Protective effect of naringin against ankylosing spondylitis via ossification, inflammation and oxidative stress in mice

Exploring the molecular mechanism of Epimedium for the treatment of ankylosing spondylitis based on network pharmacology, molecular docking, and molecular dynamics simulations

Ankylosing spondylitis (AS) is a rheumatic disease that causes inflammation and bone formation in the spine. Despite significant advances in treatment, adverse side effects have triggered research into natural compounds. Epimedium (EP) is a traditional Chinese herb with a variety of pharmacological activities, including antirheumatic, anti-inflammatory, and immunomodulatory activities; however, its direct effects on AS treatment and the underlying molecular mechanisms have not been systematically studied. Thus, here, we used network pharmacology, molecular docking, and molecular dynamics simulations to explore the targets of EP for treating AS. We constructed an interaction network to elucidate the complex relationship between EP and AS. Sixteen active ingredients in EP were screened; 80 potential targets were identified. In particular, 8-(3-methylbut-2-enyl)-2-phenylchromone, anhydroicaritin, and luteolin were the core components and TNF, IL-6, IL-1β, MMP9, and PTGS2 were the core targets. The GO and KEGG analyses indicated that EP may modulate multiple biological processes and pathways, including the AGE-RAGE, TNF, NF-κB/MAPK, and TLR signaling pathways, for AS treatment. Molecular docking and molecular dynamics simulations showed good affinity between the active components and core targets of EP, with stable binding within 100 nanoseconds. In particular, 8-(3-methylbut-2-enyl)-2-phenylchromone possessed the highest free energy of binding to PTGS2 and TNF (-115.575 and - 87.676 kcal/mol, respectively). Thus, EP may affect AS through multiple pathways, including the alleviation of inflammation, oxidative stress, and immune responses. In summary, we identified the active components and potential targets of EP, highlighting new strategies for the further experimental validation and exploration of lead compounds for treating AS.

Naringenin modifies T-helper responses and macrophage activities in BALB/c mice

Objective

Naringenin is a naturally occurring flavonoid found in citrus fruits. This study was done to compare the oral immunomodulatory effects of naringenin and prednisolone.

Materials and Methods

The effect of one-month oral administration of naringenin (10, 20, and 40 mg/kg) and prednisolone (2 mg/kg) on peritoneal macrophage was compared in the first set of experiments. Separate evaluations were conducted on the effects of naringenin on in vivo and ex vivoT-helper (Th) lymphocyte responses and their subsets in mice immunized with ovalbumin (OVA). Animals challenged with OVA received oral doses of naringenin or prednisolone from two days prior to immunization to 28 days after immunization.

Results

Naringenin and prednisolone increased macrophages' respiratory burst, and nitric oxide and interleukin (IL)-10 production while decreasing IL-12 production. Macrophages isolated from mice administered with 40 mg/kg naringenin had greater phagocytic potential than those isolated from mice administered with prednisolone. OVA-challenged mice treated with 40 mg/kg naringenin or prednisolone had decreased delayed-type hypersensitivity comparable to control mice. The splenocyte proliferation index was lower in the prednisolone-treated group than the naringenin-treated group, even at 40 mg/kg. In the splenocyte cultures, both agents decreased T-bet expression. Naringenin, in contrast to prednisolone, did not affect GATA3expression. The 40 mg/kg naringenin dose reduced RORγt more effectively than prednisolone.

Conclusion

All these findings indicate the potential of naringenin as a modifying agent of immune responses. Consequently, naringenin may be beneficial in controlling some immunopathological conditions.

Naringin mitigates LPS-induced intestinal barrier injury in mice

The aim of this study was to investigate the effect of naringin on lipopolysaccharide (LPS)-induced jejunal barrier function in mice. Forty-five 3-week-old healthy male Balb/c mice with similar body weights were randomly divided into control group, LPS group, LPS + naringin group, with 15 mice in each treatment group. The mice were intraperitoneally injected with the same dose of saline or LPS (10 mg per kg BW) at 43 d. The blood samples, liver and jejunal tissues were collected after 3 h of injection. The results showed that LPS significantly increased the serum diamine oxidase (DAO) activity, D-lactate (D-LA) concentration, and malondialdehyde (MDA) content in liver and jejunum, while decreased the activities of superoxide dismutase (SOD), glutathione peroxidase (Gpx) and catalase (CAT) in liver and jejunum. The LPS treatment caused an increase in the crypt depth and a decrease in the villus height and the ratio of villus height to crypt depth (V/C) of the jejunum. In addition, the LPS treatment significantly increased the mRNA expressions of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), IL-6, toll-like receptor 4 (TLR4), p38-mitogen-activated protein kinase (p38 MAPK), nuclear factor-κB (NF-κB) and kelch-like ECH-associated protein 1 (Keap1), while decreased mRNA expressions of zonula occludens 1 (ZO-1), occludin, claudin, mucin 2 (MUC2) and junctional adhesion molecule 2 (JAM2), Gpx, SOD1, GST, CAT and nuclear factor-erythroid 2-related factor 2 (Nrf2). However, the naringin treatment mitigated these effects induced by LPS. Taken together, our findings suggested that naringin attenuates LPS-induced intestinal barrier damage by inhibiting inflammatory factors and improving antioxidant function and intestinal tight junction, which might be mediated by activating the Nrf2 signaling and suppressing the TLR4/p38 MAPK/NF-κB signaling.

Stretching Training Rehabilitation Has Potential to Alleviate Ankylosing Spondylitis in Mice by Inactivating the Wnt/β-Catenin Pathway

Ankylosing spondylitis (AS) is a chronic inflammatory disease characterized by invasion of the joints of the central axis that involves soft tissues and joints surrounding the spine. Stretching training rehabilitation (STR) has been widely applied for the treatment of AS. The Wnt/β-catenin signalling pathway is closely related to AS. In this study, we aimed to explore the potential molecular mechanisms underlying the protective effect of STR on AS both in vitro and in vivo. Male DBA/1 mice were employed to establish an AS animal model. Hematoxylin-eosin staining showed that STR reversed pathological damages in bone tissues and the total antioxidant capacity of AS mice and increased the antioxidant capacity by upregulating superoxide dismutase and malondialdehyde expression in DBA/1 mice. The MTT, RT-qPCR, and Western blotting results further indicated that STR improved the survival rate of cells by downregulating the expression of target genes in the Wnt/β-catenin pathway and by inhibiting cell inflammation and apoptosis. In conclusion, our findings indicated that STR treatment might be an effective therapeutical strategy for AS.

Naringin promotes osteogenesis and ameliorates osteoporosis development by targeting JAK2/STAT3 signalling

Osteoporosis is a systemic bone metabolism disorder, which increases the risk of fractures, and in severe cases it may cause disability or even death. An important factor contributing to osteoporosis is the imbalance between bone formation and resorption. Naringin was reported to promote osteoblast differentiation, thus enhancing bone formation and alleviating osteoporosis development. However, the signalling pathways related to the regulatory mechanism of naringin in osteoporosis development are not clear. Proliferation of bone mesenchymal stem cells (BMSCs) treated with naringin in vitro was detected by CCK-8. An osteogenesis differentiation medium supplemented with naringin was applied to explore the effects of naringin on BMSC osteogenic differentiation, as detected by Alizarin red staining. Ovariectomy (OVX)-induced postmenopausal osteoporosis (PMOP) rats were orally administered with naringin. Dual-energy X-ray absorptiometry (DEXA) and micro-CT were applied to measure bone mineral density (BMD), bone volume/total volume (BV/TV), trabecula thickness (Tb.Th), trabecula number (Tb.N), trabecular separation (Tb.Sp) and bone surface/bone volume (BS/BV). H&E staining was performed to show pathological changes of the femur in PMOP rats after naringin treatment. Bone metabolism indicators were assessed by ELISA. We found that naringin suppressed the activation of the JAK2/STAT3 pathway. Naringin promoted BMSC proliferation and osteogenic differentiation. Furthermore, naringin alleviates bone loss and improves abnormal bone metabolism of PMOP rats. Collectively, naringin promotes BMSC osteogenic differentiation to ameliorate osteoporosis development by targeting JAK2/STAT3 signalling.

Re-appraising the potential of naringin for natural, novel orthopedic biotherapies

Naringin is a naturally occurring flavonoid found in plants of the Citrus genus that has historically been used in traditional Chinese medical regimens for the treatment of osteoporosis. Naringin modulates signaling through numerous molecular pathways critical to musculoskeletal development, cellular differentiation, and inflammation. Administration of naringin increases in vitro expression of bone morphogenetic proteins (BMPs) and activation of the Wnt/β-catenin and extracellular signal-related kinase (Erk) pathways, thereby promoting osteoblastic proliferation and differentiation from stem cell precursors for bone formation. Naringin also inhibits osteoclastogenesis by both modifying RANK/RANKL interactions and inducing apoptosis in osteoclasts in vitro. In addition, naringin acts on the estrogen receptor in bone to mimic the native bone-preserving effects of estrogen, with few systemic side effects on other estrogen-sensitive tissues. The efficacy of naringin therapy in reducing the osteolysis characteristic of common musculoskeletal pathologies such as osteoporosis, degenerative joint disease, and osteomyelitis, as well as inflammatory conditions affecting bone such as diabetes mellitus, has been extensively demonstrated in vitro and in animal models. Naringin thus represents a naturally abundant, cost-efficient agent whose potential for use in novel musculoskeletal biotherapies warrants re-visiting and further exploration through human studies. Here, we review the cellular mechanisms of action that have been elucidated regarding the action of naringin on bone resident cells and the bone microenvironment, in vivo evidence of naringin’s osteostimulative and chondroprotective properties in the setting of osteolytic bone disease, and current limitations in the development of naringin-containing translational therapies for common musculoskeletal conditions.

Punicalagin Exerts Protective Effects against Ankylosing Spondylitis by Regulating NF-κB-TH17/JAK2/STAT3 Signaling and Oxidative Stress

Background

Ankylosing spondylitis (AS) is a chronic inflammatory disease characterized by sacroiliitis and spinal rigidity of the axial joints. The role of oxidative stress and increased proinflammatory cytokines is well documented in AS pathogenesis. Punicalagin (2,3-hexahydroxydiphenoyl-gallagyl-D-glucose), an ellagitannin widely present in pomegranates, is found to exhibit potent anti-inflammatory, antiproliferative, and antioxidative effects. The present study was undertaken to investigate the effects of punicalagin in a rodent model of AS.

Methods

BALB/c mice induced spondylitis were sacrificed 24 h after the last injection of proteoglycan extract. Histological scoring was done to assess the degree of the disease. The expression of JAK2/STAT3 proteins and proteins of the nuclear factor-κB (NF-κB) pathway was determined by immunoblotting. Serum levels of inflammatory mediators—TNF-α, IL-1β, IL-6, IL-17A, and IL-23—were assessed. Levels of lipid peroxidation and reactive oxygen species (ROS) were quantified. Antioxidant status as a measure of activities of antioxidant enzymes—catalase (CAT), glutathione peroxidase (GPx), and superoxide dismutase (SOD)—was determined.

Results

Punicalagin effectively improved antioxidant status and decreased lipid peroxidation, ROS production, and serum levels of inflammatory mediators. NF-κB pathway and JAK2/STAT3 signaling were significantly (p < 0.05) downregulated. Punicalagin effectively regulated the production of cytokines by the Th17 cells and the IL-17A/IL-23 axis.

Conclusion

The observations suggest that punicalagin exerts a protective role in AS via reducing oxidative stress and regulating NF-κB/TH17/JAK2/STAT3 signal. Punicalagin thus could be explored further as a potent candidate compound in the treatment of AS.

Oxidative and Antioxidative Stress Linked Biomarkers in Ankylosing Spondylitis: A Systematic Review and Meta-analysis

Objective. Ankylosing spondylitis (AS) is a chronic inflammatory disease that affects the axial skeleton, leading to joint disability. Our study aims at investigating the change of oxidative and antioxidative stress linked biomarkers in AS. Methods. This systematic review and meta-analysis was performed following the Preferred Reporting Items of Systematic Reviews and Meta-Analyses (PRISMA) statement. PubMed, Web of Science, and Cochrane Library databases till May 2020 were searched. Only articles published in English were included. Two reviewers screened relevant studies, extracted data, and assessed the quality of included studies using the Newcastle-Ottawa scale independently. Either random or fixed effect model was adopted base on the heterogeneity testing by $I^2$ statistic. Standardized mean difference (SMD) and 95% confidence intervals (CI) of oxidative and antioxidative markers were calculated. $p$ value <0.05 was considered statistically significant. Results. A total of 22 studies including 931 AS patients and 917 healthy controls met the selection criteria. Significantly increased levels of all oxidative stress markers except myeloperoxidase, and significantly decreased levels of total antioxidant status ( $\text{SMD}=-1.19$ , 95% CI -2.35 to -0.03, $p=0.044$ ) and paraoxonase 1( $\text{SMD}=-1.01$ , 95% CI -1.78 to -0.24, $p=0.010$ ) in serum were observed in AS patients when compared with healthy controls. However, there were no significant differences of all oxidative and anti-oxidative stress biomarkers in erythrocytes. Additionally, the levels of malondialdehyde ( $\text{SMD}=0.51$ , 95% CI 0.21 to 0.81, $p=0.001$ ) and advanced oxidation protein products ( $\text{SMD}=0.95$ , 95% CI 0.58 to 1.31, $p<0.001$ ) in serum were significantly higher in active patients when compared with inactive AS patients. Conclusion. This meta-analysis demonstrated an overall increase of oxidative markers and decrease of antioxidative markers in AS, suggesting that oxidative stress may play an important role in the pathogenesis of AS.

Mangiferin nanoemulsions in treatment of inflammatory disorders and skin regeneration

In this paper mangiferin nanoemulsions were developed using hyaluronic acid of different molecular weight, in absence or presence of Transcutol-P. An extensive study was carried out on the physico-chemical properties of nanoemulsions. Nanosizer and transmission electron microscopy showed oil droplets average size 296 nm with monodisperses distribution (PI ≤ 0.30). The zeta potential was highly negative (-30 mV). FTIR analysis confirms the existence of physical interactions among compounds. Rheological measurements allowed to conclude that all formulations present a pseudoplastic behavior (s ∼ 0.4) in presence of the biopolymer. Moreover, mangiferin release depends on the molecular weight of the polymer. Permeability assays on pig epidermis showed that nanoemulsions with low molecular weight hyaluronic acid improve the permeation, being this effect more pronounced in nanoemulsions with Transcutol-P. Administration of mangiferin nanoemulsions on TPA-inflamed skin mice model provided an attenuation of oedema and leucocyte infiltration. Macroscopic appearance of mice skin lesions has a good correlation with the histological study. The topical application of these formulations shows an appropriate anti-inflammatory effect.

Bioinspired bone therapies using naringin: applications and advances

The use of natural compounds for treating chronic bone diseases holds remarkable potential. Among these therapeutics, naringin, a flavanone glycoside, represents one of the most promising candidates owing to its multifaceted effect on bone tissues. This review provides an up-to-date overview on naringin applications in the treatment of bone disorders, such as osteoporosis and osteoarthritis, and further highlights its potential for stem cell pro-osteogenic differentiation therapies. A critical perspective on naringin clinical translation is also provided. The topic is discussed in light of recently developed biomaterial-based approaches that potentiate its bioavailability and bioactivity. Overall, the reported pro-osteogenic, antiresorptive and antiadipogenic properties establish this flavanone as an exciting candidate for application in bone tissue engineering and regenerative medicine.

Naringin prevents the inhibition of intestinal Ca2+ absorption induced by a fructose rich diet

This study tries to elucidate the mechanisms by which fructose rich diets (FRD) inhibit the rat intestinal Ca²⁺ absorption, and determine if any or all underlying alterations are prevented by naringin (NAR). Male rats were divided into: 1) controls, 2) treated with FRD, 3) treated with FRD and NAR. The intestinal Ca²⁺ absorption and proteins of the transcellular and paracellular Ca²⁺ pathways were measured. Oxidative/nitrosative stress and inflammation parameters were evaluated. FRD rats showed inhibition of the intestinal Ca²⁺ absorption and decrease in the protein expression of molecules of both Ca²⁺ pathways, which were blocked by NAR. FRD rats showed an increase in the superoxide anion, a decrease in the glutathione and in the enzymatic activities of the antioxidant system, as well as an increase in the NO content and in the nitrotyrosine content of proteins. They also exhibited an increase in both IL-6 and nuclear NF-κB. All these changes were prevented by NAR. In conclusion, FRD inhibit both pathways of the intestinal Ca²⁺ absorption due to the oxidative/nitrosative stress and inflammation. Since NAR prevents the oxidative/nitrosative stress and inflammation, it might be a drug to avoid alteration in the intestinal Ca²⁺ absorption caused by FRD.

The beneficial role of Naringin- a citrus bioflavonoid, against oxidative stress-induced neurobehavioral disorders and cognitive dysfunction in rodents: A systematic review and meta-analysis

OBJECTIVES

Naringin is a bioflavonoid, very abundantly found in citrus species. In literature, naringin has been scientifically well documented for its beneficial effects in various neurological disorders. In this systematic review and meta-analysis, we have made an attempt to correlate the protective role of naringin against oxidative stress-induced neurological disorders in rodents.

METHODS

The systematic search was performed using electronic databases; the search was mainly focused on the role of naringin in oxidative stress-induced neuropathological conditions in rodents. While, the meta-analysis was performed on the effect of naringin on oxidative stress markers [superoxide dismutase (SOD), catalase (CAT), glutathione-S-transferase (GST), reduced glutathione (GSH), lipid peroxidation (LPO)], nitrite, mitochondrial complexes (I to IV) and enzymes (acetylcholinesterase, Na⁺-K⁺-ATPase, Ca²⁺-ATPase, and Mg²⁺-ATPase) in the rodent brain. The data was analyzed using Review Manager Software.

THE RESULTS

Based on the inclusion and exclusion criteria, twenty studies were selected. The meta-analysis revealed that, naringin could significantly inhibit various physical and chemical stimuli- induced neurological perturbances in the rodent brain, mediated through oxidative stress. Further, naringin also significantly restored the levels of all the oxidative stress markers (oxidative, nitrosative, enzymes, and mitochondrial complexes) in different parts of the rodent brain.

SUMMARY

This systematic review and meta-analysis supports the available scientific evidence on the beneficial role of naringin in the management of various neurological ailments. However, further studies involving human subjects is recommended to establish the safety and therapeutic efficacy in humans.