Rhoifolin regulates oxidative stress and proinflammatory cytokine levels in Freund's adjuvant-induced rheumatoid arthritis via inhibition of NF-κB

Omics-based pharmacological evaluation reveals Yuanhu Zhitong oral liquid ameliorates arthritis by regulating PKC/ERK/NF-κB signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Successful use of herbal medicine in the treatment of rheumatoid arthritis (RA) creates opportunities for alternative therapies. Yuanhu Zhitong oral liquid (YZOL) is an herbal preparation known for its potent analgesic and anti-inflammatory properties in traditional use. However, the pharmacological mechanism of YZOL for treating RA remains unclear.

AIM OF THE STUDY

The aim of this study was to evaluate the efficacy of YZOL in the treatment of RA and to explore its potential mechanisms through omics analysis.

MATERIALS AND METHODS

Type II collagen was used to induce an arthritis rat model. The effects of YZOL on paw swelling, inflammatory cytokines, oxidative stress, and histopathological changes were systematically investigated. A pathway-driven transcriptomic analysis was performed to identify key signaling pathways associated with YZOL therapy. The key alterations were validated by qRT-PCR, Western blot, and immunohistochemistry assays.

RESULTS

YZOL significantly attenuated arthritis progression, reduced paw swelling rate, and lowered arthritis score in CIA rats. YZOL also inhibited systemic inflammation and associated oxidative stress during RA. Transcriptomic analysis identified 341 genes with significantly altered expression following YZOL treatment. These genes were enriched in inflammation-related pathways, particularly in the NF-κB and MAPK signaling pathways. In addition, we discovered that YZOL can alleviate inflammation in the local synovial tissue. The effect of YZOL was confirmed by the suppression of PKC/ERK/NF-κB p65 signaling at systemic and local levels.

CONCLUSIONS

This study provides novel evidence that YZOL treatment ameliorates RA by suppressing the PKC/ERK/NF-κB pathway, suggesting its potential as an alternative therapy for RA.

Mechanistic insights into anti-inflammatory and immunosuppressive effects of plant secondary metabolites and their therapeutic potential for rheumatoid arthritis

The anti-inflammatory and immunosuppressive activities of plant secondary metabolites are due to their diverse mechanisms of action against multifarious molecular targets such as modulation of the complex immune system associated with rheumatoid arthritis (RA). This review discussed and critically analyzed the potent anti-inflammatory and immunosuppressive effects of several phytochemicals and their underlying mechanisms in association with RA in experimental studies, including preliminary clinical studies of some of them. A wide range of phytochemicals including phenols, flavonoids, chalcones, xanthones, terpenoids, alkaloids, and glycosides have shown significant immunosuppressive and anti-inflammatory activities in experimental RA models and a few have undergone clinical trials for their efficacy and safety in reducing RA symptoms and improve patient outcomes. These phytochemicals have potential as safer alternatives to the existing drugs in the management of RA, which possess a wide range of serious side effects. Sufficient preclinical studies on safety and efficacy of these phytochemicals must be performed prior to proper clinical studies. Further studies are needed to address the barriers that have so far limited their human use before the therapeutic potential of these plant-based chemicals as anti-arthritic agents in the treatment of RA is fully realized.

Naringenin ameliorates collagen-induced arthritis through activating AMPK-mediated autophagy in macrophages

BACKGROUND

Naringenin is widely recognized for its notable attributes, including anti-inflammatory, anti-cancer, and immunomodulatory activities. However, its specific implications for rheumatoid arthritis (RA) and the underlying mechanisms remain to be explored. This study aimed to investigate the therapeutic efficacy and pharmacological mechanism of Naringenin in the treatment of collagen-induced arthritis (CIA).

METHODS

A CIA model was established in DBA/1 mice, and various doses of Naringenin were administered orally to assess its impact on RA. The study also involved lipopolysaccharides (LPS)-induced RAW264.7 cells to further evaluate the effects of Naringenin. Mechanistic studies were conducted to elucidate the signaling pathways involved in Naringenin's actions.

RESULTS

Naringenin significantly alleviated foot inflammation in DBA/1 CIA mice and attenuated the levels of pro-inflammatory cytokines in serum. It also enhanced antioxidant capacity in the CIA model. In vitro studies with LPS-induced RAW264.7 cells demonstrated that Naringenin attenuated pro-inflammatory cytokines and reactive oxygen species (ROS) levels. Mechanistic studies confirmed that Naringenin activated autophagy and increased autophagic flux. Blocking autophagy, either by silencing Atg5 or inhibiting autophagolysosome using chloroquine, effectively counteracted the impact of Naringenin on pro-inflammatory cytokines. Further exploration revealed that Naringenin activated the AMPK/ULK1 signaling pathway, and inhibition of AMPK reversed the initiation of autophagy and reduced pro-inflammatory cytokine secretion induced by Naringenin.

CONCLUSIONS

This study unveils a novel mechanism by which Naringenin may be used to treat RA. It demonstrates the therapeutic efficacy of Naringenin in a CIA model by reducing inflammation, modulating cytokine levels, and enhancing antioxidant capacity. Moreover, the activation of autophagy through the AMPK/ULK1 signaling pathway appears to play a critical role in Naringenin's anti-inflammatory effects. These findings suggest potential strategies for the development of anti-rheumatic medications based on Naringenin.

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.

[Erchen Decoction improves iron homeostasis in mice with non-alcoholic fatty liver disease by regulating iron transport capacity in the spleen]

OBJECTIVE

To investigate the effect of Erchen Decoction on iron homeostasis in mice with nonalcoholic fatty liver disease (NAFLD) and its mechanism for regulating iron transport in spleen cells.

METHODS

Thirty male C57BL/6J mice were given a high-fat diet for 12 weeks and randomized (n=6) at the 7th week for gavage (3 times a week) of drinking water (NAFLD model group), Erchen Decoction at low, medium and high doses (7.5, 15, and 30g/kg, respectively), or polyene phosphatidyl choline (PPC; 9.12 mg/kg), with another 6 mice with low-fat and low-sugar feeding as the control group. The active components of Erchen Decoction were determined by HPLC-MS. Lipid accumulation in the liver was evaluated by HE staining and Nile red staining. Prussian blue staining was used to observe iron content in the spleen. The iron ion content in the liver tissue was detected using a detection kit. The expressions of ferroportin1 (Fpn1), transferrin receptor (TfR), Steap3, HO-1, Ter-119, CD163 and CD68 were detected using Western blotting, immunohistochemistry and immunofluorescence staining.

RESULTS

Medium- and high-dose Erchen Decoction partially reversed the increase of lipid accumulation in the liver of NAFLD mice and showed better lipid-lowering effect than PPC. The NAFLD mice showed significantly decreased iron ion content in the spleen with increased hepatic and serum iron contents (P < 0.05), decreased TfR protein expression (P < 0.05), and increased Fpn1 and Steap3 protein expressions (P < 0.05), and these changes were significantly improved by the drug interventions. Erchen Decoction also improved the function of CD163 macrophages in the spleen of NAFLD mice by up-regulating the expression of HO-1 (P < 0.05).

CONCLUSION

Erchen Decoction can alleviate high-fat diet-induced iron metabolism disorder by improving the iron ion transport ability of the spleen cells to delay the progression of NAFLD.

miR-210/NF-κB axis: A new direction for regulating cadmium-induced pig artery inflammatory injury

Cadmium (Cd) is a toxic metal pollutant that still exists in the environment. The microRNA (miRNA) is a type of noncoding RNA that plays an important role in gene posttranscriptional regulation and disease development. Although the toxic effects of Cd have been extensively studied, studies on the mechanism of Cd from the perspective of miRNA are still limited. So, we established a Cd-exposure pig model, which confirmed that Cd exposure would cause pig artery damage. The miR-210 with the most reduced expression and the nuclear factor kappa B (NF-κB) that had a targeting relationship with miR-210 were screened. The effect of miR-210/NF-κB on the artery damage induced by Cd exposure was investigated by acridine orange/ethidium bromide staining, reactive oxygen species (ROS) staining, quantitative PCR, and western blotting. The results showed that miR-210 inhibitor, pcDNA-NF-κB could induce ROS overproduction in pig hip artery endothelial cells, thus inducing Th1/Th2 imbalance and necroptosis, leading to increased inflammation, while small interfering RNA-NF-κB played a mitigating role. In conclusion, Cd can induce artery necroptosis and Th1/Th2 imbalance by regulating the miR-210/NF-κB axis, so as to lead to artery inflammatory damage. In this study, we explored the way in which Cd exposure causes artery damage in pig, providing a new perspective on the regulatory damage of miR-210/NF-κB axis.

Enalapril attenuated CFA provoked arthritic manifestation by modulating proinflammatory and anti-inflammatory cytokine network

Enalapril with documented anti-inflammatory potential was evaluated in current investigation to explore its anti-arthritic efficacy. For anti-arthritic evaluation of enalapril, CFA-instigated arthritic model was employed after which various parameters comprising paw volume, body weight, arthritic index, hematological and biochemical parameters, radiographic analysis and level of various cytokines were estimated. Enalapril demonstrated significant (p˂0.001) anti-arthritic activity by suppressing paw volume, arthritic index while preserved CFA instigated weight loss. Likewise, enalapril also normalized the hematological and biochemical alterations, suppressed the level of proinflammatory cytokines with elevation of anti-inflammatory cytokines. Radiographic and histopathological analysis also further validates the anti-arthritic attribute of enalapril where enalapril preserved the normal architecture of arthritis induced joints. Outcomes of the study pointed out a notable anti-arthritic activity of enalapril. However detailed mechanistic studies are still required to point out the exact mechanism of action.

Impact of nutraceuticals on immunomodulation against viral infections-A review during COVID-19 pandemic in Indian scenario

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) originated in Wuhan, China, in early December 2019 is a censorious global emergency after World War II. Research on the coronavirus uncovered essential information that aided in the development of the vaccine, and specific coronavirus disease 2019 (COVID-19) vaccines were later developed and were approved for usage in humans. But then, mutations in the coronavirus gave rise to new variants and questioned the vaccine's efficacy against them. On the other hand, the investigation of traditional medicine was also on its path to find a novel outcome against COVID-19. On a comparative analysis between India and the United States, India had low death rate and high recovery rate than the latter. The dietary regulation of immunity may be the factor that makes the above difference. The immunity gained from the regular diet of Indian culture nourishes Indian people with essential phytochemicals that support immunity and metabolism. Dietary phytochemicals or nutraceuticals possess antioxidant, anti-inflammatory, and anticancer properties, out of which our concern will be on immune-boosting phytochemicals from our daily nutritional supplements. In several case studies, dietary substance like lemon, ginger, and spinach was reported in the recovery of COVID-19 patients. Thus in this review, we discuss coronavirus and its available variants, vaccines, and the effect of nutraceuticals against the coronavirus. Further, we denote that the immunity of the Indian population may be high because of their diet, which adds natural phytochemicals to boost their immunity and metabolism.

New Targets and Strategies for Rheumatoid Arthritis: From Signal Transduction to Epigenetic Aspect

Rheumatoid arthritis (RA) is a chronic autoimmune disease that can lead to joint damage and even permanent disability, seriously affecting patients' quality of life. At present, the complete cure for RA is not achievable, only to relieve the symptoms to reduce the pain of patients. Factors such as environment, genes, and sex can induce RA. Presently, non-steroidal anti-inflammatory drugs, DRMADs, and glucocorticoids are commonly used in treating RA. In recent years, some biological agents have also been applied in clinical practice, but most have side effects. Therefore, finding new mechanisms and targets for treating RA is necessary. This review summarizes some potential targets discovered from the perspective of epigenetics and RA mechanisms.

Rhoifolin protects cecal ligation and puncture induced sepsis mice model by regulating inflammatory pathway

Sepsis is a systemic infection affects several organs, which needs novel therapy for the management of it, thus protective effect of Rhoifolin was estimated against sepsis. Cecal ligation and puncture (CLP) method was used to induce sepsis and thereafter mice were treated with rhoifolin (10 and 20 mg/kg, p.o.) for one week. Food intake and survival rate was determined sepsis mice, moreover liver function test and cytokines was estimated in the serum of sepsis mice. In the lung tissue homogenate, oxidative stress parameters were determined, histopathological analysis was performed in liver and lung tissue of sepsis mice. Food intake and percentage of survival was improved in rhoifolin treated group than sham group. Level of liver function enzyme and cytokine was reduced significantly in the serum of rhoifolin treated sepsis mice. Treatment with rhoifolin ameliorates the altered oxidative stress parameters, and mRNA expression of Toll-like receptor 4 (TLR-4) in lung tissue of sepsis mice. Histopathological changes were also reverse in rhoifolin treated group than sham group of mice. In conclusion, result of report indicates Rhoifolin treatment reduces oxidative stress and inflammation in CLP induced sepsis mice, as it regulates TLR4/MyD88/NF-κB pathway.

A Comprehensive Review on Anti-Inflammatory Response of Flavonoids in Experimentally-Induced Epileptic Seizures

Flavonoids, a group of natural compounds with phenolic structure, are becoming popular as alternative medicines obtained from plants. These compounds are reported to have various pharmacological properties, including attenuation of inflammatory responses in multiple health issues. Epilepsy is a disorder of the central nervous system implicated with the activation of the inflammatory cascade in the brain. The aim of the present study was to summarize the role of various neuroinflammatory mediators in the onset and progression of epilepsy, and, thereafter, to discuss the flavonoids and their classes, including their biological properties. Further, we highlighted the modulation of anti-inflammatory responses achieved by these substances in different forms of epilepsy, as evident from preclinical studies executed on multiple epilepsy models. Overall, the review summarizes the available evidence of the anti-inflammatory potential of various flavonoids in epilepsy.

Diosmin and Trolox Have Anti-Arthritic, Anti-Inflammatory and Antioxidant Potencies in Complete Freund’s Adjuvant-Induced Arthritic Male Wistar Rats: Roles of NF-κB, iNOS, Nrf2 and MMPs

Rheumatoid arthritis (RA) is a chronic, progressive, autoimmune disease caused by a malfunction of the immune system. The aim of this study was to examine the anti-arthritic effects and suggest the mechanisms of actions of diosmin and trolox in male Wistar rats. Complete Freund’s adjuvant (CFA) was used to establish RA in the animals by subcutaneous injection of 100 µL CFA/rat into plantar region of right hind leg in two consecutive days. Diosmin and/or trolox were administered orally at a dosage of 20 mg/kg/day to CFA-induced arthritic rats for 2 weeks. The normal and arthritic control groups were orally given the same equivalent volume of a vehicle (1% carboxymethyl cellulose) in which treatment agents were dissolved. At the end of the experiment, blood samples were collected from the jugular vein for the detection of the total leukocyte count (TLC) and differential leukocyte count (DLC) in blood and the detection of rheumatoid factor (RF), anti-citrullinated protein antibodies (ACPA), tumor necrosis factor-α (TNF-α), interleukin-13 (IL-13), and interleukin-17 (IL-17) levels by enzyme-linked immunosorbent assay (ELISA), as well as markers of oxidative stress and the antioxidant defense system in serum. The right hind ankle regions of three rats from each group were dissected out and fixed in 10% neutral-buffered formalin for histological examination and the other three were kept at −30 °C for Western blot analysis of nuclear factor-kappa B (NF-κB) protein 50 (NF-κB p50), NF-κB p65, inducible nitric oxide synthase (iNOS), nuclear factor erythroid-2-related factor 2 (Nrf2), and matrix metalloproteinase (MMP)-1 (MMP-1), MMP-3, and MMP-9. The CFA injection was deleterious to the ankle joint’s histological architecture, manifesting as infiltration of inflammatory cells into the articular cartilage, hyperplasia of the synovium, and erosion of the cartilage. All these effects were ameliorated by diosmin and/or trolox, with the combined dose being the most effective. The two compounds significantly lowered the elevated serum levels of RF, ACPA, TNF-α, and IL-17, as well as other pro-inflammatory mediators, such as NF-κB p50, NF-κB p65, iNOS, MMP-1, MMP-3 and MMP-9. They also increased the levels of the anti-inflammatory cytokine, IL-13, and the cytoprotective transcription factor Nrf2. The compounds stimulated higher activities of antioxidants, such as glutathione, glutathione-S-transferase, catalase, and superoxide dismutase, and reduced lipid peroxidation in the serum of arthritic rats. In conclusion, diosmin, trolox, and their combination, which was the most potent, exerted anti-arthritic, anti-inflammatory and antioxidant effects by suppressing NF-κB signaling, inhibiting matrix metalloproteinases, and activating Nrf2.

Combined LC-MS/MS and Molecular Networking Approach Reveals Antioxidant and Antimicrobial Compounds from Erismadelphus exsul Bark

Erismadelphus exsul Mildbr bark is widely used in Gabonese folk medicine. However, little is known about the active compounds associated with its biological activities. In the present study, phytochemical profiling of the ethanolic extract of Erismadelphus exsul was performed using a de-replication strategy by coupling HPLC-ESI-Q/TOF with a molecular network approach. Eight families of natural compounds were putatively identified, including cyclopeptide alkaloids, esterified amino acids, isoflavonoid- and flavonoid-type polyphenols, glycerophospholipids, steroids and their derivatives, and quinoline alkaloids. All these compounds were identified for the first time in this plant. The use of molecular networking obtained a detailed phytochemical overview of this species. Furthermore, antioxidant (2,2-diphenyl-1-picryl-hydrazylhydrate (DPPH) and ferric reducing capacity (FRAP)) and in vitro antimicrobial activities were assessed. The crude extract, as well as fractions obtained from Erismadelphus exsul, showed a better reactivity to FRAP than DPPH. The fractions were two to four times more antioxidant than ascorbic acid while reacting to FRAP, and there was two to nine times less antioxidant than this reference while reacting to DPPH. In addition, several fractions and the crude extract exhibited a significant anti-oomycete activity towards the Solanaceae phytopathogen Phytophthora infestans in vitro, and, at a lower extent, the antifungal activity against the wheat pathogen Zymoseptoria tritici had growth inhibition rates ranging from 0 to 100%, depending on the tested concentration. This study provides new insights into the phytochemical characterization and the bioactivities of ethanolic extract from Erismadelphus exsul bark.

Rhoifolin Alleviates Alcoholic Liver Disease In Vivo and In Vitro via Inhibition of the TLR4/NF-κB Signaling Pathway

Background: Alcoholic liver disease (ALD) is a common chronic liver disorder worldwide, which is detrimental to human health. A preliminary study showed that the total flavonoids within Citrus grandis “Tomentosa” exerted a remarkable effect on the treatment of experimental ALD. However, the active substances of Citrus grandis “Tomentosa” were not elucidated. Rhoifolin (ROF) is a flavonoid component present in high levels. Therefore, this research aimed to evaluate the hepatoprotective effects of ROF and its possible mechanisms.

Methods: Molecular docking was performed to analyze the binding energy of ROF to the main target proteins related to ALD. Subsequently, mice were fed ethanol (ETH) for 49 days to establish the chronic alcoholic liver injury models. The liver pathological injury, serum aminotransferase levels, and oxidative stress levels in the liver tissue were measured. Human normal hepatocytes (LO2 cells) were incubated with ETH to construct the alcoholic liver cell model. The inflammatory markers and apoptosis factors were evaluated using real-time PCR and flow cytometry. Finally, the effects of ROF on the CYP2E1 and NF-κB signaling pathways were tested in vitro and in vivo.

Results: Molecular docking results demonstrated that ROF was able to successfully dock with the target proteins associated with ALD. In animal studies, ROF attenuated ETH-induced liver damage in mice by decreasing the serum concentrations of AST and ALT, reducing the expression of inflammatory cytokines, and maintaining antioxidant balance in the liver tissue. The in vitro experiments demonstrated that ROF suppressed ETH-induced apoptosis in LO2 cells by promoting Bcl-2 mRNA and inhibiting Bax mRNA and caspase 3 protein expression. ROF decreased the level of LDH, ALT, AST, ROS, and MDA in the supernatant; induced the activity of GSH and SOD; and inhibited TNF-α, IL-6, and IL-1β expression levels. Mechanistically, ROF could significantly downregulate the expression levels of CYP2E1, TLR4, and NF-κB phosphorylation.

Conclusion: This study indicates that ROF is the active component within the total flavonoids, which may alleviate ETH-induced liver injury by inhibiting NF-κB phosphorylation. Therefore, ROF may serve as a promising compound for treating ALD.

Analyses of Physical and Chemical Compositions of Different Medicinal Specifications of CRPV by Use of Multiple Instrumental Techniques Combined with Multivariate Statistical Analysis

Citri Reticulatae Pericarpium Viride (CRPV) is the processed product of Citrus reticulata Blanco. We systematically analyzed two CRPV types, Geqingpi (GQP) and Sihuaqingpi (SHQP), based on powder color, microscopic characteristics, and chemical composition. In addition, we characterized their constituents via ultra-high-performance liquid chromatography with hybrid quadrupole-orbitrap mass spectrometry (UHPLC-Q-Exactive Orbitrap-MS). Both showed significant differences in their powder color and microscopic characteristics. Fourier-transform infrared (FT-IR) spectroscopic analysis results showed that the C=O peak absorption of carboxylic acids and their carbonyl esters in SHQP was higher than that of GQP, while the C-OH and C-H plane bending peaks of polysaccharides were lower than those of GQP. We analyzed these data via similarity analysis, PCA, and OPLS-DA. GQP and SHQP had large distinct differences. Based on the mass measurements for molecular and characteristic fragment ions, we identified 44 main constituents from CRPV, including different flavonoid glycosides and flavonoid aglycones in SHQP and GQP, respectively. We found luteolin-6-C-glucoside, orientin, rhoifolin, and pilloin solely in SHQP, and naringenin and hesperetin only in GQP. The peak area measurements showed GQP having a higher flavonoid glycoside (narirutin, hesperidin, etc.) content, whereas SHQP had a higher polymethoxyflavone (nobiletin, tangeretin, etc.) content. Since we holistically analyzed two CRPV types, the results can not only support future pharmacological research, but also provide a scientific basis for formulating more reasonable CRPV quality standards and guide its clinical potential as a precision medicine.

Wound-Healing Potential of Rhoifolin-Rich Fraction Isolated from Sanguisorba officinalis Roots Supported by Enhancing Re-Epithelization, Angiogenesis, Anti-Inflammatory, and Antimicrobial Effects

A wound is a complicated bioprocess resulting in significant tissue damage, which is worsened by a secondary bacterial infection, commonly Pseudomonas aeruginosa and Staphylococcus aureus. The goal of our study was to investigate the metabolic profile and possible wound-healing effect of Sanguisorba officinalis roots rhoifolin rich fraction (RRF). The LC-ESI-MS/MS analysis of S. officinalis roots crude ethanol extract resulted in a tentative identification of 56 bioactive metabolites, while a major flavonoid fraction was isolated by column chromatography and identified by thin-layer chromatography coupled with electrospray ionization/mass spectrometry (TLC-ESI/MS), where rhoifolin was the major component representing 94.5% of its content. The antibiofilm activity of RRF on the mono-species and dual-species biofilm of P. aeruginosa and S. aureus was investigated. RRF exhibited inhibitory activity on P. aeruginosa and S. aureus mono-species biofilm at 2× minimum inhibitory concentration (MIC) and 4× MIC values. It also significantly inhibited the dual-species biofilm at 4× MIC values. Moreover, the wound-healing characteristics of RRF gel formulation were investigated. Rats were randomly allocated into four groups (eight rats in each): Untreated control; Blank gel; Betadine cream, and RRF gel groups. Animals were anesthetized, and full-thickness excisional skin wounds were created on the shaved area in the dorsal skin. The gels were topically applied to the wound’s surface daily for 10 days. The results demonstrated that RRF had a promising wound-healing effect by up-regulating the platelet-derived growth factor (PDGF), vascular endothelial growth factor (VEGF), keratinocyte growth factor (KGF), and fibronectin, while metalloproteinase-1 (MMP-1), interleukin-6 (IL-6), IL-1β, and nitric oxide (NO) levels were suppressed. It also enhanced the immune staining of transforming growth factor (TGF-β) and improved histopathological findings. Furthermore, it displayed an immunomodulatory action on lipopolysaccharide-induced peripheral blood mononuclear cells. Hence, the wound-healing effect of rhoifolin was confirmed by supporting re-epithelization, angiogenesis, antibacterial, immunomodulatory, and anti-inflammatory activities.

The role of flavonoids in inhibiting IL-6 and inflammatory arthritis

Rheumatoid arthritis (RA) is a chronic autoimmune disease that primarily affects the synovial joints. RA has well-known clinical manifestations and can cause progressive disability and premature death along with socioeconomic burdens. Interleukin-6 (IL-6) has been implicated in the pathology of RA where it can stimulate pannus formation, osteoclastogenesis, and oxidative stress. Flavonoids are plant metabolites with beneficial pharmacological effects, including anti-inflammatory, antioxidant, antidiabetic, anticancer, and others. Flavonoids are polyphenolic compounds found in a variety of plants, vegetables, and fruits. Many flavonoids have demonstrated anti-arthritic activity mediated mainly through the suppression of pro-inflammatory cytokines. This review thoroughly discusses the accumulate data on the role of flavonoids on IL-6 in RA.

Phytochemicals Mediate Autophagy Against Osteoarthritis by Maintaining Cartilage Homeostasis

Osteoarthritis (OA) is a common degenerative joint disease and is a leading cause of disability and reduced quality of life worldwide. There are currently no clinical treatments that can stop or slow down OA. Drugs have pain-relieving effects, but they do not slow down the course of OA and their long-term use can lead to serious side effects. Therefore, safe and clinically appropriate long-term treatments for OA are urgently needed. Autophagy is an intracellular protective mechanism, and targeting autophagy-related pathways has been found to prevent and treat various diseases. Attenuation of the autophagic pathway has now been found to disrupt cartilage homeostasis and plays an important role in the development of OA. Therefore, modulation of autophagic signaling pathways mediating cartilage homeostasis has been considered as a potential therapeutic option for OA. Phytochemicals are active ingredients from plants that have recently been found to reduce inflammatory factor levels in cartilage as well as attenuate chondrocyte apoptosis by modulating autophagy-related signaling pathways, which are not only widely available but also have the potential to alleviate the symptoms of OA. We reviewed preclinical studies and clinical studies of phytochemicals mediating autophagy to regulate cartilage homeostasis for the treatment of OA. The results suggest that phytochemicals derived from plant extracts can target relevant autophagic pathways as complementary and alternative agents for the treatment of OA if subjected to rigorous clinical trials and pharmacological tests.

Rhoifolin Loaded in PLGA Nanoparticles Alleviates Oxidative Stress and Inflammation In Vitro and In Vivo

Rhoifolin (ROF) is a bioactive plant flavonoid with potent antioxidant and anti-inflammatory activity. However, no delivery system has yet been developed for ROF to overcome its biopharmaceutical limitations. The purpose...

Rhoifolin Ameliorates Osteoarthritis via Regulating Autophagy

Osteoarthritis (OA) is a common age-related joint disease. Its development has been generally thought to be associated with inflammation and autophagy. Rhoifolin (ROF), a flavanone extracted from Rhus succedanea, has exhibited prominent anti-oxidative and anti-inflammatory properties in several diseases. However the exact role of ROF in OA remains unclear. Here, we investigated the therapeutic effects as well as the underlying mechanism of ROF on rat OA. Our results indicated that ROF could significantly alleviate the IL-1β-induced inflammatory responses, cartilage degradation, and autophagy downregulation in rat chondrocytes. Moreover, administration of autophagy inhibitor 3-methyladenine (3-MA) could reverse the anti-inflammatory and anti-cartilage degradation effects of ROF. Furthermore, P38/JNK and PI3K/AKT/mTOR signal pathways were involved in the protective effects of ROF. In vivo, intra-articular injection of ROF could notably ameliorate the cartilage damage in rat OA model. In conclusion, our work elucidated that ROF ameliorated rat OA via regulating autophagy, indicating the potential role of ROF in OA therapy.

β-Selective Glycosylation Using Axial-Rich and 2-O-Rhamnosylated Glucosyl Donors Controlled by the Protecting Pattern of the Second Sugar

Herein, we describe two counterexamples of the previously reported β/α-selectivity of 96/4 for glycosylation using ethyl 2-O-[2,3,4-tris-O-tert-butyldimethylsilyl (TBS)-α-L-rhamnopyranosyl]-3,4,6-tris-O-TBS-thio-β-D-glucopyranoside as the glycosyl donor. Furthermore, we investigated the effects of protecting group on the rhamnose moieties in the glycosylation with cholestanol and revealed that β-selectivity originated from the two TBS groups at the 3-O and 4-O positions of rhamnose. In contrast, the TBS group at the 2-O position of rhamnose hampered the β-selectivity. Finally, the β/α-selectivity during the glycosylation was enhanced to ≥99/1. The results obtained herein suggest that the protecting groups on the sugar connected to the 2-O of a glycosyl donor with axial-rich conformation can control the stereoselectivity of glycosylation.

Mst1 promotes mitochondrial dysfunction and apoptosis in oxidative stress-induced rheumatoid arthritis synoviocytes

In this study, we investigated the role of macrophage stimulating 1 (Mst1) and the AMPK-Sirt1 signaling pathway in the oxidative stress-induced mitochondrial dysfunction and apoptosis seen in rheumatoid arthritis-related fibroblast-like synoviocytes (RA-FLSs). Mst1 mRNA and protein expression was significantly higher in hydrogen peroxide (H₂O₂)-treated RA-FLSs than untreated controls. H₂O₂ treatment induced the mitochondrial apoptotic pathway by activating caspase3/9 and Bax in the RA-FLSs. Moreover, H₂O₂ treatment significantly reduced mitochondrial membrane potential and mitochondrial state-3 and state-4 respiration, but increased reactive oxygen species (ROS). Mst1 silencing significantly reduced oxidative stress-induced mitochondrial dysfunction and apoptosis in RA-FLSs. Sirt1 expression was significantly reduced in the H₂O₂-treated RA-FLSs, but was higher in the H₂O₂-treated Mst1-silenced RA-FLSs. Pretreatment with selisistat (Sirt1-specific inhibitor) or compound C (AMPK antagonist) significantly reduced the viability and mitochondrial function in H₂O₂-treated Mst1-silenced RA-FLSs by inhibiting Sirt1 function or Sirt1 expression, respectively. These findings demonstrate that oxidative stress-related upregulation and activation of Mst1 promotes mitochondrial dysfunction and apoptosis in RA-FLSs by inhibiting the AMPK-Sirt1 signaling pathway. This suggests the Mst1-AMPK-Sirt1 axis is a potential target for RA therapy.

Ameliorative Effects of Rhoifolin in Scopolamine-Induced Amnesic Zebrafish (Danio rerio) Model

Rhoifolin (Rho) exerts many biological activities such as anticancer, antidiabetic, hepatoprotective, antirheumatic, antibacterial, and antiviral properties. The neuroprotective action of this compound has not been studied. The goal of this study was to investigate the improvement impact of Rho on scopolamine (Sco)-induced zebrafish anxiety, amnesia, and brain oxidative stress and to elucidate the underlying mechanisms involved. Zebrafish were treated with Rho (1, 3, and 5 μg/L) for nine consecutive days and were subsequently subjected to Sco (100 μM) 30 min before behavioral tests (novel tank diving test, Y-maze, and novel object recognition tests). Rho was isolated from Chorisia crispiflora (Malvaceae) leaves and identified by different spectroscopic techniques. To further assess the possible mechanisms of Rho in enhancing the memory capacities in zebrafish, the in vivo antioxidant status and acetylcholinesterase (AChE) activity was also evaluated. Rho from Chorisia crispiflora leaves was identified. Rho could alleviate anxiety, memory deficits, and brain oxidative stress in Sco-treated zebrafish and could regulate the cholinergic function by inhibiting the AChE activity. Our results demonstrated that Rho could be a promising candidate compound against anxiety and amnesia by restoring the cholinergic activity and the amelioration of brain oxidative stress.

Parthenolide ameliorates tweak-induced podocytes injury

Parthenolide (PTL) is a natural product from the shoots of Tanacetum parthenium, which has immunomodulatory effects in multiply type of diseases. This study aimed to explore the effect and the underlying mechanism of PTL on the anti-apoptotic and anti- inflammatory ability of tweak-induced podocytes. Conditionally immortalized mouse podocytes were incubated with Tumor necrosis factor-like weak inducer of apoptosis (Tweak, 100 ng/ml), PTL(10 µM) or Tweak + PTL for 12 h, 24 and 48 h, respectively. Podocytes viability was detected by CCK-8 assay. Tweak and Cxcl16 expression were evaluated by western blot and immunofluorescence assay. Dil-oxLDL stain was detected by immunofluorescence analysis. Intracellular Total Cholesterol (TC) content was measured through TC detection Kit. These results demonstrated that the podocytes cells viability was gradually decreased after treatment with different concentrations of Tweak (0, 50, 100, 150). Tweak and Cxcl16 protein expression in mouse podocytes treated with tweak were remarkably elevated and were found to have higher intracellular lipid accumulation compared with the control group, whereas co-administration with PTL, tweak and Cxcl16 expression as well as the intracellular lipid accumulation were notablely decreased in tweak-induced podocytes. Therefore, our conclusion was that tweak and Cxcl16 were involved in the regulation of tweak-induced podocytes injury. Meanwhile, the anti-apoptotic and anti-inflammatory effect of PTL may be correlated with the tweak and Cxcl16 expression decreased.