Paeonol alleviates postmenopause-induced neuropsychiatric symptoms through the modulation of GPR30 in ovariectomized mice

ETHNOPHARMACOLOGICAL RELEVANCE

The Moutan cortex (MC), the root bark of Paeonia suffruticosa Anderws (Paeoniaceae), has been historically employed in traditional herbal medicine for addressing women's ailments by replenishing kidney Yin.

AIM OF THE STUDY

We aimed to explore if paeonol, an active constituent of MC, could ameliorate neuropsychiatric symptoms, such as anxiety, depression, and cognitive impairments, associated with post-menopausal syndrome (PMS) in an ovariectomized (OVX) mouse model.

MATERIALS AND METHODS

The experimental design comprised 6 groups, including a sham group, OVX group, paeonol administration groups (3, 10 or 30 mg/kg, p.o.), and an estradiol (E2)-treated positive control group. Behavioral tests including the open field, novel object recognition, Y-maze, elevated plus-maze, splash, and forced swimming tests were conducted. In addition, we investigated the effets of paeonol on the phosphorylated levels of phosphatidylinositol 3-kinase (PI3K), Akt, and mammalian target of rapamycin (mTOR), as well as on the expression levels of G protein-coupled receptor (GPR30) and brain-derived neurotrophic factor (BDNF) in the prefrontal cortex and hippocampus.

RESULTS

Paeonol treatment (10 and 30 mg/kg, p.o.) effectively reversed the cognitive decline in OVX mice, measured by the novel object recognition and Y-maze tests, similar to that in the positive control group. Additionally, it alleviated anxiety- and depressive-like behaviors, as evaluated by the elevated plus-maze test, splash test, and forced swimming test. Paeonol restored GPR30 expression levels in the prefrontal cortex and hippocampus, mirroring the effects of E2 administration. Furthermore, it reversed the reduced expression levels of the PI3K-Akt-mTOR signaling pathway in the prefrontal cortex and hippocampus and increased BDNF expression in the hippocampus of OVX mice.

CONCLUSION

This research suggests that paeonol would be beneficial for alleviating PMS-associated cognitive impairment, anxiety and depression.

The anti-atherosclerotic effect of Paeonol against the lipid accumulation in macrophage-derived foam cells by inhibiting ferroptosis via the SIRT1/NRF2/GPX4 signaling pathway

Atherosclerosis (AS) is the underlying cause of many severe vascular diseases and is primarily characterized by abnormal lipid metabolism. Paeonol (Pae), a bioactive compound derived from Paeonia Suffruticosa Andr., is recognized for its significant role in reducing lipid accumulation. Our research objective is to explore the link between lipid buildup in foam cells originating from macrophages and the process of ferroptosis, and explore the effect and mechanism of Pae on inhibiting AS by regulating ferroptosis. In our animal model, ApoE-deficient mice, which were provided with a high-fat regimen to provoke atherosclerosis, were administered Pae. The treatment was benchmarked against simvastatin and ferrostatin-1. The results showed that Pae significantly reduced aortic ferroptosis and lipid accumulation in the mice. In vitro experiments further demonstrated that Pae could decrease lipid accumulation in foam cells induced by oxidized low-density lipoprotein (LDL) and challenged with the ferroptosis inducer erastin. Crucially, the protective effect of Pae against lipid accumulation was dependent on the SIRT1/NRF2/GPX4 pathway, as SIRT1 knockdown abolished this effect. Our findings suggest that Pae may offer a novel therapeutic approach for AS by inhibiting lipid accumulation through the suppression of ferroptosis, mediated by the SIRT1/NRF2/GPX4 pathway. Such knowledge has the potential to inform the creation of novel therapeutic strategies aimed at regulating ferroptosis within the context of atherosclerosis.

Paeonol interferes with lupus nephritis by regulating M1/M2 polarization of macrophages

Systemic lupus erythematosus (SLE) is a complex autoimmune disease of unknown etiology. It is marked by the production of pathogenic autoantibodies and the deposition of immune complexes. Lupus nephritis (LN) is a prevalent and challenging clinical complications of SLE. Cortex Moutan contains paeonol as its main effective component. In this study, using the animal model of SLE induced by R848, it was found that paeonol could alleviate the lupus-like symptoms of lupus mouse model induced by R848 activating TLR7, reduce the mortality and ameliorate the renal damage of mice. In order to explore the mechanism of paeonol on lupus nephritis, we studied the effect of paeonol on the polarization of Raw264.7 macrophages in vitro. The experimental results show that paeonol can inhibit the polarization of macrophages to M1 and promote their polarization to M2, which may be related to the inhibition of MAPK and NF-κB signaling pathways. Our research provides a new insight into paeonol in the treatment of lupus nephritis, which is of great importance for the treatment of systemic lupus erythematosus and its complications.

Paeonol attenuates nonalcoholic steatohepatitis by regulating intestinal flora and AhR/NLRP3/Caspase-1 metabolic pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Non-alcoholic steatohepatitis (NASH) is a common metabolic liver injury disease that is closely associated with obesity and metabolic disorders. Paeonol, an active ingredient found in Moutan Cortex, a traditional Chinese medicine which exhibits significant therapeutic effect on liver protection, has shown promising effects in treating liver diseases, particularly NASH. However, the specific intervention mechanism of paeonol on NASH is still unknown.

AIM OF THE STUDY

Our objective is to elucidate the pharmacological mechanism of paeonol in intervening NASH at the in vivo level, focusing on the impact on intestinal flora, tryptophan-related targeted metabolome, and related Aryl hydrocarbon receptor (AhR) pathways.

MATERIALS AND METHODS

Here, we explored the intervention effect of paeonol on NASH by utilizing the NASH mouse model. The Illumina highthroughput sequencing technology was preformed to determine the differences of gut microbiota of model and paeonol treatment group. The concentration of Indoleacetic acid is determined by ELISA. The intervention effect of NASH mouse and AhR/NLRP3/Caspase-1 metabolic pathway is analyzed by HE staining, oil red O staining, Immunohistochemistry, Immunofluorescence, Western blot and qRT-PCR assays. Fecal microbiota transplantation experiment also was performed to verify the intervention effect of paeonol on NASH by affecting gut microbiota.

RESULTS

Firstly, we discovered that paeonol effectively reduced liver pathology and blood lipid levels in NASH mice, thereby intervening in the progression of NASH. Subsequently, through 16S meta-analysis, we identified that paeonol can effectively regulate the composition of intestinal flora in NASH mice, transforming it to resemble that of normal mice. Specifically, paeonol decreased the abundance of certain Gram-negative tryptophan-metabolizing bacteria. Moreover, we discovered that paeonol significantly increased the levels of metabolites Indoleacetic acid, subsequently enhancing the expression of AhR-related pathway proteins. This led to the inhibition of the NOD-like receptor protein 3 (NLRP3) inflammasome production and inflammation generation in NASH. Lastly, we verified the efficacy of paeonol in intervening NASH by conducting fecal microbiota transplantation experiments, which confirmed its role in promoting the AhR/NLRP3/cysteinyl aspartate specific proteinase (Caspase-1) pathway.

CONCLUSIONS

Our findings suggest that paeonol can increase the production of Indoleacetic acid by regulating the gut flora, and promote the AhR/NLRP3/Caspase-1 metabolic pathway to intervene NASH.

MicroRNA let-7g links foam cell formation and adipogenic differentiation: A key regulator of Paeonol treating atherosclerosis-osteoporosis

BACKGROUD

High comorbidity rates have been reported in patients with atherosclerosis and osteoporosis, posing a serious risk to the health and well-being of elderly patients. To improve and update clinical practice regarding the joint treatment of these two diseases, the common mechanisms of atherosclerosis and osteoporosis need to be clarified. MicroRNAs (miRNAs), are importance molecules in the pathogenesis of human diseases, including in cardiovascular and orthopedic fields. They have garnered interest as potential targets for novel therapeutic strategies. However, the key miRNAs involved in atherosclerosis and osteoporosis and their precise regulation mechanisms remain unknown. Paeonol (Pae), an active ingredient in Cortex Moutan, has shown promising results in improving both lipid and bone metabolic abnormalities. However, it is uncertain whether this agent can exert a cotherapeutic effect on atherosclerosis and osteoporosis.

OBJECTIVE

This study aimed to screen important shared miRNAs in atherosclerotic and osteoporotic complications, and explore the mechanism of the protective effects of Pae against atherosclerosis and osteoporosis in high-fat diet (HFD)-fed ApoE-/- mice.

METHODS

An experimental atherosclerosis and osteoporosis model was established in 40-week-old HFD ApoE-/- mice. Various techniques such as Oil Red O staining, HE staining and micro-CT were used to confirm the co-occurrence of these two diseases and efficacy of Pae in addition to the associated biochemical changes. Bioinformatics was used to screen key miRNAs in the atherosclerosis and osteoporosis model, and gene involvement was assessed through serum analyses, qRT-PCR, and western blot. To investigate the effect of Pae on the modulation of the miR let-7g/HMGA2/CEBPβ pathway, Raw 264.7 cells were cocultured with bone marrow mesenchymal stem cells (BMSCs) and treated with an miR let-7g mimic/inhibitor.

RESULTS

miR let-7g identified using bioinformatics was assessed to evaluate its participation in atherosclerosis-osteoporosis. Experimental analysis showed reduced miR let-7g levels in the atherosclerosis-osteoporosis mice model. Moreover, miR let-7g was required for BMSC - Raw 264.7 cell crosstalk, thereby promoting foam cell formation and adipocyte differentiation. Treatment with Pae significantly reduced plaque accumulation and foam cell number in the aorta while increasing bone density and improving trabecular bone microarchitecture in HFD ApoE-/- mice. Pae also increased the level of miR let-7g in the bloodstream of model mice. In vitro studies, Pae enhanced miR let-7g expression in BMSCs, thereby suppressing the HMGA2/CEBPβ pathway to prevent the formation of foam cells and differentiation of adipocytes induced by oxidized low-density lipoprotein (ox-LDL).

CONCLUSION

The study results suggested that miR let-7g participates in atherosclerosis -osteoporosis regulation and that Pae acts as a potential therapeutic agent for preventing atherosclerosis-osteoporosis through regulatory effects on the miR let-7g/HMGA2/CEBPβ pathway to hinder foam cell formation and adipocyte differentiation.

Paeonol promotes longevity and fitness in Caenorhabditis elegans through activating the DAF-16/FOXO and SKN-1/Nrf2 transcription factors

Paeonol, as one of the most abundant plant-derived polyphenols, has multiple bioactivities including anti-inflammatory, anti-tumor, and anti-cardiovascular diseases. Nevertheless, the anti-aging effects and related mechanisms of paeonol are rarely reported. In this study, we found that paeonol significantly prolonged the mean lifespan of Caenorhabditis elegans (C. elegans) by 28.49% at a dose of 200 μM. Moreover, paeonol promoted the health of C. elegans by increasing the body bending and pharyngeal pumping rates and reducing the lipofuscin accumulation level. Meanwhile, paeonol induced the expression of stress-related genes or proteins by activating the transcription factors DAF-16/FOXO, SKN-1/Nrf2, and HSF-1, which in turn enhanced oxidative and thermal stress tolerance. The mechanism behind the anti-aging effect of paeonol occurred by down-regulating the insulin/IGF-1 signaling (IIS) pathway. Our findings shed new light on the application of paeonol for longevity promotion and human health.

Paeonol can improve hypoxic-induced H9c2 cells injury and ion channel activity by up-regulating the expression of CKIP-1

BACKGROUND

Paeonol is a representative active ingredient of the traditional Chinese medicinal herbs Cortex Moutan, which has a well-established cardioprotective effect on ischemic heart disease. However, there is little evidence of the protective effect of paeonol, and its pharmacological mechanism is also unclear. This study aims to explore the protective effect and mechanism of Paeonol on myocardial infarction rat and hypoxic H9c2 cells.

METHODS

Myocardial ischemia/reperfusion (I/R) was induced by occlusion of the left anterior descending coronary artery for 1 h followed by 3 h of reperfusion, and then gavage with Paeonol for 7 days. H9c2 cells were applied for the in vitro experiments and hypoxia/reoxygenation (H/R) model was established. CKIP-1 expression was evaluated by qPCR and western blot. The expression of genes involved in apoptosis, inflammation and ion channel was measured by western blot. The currents levels of Nav1.5 and Kir2.1 were measured by whole-cell patch-clamp recording.

RESULTS

CKIP-1 expression was decreased in H/R-induced H9c2 cells, which was inversely increased after Paeonol treatment. Paeonol treatment could increase the viability of H/R-induced H9c2 cells and diminish the apoptosis and inflammation of H/R-induced H9c2 cells, while si-CKIP-1 treatment inhibited the phenomena. Moreover, the currents levels of Nav1.5 and Kir2.1 were reduced in H/R-induced H9c2 cells, which were inhibited after Paeonol treatment. Intragastric Paeonol can reduce the ventricular arrhythmias in rats with myocardial infarction.

CONCLUSIONS

The protective effects of Paeonol on myocardial infarction rats and hypoxic H9c2 cells were achieved by up-regulating CKIP-1.

Protective mechanism of Paeonol on central nervous system

Cerebrovascular diseases involve neuronal damage, resulting in degenerative neuropathy and posing a serious threat to human health. The discovery of effective drug components from natural plants and the study of their mechanism are a research idea different from chemical synthetic medicines. Paeonol is the main active component of traditional Chinese medicine Paeonia lactiflora Pall. It widely exists in many medicinal plants and has pharmacological effects such as anti-atherosclerosis, antiplatelet aggregation, anti-oxidation, and anti-inflammatory, which keeps generally used in the treatment of cardiovascular and cerebrovascular diseases. Based on the therapeutic effects of Paeonol for cardiovascular and cerebrovascular diseases, this article reviewed the pharmacological effects of Paeonol in Alzheimer's disease, Parkinson's disease, stroke, epilepsy, diabetes encephalopathy, and other neurological diseases, providing a reference for the research of the mechanism of Paeonol in central nervous system diseases.

Paeonol upregulates expression of tumor suppressors TNNC1 and SCARA5, exerting anti-tumor activity in non-small cell lung cancer cells

Paeonol, a naturally bioactive phenolic ingredient predominantly isolated from Paeonia suffruticosa, has recently garnered significant interest as an anti-tumor agent against diverse carcinomas including non-small cell lung cancer (NSCLC). However, the anti-tumor mechanism of paeonol in NSCLC remains unclear. Cell viability, caspase-3 activity, and apoptosis were evaluated using CCK-8 assay, Caspase-3 Colorimetric Assay Kit, and flow cytometry analysis, respectively. GSE186218 was downloaded from NCBI Gene Expression Omnibus (GEO). The common genes were screened using GEO2R and Draw Venn Diagram software. Expression of troponin C type 1 (TNNC1), scavenger receptor class A member 5 (SCARA5), phosphorylated protein kinase B (AKT) (p-AKT) and AKT was examined using GEPIA database, qRT-PCR and western blot analysis. Paeonol treatment concentration-dependently inhibited cell viability and increased caspase-3 activity and apoptotic rate in NSCLC cells. Only 5 overlapping genes including TNNC1 and SCARA5 were obtained among 232 upregulated genes in GSE186218, 200 underexpressed genes in TCGA-LUAD, and 200 underexpressed genes in TCGA-LUSC according to the Venn diagram software. TNNC1 and SCARA5, two known tumor suppressors, were significantly downregulated in LUAD and LUSC tissues and NSCLC cells. Paeonol dose-dependently upregulated TNNC1 and SCARA5 expression in NSCLC cells. Paeonol suppressed the AKT pathway by upregulating TNNC1 and SCARA5 expression. AKT inhibitor attenuated the effects of TNNC1 or SCARA5 knockdown on the anti-tumor activity of paeonol. In conclusion, paeonol exhibited anti-cancer activity in NSCLC cells through inactivating the AKT pathway by upregulating TNNC1 or SCARA5.

Paeonol improves renal and vascular angiotensin II type 1 receptor function via inhibiting oxidative stress in spontaneously hypertensive rats

BACKGROUND

Oxidative stress has been shown to play a critical role in the pathogenesis of hypertension. Paeonol, a major phenolic component extracted from Moutan Cortex, exerts a beneficial effect in preventing cardiovascular disease via reducing oxidative stress. The present study investigated the protective mechanism of paeonol against high blood pressure in spontaneous hypertension rats (SHRs).

METHODS

Wistar-Kyoto (WKY) rats and SHRs received vehicle or peaonol in the drinking water for 5 weeks. Blood pressure was measured by tail-cuff plethysmography and oxidative stress in kidney and vascular tissue was examined by enzyme-linked immunosorbed assay. The functions of angiotensin II type 1 receptors (AT₁R) in the kidney and mesenteric artery were measured by natriuresis and vasoconstrictor response, respectively.

RESULTS

Compared with vehicle-treated WKY rats, vehicle-treated SHRs exhibited higher blood pressure, increased oxidative stress, accompanied by exaggerated diuretic and natriuretic responses to candesartan (AT₁ receptor antagonist) and vasoconstrictor responses to angiotensin II (Ang II). Moreover, SHRs had higher ACE and AT₁R in the kidney and mesenteric artery, and higher Ang II and lower renin levels. Interestingly, paeonol treatment reduced the candesartan-induced increase in diuresis and natriuresis and vasoconstrictor responses to Ang II, and lowered blood pressure in SHRs, accompanied by reducing AT₁R protein expression in the kidney and mesenteric artery of SHR, and Ang II levels in plasma and increasing renin levels in renal cortex. In addition, these changes were associated with reducing oxidative stress.

CONCLUSIONS

The present study suggests that paeonol improves renal and vascular AT₁R functions by inhibition of oxidative stress, thus lowering blood pressure in SHRs.

Investigation on the inhibition mechanism and binding behavior of paeonol to tyrosinase and its anti-browning property by multi-spectroscopic and molecular docking methods

Paeonol, as one effective tyrosinase inhibitor, had been used as food preservative and clinical medication for skin disorders. In this study, the inhibition mechanism and binding behavior of paeonol to tyrosinase and its anti-browning property were investigated using multi-spectroscopic and molecular docking methods. Activity assay and kinetic results confirmed paeonol as a reversible mixed-type tyrosinase inhibitor. Results of the mechanistic studies were clarified using fluorescence quenching, synchronous fluorescence, CD spectra and 3D fluorescence, and showed that the binding of paeonol to tyrosinase might change the chromophore microenvironment and conformation of tyrosinase to inhibit enzyme catalytic activity. Molecular docking results revealed the detailed binding between paeonol and tyrosinase. Moreover, paeonol could prevent the browning of fresh-cut apples, as well as inhibiting PPO and POD activities and increasing APX activity. All above findings established a reliable basis for the inhibitory mechanism of paeonol against tyrosinase and therefore contributed to its application in anti-browning.

Paeonol ameliorates hippocampal neuronal damage by inhibiting GRM5/GABBR2/β-arrestin2 and activating the cAMP-PKA signaling pathway in premenstrual irritability rats

Premenstrual dysphoric disorder (PMDD) is a periodic psychiatric disorder with high prevalence in women of childbearing age, seriously affecting patients' work and life. Currently, the international first-line drugs for PMDD have low efficiency and increased side effects. Paeonol, a major component of the traditional Chinese medicine Cortex Moutan, has been applied in treating PMDD in China with satisfactory results, but the therapeutic mechanism is not fully understood. This study aims to evaluate the therapeutic effects and pharmacological mechanisms of paeonol on the main psychiatric symptoms and hippocampal damage in PMDD. We established a premenstrual irritability rat model by the resident-intruder paradigm and performed elevated plus maze and social interactions. And we employed the HE and Nissl staining techniques to observe the therapeutic effect of paeonol on hippocampal damage in PMDD rats. Subsequently, Elisa, qRT-PCR Array, Western Blotting, and cell models were utilized to elucidate the underlying molecular mechanisms through which paeonol intervenes in treating PMDD. In this study, we demonstrated the therapeutic effects of paeonol on irritability, anxiety, and social withdrawal behaviors in rats. In addition, we found that paeonol significantly reduced the serum corticosterone (CORT) level, improved hippocampal morphological structure and neuron number, and reduced hippocampal neuron apoptosis in PMDD rats. Paeonol reduced GRM5, GABBR2, β-arrestin2, and GRK3 expression levels in hippocampal brain regions of PMDD rats and activated the cAMP/PKA signaling pathway. Inhibitor cell experiments showed that paeonol specifically ameliorated hippocampal injury by modulating the β-arrestin2/PDE4-cAMP/PKA signaling pathway. The present study demonstrates, for the first time, that paeonol exerts a therapeutic effect on periodic psychotic symptoms and hippocampal injury in PMDD through inhibiting GRM5/GABBR2/β-arrestin2 and activating cAMP-PKA signaling pathway. These findings enhance our understanding of the pharmacological mechanism underlying paeonol and provide a solid scientific foundation for its future clinical application.

Paeonol alleviates ulcerative colitis in mice by increasing short-chain fatty acids derived from Clostridium butyricum

BACKGROUND

Increasing evidence suggests that repairing the damaged intestinal epithelial barrier and restoring its function is the key to solving the problem of prolonged ulcerative colitis. Previous studies have shown that paeonol (pae) can alleviate colitis by down-regulating inflammatory pathways. In addition, pae also has a certain effect on regulating intestinal flora. However, it remains unclear whether pae can play a role in repairing the intestinal barrier and whether there is a relationship between the therapeutic effect and the gut microbiota.

PURPOSES

The aim of this study is to investigate the effect of pae on intestinal barrier repair in UC mice and how the gut microbiota plays a part in it.

STUDY DESIGN AND METHODS

The therapeutic effect of pae was evaluated in a 3% DSS-induced UC mouse model. The role of pae in repairing the intestinal barrier was evaluated by detecting colonic cupped cells by Alcian blue staining, the expression of colonic epithelial tight junction protein by immunofluorescence and western blot, and the proportion of IL-22+ILC3 cells in the lamina propria lymphocytes by flow cytometry. Subsequently, 16S rRNA sequencing was used to observe the changes in intestinal flora, GC-MS was used to detect the level of SCFAs, and qPCR was used to identify the abundance of Clostridium butyricum in the intestine to evaluate the effect of pae on the gut microbiota. The antibiotic-mediated depletion of the gut flora was then used to verify that pae depends on C. butyricum to play a healing role. Finally, non-targeted metabolomics was employed to investigate the potential pathways of pae regulating C. butyricum.

RESULTS

Pae could improve intestinal microecological imbalance and promote the production of short-chain fatty acids (SCFAs). Most importantly, we identified C. butyricum as a key bacterium responsible for the intestinal barrier repair effect of pae in UC mice. Eradication of intestinal flora by antibiotics abolished the repair of the intestinal barrier and the promotion of SCFAs production by pae, while C. butyricum colonization could restore the therapeutic effects of pae in UC mice, which further confirmed that C. butyricum was indeed the "driver bacterium" of pae in UC treatment. Untargeted metabolomics showed that pae regulated some amino acid metabolism and 2-Oxocarboxylic acid metabolism in C. butyricum.

CONCLUSIONS

Our study showed that the restoration of the impaired intestinal barrier by pae to alleviate colitis is associated with increased C. butyricum and SCFAs production, which may be a promising strategy for the treatment of UC.

Paeonol reduces microbial metabolite α-hydroxyisobutyric acid to alleviate the ROS/TXNIP/NLRP3 pathway-mediated endothelial inflammation in atherosclerosis mice

Gut microbiota dysbiosis is an avenue for the promotion of atherosclerosis (AS) and this effect is mediated partly via the circulating microbial metabolites. More microbial metabolites related to AS vascular inflammation, and the mechanisms involved need to be clarified urgently. Paeonol (Pae) is an active compound isolated from Paeonia suffruticoas Andr. with anti-AS inflammation effect. However, considering the low oral bioavailability of Pae, it is worth exploring the mechanism by which Pae reduces the harmful metabolites of the gut microbiota to alleviate AS. In this study, ApoE-/- mice were fed a high-fat diet (HFD) to establish an AS model. AS mice were administrated with Pae (200 or 400 mg·kg-1) by oral gavage and fecal microbiota transplantation (FMT) was conducted. 16S rDNA sequencing was performed to investigate the composition of the gut microbiota, while metabolomics analysis was used to identify the metabolites in serum and cecal contents. The results indicated that Pae significantly improved AS by regulating gut microbiota composition and microbiota metabolic profile in AS mice. We also identified α-hydroxyisobutyric acid (HIBA) as a harmful microbial metabolite reduced by Pae. HIBA supplementation in drinking water promoted AS inflammation in AS mice. Furthermore, vascular endothelial cells (VECs) were cultured and stimulated by HIBA. We verified that HIBA stimulation increased intracellular ROS levels, thereby inducing VEC inflammation via the TXNIP/NLRP3 pathway. In sum, Pae reduces the production of the microbial metabolite HIBA, thus alleviating the ROS/TXNIP/NLRP3 pathway-mediated endothelial inflammation in AS. Our study innovatively confirms the mechanism by which Pae reduces the harmful metabolites of gut microbiota to alleviate AS and proposes HIBA as a potential biomarker for AS clinical judgment.

Paeonol accelerates skin wound healing by regulating macrophage polarization and inflammation in diabetic rats

Diabetic ulcer is usually seen in people with uncontrolled blood sugar. Reportedly, many factors such as impaired glucose metabolism, and macrovascular and microvascular diseases caused angiogenesis disorders and delayed the healing of diabetic ulcers, thus affecting the body's metabolism, nutrition, and immune function. This study aimed to explore the effect of paeonol on skin wound healing in diabetic rats and the related mechanism. A rat model of diabetic ulcer was established. High glucose-treated mouse skin fibroblasts were co-cultured with M1 or M2-polarized macrophages treated with or without paeonol. H&E and Masson staining were used to reveal inflammatory cell infiltration and collagen deposition, respectively. Immunohistochemistry visualized the expression of Ki67, CD31, and vascular endothelial growth factor (VEGF). Western blot was used to detect interleukin (IL)-1β, tumor necrosis factor (TNF)-α, IL-4, IL-10, CD31, VEGFA, and collagen I/III. The expression of iNOS and arginase 1 was revealed by immunofluorescence staining. Paeonol treatment augmented collagen deposition and the expression of Ki67, CD31, VEGF, and macrophage M2 polarization markers (IL-4 and IL-10) and reduced wound area, inflammatory cell infiltration, and macrophage M1 polarization markers (IL-1β and TNF-α) in the ulcerated area. In vitro, paeonol treatment promoted M2-polarization and repressed M1-polarization in macrophages, thereby improving the repair of cell damage induced by high glucose. Paeonol accelerates the healing of diabetic ulcers by promoting M2 macrophage polarization and inhibiting M1 macrophage polarization.

Paeonol repurposing for cancer therapy: From mechanism to clinical translation

Paeonol (PAE) is a natural phenolic monomer isolated from the root bark of Paeonia suffruticosa that has been widely used in the clinical treatment of some inflammatory-related diseases and cardiovascular diseases. Much preclinical evidence has demonstrated that PAE not only exhibits a broad spectrum of anticancer effects by inhibiting cell proliferation, invasion and migration and inducing cell apoptosis and cycle arrest through multiple molecular pathways, but also shows excellent performance in improving cancer drug sensitivity, reversing chemoresistance and reducing the toxic side effects of anticancer drugs. However, studies indicate that PAE has the characteristics of poor stability, low bioavailability and short half-life, which makes the effective dose of PAE in many cancers usually high and greatly limits its clinical translation. Fortunately, nanomaterials and derivatives are being developed to ameliorate PAE's shortcomings. This review aims to systematically cover the anticancer advances of PAE in pharmacology, pharmacokinetics, nano delivery systems and derivatives, to provide researchers with the latest and comprehensive information, and to point out the limitations of current studies and areas that need to be strengthened in future studies. We believe this work will be beneficial for further exploration and repurposing of this natural compound as a new clinical anticancer drug.

Paeonol improves angiotensin II-induced cardiac hypertrophy by suppressing ferroptosis

The aim of this study was to investigate the protective effect of paeonol (pae) on an angiotensin II (AngII)-induced cardiac hypertrophy mouse model. First, AngII mouse models were constructed and randomly grouped into the control (con), AngII, and AngII + Pae groups. Compared with that in the blank group, the surface area of myocardial cells in the AngII group increased significantly. In contrast to that in the AngII group, the cardiomyocyte surface area in the Pae group was significantly reduced. Ultrasound results showed that the myocardial function of mice in the AngII group was decreased compared with that in the Con group, while the myocardial function of mice in the Pae treatment was significantly improved. Moreover, the Fe2+ and lipid peroxide levels of primary cardiomyocytes were significantly increased after treatment with AngII and were significantly decreased after the addition of Pae. Compared with those in the Con group, cristae were reduced and the outer membrane was lost in the myocardial tissues of the AngII group, and myocardial MDA, ROS, and Fe2+ levels were increased. However, myocardial damage was significantly alleviated after Pae treatment, and myocardial MDA, ROS, and Fe2+ levels were reduced. Moreover, in myocardial tissue, AngII reduced the protein levels of xCT and GPX4, while the levels of both xCT and GPX4 were increased after Pae treatment. In conclusion, Pae protected the hearts of AngII mice by upregulating the protein expression of xCT and GPX4 and resisting AngII-induced ferroptosis in cardiomyocytes.

Paeonol Promotes Reendothelialization After Vascular Injury Through Activation of c-Myc/VEGFR2 Signaling Pathway

Purpose

Dysfunction of endothelium is associated with multiple pathological vascular diseases. However, how to regulate reendothelialization after vascular injury is not well defined. This study aims to determine whether and how Paeonol controls reendothelialization following artery injury.

Methods

The endothelium of murine carotid artery was denuded by catheter guide wires injury. H&E staining and IF staining were performed to determine whether Paeonol is critical for reendothelialization. BRDU Incorporation Assay, Boyden Chamber Migration Assay, Tube Formation Assay, and Spheroid Sprouting Assay were used to investigate whether Paeonol is involved in regulating proliferation and migration of endothelial cells. The underlying mechanism of how Paeonol regulates reendothelialization was determined by Molecular docking simulation and CO-IP Assay.

Results

Paeonol treatment significantly inhibits neointima formation in carotid artery ligation model by promoting proliferation and migration of endothelial cells. Mechanistically, Paeonol enhances c-Myc expression, consequently interacts with VEGFR2 results in activating VEGF signaling pathway, and eventually promotes reendothelialization after vascular injury.

Conclusion

Our data demonstrated that Paeonol plays a critical role in regulating vascular reendothelialization, which may be therapeutically used for treatment of pathological vascular diseases.

Paeonol attenuates Substance P-induced urticaria by inhibiting Src kinase phosphorylation in mast cells

BACKGROUND

Treatment of chronic urticaria is challenging, the discovery of effective therapeutic drugs is urgently in demand.

PURPOSE

To study the effect and mechanism of Paeonol targeting mast cells and its therapeutic effect on chronic urticaria.

STUDY DESIGN

We developed a chronic urticaria model in vivo and mast cell model in vitro examined the effect of Paeonol in the treatment of chronic urticaria and its mechanism of action in mast cells.

METHOD

The anti-anaphylactoid effect of Paeonol was evaluated in PCA and systemic anaphylaxis models. The treatment role of Paeonol was studied in urticaria model. The release of cytokines and chemokines was measured using enzyme immunoassay kits. Western blot analysis was conducted to investigate phosphorylation of Src, PI3K, and PLC. In vitro kinase assays were conducted to investigate the kinase activity of Lyn, PLC, PI3K and Src.

RESULTS

In our study, Paeonol was able to attenuate evans blue leakage, serum histamine and chemokine release in a passive skin allergic reaction model. Simultaneously, Paeonol inhibited vasodilation and mast cell degranulation in C57BL/6 mice. Further research found that Paeonol alleviated symptoms such as erythema and rash in the Substance P-induced urticaria model, this is accompanied by inhibiting the release of related inflammatory factors. Validation experiments on mast cells in vitro found that Paeonol inhibited the activation of Src-PI3K/Lyn-PLC-NF-κB signaling pathway by crosslinking with Src kinase. Moreover, calcium influx, mast cell degranulation, cytokines generation and chemotaxis were reduced in LAD2 cells. Molecular docking experiments revealed that Paeonol is a specific antagonist targeting Src kinase in the treatment of skin diseases such as urticaria.

CONCLUSION

Paeonol, a herb-derived phenolic compound, can provide drug candidate for developing new drug in treatment of skin disease such as urticaria.

SIGNIFICANCE STATEMENT

In this study, we primarily examined the effect of Paeonol in the treatment of chronic urticaria and its mechanism of action in mast cells. Interestingly, Paeonol was found to regulate Src kinase activity downstream of MRGPRX2 triggered signaling cascade in mast cells. Therefore, this plant-derived phenolic compound may provide a therapeutic option for the treatment of chronic urticaria.

Paeonol, the active component of Cynanchum paniculatum, ameliorated schizophrenia-like behaviors by regulating the PI3K-Akt-GSK3β-NF-κB signalling pathway in MK-801-treated mice

ETHNOPHARMACOLOGICAL RELEVANCE

Cynanchum paniculatum (Bunge) Kitag. ex H. Hara (Asclepiadaceae) have been traditionally used in East Asia as analgesic or antiviral agents. Interestingly, some Chinese and Korean traditional medicinal books reported that the use of C. paniculatum in the treatment of psychotic symptoms, such as hallucinations and delusions.

AIM OF THE STUDY

In this study, we aimed to investigate whether C. paniculatum could improve sensorimotor gating disruption in mice with MK-801-induced schizophrenia-like behaviors. We also aimed to identify the active component of C. paniculatum that could potentially serve as a treatment for schizophrenia and found that paeonol, the major constituent compound of C. paniculatum, showed potential as a treatment for schizophrenia.

MATERIALS AND METHODS

To assess the effect of paeonol on mice with MK-801-induced schizophrenia-like behaviors, we carried out a series of behavioral tests related with symptoms of schizophrenia. In addition, we utilized Western blotting and ELISA techniques to investigate the antipsychotic actions of paeonol.

RESULT

C. paniculatum extract (100 or 300 mg/kg) and paenol (10 or 30 mg/kg) significantly reversed MK-801-induced prepulse deficits in acoustic startle response test. In addition, paeonol (10 or 30 mg/kg) attenuated social novelty preference and novel object recognition memory on MK-801-induced schizophrenia-like behaviour in mice. Furthermore, the phosphorylation levels of PI3K, Akt, GSK3β and NF-κB, as well as related pro-inflammatory cytokine, such as IL-1β and TNF-α, were significantly reversed by the administration of paeonol (10 or 30 mg/kg) in the prefrontal cortex of MK-801-treated mice.

CONCLUSIONS

Collectively, these data show that paeonol can potentially be used as an agent for treating sensorimotor gating deficits, negative symptoms, and cognitive deficits, such as those observed in schizophrenia with few adverse effects.

Paeonol alleviates neuropathic pain by modulating microglial M1 and M2 polarization via the RhoA/p38MAPK signaling pathway

BACKGROUND

This study aimed to investigate the potential mechanism of paeonol in the treatment of neuropathic pain.

METHODS

Relevant mechanisms were explored through microglial pseudotime analysis and the use of specific inhibitors in cell experiments. In animal experiments, 32 SD rats were randomly divided into the sham operation group, the chronic constrictive injury (CCI) group, the ibuprofen group, and the paeonol group. We performed behavioral testing, ELISA, PCR, Western blotting, immunohistochemistry, and immunofluorescence analysis.

RESULTS

The pseudotime analysis of microglia found that RhoA, Rock1, and p38MAPK were highly expressed in activated microglia, and the expression patterns of these genes were consistent with the expression trends of the M1 markers CD32 and CD86. Paeonol decreased the levels of M1 markers (IL1β, iNOS, CD32, IL6) and increased the levels of M2 markers (IL10, CD206, ARG-1) in LPS-induced microglia. The expression of iNOS, IL1β, RhoA, and Rock1 was significantly increased in LPS-treated microglia, while paeonol decreased the expression of these proteins. Thermal hyperalgesia occurred after CCI surgery, and paeonol provided relief. In addition, paeonol decreased the levels of IL1β and IL8 and increased the levels of IL4 and TGF-β in the serum of CCI rats. Paeonol decreased expression levels of M1 markers and increased expression levels of M2 markers in the spinal cord. Paeonol decreased IBA-1, IL1β, RhoA, RhoA-GTP, COX2, Rock1, and p-p38MAPK levels in the spinal dorsal horn.

CONCLUSION

Paeonol relieves neuropathic pain by modulating microglial M1 and M2 phenotypes through the RhoA/p38 MAPK pathway.

Paeonol inhibits melanoma growth by targeting PD1 through upregulation of miR-139-5p

The abnormal immune response mediated by malignant melanoma is related to PD1. Paeonol has pharmacological antitumor activity. Previous studies have indicated that paeonol induces tumor cell apoptosis, but its underlying mechanism in tumor immunity remains unknown. In this study, malignant melanoma was established in normal and thymectomized mice to determine the important role of the thymus in the antitumor effects of paeonol. Paeonol-treated thymocytes were cocultured with melanoma cell spheres to further evaluate the regulatory role of thymocytes in tumor immune dysfunction. Studies have shown that PD1 may be targeted by miR-139-5p. Our results revealed that tumor-induced thymic atrophy was significantly accompanied by high PD1 expression and low miR-139-5p expression. Interestingly, paeonol significantly reversed thymic atrophy and largely protected thymocytes against low PD1 expression and high miR-139-5p expression. Dual-luciferase assays indicated that miR-139-5p interacted with the 3' untranslated region (3'-UTR) of PD1. These results showed that paeonol alleviates PD1-mediated antitumor immunity by reducing miR-139-5p expression and demonstrated a novel mechanism for melanoma immunotherapy.

Paeonol Attenuates the Endothelial-to-Mesenchymal Transition Induced by TGF-β1 in Human Umbilical Vein Endothelial Cells through ALK5-Smad2/3 Signaling Pathway

Background： Paeonol (Pae)， the main active compound of the root of Paeonia albiflora, is efficacious in treating atherosclerosis (AS). Endothelial dysfunction is throughout the pathological progression of AS. It is expected that inhibition of Endothelial-to-mesenchymal transition (EndMT) will be a key target for AS treatment. Objective： In this study, we investigated the molecular mechanism of the regulatory effect of Pae on EndMT in human umbilical vein endothelial cells (HUVECs). Methods： Cell cytotoxicity, proliferation, and migration were detected by CCK-8, the wound healing assay, and EdU staining, respectively. The protein expressions were measured by Western blot or immunofluorescence staining. Immunofluorescence staining was performed to indicate endothelial cells undergoing EndMT in ApoE-/- mice. In vitro TGF-β1-induced EndMT assays were performed in HUVECs and the effect of Pae was explored. Results：We demonstrated that Pae could improve induced TGF-β1-EndMT in vivo and in vitro. Mechanism study revealed that Pae directly bonds to the activin-like kinase 5 (ALK5, also known as TGFβ type I receptor), inhibited downstream Smad2/3 phosphorylation, and thus alleviated EndMT. Notably, overexpression of ALK5 significantly reversed the inhibitory effect of Pae on EndMT in HUVECs. Conclusion：Our results indicate that ALK5 is a promising druggable target for AS, and pharmacological regulation of ALK5-Smad2/3 signaling pathway with small-molecule holds great potential to benefit AS patients.

Paeonol ameliorates endometrial hyperplasia in mice via inhibiting PI3K/AKT pathway-related ferroptosis

BACKGROUND

Paeonol (Pae) is one of the active ingredients from components of Guizhi Fuling Capsule, a traditional Chinese medicine widely used for the treatment of women's diseases, which exhibits various biological and pharmacological activities.

PURPOSE

The objective of this study was to investigate the molecular mechanism underlying the role of Pae in protecting against endometrial hyperplasia (EH).

METHODS

CCK-8 assay was performed to detect the effect of Pae on cell proliferation. Hematoxylin and eosin (H&E) staining was performed to evaluate uterine tissue structure. A network pharmacology study was performed to search the disease targets. Single-cell transcriptome analysis was performed with uterine tissues from 3 healthy donors and 3 EH patients on 10X Genomics platform. Changes in lipid peroxidation were detected by the MDA reaction. IHC assay, Western blot, immunofluorescence and RT-qPCR were used to study the effects of estradiol and Pae on the expression levels of GPX4, PI3K, AKT, p-PI3K, p-AKT in mice.

RESULTS

Pae treatment resulted in a decrease in cell viability of endometrial epithelial cells. Loss of uterus weight and morphology changes were observed in mice. In addition, Fe iron concentration and MDA levels increased, while the expression of GPX4, p-PI3K and p-AKT diminished.

CONCLUSIONS

Pae exhibited obvious alleviative activity in estradiol-induced mice via PI3K/AKT signaling pathway-regulated ferroptosis.

Paeonol attenuates heart failure induced by transverse aortic constriction via ERK1/2 signalling

CONTEXT

Paeonol (PAE) is the main phytochemical from Cortex Moutan. Its main pharmacological effects are anti-inflammatory and antioxidant, but its cardioprotective effect is unclear.

OBJECTIVE

The study investigates the effects and underlying mechanisms of PAE on transverse aortic constriction (TAC)-induced heart failure (HF) in mice.

MATERIALS AND METHODS

C57BL/6 mice were randomly divided into five groups: sham, TAC, PAE10 (TAC + PAE 10 mg/kg), PAE20 (TAC + PAE 20 mg/kg) and PAE 50 (TAC + PAE 50 mg/kg). Paeonol was intragastrically administered to mice for 4 weeks. Mice were anaesthetized with pentobarbital sodium and underwent cardiac echocardiography using echocardiography system. Serum levels of atrial natriuretic peptide (ANP), tumour necrosis factor-α (TNF-α) and interleukin-6 (IL-6) were measured by enzyme-linked immunosorbent assay (ELISA). Myocardial apoptosis was detected with terminal deoxynucleotidyl transferase-mediated dUTP nick end-labelling (TUNEL) staining. Haematoxylin-eosin (H&E) and Masson's staining were used for histopathological evaluation. Western and quantitative real-time PCR (qRT-PCR) were performed to detect levels of apoptosis and fibrosis-related proteins.

RESULTS

Echocardiography showed PAE improved cardiac function (LVEF: TAC, 52.3±6.8%; PAE20, 65.8±3.6%; PAE50, 71.4±2.5%) and H&E staining showed PAE alleviated myocardial injury (TAC: 1170.3 ± 134.6 μm²; PAE50: 576.0 ± 53.5 μm²). Western and qRT-PCR results showed that PAE down-regulated the levels of ANP, BNP and α-MHC. In addition, TUNEL and western results showed PAE significantly inhibited apoptosis. Masson and western results showed PAE inhibited cardiac hypertrophy. Western results showed the ERK1/2/JNK pathway could be inhibited by PAE.

DISCUSSION AND CONCLUSIONS

Paeonol regulates ERK1/2/JNK to improve cardiac function, which provides theoretical support for the extensive clinical treatment of HF.

Paeonol protects against doxorubicin-induced cardiotoxicity by promoting Mfn2-mediated mitochondrial fusion through activating the PKCε-Stat3 pathway

INTRODUCTION

The anti-cancer medication doxorubicin (Dox) is largely restricted in clinical usage due to its significant cardiotoxicity. The only medication approved by the FDA for Dox-induced cardiotoxicity is dexrazoxane, while it may reduce the sensitivity of cancer cells to chemotherapy and is restricted for use. There is an urgent need for the development of safe and effective medicines to alleviate Dox-induced cardiotoxicity.

OBJECTIVES

The objective of this study was to determine whether Paeonol (Pae) has the ability to protect against Dox-induced cardiotoxicity and if so, what are the underlying mechanisms involved.

METHODS

Sprague-Dawley rats and primary cardiomyocytes were used to create Dox-induced cardiotoxicity models. Pae's effects on myocardial damage, mitochondrial function, mitochondrial dynamics and signaling pathways were studied using a range of experimental methods.

RESULTS

Pae enhanced Mfn2-mediated mitochondrial fusion, restored mitochondrial function and cardiac performance both in vivo and in vitro under the Dox conditions. The protective properties of Pae were blunted when Mfn2 was knocked down or knocked out in Dox-induced cardiomyocytes and hearts respectively. Mechanistically, Pae promoted Mfn2-mediated mitochondria fusion by activating the transcription factor Stat3, which bound to the Mfn2 promoter in a direct manner and up-regulated its transcriptional expression. Furthermore, molecular docking, surface plasmon resonance and co-immunoprecipitation studies showed that Pae's direct target was PKCε, which interacted with Stat3 and enabled its phosphorylation and activation. Pae-induced Stat3 phosphorylation and Mfn2-mediated mitochondrial fusion were inhibited when PKCε was knocked down. Furthermore, Pae did not interfere with Dox's antitumor efficacy in several tumor cells.

CONCLUSION

Pae protects the heart against Dox-induced damage by stimulating mitochondrial fusion via the PKCε-Stat3-Mfn2 pathway, indicating that Pae might be a promising therapeutic therapy for Dox-induced cardiotoxicity while maintaining Dox's anticancer activity.

Protective effects of paeonol against lipopolysaccharide-induced liver oxidative stress and inflammation in gibel carp (Carassius auratus gibelio)

Paeonol (2'-hydroxy-4'-methoxyacetophenone) is a phenol that exhibits antioxidant and anti-inflammatory capabilities. In this study, the underlying mechanism of paeonol against LPS-induced oxidative stress and inflammatory responses in gibel carp was investigated. Three hundred healthy gibel carp were divided into five groups (n = 9), intraperitoneally injected with LPS and thereafter treated with paeonol (16 mg/kg and 64 mg/kg). Fish were anesthetized with MS-222 (100 mg/L), and samples were collected at 72 h to investigate plasma biochemical indexes, liver histopathology, antioxidant enzymatic activity, and TLR receptor-related gene expression. Fish injected with LPS (20 mg/kg) exhibited significantly increased plasma aminotransferase (ALT), aminotransferase (AST), lactate dehydrogenase (LDH), glucose (GLU), diamine oxidase (DAO), and alkaline phosphatase (ALP) levels (P < 0.05). In addition, LPS challenge significantly enhanced myeloperoxidase (MPO) and malondialdehyde (MDA) contents, whereas those of catalase (CAT) and glutathione peroxidase (GSH-Px) decreased (P < 0.05). However, treatment with paeonol attenuated these LPS-induced changes (P < 0.05). The mRNA expression of TLR4, TIRAP, MyD88, TRAF6, NF-κB, TNF-α, IL-1β, and IL-8, which were activated by LPS challenge (P < 0.05), were downregulated by paeonol. Additionally, histopathological examination demonstrated that paeonol alleviates LPS-induced hepatic tissue lesions in fish. Taken together, the results suggest that paeonol mitigates LPS-induced liver oxidative stress and inflammation in gibel carp.

Paeonol triggers apoptosis in HeLa cervical cancer cells: the role of mitochondria-related caspase pathway

Paeonol is a biologically active component purified from the root bark of Cortex Moutan that exerts pharmacological effects on the cervical cancer. In this study, we aim to evaluate the anti-cervical cancer capacity of paeonol and to investigate the mechanism driving its anti-cervical cancer effect. Paeonol administration markedly restrained the proliferation and caused apoptosis in HeLa cells. Furthermore, paeonol treatment resulted in a mitochondrial dysfunction in HeLa cells, including the inducing of mitochondrial membrane potential (MMP), reactive oxygen species (ROS) production, and the release of cytochrome c. Moreover, the Bcl-2/Bax proportion was obviously downregulated and cleaved caspase-3 expression was evaluated through paeonol treatment. Additionally, the expression of p-PI3K and p-Akt was noticeably reduced in response to paeonol treatment in HeLa cells. Our findings indicated that paeonol exerts an anticancer potential in HeLa cells, at least in a manner, via triggering the mitochondrial pathway of cellular apoptosis by inhibiting PI3K/Akt signaling. Thus, paeonol has great potential as a promising therapeutic compound to resist human cervical cancer.

Paeonol exerts neuroprotective and anticonvulsant effects in intrahippocampal kainate model of temporal lobe epilepsy

Temporal lobe epilepsy (TLE) is presented the most common form of focal epilepsy with involvement of oxidative stress and neuroinflammation as important factors in its development. About one third of epileptic patients are intractable to currently available medications. Paeonol isolated from some herbs with traditional and medicinal uses has shown anti-oxidative and anti-inflammatory effects in different models of neurological disorders. In this research, we tried to evaluate the possible protective effect of paeonol in intrahippocampal kainate murine model of TLE. To induce TLE, kainate was microinjected into CA3 area of the hippocampus and paeonol was administered at two doses of 30 or 50mg/kg. The results of this study showed that paeonol at the higher dose significantly reduces incidence of status epilepticus, hippocampal aberrant mossy fiber sprouting and also preserves neuronal density. Beneficial protective effect of paeonol was in parallel with partial reversal of some hippocampal oxidative stress markers (reactive oxygen species and malondialdehyde), caspase 1, glial fibrillary acidic protein, heme oxygenase 1, DNA fragmentation, and inflammation-associated factors (nuclear factor-kappa B, toll-like receptor 4, and tumor necrosis factor α). Our obtained data indicated anticonvulsant and neuroprotective effects of paeonol which is somewhat attributed to its anti-oxidative and anti-inflammation properties besides its attenuation of apoptosis, pyroptosis, and astrocyte activity.

Hyaluronic acid-cyclodextrin encapsulating paeonol for treatment of atopic dermatitis

The cyclodextrin (CD) was grafted onto hyaluronic acid (HA) to form a topical delivery carrier (HACD) in which Paeonol was loaded in its CD cavity and self-assemble into the polymeric micelles (HACD-PAE) for the treatment of atopic dermatitis. Fluorescence microscope observed that HACD could fast penetrate into the skin and remain stable within 12 h. In vitro penetration test (IVPT) results showed the PAE retentions of HACD-PAE group in the stratum corneum and dermis were 3.35 and 1.78 times improvement than that of PAE group. ATR-FTIR and H&E staining assays indicated HACD could increase the gap of keratinocytes by interacting with corneum lipids and loosening the keratin. Furthermore, HACD-PAE showed the best therapeutic effect on atopic dermatitis mice. Thus HACD could be a promising skin-specific delivery carrier, not only promoting the drug penetrating but increasing its remaining in the skin and play the skin disease therapy and skin-care role.

Paeonol increases the antioxidant and anti-inflammatory capacity of gibel carp (Carassius auratus gibelio) challenged with Aeromonas hydrophila

Paeonol, a naturally occurring polyphenol isolated from medical plant, has been known to exhibit anti-oxidative and anti-inflammatory effects. In order to evaluate the effect of paeonol on Carassius auratus gibelio infected by pathogenic bacteria Aeromonas hydriphila. 750 fish were randomly divided into 5 groups, which separately treated with 0.85% sterile saline (blank), A. hydriphila (negative control), A. hydriphila with paeonol (4 mg/kg, 64 mg/kg), and A. hydriphila with enrofloxacin (12 mg/kg, positive control). Fish were anaesthetized with MS-222 (100 mg/L), and samples were collected at 6 and 72 h after A. hydriphila challenge. The results showed that compared with the negative group, the survival in paeonol groups marked increased by 14.75% and 18.94%. The plasma immunoglobulin M (IgM) was notably increased, and low density lipoprotein (LDL) was significantly decreased in paeonol groups at 6 h (P < 0.05). The antioxidative enzymes catalase (CAT), total antioxidant capacity (T-AOC) and glutathione peroxidase (GSH-Px) were significantly increased in paeonol groups at 6 h, while malondialdehyde (MDA) and myeloperoxidase (MPO) contents were lower (P < 0.05). The inflammatory related genes MyD88 and TLR-5 were significantly downregulated, and the TLR-3 was significantly increased in paeonol groups at 72 h (P < 0.05). In addition, histopathological analyses showed that the lesion in liver, spleen and caudal kidney were considerably attenuated in paeonol groups. In conclusion, paeonol could increase the survival rate, mitigate oxidative damage, inflammation, tissue lesions, and improve the immunity of gibel carp challenged with A. hydrophila.

Paeonol regulates NLRP3 inflammasomes and pyroptosis to alleviate spinal cord injury of rat

Background

Spinal cord injury (SCI) is a life-threatening traumatic disorder. Paeonol has been confirmed to be involved in a variety of diseases. The purpose of this study is to investigate the role of paeonol on SCI progression.

Methods

Sprague Dawley (SD) rat was used for the establishment of SCI model to explore the anti-inflammation, anti-oxidation, and neuroprotective effects of paeonol (60 mg/kg) on SCI in vivo. For in vitro study, mouse primary microglial cells (BV-2) were induced by lipopolysaccharide (LPS)/adenosine triphosphate (ATP) treatment. The effect of paeonol on the polarization of LPS/ATP-induced BV-2 cells was determined by detection the expression inducible nitric oxide synthase (iNOS), tumour necrosis factor alpha (TNF-α), arginase-1 (Arg-1), and interleukin (IL)-10 using qRT-PCR. ELISA was used to assess the levels of IL-1β, IL-18, TNF-α, malondialdehyde (MDA), and glutathione (GSH). Western blotting was conducted to determine the levels of NLRP3 inflammasomes and TLR4/MyD88/NF-κB (p65) pathway proteins.

Results

Paeonol promoted the recovery of locomotion function and spinal cord structure, and decreased spinal cord water content in rats following SCI. Meanwhile, paeonol reduced the levels of apoptosis-associated speck-like protein (ASC), NLRP3, active caspase 1 and N-gasdermin D (N-GSDMD), repressed the contents of IL-1β, IL-18, TNF-α and MDA, and elevated GSH level. In vitro, paeonol exerted similarly inhibiting effects on pyroptosis and inflammation. Meanwhile, paeonol promoted BV-2 cells M2 polarization. In addition, paeonol also inactivated the expression of TLR4/MyD88/NF-κB (p65) pathway.

Conclusion

Paeonol may regulate NLRP3 inflammasomes and pyroptosis to alleviate SCI, pointing out the potential for treating SCI in clinic.

Investigation on the antitumor effects of paeonol against renal cell carcinoma based on network pharmacology and experimental validation

ETHNOPHARMACOLOGICAL RELEVANCE

Renal cell carcinoma (RCC) is the most common cancer of the urinary system, the current treatments for RCC are unsatisfactory. Paeonol is the main pharmacologically active ingredient of the traditional Chinese medicine (TCM) moutan cortex (Paeonia suffruticosa Andrews) and Paeonia albiflora Pall, and has been used in TCM to treat various diseases including cancer. However, the underlying therapeutic mechanisms of paeonol in RCC have not been investigated yet.

AIM OF THE STUDY

This study aimed to explore the potential antitumor effects and mechanisms of paeonol on RCC based on network pharmacology and experimental validation.

MATERIALS AND METHODS

Network pharmacological analysis was performed to predict the potential targets and mechanism of paeonol against RCC. The antitumor effects and the priority targets of paeonol against RCC were further assessed by in vitro experiments.

RESULTS

104 intersection targets shared by paeonol and RCC were collected, 15 hub genes were obtained, among these genes, VEGFA expression was higher in RCC, and the higher expression of IL-6 or lower expression of AKT1, JUN, MAPK1, and MAPK8 were correlated to the shorter overall survival (OS) in RCC patients. GO and KEGG analyses suggested that the genes were mainly enriched in the positive regulation of cell death and apoptosis pathway. In vitro experiments showed that paeonol inhibited 786-O cell proliferation, migration, invasion, and promoted apoptosis. When 786-O cells were treated with paeonol, the expression of Bax increased while Bcl-2 and VEGFA decreased.

CONCLUSION

The present study demonstrated that paeonol might play an essential role in RCC by regulating cell proliferation, apoptosis, metastasis, and invasion through the Bcl-2/Bax signaling pathway and VEGFA, providing a theoretical and experimental scientific basis for future investigations of the antitumor effects of paeonol against RCC.

Paeonol protects against acute pancreatitis by inhibiting M1 macrophage polarization via the NLRP3 inflammasomes pathway

The excessive inflammatory response mediated by macrophage is one of the key factors for the progress of acute pancreatitis (AP). Paeonol (Pae) was demonstrated to exert multiple anti-inflammatory effects. However, the role of Pae on AP is not clear. In the present study, we aimed to investigate the protective effect and mechanism of Pae on AP in vivo and vitro. In the caerulein-induced mild acute pancreatitis (MAP) model, we found that Pae administration reduced serum levels of amylase, lipase, IL-1β and IL-6 and alleviated the histopathological manifestations of pancreatic tissue in a dose-dependent manner. And Pae decrease the ROS generated, restore mitochondrial membrane potential (ΔΨm), inhibit M1 macrophage polarization and NLRP3 inflammasome in bone marrow-derived macrophages (BMDMs) in vitro. In addition, specific NLRP3 inhibitor MCC950 eliminated the protective effect of Pae on AP induced by caerulein in mice. Correspondingly, the inhibitory effect of Pae on ROS generated and M1 polarization was not observed in BMDMs with MCC950 in vitro. Taken together, our datas for the first time confirmed the protective effects of Pae on AP via the NLRP3 inflammasomes Pathway.

Paeonol inhibits the malignancy of Apatinib-resistant gastric cancer cells via LINC00665/miR-665/MAPK1 axis

BACKGROUND

Paeonol is the extractive of Paeonia suffruticosa Andr and is reported to reverse the chemotherapy resistance of cancer cells. The present study explores the role of paeonol in inhibiting the malignant biological behaviors of Apatinib-resistant gastric cancer (GC) cells.

METHODS

The Traditional Chinese Medicine Systems Pharmacology (TCMSP) database was adopted to screen the target genes of paeonol, and the STRING database was employed to construct a protein-protein interaction (PPI) network. The Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis of the target genes was performed employing DAVID online database. The expressions of these target genes in GC tissues and para-cancerous tissues were analyzed with GEPIA database, and GEO datasets (GSE109476 and GSE93415) were utilized to analyze differentially expressed lncRNAs and miRNAs in GC tissues and para-cancerous tissues. The expressions of LINC00665, miR-665 and MAPK1 mRNA in Apatinib-resistant GC cells were detected through quantitative real-time polymerase chain reaction (qRT-PCR). Cell counting kit-8 (CCK-8) assay was conducted to detect cell proliferation; Transwell assays were employed to detect cell migration and invasion, and TdT-mediated dUTP nick end labeling (TUNEL) assay was utilized to detect cell apoptosis. Dual-luciferase reporter gene assay was performed to detect the binding relationships between miR-665 and LINC00665, as well as between miR-665 and MAPK1 mRNA. The expressions of MAPK1 protein and glycolysis-associated proteins (GLUT1, LDHB and HK2) were detected by Western blot. Additionally, a tumor xenograft mice model was constructed to evaluate the effects of paeonol on lung metastasis.

RESULTS

Paeonol could inhibit the proliferation, migration, invasion and glycolysis, and promote the apoptosis of Apatinib-resistant GC cells. TCMSP database suggested that Paeonol had 17 target genes, and 17 target genes were mainly enriched in signaling pathways related to apoptosis, glucose and lipid metabolism, etc.; GEPIA database suggests that MAPK1, among the 17 target genes, was markedly elevated in GC tissues. Paeonol could decrease LINC00665 and MAPK1 expressions in GC cells but increase the expression of miR-665. LINC00665 overexpression, MAPK1 overexpression or inhibition of miR-665 could abolish the inhibitive effects of paeonol on the malignant phenotypes of Apatinib-resistant GC cells. miR-665 is verified as an upstream regulator of MAPK1 and a target of LINC00665. Additionally, paeonol could significantly inhibit the lung metastasis in the tumor xenograft mice model.

CONCLUSIONS

Paeonol can inhibit the malignancy of Apatinib-resistant GC cells through LINC00665/miR-665/MAPK1 axis. For the first time, our study imply that paeonol may be a potential drug to reverse Apatinib-resistant of GC cells.

Effect of paeonol against bacterial growth, biofilm formation and dispersal of Staphylococcus aureus and Listeria monocytogenes in vitro

Previous studies have demonstrated the antibacterial activity of paeonol against bacterial pathogens, but its anti-biofilm activities against Staphylococcus aureus and Listeria monocytogenes remain largely unexplored. Here, the antibacterial and anti-biofilm activities of paeonol against S. aureus and L. monocytogenes were examined using the crystal violet staining assay (CVSA), field emission scanning electron microscopy (FESEM), and confocal laser scanning microscopy (CLSM) analysis. Paeonol effectively inhibited the growth of S. aureus and L. monocytogenes with a minimum inhibitory concentration (MIC) of 500 and 125 μg ml^-1, respectively, and disrupted the integrity of cell membranes. Moreover, sub-MIC paeonol exhibited an inhibitory effect on the attachment of S. aureus and L. monocytogenes to the abiotic surface and biofilm formation. Further, paeonol effectively destroyed cell membranes within biofilms, and dispersed mature biofilms of both strains. The results indicate that paeonol might be a promising antibacterial and anti-biofilm agent for combating infections caused by S. aureus and L. monocytogenes.

Paeonol Ameliorates Cuprizone-Induced Hippocampal Demyelination and Cognitive Deficits through Inhibition of Oxidative and Inflammatory Events

Multiple sclerosis (MS) is a chronic and inflammatory disorder of the central nervous system with autoimmune nature that is typified by varying degrees of demyelination and axonal damage. Paeonol is an active ingredient in some medicinal plants with anti-inflammatory and neuroprotective property. This study was conducted to reveal whether paeonol can alleviate hippocampal demyelination and cognitive deficits in cuprizone-induced murine model of demyelination as a model of MS. C57BL/6 mice received oral cuprizone (400 mg/kg) for 6 weeks, and paeonol was administered p.o. at two doses of 25 or 100 mg/kg, starting from the second week post-cuprizone for 5 weeks. After assessment of learning and memory in different tasks, oxidative stress and inflammation were evaluated besides immunohistochemical assessment of hippocampal myelin basic protein (MBP). Paeonol (100 mg/kg) properly ameliorated cognitive deficits in Y maze, novel object discrimination (NOD) test, and Barnes maze with no significant improvement of performance in passive avoidance task. In addition, paeonol treatment at the higher dose was also associated with partial restoration of hippocampal level of oxidative stress and inflammatory markers including MDA, ROS, GSH, SOD, catalase, NF-kB, and TNF. Besides, paeonol improved MMP as an index of mitochondrial integrity and health and reduced MPO as a factor of neutrophil infiltration. Furthermore, paeonol treatment prevented hippocampal MBP immunoreactivity, indicating its prevention of demyelination. In conclusion, the current study showed the preventive effect of paeonol against cuprizone-induced demyelination and cognitive deficits through reversing most oxidative stress- and inflammation-related parameters in addition to its improvement of mitochondrial health.

Synthesis of novel 3/5(3,5)-(di)nitropaeonol hydrazone derivatives as nematicidal agents

Eighteen novel 3/5(3,5)-(di)nitropaeonol hydrazone derivatives were prepared, and their structures well characterized by ¹H NMR, HRMS, and mp. Due to the steric hindrance, the substituents on the C = N double bond of all hydrazine compounds (except E/Z = 4/1 for IV-1g, IV-1l, IV-2b, and E/Z = 3/2 for IV-1n, IV-3a) adopted E configuration. Among all compounds, four compounds 2, 4, IV-1j, and IV-1n exhibited potent nematicidal activity than their precursor paeonol, especially 5-nitropaeonol (2) and 3,5-dinitropaeonol (4) displayed the most potent nematicidal activity Heterodera glycines in vivo with LC₅₀ values of 32.3307 and 36.7074 mg/L, respectively.

Paeonol administration alleviates cognitive deficits and attenuates neural pathological changes in APP/PS1 mice

Alzheimer's disease typically presents with impaired cognition and pathological morphologic changes, including the accumulation of amyloid-β plaques. Disease-modifying drugs are in urgent need as neuroprotective therapies. Exploration of novel therapeutics for alleviating symptoms of Alzheimer's disease has found promise in plant extracts of functional phenols. Paeonol is a water-soluble phenolic substance that has been shown to confer diverse biological effects, including neuroprotection. An Alzheimer's disease model of APP/PS1 double transgenic mice was used in this study, and the therapeutic effects of paeonol were assessed after three weeks' administration. It was found that paeonol treatment significantly increased behavioral performance in the Morris water maze test and increased discrimination rate in the novel object recognition test compared to vehicle-treated APP/PS1 mice. Histologically, paeonol treatment significantly alleviated the Aβ plaque burden, reduced neural loss, inhibited microglia activation, and decreased neuroinflammation in the brain of APP/PS1 mice. In addition, a number of Alzheimer's disease-related synaptic plasticity deficits were ameliorated. The present results indicate that paeonol significantly relieved amyloid-β deposition and amyloid-β -mediated neuropathology in the brain of APP/PS1 mice, suggesting the potential of paeonol as a preventive and therapeutic agent for Alzheimer's disease.

Paeonol Ameliorates Cognitive Deficits in Streptozotocin Murine Model of Sporadic Alzheimer's Disease via Attenuation of Oxidative Stress, Inflammation, and Mitochondrial Dysfunction

Intracerebroventricular (ICV) microinjection of diabetogenic drug streptozotocin (STZ) in rodents consistently produces a model of sporadic Alzheimer's disease (sAD) which is characterized by tau pathology and concomitant cognitive decline, insulin resistance, neuroinflammation, oxidative stress, and mitochondrial malfunction. Paeonol is an active phenolic component in some medicinal plants like Cortex Moutan with neuroprotective efficacy via exerting anti-inflammatory and anti-oxidative effects. This study was conducted to assess beneficial effect of paeonol in amelioration of cognitive deficits in ICV STZ rat model of sAD. STZ (3 mg/kg) was microinjected into the lateral ventricles on days 0 and 2, and paeonol was given p.o. at two doses of 25 (low) or 100 (high) mg/kg from day 0 (post-surgery) till day 24 post-STZ. Cognitive performance was evaluated in different tasks, and oxidative stress- and inflammation-related parameters were measured in addition to immunohistochemical assessment of glial fibrillary acidic protein (GFAP) as a marker of astrocytes. Paeonol at the higher dose ameliorated cognitive deficits in Barnes maze, novel object recognition (NOR) task, Y maze, and passive avoidance test. In addition, paeonol partially reversed hippocampal malondialdehyde (MDA), reactive oxygen species (ROS), total antioxidant capacity (TAC), superoxide dismutase (SOD), catalase, glutathione reductase, tumor necrosis factor α (TNFα), interleukin 6 (IL-6), mitochondrial membrane potential (MMP), myeloperoxidase (MPO), and acetylcholinesterase (AChE) activity. Paeonol treatment was also associated with lower hippocampal immunoreactivity for GFAP. This study showed that paeonol can alleviate cognitive disturbances in ICV STZ rat model of sAD via ameliorating neuroinflammation, oxidative stress, mitochondrial dysfunction, and also through its attenuation of astrogliosis.

Paeonol inhibits profibrotic signaling and HOTAIR expression in fibrotic buccal mucosal fibroblasts

BACKGROUND/PURPOSE

Betel nut chewing is the major risk factor of oral submucous fibrosis (OSF). Various studies have sought to discover alternative strategies to alleviate oral fibrogenesis. In the present study, we aimed to evaluate the anti-fibrosis effect of paeonol, a phenolic component derived from Paeonia Suffruticosa.

METHODS

The cytotoxicity of paeonol was tested using normal and fibrotic buccal mucosal fibroblasts (fBMFs) derived from OSF tissues. Collagen gel contraction, Transwell migration, invasion, and wound healing capacities were examined. Besides, the activation of TGF-β/Smad2 signaling and expression levels of type I collagen, α-SMA, and long non-coding RNA HOTAIR were measured as well.

RESULTS

Paeonol exerted a higher cytotoxic effect on fBMFs compared to normal BMFs. The arecoline-induced myofibroblast activities, including collagen gel contractility, cell motility, and wound healing ability were all suppressed by paeonol treatment. In addition, the activation of the TGF-β/Smad2 pathway was inhibited along with a lower expression of α-SMA and type I collagen in paeonol-treated cells. Also, the administration of paeonol decreased the mRNA expression of HOTAIR in fBMFs.

CONCLUSION

Our results indicate that paeonol may be a promising compound to attenuate the progression of oral fibrogenesis in OSF patients.

Paeonol inhibits human lung cancer cell viability and metastasis in vitro via miR-126-5p/ZEB2 axis

Paeonol exerted an effect in lung cancer, but the underlying mechanism remained vague. In this research, we assessed the effects of Paeonol and microRNA (miR)-126-5p on the viability, migration, invasion, and epithelial-mesenchymal transition (EMT) of lung cancer cells. Lung cancer cells and BEAS-2B cells were treated with Paeonol, and viability was detected by 3-(4,5)-dimethylthiahiazo (-z-y1)-3,5-di- phenytetrazoliumromide (MTT) assay. The migration and invasion of lung cancer cells after treatment with Paeonol at 40 μg/mL or 80 μg/mL were detected by wound healing assay and Transwell assay, respectively. The effects of Paeonol on transforming growth factor-β1 (TGF-β1)-induced EMT and relative expressions of EMT-related proteins were determined using Western blot. The target gene of miR-126-5p and the binding sites between them were predicted by TargetScan, and confirmed using dual-luciferase reporter assay. Relative expressions of miR-126-5p, its target gene and EMT-related proteins were determined by quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot. Rescue assay was performed to analyze the relation between Paeonol and miR-126-5p. Paeonol down-regulated cell viability and inhibited migration, invasion and TGF-β1-induced EMT while up-regulating miR-126-5p expression in lung cancer cells as the dose increased. However, miR-126-5p inhibitor could reverse the effect of Paeonol. ZEB2 was the target gene of miR-126-5p, and silencing ZEB2 expression reversed the effects of miR-126-5p downregulation. Paeonol also regulated the expression of ZEB2 in lung cancer cells, and this regulation depends on the regulation of miR-126-5p. Paeonol inhibits human lung cancer cell viability and metastasis via the miR-126-5p/ZEB2 axis, and could be adopted as a potential agent for lung cancer treatment.

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 alleviates migration and invasion of endometrial stromal cells by reducing HIF-1α-regulated autophagy in endometriosis

Background: Dysregulated migration and invasion of endometrial stromal cells is implicated in the pathogenesis of endometriosis. Hypoxia functions as critical microenvironmental factor that results in promotion of endometrial stromal cells migration and invasion through up-regulation of autophagy. Paeonol functioned as a tumor suppressor in human ovarian cancer and promoted cytoprotective autophagy. However, the role of paeonol in hypoxia-induced autophagy in endometriosis remains unknown. Methods: Stromal cells were isolated from endometriotic patients by enzymatic digestion of ectopic endometrial tissues, and then characterized by immunohistochemical analysis of cytoskeleton 19 (CK19) and vimentin. Cellular morphology was evaluated under microscope. Cell viability, proliferation and apoptosis of stromal cells were assessed by Cell Counting Kit-8, EdU labeling and flow cytometry, respectively. Wound healing and transwell assays were performed to detect metastasis of the stromal cells. Hypoxia-induced autophagy was evaluated through immunohistochemistry and western blot. Results: Paeonol treatment dosage dependently decreased cell proliferation and metastasis of the ectopic endometrial stromal cells (ecESCs), while promoted the cell apoptosis. Hypoxia-induced autophagy in the ecESCs was repressed by paeonol through down-regulation of LC3-II/LC3-I and Beclin-1, while up-regulation of p62. Hypoxia-inducible factor-1α (HIF-1α) was reduced post paeonol treatment, and paeonol-induced increase of p62 and decrease of LC3-II/LC3-I and Beclin-1 were reversed by over-expression of HIF-1α. Over-expression of HIF-1α also attenuated the suppressive effect of paeonol on cell growth of ecESCs. Conclusions: Paeonol attenuated HIF-1α-induced promotion of ecESCs migration and invasion through reducing autophagy, and reduced HIF-1α-induced endometriotic lesion in rats, providing potential therapeutic strategy for the treatment of endometriosis.

Exploring targets and signaling pathways of paeonol involved in relieving inflammation based on modern technology

Paeonol, derived from natural plants (Moutan Cortex), has a wide range of biological effects, including anti-inflammatory and antitumor effects as well as favorable effects against cardiovascular and neurodegenerative diseases. The anti-inflammatory action is the main pharmacological activity of paeonol and has the greatest clinical relevance. However, the anti-inflammatory mechanism of paeonol has not been reported in sufficient detail. We systematically analyzed the anti-inflammatory mechanism of paeonol using network pharmacological databases and platforms, including TCMSP, Swiss TargetPrediction, OMIM, DrugBank, TTD, Jevnn, STRING11.0, and Metascape. Furthermore, we used high-throughput molecular docking method to prove the results of the above analyses, providing a reference for exploring the mechanism of paeonol and developing targeted drugs.

Synthesis and evaluation of acetylferulic paeonol ester and ferulic paeonol ester as potential antioxidants to inhibit fish oil oxidation

Acetylferulic paeonol ester (APE) and ferulic paeonol ester (FPE) were synthesized, and their structures were confirmed by NMR, mass spectra, IR and UV-vis data. The antioxidant properties of the synthesized compounds were evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and [(2-azino-bis (3-ethylbenzthiazoline)-6 -sulfonic acid] (ABTS) assay as well as the production of oxidation products (peroxides, conjugated dienes, thiobarbituric acid-reactive substances, free fatty acids and total aldehydes) in an elevated temperature (60 °C) storage trial of fish oil extracted from anchovy. Furthermore, the changes in fatty acid composition were monitored by gas chromatography-mass spectrometry. The results showed that APE was more effective in restraining fish oil oxidation compared to FPE, ferulic acid, paeonol and the commercial antioxidant-butylated hydroxytoluene (BHT). This study demonstrated molecular combinations obtained by covalent bonding two antioxidant active molecules can result in novel compounds with enhanced antioxidant activities.

Paeonol-loaded PLGA nanoparticles as an oral drug delivery system: Design, optimization and evaluation

Herein, we report a novel type of NPs by loading paeonol (Pae) into PLGA NPs, to enhance drug stability and oral bioavailability. The paeonol (Pae)-loaded polylactic-co-Gly-colic acid (PLGA) nanoparticles (Pae-PLGA-NPs) were prepared by nanoprecipitation method. The resultant NPs were in spherical shape with an average particle size around 237.7 ± 4.92 nm, and the PDI and zeta potential were 0.110 ± 0.01 and -25.33 ± 1.37 mV, respectively. The encapsulation efficiency (EE) and drug loading (DL) of the Pae-PLGA-NPs were 86.26 ± 1.12 and 12.74 ± 0.37% respectively. The in vitro drug release, in vivo pharmacokinetics and in situ single-pass intestinal perfusion (SPIPs) of Pae-PLGA-NPs was investigated. In vivo, the AUC_(0-t), C _max, MRT_(0-t), and T_1/2z of the Pae-PLGA-NPs group were 3.79-, 1.89-, 1.40- and 1.49-fold greater than those of the Pae suspension group, respectively. The in situ single-pass intestinal perfusion of NPs results showed the Ka values in the duodenum, jejunum, ileum and colon were 1.12-, 1.40-, 1.52- and 2.21-fold higher than those of Pae solution, respectively. Moreover, the Papp values of the ileum and colon were 1.27- and 1.31-fold higher than those of the solution group. Such findings suggested the Pae-PLGA-NPs can significantly improve the intestinal absorption characteristics, and have a beneficial effect on oral administration as a nanometer-sized carrier.

Paeonol-loaded PLGA nanoparticles as an oral drug delivery system: Design, optimization and evaluation

Herein, we report a novel type of NPs by loading paeonol (Pae) into PLGA NPs, to enhance drug stability and oral bioavailability. The paeonol (Pae)-loaded polylactic-co-Gly-colic acid (PLGA) nanoparticles (Pae-PLGA-NPs) were prepared by nanoprecipitation method. The resultant NPs were in spherical shape with an average particle size around 237.7 ± 4.92 nm, and the PDI and zeta potential were 0.110 ± 0.01 and -25.33 ± 1.37 mV, respectively. The encapsulation efficiency (EE) and drug loading (DL) of the Pae-PLGA-NPs were 86.26 ± 1.12 and 12.74 ± 0.37% respectively. The in vitro drug release, in vivo pharmacokinetics and in situ single-pass intestinal perfusion (SPIPs) of Pae-PLGA-NPs was investigated. In vivo, the AUC_(0-t), C _max, MRT_(0-t), and T_1/2z of the Pae-PLGA-NPs group were 3.79-, 1.89-, 1.40- and 1.49-fold greater than those of the Pae suspension group, respectively. The in situ single-pass intestinal perfusion of NPs results showed the Ka values in the duodenum, jejunum, ileum and colon were 1.12-, 1.40-, 1.52- and 2.21-fold higher than those of Pae solution, respectively. Moreover, the Papp values of the ileum and colon were 1.27- and 1.31-fold higher than those of the solution group. Such findings suggested the Pae-PLGA-NPs can significantly improve the intestinal absorption characteristics, and have a beneficial effect on oral administration as a nanometer-sized carrier.

The paeonol target gene autophagy-related 5 has a potential therapeutic value in psoriasis treatment

Background

Paeonol is a potent therapy for psoriasis. This study aimed to screen out paeonol-targeted genes in psoriasis and validate the potential of using paeonol for the management of psoriasis.

Methods

Microarray datasets were obtained from the Gene Expression Omnibus. The differentially expressed genes (DEGs) in the lesional skin samples and the overlapping genes between DEGs and paeonol- and psoriasis-related genes were defined as potential targets for psoriasis. After being treated with si-ATG5 and pc-ATG5, human HaCaT cells were treated with 100 ng/ml IL-22 and 10 ng/ml TNF-α with and without paeonol. Cell proliferation, apoptosis, and expression of interleukin (IL)-6, IL-1β, Beclin 1, ATG5, and p62 in HaCaT cells were determined using ESLIA, PCR, and Western blot analysis.

Results

A total of 779 DEGs were identified in the lesional skin samples compared with the non-lesional tissues. The autophagy-related 5 (ATG5) gene was the only gene that overlapped between the DEGs and genes related to paeonol and psoriasis. Cell proliferation, inflammatory cytokines (IL-6 and IL-1β), and ATG5 expression were increased in IL-22/TNF-α-stimulated HaCaT (model) cells compared with control. Paeonol treatment rescued all changes. si-ATG5 transfection increased inflammation and apoptosis in model cells compared with controls. pc-ATG5 prevented IL-22/TNF-α-induced changes in HaCaT cells. Also, si-ATG5 decreased p62 and Beclin 1 proteins, while pc-ATG5 increased them both.

Conclusions

ATG5-dependent autophagy plays a crucial role in psoriasis. The ATG5 gene might be a therapeutic target for the management of in vitro psoriasis.

Neuroprotective effect of paeonol in streptozotocin-induced diabetes in rats

BACKGROUND

Diabetic neuropathy is one of the most common microvascular complication of diabetes. It is associated with neuronal dysfunction and pain. Paeonol is an important natural product reported for its antioxidant, anti-inflammatory and antidiabetic activities.

AIM

The present research was planned to study effect of paeonol in diabetic peripheral neuropathy in rats.

METHODS

Diabetes was induced in Sprague Dawley rats by using Streptozotocin (55 mg/kg, i.p.). After six weeks, diabetic animals were treated daily with paeonol at a dose of 50, 100 and 200 mg/kg for four weeks. At the end of the treatment, plasma glucose, mechanical allodynia, mechanical hyperalgesia, thermal hyperalgesia and nerve conduction velocities were recorded. Oxidative stress parameters were studied in sciatic nerve. Histopathology study of sciatic nerve, NF-κB and MCP-1 expression were also studied at the end of study.

KEY FINDINGS

Paeonol treatment significantly lowered the plasma glucose levels, mechanical allodynia, mechanical hyperalgesia and thermal hyperalgesia as compared to diabetic control group. Paeonol treatment also enhanced the motor and sensory nerve conduction velocity. Paeonol treated diabetic animals showed significant changes in oxidative stress parameters. Histopathology study indicated that paeonol treatment prevented the neuronal damage, lowered demyelination and leukocyte infiltration. NF-κB and MCP-1 expression was significantly decreased in sciatic nerve of diabetic animals treated with paeonol.

SIGNIFICANCE

Results of the present study indicate that paeonol may be considered as effective option for management of diabetic neuropathy.