Paeonol prevents IL-1β-induced inflammatory response and degradation of type II collagen in human primary chondrocytes

Anti-Inflammatory Activity of APPA (Apocynin and Paeonol) in Human Articular Chondrocytes

Osteoarthritis (OA) is a chronic joint disease leading to cartilage loss and reduction in the joint space which results in pain. The current pharmacological treatment of OA is inadequate and pharmacological interventions focus on symptom management. APPA, a combination of apocynin (AP) and paeonol (PA), is a potential drug for treating OA. The aim of this study was to analyze the effects of APPA on the modulation of the inflammatory response in chondrocytes. Samples were incubated with IL-1β and APPA, and their responses to proinflammatory cytokines, catabolic mediators and redox responses were then measured. The effect of APPA on mitogenesis was also evaluated. Results show that APPA attenuated the expression of IL-8, TNF-α, MMP-3, MMP-13, SOD-2 and iNOS, resulting in the protection of human articular cartilage. APPA decreased PGC-1α gene expression induced by IL-1β. APPA did not modulate the gene expression of Mfn2, Sirt-1 or Sirt-3. The overall findings indicate that APPA may be an effective treatment for OA by targeting several of the pathways involved in OA pathogenesis.

Paeonia × suffruticosa (Moutan Peony)-A Review of the Chemical Composition, Traditional and Professional Use in Medicine, Position in Cosmetics Industries, and Biotechnological Studies

The aim of this review is to perform a systematic review of scientific papers and an in-depth analysis of the latest research related to Paeonia × suffruticosa Andrews as a valuable plant species, important in pharmacy and cosmetology. P. × suffruticosa bark root-Moutan cortex is a medicinal raw material formerly known from traditional Chinese medicine (TCM) but less common in official European medicine. It was introduced for the first time in the European Pharmacopoeia Supplement 9.4 in 2018. In this work, the numerous possible applications of this raw material were depicted based on modern professional pharmacological studies documenting its very valuable medicinal values, including antioxidant, cytoprotective, anti-cancer, anti-inflammatory, cardioprotective, anti-atherosclerotic, anti-diabetic and hepatoprotective activities. The scientific studies indicated that the profile of raw material activity is mainly due to paeonol, paeoniflorin and 1,2,3,4,6-penta-O-galloyl-β-D-glucopyranose. Moreover, the significance of this plant (its different organs) in the production of cosmetics was underlined. P. × suffruticosa finds increasing application in cosmetology due to research on its chronic dermatitis, anti-aging and brightening effects. Furthermore, some biotechnological research has been described aimed at developing effective in vitro micropropagation protocols for P. × suffruticosa.

Small molecules of herbal origin for osteoarthritis treatment: in vitro and in vivo evidence

Osteoarthritis (OA) is one of the most common musculoskeletal degenerative diseases and contributes to heavy socioeconomic burden. Current pharmacological and conventional non-pharmacological therapies aim at relieving the symptoms like pain and disability rather than modifying the underlying disease. Surgical treatment and ultimately joint replacement arthroplasty are indicated in advanced stages of OA. Since the underlying mechanisms of OA onset and progression have not been fully elucidated yet, the development of novel therapeutics to prevent, halt, or reverse the disease is laborious. Recently, small molecules of herbal origin have been reported to show potent anti-inflammatory, anti-catabolic, and anabolic effects, implying their potential for treatment of OA. Herein, the molecular mechanisms of these small molecules, their effect on physiological or pathological signaling pathways, the advancement of the extraction methods, and their potential clinical translation based on in vitro and in vivo evidence are comprehensively reviewed.

Rhoifolin ameliorates osteoarthritis via the Nrf2/NF-κB axis: in vitro and in vivo experiments

OBJECTIVE

Osteoarthritis (OA) is an age-related degenerative disease accompanied by an increasing number of senescent cells and chronic low-grade inflammation. Rhoifolin (ROF) showed considerable inhibition to inflammation, but its role in chondrocyte senescence and OA progress has not been fully characterized. We aimed to evaluate the protective effects of ROF on OA through a series of in vitro and in vivo experiments.

METHODS

The role of ROF in the expression of senescence-associated secretory phenotype (SASP) factors was investigated using RT-qPCR, western blotting, and ELISA. Chondrocyte senescence was assessed by SA-β-gal staining. We applied molecular docking to screen candidate proteins regulated by ROF. Meanwhile, SASP factors and cellular senescence were further assessed after the transfection of Nrf2 siRNA. In the anterior cruciate ligament transection (ACLT) rat model, X-ray, hematoxylin-eosin (HE), and Masson's staining were performed to evaluate the therapeutic effects of ROF on OA.

RESULTS

We found that ROF inhibited SASP factors expression and senescence phenotype in IL-1β-treated chondrocytes. Furthermore, ROF suppressed IL-1β-induced activation of the NF-κB pathway cascades. Also, molecular docking and knock-down studies demonstrated that ROF might bind to Nrf2 to suppress the NF-κB pathway. In vivo, ROF ameliorated the OA process in the ACLT rat model.

CONCLUSIONS

ROF inhibits SASP factors expression and senescence phenotype in chondrocytes and ameliorates the progression of OA via the Nrf2/NF-κB axis, which supports ROF as a potential therapeutic agent for the treatment of OA.

Paeonol inhibits inflammatory response and protects chondrocytes by upregulating sirtuin 1

Paeonol is the bioactive component in Paeonia lactiflora Pall., Cynanchum paniculatum and Paeonia × suffruticosa Andr. Paeonol has been previously demonstrated to inhibit the release of tumor necrosis factor α (TNF-α) and interluekin 6 (IL-6) in chondrocytes. Sirtuin 1 (SIRT1) is downregulated in degraded cartilage and paeonol could induce nuclear accumulation of SIRT1. Therefore, the present study aims to investigate the possible role of paeonol in chondrocyte inflammation and cartilage protection in osteoarthritis (OA) as well as its regulation of SIRT1. Primary chondrocytes from rat knee joints were transfected with short hairpin (sh) - SIRT1 and (or) paeonol prior to IL-1β exposure, and then inflammatory response, apoptosis, and extracellular matrix (ECM) degradation in the cells were evaluated concurrent with the activation of the nuclear factor κβ (NF-κβ) signaling pathway. Increased levels of TNF-α, IL-17, IL-6, matrix metalloproteinase 1 (MMP-1), MMP-3, and MMP-13 along with decreased tissue inhibitor of metalloproteinases 1 and type II collagen levels were found in IL-1β-stimulated chondrocytes. Chondrocyte apoptosis was elevated and the NF-κβ signaling pathway was activated in response to IL-1β treatment. Paeonol enhanced SIRT1 expression to inactivate the NF-κβ signaling pathway, thereby ameliorating inflammatory cytokine secretion, ECM degradation, and chondrocyte apoptosis. In conclusion, the results of the present study confirm the potential of paeonol as a candidate OA drug.

Positive feedback loop of lncRNA FAM201A/miR‑146a‑5p/POU2F1 regulates IL‑1β‑induced chondrocyte injury in vitro

Numerous studies have previously demonstrated that long non-coding RNAs (lncRNAs) serve an important regulatory role in osteoarthritis (OA). In particular, the lncRNA family with sequence similarity 201 member A (FAM201A) was previously found to be downregulated in necrotic femoral head samples. However, the role of FAM201A in IL-1β-induced chondrocyte injury remains unclear. It was hypothesized that FAM201A may exert a protective effect on IL-1β-induced chondrocyte injury in OA by sponging microRNAs (miRNAs/miRs). The purpose of the present study was to explore the role and molecular mechanism of FAM201A in IL-1β-induced chondrocyte injury. A model of OA was established by stimulation C-28/I2 cell with IL-1β in vitro. The expression levels of FAM201A following IL-1β-induced chondrocyte injury were detected via reverse transcription-quantitative PCR. Luciferase reporter assay was used to assess the possible associations among FAM201A, miR-146a-5p and POU class 2 homeobox 1 (POU2F1). Chromatin immunoprecipitation assay was performed to analyze the interaction between POU2F1 and miR-146a-5p. ELISA, TUNEL and western blotting were performed to measure the level of inflammation, lactate dehydrogenase release, apoptosis and the expression of apoptosis-related proteins (Bcl-2, Bax, cleaved caspase 3 and cleaved caspase 9), respectively. The expression levels of FAM201A were found to be downregulated following IL-1β-induced chondrocyte injury. Overexpression of FAM201A exerted a protective effect against IL-1β-induced chondrocyte injury. In addition, FAM201A could upregulate the expression levels of POU2F1 by sponging miR-146a-5p. Further experiments revealed that POU2F1 could bind to the promoter region of FAM201A and subsequently regulate the expression levels of POU2F1, indicating a role for the FAM201A/miR-146a-5p/POU2F1 positive feedback loop in IL-1β-induced chondrocyte injury. The present study revealed the protective effects of the FAM201A/miR-146a-5p/POU2F1 positive feedback loop on IL-1β-induced chondrocyte injury and provided a potential therapeutic target for OA.

Paeonol promotes Opa1-mediated mitochondrial fusion via activating the CK2α-Stat3 pathway in diabetic cardiomyopathy

Diabetes disrupts mitochondrial function and often results in diabetic cardiomyopathy (DCM). Paeonol is a bioactive compound that has been reported to have pharmacological potential for cardiac and mitochondrial protection. This study aims to explore the effects of paeonol on mitochondrial disorderes in DCM and the underlying mechanisms. We showed that paeonol promoted Opa1-mediated mitochondrial fusion, inhibited mitochondrial oxidative stress, and preserved mitochondrial respiratory capacity and cardiac performance in DCM in vivo and in vitro. Knockdown of Opa1 blunted the above protective effects of paeonol in both diabetic hearts and high glucose-treated cardiomyocytes. Mechanistically, inhibitor screening, siRNA knockdown and chromatin immunoprecipitation experiments showed that paeonol-promoted Opa1-mediated mitochondrial fusion required the activation of Stat3, which directly bound to the promoter of Opa1 to upregulate its transcriptional expression. Moreover, pharmmapper screening and molecular docking studies revealed that CK2α served as a direct target of paeonol that interacted with Jak2 and induced the phosphorylation and activation of Jak2-Stat3. Knockdown of CK2α blunted the promoting effect of paeonol on Jak2-Stat3 phosphorylation and Opa1-mediated mitochondrial fusion. Collectively, we have demonstrated for the first time that paeonol is a novel mitochondrial fusion promoter in protecting against hyperglycemia-induced mitochondrial oxidative injury and DCM at least partially via an Opa1-mediated mechanism, a process in which paeonol interacts with CK2α and restores its kinase activity that subsequently increasing Jak2-Stat3 phosphorylation and enhancing the transcriptional level of Opa1. These findings suggest that paeonol or the promotion of mitochondrial fusion might be a promising strategy for the treatment of DCM.

Paeonol assists fluconazole and amphotericin B to inhibit virulence factors and pathogenicity of Candida albicans

This study aimed to evaluate the mono- and dual- antifungal activities of paeonol (PAE) and fluconazole (FLZ)/amphotericin B (AmB). To this end, the effects of PAE and FLZ/AmB on cell surface hydrophobicity, hydrolase activity, morphological transition were investigated in vitro and in a Galleria mellonella infection model. The results showed a relatively high minimum inhibitory concentration (MIC) and sessile MIC (SMIC) of PAE alone. However, compared with the single drug, the combined use of PAE and FLZ/AmB had a potent synergistic potential to inhibit the virulence factors for Candida. The concomitant use of two drugs was consistently more effective than either drug alone for increasing survival rate, decreasing the fungal burden, and alleviating the pathological features of G. mellonella infected by the fungus. Taken together, these findings demonstrate the anti-Candida effects of PAE plus FLZ/AmB and their potential to increase the sensitivity of C. albicans to FLZ/AmB of PAE.

Role of adipose tissues in osteoarthritis

PURPOSE OF REVIEW

Epidemiologic studies reveal that the link between obesity and osteoarthritis cannot be uniquely explained by overweight-associated mechanical overload. For this reason, much attention focuses on the endocrine activity of adipose tissues. In addition to the systemic role of visceral and subcutaneous adipose tissues, many arguments highlight the involvement of local adipose tissues in osteoarthritis.

RECENT FINDINGS

Alteration in MRI signal intensity of the infrapatellar fat pad may predict both accelerated knee osteoarthritis and joint replacement. In this context, recent studies show that mesenchymal stromal cells could play a pivotal role in the pathological remodelling of intra-articular adipose tissues (IAATs) in osteoarthritis. In parallel, recent findings underline bone marrow adipose tissue as a major player in the control of the bone microenvironment, suggesting its possible role in osteoarthritis.

SUMMARY

The recent description of adipose tissues of various phenotypes within an osteoarthritic joint allows us to evoke their direct involvement in the initiation and progression of the osteoarthritic process. We can expect in the near future the discovery of novel molecules targeting these tissues.

Paeonol alleviates dextran sodium sulfate induced colitis involving Candida albicans-associated dysbiosis

Inflammatory bowel disease (IBD), which consists of ulcerative colitis (UC) and Crohn's disease (CD), is a chronic inflammatory disorder of the gastrointestinal tract. Occurrence and development of UC have been associated with multiple potential causative factors, which include fungal dysbiosis. Growing evidence reveals that Candida albicans-associated dysbiosis is correlated with clinical deterioration in UC. Paeonol (PAE) is a commonly used traditional medicine with multiple reported properties including effective alleviation of UC. In this study, a murine UC model was established by colonizing mice with additional C. albicans via gavage prior to dextran sodium sulfate (DSS) administration. Effects of PAE treatment were also assessed at initiation and in preestablished C. albicans-associated colitis. The results showed that C. albicans supplementation could aggravate disease activity index (DAI), compromise mucosal integrity, exacerbate fecal and tissue fungal burdens, increase serum β-glucan and anti-Saccharomyces cerevisiae antibody (ASCA) levels, promote serum and colonic tissue pro-inflammatory cytokine secretion (tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, and IL-8) and decrease the anti-inflammatory cytokine IL-10 level. It also stimulated Dectin-1, TLR2 and TLR4 as well as expression of their downstream effector NF-κB in colonic tissue. After PAE treatment, the adverse impacts of C. albicans on colitis were relieved, via decreased receptor-associated local and systemic inflammation. Our study suggests that PAE should be a candidate for treatment of fungal dysbiosis-associated UC and may act through the Dectin-1/NF-κB pathway in collaboration with TLR2 and TLR4.

LAY SUMMARY

Candida albicans is believed to be an important stimulator in ulcerative colitice (UC) development. Suppressing the growth of intestinal C. albicans can be contributory to the amelioration of UC. Paeonol (PAE) is a commonly used traditional medicine with multiple biological functions. In this study, we observed that PAE could alleviate symptoms in mice UC model accompanying with burden reduction of C. albicans. Therefore, we suppose that PAE can be a candidate in the treatment of C. albicans-associated UC.

Resveratrol Exerts Anti-Osteoarthritic Effect by Inhibiting TLR4/NF-κB Signaling Pathway via the TLR4/Akt/FoxO1 Axis in IL-1β-Stimulated SW1353 Cells

Purpose

Osteoarthritis (OA) is associated with chronic low-grade inflammation. Resveratrol exerts protective effects on OA through its anti-inflammatory property; however, the mechanism of resveratrol on anti-inflammatory signaling pathways has not been fully elucidated yet. The aim of the present study was to investigate whether resveratrol-mediated PI3K/Akt expression is linked to TLR4/NF-κB pathway and the role of TLR4/Akt/FoxO1 axis in the anti-osteoarthritic effect of resveratrol.

Methods

SW1353 cells stimulated by IL-1β (10 ng/mL) were cultured in the presence or absence of resveratrol (50 μM) and then treated with TLR4 siRNA, PI3K inhibitor LY294002 or FoxO1 siRNA, respectively. The associated proteins of TLR4 signaling pathways and TLR4/Akt/FoxO1 axis were evaluated by Western blot. The level of IL-6 in the supernatant was detected by ELISA.

Results

IL-1β treatment increased the expression of TLR4/NF-κB and phosphorylation of PI3K/Akt and FoxO1, while additional resveratrol further upregulated the expression of PI3K/Akt and FoxO1 phosphorylation but downregulated TLR4 signals in SW1353 cells. Further analyses by the inhibition of TLR4, PI3K/Akt and FoxO1 signaling pathways, respectively, showed that the activation of TLR4 can induce PI3K/Akt phosphorylation, which increases the phosphorylation of FoxO1 and inactivates it. Next, inactivated-FoxO1 can reduce the expression of TLR4, which forms a self-limiting mechanism of inflammation. Resveratrol treatment can upregulate PI3K/Akt phosphorylation and inactivate FoxO1, thereby reducing TLR4 and inflammation.

Conclusion

This study reveals that TLR4/Akt/FoxO1 inflammatory self-limiting mechanism may exist in IL-1β-stimulated SW1353 cells. This study reveals a novel cross-talk mechanism which is between integrated PI3K/Akt/FoxO1 signaling network and TLR4-driven innate responses in IL-1β-stimulated SW1353 cells. Resveratrol may exert anti-OA effect by enhancing the self-limiting mechanism of inflammation through TLR4/Akt/FoxO1 axis.

Paeonol protects against testicular ischaemia-reperfusion injury in rats through inhibition of oxidative stress and inflammation

Ischaemia-reperfusion (IR) is the most common form of testicular injury that results in oxidative damage and inflammation ending by subinfertility. Paeonol, a natural phenolic compound, exhibits antioxidant and anti-inflammatory effects. Thus, the present study investigated the role of paeonol in rat testicular IR injury. Thirty adult Wistar rats were randomly divided into five groups; sham, sham treated with paeonol, IR injury, and IR pre-treated with paeonol at low and high doses. Serum testosterone and testicular levels of malondialdehyde and reduced glutathione (GSH) besides superoxide dismutase (SOD) activity were determined. Gene quantifications for tumour necrosis factor-α (TNF-α), hypoxia-inducible factor-1α (HIF-1α) and heat shock protein 70 (HSP70) were also assessed. Histopathological pictures and the immunohistochemical expression of testicular nuclear factor erythroid 2-related factor 2 (Nrf2), interleukin-1β (IL-1β) and interleukin-6 (IL-6) were shown. Pre-treatment with paeonol prevented the drop in serum testosterone, alongside with improvement of testicular malondialdehyde and GSH levels plus SOD activity. Paeonol regained the normal spermatogenesis with prevention of IR-induced increase in TNF-α, HIF-1α and HSP70 gene expression besides IL-1β and IL-6 immunostaining and reduction in Nrf2 protein expression. Paeonol exerted a dose-dependent beneficial effect on testicular IR injury. This effect was achieved by its antioxidant and anti-inflammatory effects.

Paeonol Attenuates Methotrexate-Induced Cardiac Toxicity in Rats by Inhibiting Oxidative Stress and Suppressing TLR4-Induced NF-κB Inflammatory Pathway

Methotrexate (MTX) is a commonly used chemotherapeutic agent. Oxidative stress and inflammation have been proved in the development of MTX toxicity. Paeonol is a natural phenolic compound with various pharmacological activities including antioxidant and anti-inflammatory properties. The aim of the present study was to evaluate the protective effect of paeonol against MTX-induced cardiac toxicity in rats and to evaluate the various mechanisms that underlie this effect. Paeonol (100 mg/kg) was administered orally for 10 days. MTX cardiac toxicity was induced at the end of the fifth day of the experiment, with or without paeonol pretreatment. MTX-induced cardiac damage is evidenced by a distortion in the normal cardiac histological structure, with significant oxidative and nitrosative stress shown as a significant increase in NADPH oxidase-2, malondialdehyde, and nitric oxide levels along with a decrease in reduced glutathione concentration and superoxide dismutase activity compared to the control group. MTX-induced inflammatory effects are evidenced by the increased cardiac toll-like receptor 4 (TLR4) mRNA expression and protein level as well as increased cardiac tumor necrosis factor- (TNF-) α and interleukin- (IL-) 6 levels along with increased nuclear factor- (NF-) κB/p65 immunostaining. MTX increased apoptosis as shown by the upregulation of cardiac caspase 3 immunostaining. Paeonol was able to correct the oxidative and nitrosative stress as well as the inflammatory and apoptotic parameters and restore the normal histological structure compared to MTX alone. In conclusion, paeonol has a protective effect against MTX-induced cardiac toxicity through inhibiting oxidative and nitrosative stress and suppressing the TLR4/NF-κB/TNF-α/IL-6 inflammatory pathway, as well as causing an associated reduction in the proapoptotic marker, caspase 3.

Therapeutic Effect of Ecdysterone Combine Paeonol Oral Cavity Direct Administered on Radiation-Induced Oral Mucositis in Rats

Radiation-induced oral mucositis represents an influential factor in cancer patients’ accepted radiation therapy, especially in head and neck cancer. This research investigates the treatment effect of Ecdysterone (a steroid derived from the dry root of Achyranthes bidentate) and Paeonol (a compound derived from Cortex Moutan) on radiation-induced oral mucositis and possible underlying mechanisms. Concisely, 20 Gy of X-rays (single-dose) irradiated the cranial localization in rats for the modeling of oral mucositis. The therapeutic effects of Ecdysterone-Paeonol oral cavity directly administered on radiation-induced oral mucositis were investigated by weight changes, direct observations, visual scoring methods, ulcer area/total area, and basic recovery days. Assessments of tumor necrosis factor α and interleukin-6 were performed to evaluate the inflammatory cytokines secretion in the damaged areas of tongues harvested post-treatment, and changes in signaling pathways were investigated by Western blotting. System Drug Target (SysDT) methods revealed the targets of Ecdysterone-Paeonol in order to support compound-target network construction. Four representative targets with different functions were chosen. The binding interactions between the compound and receptor were evaluated by molecular docking to investigate the binding affinity of the ligand to their protein targets. Ecdysterone-Paeonol, administered orally, effectively improved radiation-induced oral mucositis in rats, and the therapeutic effect was better than Ecdysterone administered orally on its own. In this study, calculational chemistry revealed that Ecdysterone-Paeonol affected 19 function targets associated with radiation-induced oral mucositis, including apoptosis, proliferation, inflammation, and wound healing. These findings position Ecdysterone-Paeonol as a potential treatment candidate for oral mucositis acting on multiple targets in the clinic.