AU-5 showed promising liver protection by lowering the level of liver function markers Serum glutamic pyruvic transaminase (SGPT), Serum glutamic-oxaloacetic transaminase (SGOT) and alkaline phosphatase (ALP) in serum. Henceforth, it might be concluded that AU-5 has an anti-arthritic effect which can be credited to the down regulation of inflammatory markers and the pro-inflammatory cytokines.

Chemometric profiling and anti-arthritic activity of aerial parts of Glinus oppositifolius (L.) Aug. DC

ETHNOPHARMACOLOGICAL RELEVANCE

Glinus oppositifolius (L.) Aug. DC. belongs to the family Molluginaceae, an annual prostrate herb traditionally used to treat inflammations, arthritis, malarial, wounds, fevers, diarrhoea, cancer, stomach discomfort, jaundice, and intestinal parasites. However, the anti-arthritic activity of the aerial part has still not been reported.

AIM OF THE STUDY

To investigate the antioxidant and anti-arthritic activity of G. oppositifolius in Complete Freund's Adjuvant (CFA) induced rats.

MATERIALS AND METHODS

The dried aerial parts of this plant material were defatted with n-hexane and extracted by methanol using a soxhlet apparatus. The in vitro anti-arthritic activity of methanolic extract of G. oppositifolius (MEGO) was evaluated in protein denaturation, membrane stabilization, and inhibition of proteinase assay at 25, 50, 100, 200, and 400 μg/ml concentrations. Female Wistar rats were immunized sub-dermally into the right hind paw with 0.1 ml of CFA. Rats were administered with MEGO at doses of 200 and 400 mg/kg once daily for fourteen days after arthritis induction. Assessment of arthritis was performed by measuring paw diameter, arthritic index, arthritic score, body weight, organ weight, and hematological and biochemical parameters, followed by the analysis of pro-inflammatory cytokines such as tumor necrosis factor-alpha (TNF-α), interleukin 6 (IL-6), interleukin-1-beta (IL-1β), cyclooxygenase-2 (COX-2), interleukin 13 (IL-13) and interleukin 10 (IL-10) and histopathological study. In vivo antioxidant effect was investigated in enzymatic assays. The presence of phytoconstituents was analyzed by Gas Chromatography-Mass Spectrometry (GC-MS) and Liquid Chromatography-Mass Spectrometry (LC-MS), respectively. In silico molecular docking study of the compounds was carried out against COX-2, IL-1β, IL-6, and TNF-α using AutoDock 4.2 and BIOVIA-Discovery Studio Visualizer software.

RESULTS

MEGO's in vitro anti-arthritic activity showed dose-dependent inhibition of protein denaturation, membrane stabilization, and proteinase inhibition, followed by significant in vivo anti-arthritic activity. The rats treated with MEGO showed tremendous potential in managing arthritis-like symptoms by restoring hematological, biochemical, and histological changes in CFA-induced rats. MEGO (200 and 400 mg/kg) showed a significant alleviation in the levels of hyper expressed inflammatory mediators (TNF-α, IL-1β, and IL-6) and oxidative stress (SOD, CAT, GSH, and LPO) in CFA-induced rats. Spergulagenin-A as identified by LC-MS analysis, exhibited the highest binding affinity against COX-2 (-8.6), IL-1β (7.2 kcal/mol), IL-6 (-7.4 kcal/mol), and TNF-α (-6.5 kcal/mol).

CONCLUSIONS

Provided with the comprehensive investigation, methanolic extract of G. oppositifolius against arthritic-like condition is a proof of concept that revalidates its ethnic claim. The presence of Spergulagenin-A might be responsible for the anti-arthritic activity.

Trans-Chalcone (1-3-diphenyl-2-propen-1-one) as a Therapeutic Candidate in Joint Inflammation via Reduction of TNF-α, IL-1β, IL-6, and IL-17 in Rodents: An In Vivo Study by RT-PCR and ELISA analysis

Autoimmune disorders include vast and distinct illnesses and are characterized by an immune system-mediated attack on the body's own tissues. Because of their ability to impact any portion of the body, their clinical symptoms are incredibly varied. The variations in symptoms are normally linked with the release and activation of vasoactive, chemotactic substances and cytokines. Cytokines perform a multitude of vital biological tasks, such as immune response control, inflammation, proliferation, and tissue repair. The reversal of inflammatory cytokines and leukocyte infiltration into the inflamed tissue by natural compounds provides an effective remedy for autoimmune diseases. Here, the oral administration of trans-chalcone (TC) for 28 days was tested with gradually increasing doses (30, 60, and 120 mg/kg) in complete Freund's adjuvant (CFA)-provoked joint tissue stiffness in rats. Paw edema, arthritic index, joint stiffness, thermal and flexion pain, C-reactive protein, and rheumatoid factor (RF) levels were determined to check the tested drug effectiveness in a chronic inflammatory model. Molecular docking studies revealed strong binding affinity with inflammatory cytokines and mediators such as TNF-α, IL-17, COX-2, and iNOS; further, they were quantified at the mRNA level by RT-PCR and ELISA analysis. Oral administration of TC significantly ameliorated paw edema, thymus and spleen indices, joint stiffness, thermal and flexion pain, C-reactive protein, RF, mobility, and stance of the treated animals. This therapeutic effectiveness was linked with a reduction in the mRNA expression of proinflammatory cytokines such as IL-1β, IL-6, and IL-17. The findings of the reported research confirmed the effectiveness of TC in ameliorating joint stiffness and flexion pain by prominently lowering the inflammatory cytokines.

Nimbolide: promising agent for prevention and treatment of chronic diseases (recent update)

Background

Nimbolide, a bioactive compound derived from the neem tree, has garnered attention as a potential breakthrough in the prevention and treatment of chronic diseases. Recent updates in research highlight its multifaceted pharmacological properties, demonstrating anti-inflammatory, antioxidant, and anticancer effects. With a rich history in traditional medicine, nimbolide efficacy in addressing the molecular complexities of conditions such as cardiovascular diseases, diabetes, and cancer positions it as a promising candidate for further exploration. As studies progress, the recent update underscores the growing optimism surrounding nimbolide as a valuable tool in the ongoing pursuit of innovative therapeutic strategies for chronic diseases.

Methods

The comprehensive search of the literature was done until September 2020 on the MEDLINE, Embase, Scopus and Web of Knowledge databases.

Results

Most studies have shown the Nimbolide is one of the most potent limonoids derived from the flowers and leaves of neem (Azadirachta indica), which is widely used to treat a variety of human diseases. In chronic diseases, nimbolide reported to modulate the key signaling pathways, such as Mitogen-activated protein kinases (MAPKs), Wingless-related integration site-β (Wnt-β)/catenin, NF-κB, PI3K/AKT, and signaling molecules, such as transforming growth factor (TGF-β), Matrix metalloproteinases (MMPs), Vascular Endothelial Growth Factor (VEGF), inflammatory cytokines, and epithelial-mesenchymal transition (EMT) proteins. Nimbolide has anti-inflammatory, anti-microbial, and anti-cancer properties, which make it an intriguing compound for research. Nimbolide demonstrated therapeutic potential for osteoarthritis, rheumatoid arthritis, cardiovascular, inflammation and cancer.

Conclusion

The current review mainly focused on understanding the molecular mechanisms underlying the therapecutic effects of nimbolide in chronic diseases.

Isorhynchophylline attenuates proliferation and migration of synovial fibroblasts via the FOXC1/β-catenin axis

Rheumatoid arthritis (RA) is a common type of chronic inflammatory disease. Elucidating the mechanism of fibroblast-like synovial (FLS) as a pathologic factor in RA may address the urgent medical requirement for the treatment of RA. Isorhynchophylline (IRN) is a tetracyclic hydroxyindole alkaloid isolated from uncinaria, which has multiple biological activities and affects the progression of osteoarthritis. However, the role of IRN in rheumatoid arthritis remains unclear. Herein, our study aimed to elucidate the potential effect of IRN on RA and reveal its mechanism. Human FLS cell line MH7A cells were stimulated with TNF-α for 24 h to construct a cell model. CCK-8, Edu, wound healing, as well as transwell assays were conducted to detect the effects of IRN on cell proliferation and motility. ELISA and Immunoblot assays were further performed to detect the production of pro-inflammatory factors and the expression levels of MMPs. Immunoblot and Immunostaining assays were conducted to uncover the mechanism. ELISA, H&E staining, and Immunoblot assays were used to confirm the effects of IRN on RA in a CIA rat model. We revealed that IRN restrained TNF-α-stimulated MH7A cell proliferation and motility. In addition, IRN blocked the production of pro-inflammatory factors and MMPs in TNF-α-stimulated-MH7A cells. We further found that IRN restrained FOXC1/β-catenin axis, and improved MH7A cell proliferation as well as migration via the FOXC1/β-catenin axis. IRN restores CIA by inhibiting pro-inflammatory cytokines in synovial tissues. In summary, IRN attenuates proliferation and migration of FLS in RA via the FOXC1 mediated β-catenin axis.

Amelioration of Rheumatoid Arthritis by Fragaria nubicola (Wild Strawberry) via Attenuation of Inflammatory Mediators in Sprague Dawley Rats

Background and Objectives: Fragaria nubicola has never been evaluated scientifically for its anti-arthritic potential despite its use in folkloric systems of medicine. The research was conducted to assess the potential of F. nubicola against rheumatoid arthritis. Materials and Methods: The current study provided scientific evidence by evaluating the effects of plants using an in vivo CFA-induced model of arthritic rats and subsequent microscopic histopathological evaluation of ankle joints along with the determination of paw edema using a digital water displacement plethysmometer. The study also gave insight by determining levels of pro-inflammatory cytokines, matrix metalloproteinase enzymes (MMPs), prostaglandin E2 (PGE2), nuclear factor kappa B (NF-κB), vascular endothelial growth factor (VEGF), and biochemical and hematological parameters. GCMS analysis was also conducted for the identification of possible anti-inflammatory plant constituents. Results: The data showed that F. nubicola-treated groups attenuated the progression of arthritis and paw edema. Microscopic histopathological evaluation validated the anti-arthritic potential by showing amelioration of bone erosion, infiltration of inflammatory cells, and pannus formation. RT-PCR analysis displayed that treatment with F. nubicola down-regulated IL1β, IL6, TNFα, NF-κB, VEGF, MMP2, MMP3, and MMP9 levels. Moreover, ELISA exhibited a reduction in levels of PGE2 levels in treatment groups. The levels of RBCs, platelets, WBCs, and Hb content were found to be nearly similar to negative control in the treated group. Statistically, a non-significant difference was found when all groups were compared for urea, creatinine, ALT, and AST analysis, indicating the safety of plant extract and fractions at test doses. GCMS analysis of extract and fractions showed the existence of many anti-inflammatory and antioxidant phytochemicals. Conclusion: In conclusion, F. nubicola possessed anti-arthritic properties that might be attributed to the amelioration of MMPs and pro-inflammatory cytokines.

Nimbolide Inhibits SOD2 to Control Pancreatic Ductal Adenocarcinoma Growth and Metastasis

Reactive oxygen species are frequently associated with various cancers including pancreatic ductal adenocarcinomas (PDACs). Superoxide dismutase 2 (SOD2) is an enzyme that plays an important role in reactive oxygen species (ROS) signaling. Investigating the molecular function and biological functions of SOD2 can help us develop new therapeutic options and uncover new biomarkers for PDAC diagnosis and prognosis. Here, we show that nimbolide (NB), a triterpene limonoid, effectively blocks the growth and metastasis of PDACs by suppressing the expression and activity of SOD2. To identify the role of SOD2 in NB-induced anticancer activity, we used RNA interference to silence and plasmid transfection to overexpress it. Silencing SOD2 significantly reduced the growth and metastatic characteristics like epithelial-to-mesenchymal transition, invasion, migration, and colony-forming capabilities of PDACs, and NB treatment further reduced these characteristics. Conversely, the overexpression of SOD2 enhanced these metastatic characteristics. ROS signaling has a strong feedback mechanism with the PI3K/Akt signaling pathway, which could be mediated through SOD2. Finally, NB treatment to SOD2-overexpressing PDAC xenografts resulted in significant inhibition of tumor growth and metastasis. Overall, this work suggests that NB, a natural and safe phytochemical that silences SOD2 to induce high levels of ROS generation, results in increased apoptosis and reduced growth and progression of PDACs. The role of SOD2 in regulating NB-induced ROS generation presents itself as a therapeutic option for PDACs.

Anti-Arthritis Effect of Ethanol Extract of Sacha Inchi (Plukenetia volubilis L.) Leaves Against Complete Freund's Adjuvant-Induced Arthritis Model in Mice

Sacha inchi (Plukenetia volubilis L.) is a well-known oleaginous plant used as food source and traditional medicine by indigenous people for a long time. This study was conducted to evaluate anti-arthritis effect of ethanol extract of Sacha inchi leaves and provide scientific evidence to develop the new anti-arthritis remedy from Sacha inchi. Rheumatoid arthritis model was established by injection of complete Freund's adjuvant into right hind footpads of mice and three doses of ethanol extract of Sacha inchi leaves (100, 200 and 300 mg/kg body weight) were used for treatment. The severity of arthritis was evaluated by measuring the ankle diameter and arthritic score, hematological and biochemical parameters (erythrocytes, leukocytes, lymphocytes, monocytes, granulocytes counts, erythrocyte sedimentation rate, C-reactive protein and rheumatoid factor). The pro-and anti-inflammatory cytokines (TNF-α, INF-γ, IL-1β, IL-6, and IL-10) and the histology change of joint were also examined. All three doses of extracts significantly alleviated ankle diameter and arthritic score. Furthermore, the extracts could ameliorate the alternation of inflammatory cytokines as well histological features of CFA-induced mice. The efficacy of extract dose of 300 mg/kg body weight is comparable with reference drug (Mobic, 0.2 mg/kg body weight). This study indicates Sacha inchi leaf extract as the promising remedy for treatment of arthritis.

Anti-Arthritic and Immunomodulatory Potential of Methanolic, n-Hexane, and Ethyl Acetate Fractions of Bark of Acacia modesta on Complete Freund's Adjuvant-Induced Arthritis in Rats

Rheumatoid arthritis is an autoimmune disorder and topic of interest for researchers due to its increasing frequency and limited treatment. Acacia modesta Wall is known to treat rheumatic disorders in the traditional system of medicinal plants. Traditional medicines are still required for the treatment of this disease due to the large number of side-effects caused by commercial medicines. In the current study, the antiarthritic potential of methanolic extract (AM-metha), n-hexane (AM-hexa) fraction, and ethyl acetate (AM-etha) fraction of the bark of A. modesta against a complete Freund's adjuvant rat model was evaluated. Evaluation using a digital plethysmometer, macroscopic evaluation, and histopathological evaluation were conducted to determine the paw volume and arthritic scoring. ELISA was performed to assess the PGE2 levels. RT-PCR was used to evaluate the expression levels of MMP2, MMP3, MMP9, NF-κB, IL6, IL1β, TNFα, and VEGF. Biochemical and hematological analyses were also conducted. GC/MS was also carried out to analyze the presence of medicinal compounds. The data revealed a marked reduction in the paw volume, arthritic scoring, and histopathological parameters, indicating the anti-arthritic potential of the plant. Treatment with plant extracts and fractions markedly down-regulated MMP2, MMP3, MMP9, NF-κB, IL6, IL1β, TNFα, and VEGF levels. Similarly, PGE2 levels were also found to be ameliorated in the treatment groups, indicating the immunomodulatory property of plant bark. Plant treatment nearly normalized hematological parameters such as counts of WBCs, RBCs, and platelets, along with Hb content, thereby validating the anti-arthritic activity. GC/MS analysis disclosed the presence of strong anti-inflammatory compounds such as lupeol, oleic acid, and squalene. The study showed that A. modesta possesses anti-arthritic and immunomodulatory potential linked to significant down-regulation of pro-inflammatory and inflammatory biomarkers.

Triterpenes as Potential Drug Candidates for Rheumatoid Arthritis Treatment

Rheumatoid arthritis (RA) is a chronic autoimmune inflammatory disease characterized by joint inflammation, swelling and pain. Although RA mainly affects the joints, the disease can also have systemic implications. The presence of autoantibodies, such as anti-cyclic citrullinated peptide antibodies and rheumatoid factors, is a hallmark of the disease. RA is a significant cause of disability worldwide associated with advancing age, genetic predisposition, infectious agents, obesity and smoking, among other risk factors. Currently, RA treatment depends on anti-inflammatory and disease-modifying anti-rheumatic drugs intended to reduce joint inflammation and chronic pain, preventing or slowing down joint damage and disease progression. However, these drugs are associated with severe side effects upon long-term use, including immunosuppression and development of opportunistic infections. Natural products, namely triterpenes with anti-inflammatory properties, have shown relevant anti-arthritic activity in several animal models of RA without undesirable side effects. Therefore, this review covers the recent studies (2017-2022) on triterpenes as safe and promising drug candidates for the treatment of RA. These bioactive compounds were able to produce a reduction in several RA activity indices and immunological markers. Celastrol, betulinic acid, nimbolide and some ginsenosides stand out as the most relevant drug candidates for RA treatment.

Nimbolide attenuates complete Freund's adjuvant induced arthritis through expression regulation of toll-like receptors signaling pathway

Nimbolide is an active constituent of Azadirachta indica and is known for its anti-inflammatory, anti-oxidant, immune-modulatory, and anti-cancer effects. Few studies suggest that nimbolide treatment influences the responses to rheumatoid arthritis, but the underlying molecular mechanisms involved are not yet well established. Therefore, the present study was designed to determine the effect of nimbolide on expression regulation of toll-like receptors to attenuate rheumatoid arthritis. The rheumatoid arthritis model was established by injecting complete Freund's adjuvant (CFA) intra-dermally into the sub-plantar region of the left hind paw of rats. Nimbolide (20 mg/kg) and piroxicam (10 mg/kg) were given to arthritic rats. Rats treated with nimbolide showed a significant reduction in inflammatory cells, rheumatoid factor, ESR, and improved the body weight. The results indicated that nimbolide possesses the capacity to attenuate rheumatoid arthritis by downregulating toll-like receptors, IL-17, IL-23, HSP70, and IFN-γ expression levels. Nimbolide treatment showed significant reduction in the severity of inflammation and destruction of joints and showed comparable effects to piroxicam, which is a standard non-steroidal anti-inflammatory drug used for the treatment of rheumatoid arthritis. It can be concluded that nimbolide can be considered as a potential candidate for therapeutic targeting of the toll-like receptors pathway in rheumatoid arthritis.

Evaluating the anti-arthritic potential of walnut (Juglans regia L.) in FCA induced Sprague Dawley rats

Rheumatoid arthritis (RA) is an autoimmune progressive disease, associated with many pathophysiological consequences. Owing to the adverse effects and higher costs of pharmaceuticals, people are now looking for complementary and alternative remedies. In this milieu, the present study was designed to explore the therapeutic potential of walnuts against FCA-induced arthritis in rat models. Purposely, 50 Sprague Dawley rats were housed in a well-ventilated animal room and separated into 5 groups of 10 rats each. The rats were categorized as G₀ (negative control), G₁ (positive control, i.e., FCA induced untreated arthritic rats), G₂ (arthritic rats treated with MTX), G₃ (arthritic rats treated with walnut feed), and G₄ (arthritic rats treated with walnut extract), with an efficacy trial lasting for 42 days. The physical analysis explicated that paw swelling was significantly improved by 10%-12.8% in treatment groups after the intervention when compared with positive control. Moreover, biochemical analyses revealed significantly lower levels of ESR, CRP, and RF in rats treated with walnut-based interventions when compared to positive control. ESR values were decreased by 62.4% and 69.92% in G₃ and G₄ , whereas CRP levels were improved by 56.20% and 77.78% in G₃ and G₄ when compared with G₁ . Likewise, RF values decreased in G₂ , G₃ , and G₄ by 64.71%, 55.88%, and 69.24%, respectively when compared to G₁ . The histological examination demonstrated the potential role of walnut-based interventions in reducing the severity of disease by decreasing cell infiltration, bone erosion, and paw inflammation. Meanwhile, the gene expression analysis revealed that walnut-based interventions protected the paw joints from damage by downregulating the RANKL-OPG pathway. Conclusively, walnut feed and extract may serve as potent anti-arthritic interventions with no side effects. PRACTICAL APPLICATIONS: Plant-based therapeutics are effective in the prevention and management of various chronic diseases. The current research explored the anti-arthritic potential of walnuts. Walnut feed and extract effectively reduced the serum arthritic biomarkers as well as downregulated the genes involved in bone destruction. Thus, the inclusion of dietary ingredients having therapeutic potential such as walnuts may be synchronized in clinical practices to ameliorate arthritis.

Research progress of meliaceous limonoids from 2011 to 2021

Covering: July 2010 to December 2021Limonoids, a kind of natural tetranortriterpenoids with diverse skeletons and valuable insecticidal and medicinal bioactivities, are the characteristic metabolites of most plants of the Meliaceae family. The chemistry and bioactivities of meliaceous limonoids are a continuing hot area of natural products research; to date, about 2700 meliaceous limonoids have been identified. In particular, more than 1600, including thirty kinds of novel rearranged skeletons, have been isolated and identified in the past decade due to their wide distribution and abundant content in Meliaceae plants and active biosynthetic pathways. In addition to the discovery of new structures, many positive medicinal bioactivities of meliaceous limonoids have been investigated, and extensive achievements regarding the chemical and biological synthesis have been made. This review summarizes the recent research progress in the discovery of new structures, medicinal and agricultural bioactivities, and chem/biosynthesis of limonoids from the plants of the Meliaceae family during the past decade, with an emphasis on the discovery of limonoids with novel skeletons, the medicinal bioactivities and mechanisms, and chemical synthesis. The structures, origins, and bioactivities of other new limonoids were provided as ESI. Studies published from July 2010 to December 2021 are reviewed, and 482 references are cited.

Development of a Novel Methotrexate-Loaded Nanoemulsion for Rheumatoid Arthritis Treatment with Site-Specific Targeting Subcutaneous Delivery

Rheumatoid arthritis (RA) is a systemic, chronic autoimmune disease that causes disability due to progressive inflammation and destruction of the tissues around the joints. Methotrexate is mainly used to prevent the progression of joint destruction and reduce the deformity. The major challenge in treating RA with methotrexate is the systemic side effects that limit dose escalation. Hence, a novel formulation of a methotrexate-loaded nanoemulsion for subcutaneous administration was developed that aims to deliver methotrexate into the system via the lymph. The methotrexate-loaded nanoemulsion was prepared by using the aqueous-titration method. The prepared nanoemulsion was investigated for particle size, surface charge, surface morphology, entrapment efficiency, DSC (differential scanning colorimetry), drug release, hemocompatibility assay, and cytotoxicity, as well as anti-arthritic and stability studies. The vesicle size, zeta potential, PDI (polydispersity index), and entrapment efficiency of the optimized nanoemulsion were 87.89 ± 2.86 nm, 35.9 ± 0.73 mV, 0.27, and 87 ± 0.25%, respectively. The DSC study showed that the crystalline methotrexate was converted to an amorphous form and the drug was fully incorporated into the vesicles. After 72 h, the optimized nanoemulsion showed a drug release of 96.77 ± 0.63%, indicating a sustained-release dosage form. Cytocompatibility testing by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide) assay on macrophage cell lines showed that the nanoemulsion was non-toxic. The formulation showed significant anti-arthritic activity compared to the marketed drug solution. In addition, the nanoemulsion containing methotrexate remained stable for three months when stored at a low temperature. Since the nanoemulsion containing methotrexate has excellent physicochemical properties and lowers systemic side effects by targeted delivery, it is a desirable technology for subcutaneous drug delivery.

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.

Co-treatment of Nimbolide augmented the anti-arthritic effects of methotrexate while protecting against organ toxicities

Prolonged exposure to the pharmacological doses of disease-modifying anti-rheumatic drugs (DMARDs) often results in major organ toxicities resulting in poor patient compliance. Methotrexate (MTX) is one of the commonly prescribed DMARDs for the treatment of arthritis, which results in vital organ dysfunction. To retain the anti-arthritic activity of MTX with the reduction in toxicities, combination therapies are warranted. Nimbolide (NMB) is a potent anticancer, anti-inflammatory and anti-fibrotic agent whose potential has been demonstrated in various pre-clinical models. Monoarthritis was developed with Complete Freund's Adjuvant in the knees of Wistar rats and treatment was given with either NMB (3 mg/kg/day) or MTX (2 mg/kg/week) alone or combination therapy (NMB + MTX). The anti-arthritic effects were evaluated by arthritic scoring, radiological imaging, synovial tissue proteins analysis, and histopathological staining. While hepato-renal toxicity was assessed in serum by evaluating the kidney and liver functional parameters, in tissues by oxidative-nitrosative stress markers, and pro-inflammatory cytokines levels. Histopathological analysis was performed to study the extent of tissue damage. Molecular studies like immunoblotting and immunohistochemistry were performed to understand the effect of combination therapy. We thereby report that monotherapy with either NMB or MTX exhibited significant anti-arthritic effects, while combination therapy resulted in augmented anti-arthritic effects with significant reduction in hepato-renal toxicity produced by MTX probably through anti-inflammatory and anti-oxidant effects. Therefore, our proposed combination of NMB and MTX may serve as a potential strategy for the effective management of arthritis.

Effects of different doses of complete Freund's adjuvant on nociceptive behaviour and inflammatory parameters in polyarthritic rat model mimicking rheumatoid arthritis

Complete Freund's adjuvant (CFA) has been used to develop the arthritic or inflammatory condition in the animal, but there is a lack of information concerning high CFA doses on nociceptive behaviour and inflammatory parameters. This study aimed to compare the effects of different high doses of CFA in rat to closely mimic nociceptive and inflammatory parameters of rheumatoid arthritis (RA) in humans. Twenty-four male Sprague-Dawley rats were randomly divided into four groups (n = 6): Control (C), CFA-induced polyarthritic groups at 5.0 mg/mL (CFA 5.0), 7.5 mg/mL (CFA 7.5) and 10.0mg/mL (CFA 10.0). The rats' right hindpaw was inoculated with CFA intradermally and developed into a polyarthritic state within 20 days. Nociceptive behavioural assessments, including von Frey and hot plate tests and spontaneous activities, were conducted on day 0, 7, 15 and 20. Bilateral ankle joints diameter and circumference, full blood count, joints and paw histological examinations were also conducted throughout the study period. Based on the results, CFA 5.0 and CFA 7.5 groups showed a significant increase in spontaneous activities and development of thermal hyperalgesia but no change in body weight and food intake, no development of tactile allodynia and haematological indices, and no significant morphological changes of joints histology. Meanwhile, CFA 10.0 group demonstrated significant and constant changes in all nociceptive and inflammatory parameters investigated. In conclusion, CFA at the dose of 10mg/mL has the most potential and reliable dosage to develop polyarthritis in a rat model to mimic RA condition in humans.

Nimbolide, a Neem Limonoid, Is a Promising Candidate for the Anticancer Drug Arsenal

Nimbolide, a major limonoid constituent of Azadirachta indica, commonly known as neem, has attracted increasing research attention owing to its wide spectrum of pharmacological properties, predominantly anticancer activity. Nimbolide is reported to exert potent antiproliferative effects on a myriad cancer cell lines and chemotherapeutic efficacy in preclinical animal tumor models. The potentiality of nimbolide to circumvent multidrug resistance and aid in targeted protein degradation broaden its utility in enhancing therapeutic modalities and outcome. Accumulating evidence indicates that nimbolide prevents the acquisition of cancer hallmarks such as sustained proliferation, apoptosis evasion, invasion, angiogenesis, metastasis, and inflammation by modulating kinase-driven oncogenic signaling networks. Nimbolide has been demonstrated to abrogate aberrant activation of cellular signaling by influencing the subcellular localization of transcription factors and phosphorylation of kinases in addition to influencing the epigenome. Nimbolide, with its ever-expanding repertoire of molecular targets, is a valuable addition to the anticancer drug arsenal.

Nimbolide exerts protective effects in complete Freund's adjuvant induced inflammatory arthritis via abrogation of STAT-3/NF-κB/Notch-1 signaling

AIM

Activation of transmembrane Notch-1 receptors through inflammatory cytokines is highly regulated by STAT-3 and NF-κB phosphorylation. Nimbolide (NMB) exhibits potent anti-inflammatory, anti-fibrotic, anticancer activities by targeting various pathways. Here, we have investigated the effect of NMB in regulation of STAT-3/NF-κB/Notch-1 axis in complete Freund's adjuvant (CFA) induced inflammatory arthritis (IA) model.

MAIN METHODS

The anti-inflammatory and anti-arthritic activity of NMB was evaluated both in vitro (IL-1β stimulated HIG-82 synovial fibroblasts) and in vivo (CFA induced rat model of IA) models. In vitro anti-arthritic activity was assessed by anti-migratory effect, while in vivo effects were evaluated through radiological and histological analysis. The effect of NMB on STAT-3, NF-κB, Notch-1 signaling pathways and proinflammatory cytokines were studied using western blot, immunohistochemistry and ELISA methods. Key findings NMB attenuated the migration of synovial fibroblasts in vitro. It reduced the progression of arthritis as evidenced from the improved radiological and histological abnormalities in arthritic rats. NMB significantly suppressed the nitrosooxidative stress and levels of pro-inflammatory cytokines. NMB also exhibited remarkable protective activity against upregulation of MAPK, STAT-3 and NF-κB phosphorylation mediated Notch-1 signaling pathway in synovial tissue of arthritic rats.

SIGNIFICANCE

NMB may have clinical therapeutic value in rheumatoid arthritis by inhibiting STAT-3/NF-κB/Notch-1 axis and also by reducing the levels of proinflammatory cytokines.

Nimbolide ameliorates pancreatic inflammation and apoptosis by modulating NF-κB/SIRT1 and apoptosis signaling in acute pancreatitis model

Acute pancreatitis (AP) is a potential gastrointestinal problem most commonly associated with pancreatic inflammation and acinar cells injury. Nimbolide (NB), isolated from the tree Azadirachta indica, possesses antioxidant and anti-inflammatory effects. Here, we aimed to investigate the pancreatic protective effects of NB in ameliorating cerulein-induced pancreatic inflammation and apoptosis in AP model and evaluate the potential mechanism of action. AP was induced in Swiss albino mice by six-hourly intraperitoneal exposures of cerulein (50 µg/kg/hr) and pre-treatment of NB (0.3 and 1 mg/kg) 7 days prior to the cerulein exposure. Various parameters associated with AP in plasma and pancreatic tissues were evaluated. Severity of AP was effectively ameliorated by NB as shown by reducing pancreatic edema, plasma amylase and lipase levels, MPO levels and in cerulein-induced histological damage. Further, the antioxidant effect of NB was associated with a significant inhibition of oxidative-nitrosative stress in Raw 264.7 cells and cerulein-induced AP mice. Moreover, NB suppressed proinflammatory cytokines, iNOS and nitrotyrosine expression. In addition, NB inhibited NF-κB activation and increased SIRT1 expression in cerulein challenged mice. Furthermore, NB also inhibited pancreatic apoptosis by downregulating cleaved caspase 3 and Bax while upregulating Bcl2 expression in cerulein-treated mice. Inhibition of pancreatic inflammation and apoptosis resulted in attenuation of cerulein-induced AP. These results suggest that NB exerts strong anti-pancreatitis effects against cerulein-induced AP by combating inflammatory and apoptosis signaling via SIRT1 activation.

Anti-arthritic activity of D-carvone against complete Freund's adjuvant-induced arthritis in rats through modulation of inflammatory cytokines

Chronic joint pain due to loss of cartilage function, degradation of subchondral bone, and related conditions are common plights of an arthritis patient. Antioxidant compounds could solve the problems in arthritic condition. The objective of this study was to evaluate the anti-arthritic activity of D-carvone against complete Freund's adjuvant (CFA)-induced arthritis in rats. D-carvone was orally administered for 25 days at the doses of 30 and 60 mg/kg against CFA-induced arthritic rats. Changes in body weight, paw swelling, organ index, hematological parameters, oxidative stress markers, inflammatory cytokines, and histopathology were recorded. Oral treatment of D-carvone significantly improved the body weight, reduced the paw swelling, edema formation, and organ index in arthritic rats. The levels of white blood cells were reduced, red blood cells and hemoglobin levels were improved in D-carvone treated arthritic rats. Lipid peroxidation levels were lowered whereas enzymatic and non-enzymatic antioxidants were significantly elevated by D-carvone administration against arthritic rats. D-carvone significantly modulated inflammatory cytokine levels and improved the ankle joint pathology against CFA-induced arthritic inflammation. In conclusion, D-carvone proved significant anti-arthritic activity against CFA-induced arthritis in rats.

Exploring the Effect of Terminalia catappa Fruit Extract in Rheumatoid Arthritis: An Evaluation of Behavioural, Hematologiocal and Histopathological Parameters

BACKGROUND AND OBJECTIVE

Rheumatoid Arthritis (RA) is an autoimmune disease characterized by failure of spontaneous resolution of inflammation with lifetime perseverance, becoming principal cause of inactivity. Many conventional therapies are in use but the side effects associated with them are equally problematic. Therefore, an urge to explore advanced therapeutic approaches with least adverse events has seeded the idea of discovering newer herbal drugs and their respective constituents in management of RA. The current research explores anti-arthritic activity of Terminalia catappa fruits hydroalcoholic extract in CFA induced Wistar rats.

METHODS

The fruits were obtained, washed, dried and processed to obtain hydroalcoholic powdered extract which was dissolved in water and given orally to the rats. Wistar rats of either sex were used in the study. The animals were injected with 0.1 ml of complete freund's adjuvant (CFA) in footpad of left hind paw. The treatment was initiated from day 0 by oral dosing of Terminalia catappa fruit extract in doses of 40 mg/kg and 80 mg/kg followed by CFA administration to day 21 and behavioral, hematological parameters besides histopathological screening were assessed simultaneously.

RESULTS

The arthritic symptoms were observed to gradually decrease in treatment groups when compared against disease control groups. The parameters like body weight and pain latency were increased whereas paw volume and arthritic score were found to significantly decrease in treatment groups as compared to disease control group. The hematological parameters were also modified and were studied in treatment groups. The histopathological estimation depicted extent of damage in joint tissue of diseased rat comparable to normal, standard and combination therapy group.

CONCLUSION

The fruits possess anti-arthritic properties and significantly reduced paw volume, arthritic score and increased pain threshold and body weight gain besides theory hematological effects like increase in Hb and RBC and decrease in WBC, platelets and ESR levels simultaneously. The histopathological estimation confirmed decreased deterioration of joint tissue in treatment groups as compared to disease control group hence proving to be an emerging therapeutic option in management of RA.