Role of AMPK pathway in lead-induced endoplasmic reticulum stress in kidney and in paeonol-induced protection in mice

In Silico Analysis of Protein-Protein Interactions of Putative Endoplasmic Reticulum Metallopeptidase 1 in Schizosaccharomyces pombe

Ermp1 is a putative metalloprotease from Schizosaccharomyces pombe and a member of the Fxna peptidases. Although their function is unknown, orthologous proteins from rats and humans have been associated with the maturation of ovarian follicles and increased ER stress. This study focuses on proposing the first prediction of PPI by comparison of the interologues between humans and yeasts, as well as the molecular docking and dynamics of the M28 domain of Ermp1 with possible target proteins. As results, 45 proteins are proposed that could interact with the metalloprotease. Most of these proteins are related to the transport of Ca2+ and the metabolism of amino acids and proteins. Docking and molecular dynamics suggest that the M28 domain of Ermp1 could hydrolyze leucine and methionine residues of Amk2, Ypt5 and Pex12. These results could support future experimental investigations of other Fxna peptidases, such as human ERMP1.

Lead toxicity and potential therapeutic effect of plant-derived polyphenols

BACKGROUND

Due to its unique physical and chemical properties, lead is still used worldwide in several applications, especially in industry. Both environmental and industrial lead exposures remain a public health problem in many developing and rapidly industrializing countries. Plant polyphenols are pleiotropic in their function and have historically made a major contribution to pharmacotherapy.

PURPOSE

To summarize available pre-clinical and limited clinical evidence on plant polyphenols as potential antidotes against lead poisoning and discuss toxic mechanisms of lead.

METHOD

A comprehensive search of peer-reviewed publications was performed from core collections of electronic databases such as PubMed, Web of Science, Google Scholar, and Science Direct. Articles written in English-language from inception until December 2022 were selected.

RESULTS

In this review, we review key toxic mechanisms of lead and its pathological effects on the neurological, reproductive, renal, cardiovascular, hematological, and hepatic systems. We focus on plant polyphenols against lead toxicity and involved mechanisms. Finally, we address scientific gaps and challenges associated with translating these promising preclinical discoveries into effective clinical therapies.

CONCLUSION

While preclinical evidence suggests that plant polyphenols exhibit bioprotective effects against lead toxicity, scant and equivocal clinical data highlight a need for clinical trials with those polyphenols.

Hepatoprotective effect of avicularin on lead-induced steatosis, oxidative stress, and inflammation in mice associated with the MAPK/HSP60/NLRP3 and SREBP1c pathway

Lead (Pb), an environmental hazard, causes severe diseases in the liver, kidney, cardiovascular system, hematopoietic system, reproductive system, and nervous system. Avicularin (AVI), the main dietary flavonoid found in many citrus fruits, exhibited potential protective properties on organs. However, the molecular mechanisms of these protective actions are currently not clear. In our study, the effects of AVI on Pb-induced hepatotoxicity were evaluated using ICR mice. Changes in oxidative stress, inflammation, lipid metabolism, and related signaling were evaluated. We found for the first time that treatment with AVI significantly reduced hepatic steatosis, inflammation, and oxidative stress induced by Pb. AVI attenuated Pb-induced liver dysfunction and lipid metabolism disorder in mice. AVI decreased the serum biochemical indicators of lipid metabolism. AVI decreased the expression levels of lipid metabolism-related protein SREBP-1c, acetyl-CoA carboxylase (ACC), and FAS. AVI suppressed Pb-induced inflammation in livers, as indicated by decreasing the TNF-α and IL-1β levels. AVI suppressed oxidative stress by increasing the activation of SOD, CAT, and GPx. Furthermore, AVI inhibited the activities of JNK, ERK, p38, and NF-κB. AVI further decreased the levels of HSP60, NLRP3, p-IκBα, and p-p65 in the livers of mice. Collectively, this study indicated that AVI mitigated Pb-induced hepatic steatosis, oxidative stress, and inflammation by regulating the SREBP-1c and MAPK/HSP60/NLRP3 signaling pathways.

Hepatoprotective and Neuroprotective Effects of Naringenin against Lead-Induced Oxidative Stress, Inflammation, and Apoptosis in Rats

Naringenin (NRG) is one of the most important naturally occurring flavonoids, predominantly found in some edible fruits, such as citrus species and tomatoes. It has several biological activities, such as antioxidant, antitumor, antiviral, antibacterial, anti-inflammatory, antiadipogenic, and cardioprotective effects. The heavy metal lead is toxic and triggers oxidative stress, which causes toxicity in many organs, including the liver and brain. This study explored the potential protective role of NRG in hepato- and neurotoxicity caused by lead acetate in rats. Four groups of ten male albino rats were included: group 1 was a control, group 2 was orally treated with lead acetate (LA) at a dose of 500 mg/kg BW, group 3 was treated with naringenin (NRG) at a dose of 50 mg/kg BW, and group 4 was treated with 500 mg/kg LA and 50 mg/kg NRG for 4 weeks. Then, blood was taken, the rats were euthanized, and liver and brain tissues were collected. The findings revealed that LA exposure induced hepatotoxicity with a significant increase in liver function markers (p < 0.05). In addition, albumin and total protein (TP) and the albumin/globulin ratio (A/G ratio) (p < 0.05) were markedly lowered, whereas the serum globulin level (p > 0.05) was unaltered. LA also induced oxidative damage, demonstrated by a significant increase in malonaldehyde (MDA) (p < 0.05), together with a pronounced antioxidant system reduction (SOD, CAT, and GSH) (p < 0.05) in both liver and brain tissues. Inflammation of the liver and brain caused by LA was indicated by increased levels of nuclear factor kappa beta (NF-κβ) and caspase-3, (p < 0.05), and the levels of B-cell lymphocyte-2 (BCL-2) and interleukin-10 (IL-10) (p < 0.05) were decreased. Brain tissue damage induced by LA toxicity was demonstrated by the downregulation of the neurotransmitters norepinephrine (NE), dopamine (DA), serotonin (5-HT), and creatine kinase (CK-BB) (p < 0.05). Additionally, the liver and brain of LA-treated rats displayed notable histopathological damage. In conclusion, NRG has potential hepato- and neuroprotective effects against lead acetate toxicity. However, additional research is needed in order to propose naringenin as a potential protective agent against renal and cardiac toxicity mediated by lead acetate.

Naringenin alleviate reproductive toxicity evoked by lead acetate via attenuation of sperm profile and biochemical alterations in male Wistar rat: Involvement of TGFβ/AKT/mTOR pathway

Exposure to Lead -causes testicular dysfunction through oxidative stress, inflammation, and apoptosis; however, naringenin (NGN) therapeutic impact against lead-evoked testicular dysfunction remains elusive. Herein, the point of the study was to examine the defensive impact of NGN on testicular dysfunction initiated by lead. Seventy-Two male Wistar rats were allotted into nine groups; control group, drug control groups, lead acetate group, as well as NGN treated groups (10, 25, and 50 mg/kg) respectively, given 5 days before lead acetate treatment. The result showed clearly the impact of lead on reduced sperm count, sperm motility as well as serum testosterone and LH levels. Additionally, it caused a significant rise in testicular inflammatory markers TNF-α, IL-1β, and TGFβ, effects that were accompanied by a reduction of AKT and mTOR levels. Lead acetate also caused degenerative changes in the testis, atrophy, and loss of spermatogenic series. Our findings revealed that NGN in a dose-dependent manner improved spermiotoxicity induced by lead acetate via restoration of the testicular function, preservation of spermatogenesis, halting inflammatory cytokines along with the enhancement of germ cell survival using upregulation of AKT/mTOR expressions. The present study discloses that NGN suppresses lead acetate toxicity that is involved in the antioxidant effect in a dose-dependent manner, besides its anti-inflammatory property.

Cynapanoside A exerts protective effects against obesity-induced diabetic nephropathy through ameliorating TRIM31-mediated inflammation, lipid synthesis and fibrosis

Obesity is a major predictive factor for the diabetic nephropathy (DN). However, the precise mechanism and therapeutic approach still require to be investigated. Cynapanosides A (CPS-A) is a glycoside derived from the Chinese drug Cynanchum paniculatum that has numerous pharmacological activities, but its regulatory function on obesity-induced kidney disease is still obscure. In the present study, we attempted to explore the renoprotective effects of CPS-A on the established DN in high fat diet (HFD)-fed mice, and the underlying mechanisms. We initially found that CPS-A significantly ameliorated the obesity and metabolic syndrome in mice with HFD feeding. Mice with HFD-induced DN exerted renal dysfunctions, indicated by the elevated functional parameters, including up-regulated blood urea nitrogen (BUN), urine albumin and creatinine, which were significantly attenuated by CPS-A in obese mice. Moreover, histological changes including glomerular enlargement, sclerosis index and collagen deposition in kidney of obese mice were detected, while being strongly ameliorated by CPS-A. Additionally, podocyte loss induced by HFD was also markedly mitigated in mice with CPS-A supplementation. HFD feeding also led to lipid deposition and inflammatory response in renal tissues of obese mice, whereas being considerably attenuated after CPS-A consumption. Intriguingly, we found that tripartite motif-containing protein 31 (TRIM31) signaling might be a crucial mechanism for CPS-A to perform its renoprotective functions in mice with DN. The anti-inflammatory, anti-fibrotic and anti-dyslipidemia capacities of CPS-A were confirmed in the mouse podocytes under varying metabolic stresses, which were however almost abolished upon TRIM31 ablation. These data elucidated that TRIM31 expression was largely required for CPS-A to perform its renoprotective effects. Collectively, our study is the first to reveal that CPS-A may be a promising therapeutic strategy for the treatment of obesity-induced DN or associated kidney disease.

Avicularin Attenuates Lead-Induced Impairment of Hepatic Glucose Metabolism by Inhibiting the ER Stress-Mediated Inflammatory Pathway

Lead (Pb), an environmental hazard, causes several human diseases. Avicularin (Avi), a main dietary flavonoid found in several plants and fruits, exhibits potential protective properties on organs. However, the molecular mechanisms of Avi's protective effects against Pb-induced damage are not clear. In our study, the effects of Avi on Pb-induced hepatotoxicity were evaluated using ICR mice. We have revealed for the first time that treatment with Avi significantly reduced hepatic inflammation, endoplasmic reticulum stress (ERS) and glucose metabolism disorder induced by Pb. Avi decreased the serum biochemical indicators of glucose metabolism. Avi increased the activities of glycogenolysis rate-limiting enzyme hexokinase (HK), pyruvate kinase (PK), glucokinase (GK) and glycogen phosphorylase (PYG) and inhibited the activities of gluconeogenesis rate-limiting enzyme phosphoenolpyruvate carboxy kinase (PEPCK) and glucose-6-phosphate dehydrogenase (G6PD). Avi decreased the protein expression levels of glucose-regulated protein 78 (GRP78), phosphorylated inositol requiring enzyme 1 (p-IRE1), phosphorylated RNA-dependent protein kinase-like ER kinase (p-PERK) and phosphorylated eukaryotic initiation factor 2α (p-eIF2α). The levels of tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6) were decreased in the liver as a result of Avi suppression Pb-induced inflammation. These results indicated that Avi attenuated Pb-induced impairment of hepatic glucose metabolism by the ERS and inflammation pathway.

Cardioprotective Effect of Paeonol on Chronic Heart Failure Induced by Doxorubicin via Regulating the miR-21-5p/S-Phase Kinase-Associated Protein 2 Axis

Background

This study primarily explored the role of paeonol in doxorubicin (DOX)-induced chronic heart failure (CHF), considering the cardioprotective effect of paeonol on an epirubicin-induced cardiac injury.

Methods

DOX-induced CHF-modeled rats were treated with paeonol. Cardiac function and myocardial damage in rats were evaluated by using the multifunction instrument, and the histopathology, apoptosis, and the expression of miR-21-5p and S-phase kinase-associated protein 2 (SKP2) in myocardium were detected. The target gene of miR-21-5p was confirmed by a dual-luciferase reporter assay. After the required transfection or paeonol treatment, the viability, apoptosis, mitochondrial membrane potential (MMP), and reactive oxygen species (ROS) of the DOX-induced cardiomyocytes were determined. Reverse-transcription quantitative-PCR (RT-qPCR) and Western blot were performed to quantify the expressions of miR-21-5p, SKP2, and apoptosis-related factors.

Results

Paeonol improved cardiac function and also ameliorated the cardiac damage of CHF-modeled rats, where the downregulation of abnormally elevated myocardial damage markers, including brain natriuretic peptide, lactate dehydrogenase, renin, angiotensin II, aldosterone, and endothelin 1, was observed. Paeonol alleviated the histopathological injury and suppressed the apoptosis in CHF-modeled rats, inhibited miR-21-5p expression, and upregulated SKP2 expression in vitro and in vivo. miR-21-5p targeted SKP2. Paeonol and SKP2 increased the viability and MMP, but reduced apoptosis and ROS in the DOX-induced cardiomyocytes. miR-21-5p exerted effects opposite to PAE and SKP2, and it downregulated the expression of Bcl-2 and mitochondrion-Cytochrome c (Cyt c) and upregulated the expression of Bax, C-caspase-3, and cytoplasm-Cyt c. miR-21-5p reversed the effects of paeonol, and its effects were further reversed by SKP2.

Conclusion

Paeonol shows a cardioprotective effect on DOX-induced CHF via regulating the miR-21-5p/SKP2 axis.

Antioxidative, anti-inflammatory and anti-apoptotic action of ellagic acid against lead acetate induced testicular and hepato-renal oxidative damages and pathophysiological changes in male Long Evans rats

Lead (Pb), is an environmental toxicant, causes multi-organ dysfunction including reproductive impairments. This study designed to investigate the prospective antioxidative, anti-inflammatory and anti-apoptotic effects of ellagic acid (EA) on Pb-mediated testicular and hepato-renal toxicity. Four experimental groups of five male Long-Evans rats each were used: control, Pb (60 mg/kg), EA (30 mg/kg), and Pb + EA groups. All groups were given their respective treatment orally for 30 days. Pb exposure altered body and organs weight, food and water consumption, rectal temperature, Pb residue levels in tissues, liver and kidney function, sperm quality parameters, serum metabolic and hematology profiles, and impaired the oxidative/antioxidative balance in the testicular and hepato-renal tissue, as shown by the decreased antioxidant proteins (superoxide dismutase, catalase, glutathione peroxidase, and reduced glutathione) and increased the oxidative (MDA, lipid hydroperoxides, conjugated dienes, protein carbonyl, fragmented DNA and GSH:GSSG ratio) stress and inflammatory (IL-1, IL-6, TNF-α, prostaglandin, LTB4, NO, myeloperoxidase, LDH) markers. Moreover, a dysregulation in the stress response (HSP-70) and apoptotic-regulating proteins (BAX, BCL-2, and active Caspase-3) were recorded upon Pb exposure. Remarkably, EA oral administration reduced the Pb residue levels in tissues, improved the liver and kidney function, revived the spermatogenesis and sperm quality, restored redox homeostasis, suppressed the oxidative stress, inflammatory and apoptotic responses in the liver, kidney and testis tissue. Our findings point out that EA can be used as a phyto-chelator to overcome the adverse effects of Pb exposure due to its potent antioxidant, anti-inflammatory, and anti-apoptotic effects.

Paeonol Protects Against Methotrexate-Induced Nephrotoxicity via Upregulation of P-gp Expression and Inhibition of TLR4/NF-κB Pathway

Methotrexate (MTX) is a well-known anticancer drug that causes nephrotoxicity as a side effect. To investigate the mechanisms by which paeonol, a natural phenolic compound, can protect against MTX-induced nephrotoxicity, paeonol (100 mg/kg/day orally) was given to rats for 10 days, with or without MTX (20 mg/kg once i.p. at day 5). Compared to control, MTX caused nephrotoxic effects manifested by increased serum urea and creatinine and distortion in renal histological architecture, with a significant increase in the mean glomerular diameter and upregulation of kidney injury molecule-1. MTX caused oxidative stress manifested by decreasing reduced glutathione and superoxide dismutase while increasing malondialdehyde and nitric oxide. MTX also induced renal inflammation by upregulating TLR4, NF-κB, and IL-1β and caused apoptosis by induction of caspase 3. Administering paeonol with MTX improved kidney functional and structural parameters, as well as all oxidative, inflammatory, and apoptotic markers tested. Interestingly, both MTX and paeonol increased the expression of the renal efflux transporter P-glycoprotein (P-gp) that helps in MTX elimination, and their drug combination further upregulated renal P-gp. In silico, paeonol was neither a substrate nor an inhibitor of P-gp, suggesting that its effect on P-gp is not on functional but on the expression level. In vitro, paeonol and MTX were administered to colon cancer cells and their combination caused a progressive cellular cytotoxic effect, which was dose-dependent with the increase of paeonol concentration. In conclusion, paeonol protects against MTX-induced nephrotoxicity through antioxidant, anti-inflammatory, and antiapoptotic mechanisms and might potentiate MTX chemotherapeutic efficacy.

Paeonol Ameliorates Chronic Itch and Spinal Astrocytic Activation via CXCR3 in an Experimental Dry Skin Model in Mice

Paeonol is a bioactive phenol presents mainly in Paeonia suffruticosa Andr. (Paeoniaceae), Paeonia lactiflora Pall., and Dioscorea japonica Thunb. (Dioscoreaceae), harboring various pharmacological activities including anti-inflammatory, antioxidant, immune regulatory activity and reverse chemoresistance. Recent reports revealed paeonol exhibited good effects on chronic dermatitis, such as atopic dermatitis (AD) and psoriasis. However, whether paeonol is effective for dry skin disease and its mechanism of action still remain unclear. In this study, we analysed the effects of paeonol on a mouse model of dry skin treated with acetone-ether-water (AEW), which showed impressive activities in reducing scratching behavior and skin inflammation. To elucidate the underlying molecular targets for the anti-pruritic ability of paeonol, we screened the expression of possible chemokine pathways in the spinal cord. The expression of CXCR3 was significantly alleviated by paeonol, which increased greatly in the spinal neurons of AEW mice. In addition, treatment of paeonol significantly inhibited AEW-induced expression of astrocyte activity-dependent genes including Tlr4, Lcn2 and Hspb1 et al. The inhibitory effects of paeonol on scratching behavior and astrocytic activation in the spinal cord induced by AEW were abolished when CXCR3 was antagonized or genetically ablated. Taken together, our results indicated that paeonol can ameliorate AEW-induced inflammatory response and itching behavior, and reduce the expression of spinal astrocyte activity-dependent genes induced by AEW, which are driven by CXCR3.

Combined lead and zinc oxide-nanoparticles induced thyroid toxicity through 8-OHdG oxidative stress-mediated inflammation, apoptosis, and Nrf2 activation in rats

A human is exposed to a chemical mixture rather than a single chemical, particularly with the wide spread of nanomaterials. Therefore, the present study evaluated the combined exposure of lead acetate (Pb) and zinc oxide-nanoparticles (ZnO-NPs) compared to each metal alone on the thyroid gland of adult rats. A total of 30 adult male albino rats were divided into four groups, group I (control), group II received Pb (10 mg/kg), group III received ZnO-NPs (85 mg/kg) and group IV co-administrated the two metals in the same previous doses. The materials were gavaged for 8 weeks. The toxicity was assessed through several biochemical parameters. Our results revealed significant body weight reduction relative to increased thyroid weights, decreased both of serum-free triiodothyronine (FT3), tetra-iodothyronine (FT4), increased thyroid-stimulating hormone (TSH), increased serum and thyroid levels of Pb and zinc, significant elevation in tumor necrosis factor-α (TNF-α), reduction in interleukin 4 (IL4), upregulation of Bax, and downregulation of Bcl-2 genes. Additionally, there was significant overexpression of nuclear factor erythroid 2-related factor 2(Nrf2), 8-Hydroxydeoxyguanosine(8-OHdG), the elevation of tissues malondialdehyde (MDA), reduction of tissues total antioxidant capacity (TAC), and disruptive thyroid structural alterations in all metals groups with marked changes in the combined metals group. In conclusion, the combined exposure of Pb and ZnO-NPs induced pronounced toxic thyroid injury, pointing to additive effects in rats than the individual metal effects through different significant changes of disruptive thyroid structural alterations related to the loading of thyroid tissues with Pb and zinc metals producing oxidative stress that mediated inflammation and apoptosis.

Aqueous extract of Paeoniae Radix Rubra prevents deep vein thrombosis by ameliorating inflammation through inhibiting GSK3β activity

BACKGROUND

Deep vein thrombosis (DVT) is a kind of blood stasis syndrome. Paeoniae Radix Rubra (PRR) has long been widely used for eliminating blood stasis in China, but its effect on DVT has not yet been reported.

PURPOSE

The present study aimed to assess the potential inhibitory effect of the aqueous extract of PRR (i.e.,PRR dispensing granule, PRRDG) on DVT and explore the underlying mechanism.

STUDY DESIGN/METHODS

The chemical profile of PRRDG was analyzed by high-performance liquid chromatography. Sprague-Dawley rats were intragastrically treated with PRRDG (0.625, 1.25 and 1.875 g crude drug/kg/d) once daily for 7 consecutive days. On the sixth day, a model of inferior vena cava (IVC) stenosis-induced DVT was established. All rats were sacrificed on the seventh day. Serum was collected for enzyme-linked immunosorbent assay. Thrombus-containing IVC was weighed and further processed for histopathologic examination, immunohistochemical analysis and western blotting. LiCl and LY294002 were adopted to block and increase the activity of glycogen synthase kinase 3β (GSK3β), respectively.

RESULTS

The chemical profile analysis showed that paeoniflorin, benzoylpaeoniflorin, albiflorin, gallic acid and catechin were the main constituents of PRRDG. LiCl decreased thrombus weight, reduced the number of inflammatory cells in thrombus and vein wall, down-regulated phosphorylated NF-κB p65 (p-p65) protein expression. Similarly, PRRDG decreased thrombus weight and tissue factor (TF) protein expression. PRRDG reduced the protein expression levels of P-selectin, monocyte chemoattractant protein-1 (MCP-1), intercellular cell adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) in venous endothelium, serum levels of tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β), and the number of inflammatory cells in thrombus and vein wall. Moreover, PRRDG down-regulated p-p65 protein expression and up-regulated phosphorylated GSK3β (p-GSK3β) protein expression. LY294002 abrogated the inhibitory effects of PRRDG on thrombus weight, TF protein expression, TNF-α and IL-1β serum levels, inflammatory cells influxes, and p-p65 protein expression.

CONCLUSION

PRRDG prevents DVT by ameliorating inflammation through inhibiting GSK3β activity.

Attenuation of Pb-induced Aβ generation and autophagic dysfunction via activation of SIRT1: Neuroprotective properties of resveratrol

This study examined the neuroprotective properties of resveratrol (Res) and its target sirtuin1 (SIRT1) against lead (Pb)-mediated toxicity and discovered that both resveratrol treatment and SIRT1 overexpression restored blocked autophagic flux as well as reduced β-amyloid (Aβ) contents. Four-week-old male C57BL/6 mice were employed to consumed 0.2% Pb(Ac)₂ solution or deionized water for 3 months followed by 12 months of Res (50 mg/kg BW) or vehicle gavage. In in vitro study, SH-SY5Y cells were pretreated with the SIRT1 activator SRT1720 (2 μM) or the inhibitor EX527 (2 μM) for 2 h, then 25 μM of Pb(Ac)₂ was added and incubated for 48 h. Western blotting, RT-qPCR, enzyme-linked immunosorbent assay (ELISA), and Lyso-Tracker Red Staining were next used to estimate the potential alterations of the autophagic pathway as well as BACE1-mediated amyloid processing in response to Pb exposure, respectively. Our data revealed that Res treatment or SIRT1 activation resisted the induction of autophagy by Pb exposure through inhibition of LC3 and Beclin-1 expression and promoted the degradation of Aβ and Tau phosphorylation. Besides, the SIRT1 activator (SRT1720) downregulated the expression of BACE1, the rate-limiting enzyme for Aβ production, by inhibiting the activation of nuclear factor-κB (NF-κB) in Pb-treated SH-SY5Y cells, which resulted in reduced Aβ production. Collectively, we verified the role of Res-SIRT1-autophagy as well as the SIRT1-NF-κB-BACE1 pathway in Pb-induced neuronal cell injury by in vivo or in vitro models. Our findings further elucidate the important role of SIRT1 and Res in counteracting Pb neurotoxicity, which may provide new interventions and targets for the subsequent treatment of neurodegenerative diseases.

Plant Polyphenols: Potential Antidotes for Lead Exposure

Lead is one of the most common heavy metal elements and has high biological toxicity. Long-term lead exposure will induce the contamination of animal feed, water, and food, which can cause chronic lead poisoning including nephrotoxicity, hepatotoxicity, neurotoxicity, and reproductive toxicity in humans and animals. In the past few decades, lead has caused widespread concern because of its significant threat to health. A large number of in vitro and animal experiments have shown that oxidative stress plays a key role in lead toxicity, and endoplasmic reticulum (ER) stress and the mitochondrial apoptosis pathway can also be induced by lead toxicity. Therefore, plant polyphenols have attracted attention, with their advantages of being natural antioxidants and having low toxicity. Plant polyphenols can resist lead toxicity by chelating lead with their special chemical molecular structure. In addition, scavenging active oxygen and improving the level of antioxidant enzymes, anti-inflammatory, and anti-apoptosis are also the key to relieving lead poisoning by plant polyphenols. Various plant polyphenols have been suggested to be useful in alleviating lead toxicity in animals and humans and are believed to have good application prospects.

The cardioprotective effects of hydrogen sulfide by targeting endoplasmic reticulum stress and the Nrf2 signaling pathway: A review

Cardiac diseases are emerging due to lifestyle, urbanization, and the accelerated aging process. Oxidative stress has been associated with cardiac injury progression through interference with antioxidant strategies and endoplasmic reticulum (ER) function. Hydrogen sulfide (H₂ S) is generated endogenously from l-cysteine in various tissues including heart tissue. Pharmacological evaluation of H₂ S has suggested a potential role for H₂ S against diabetic cardiomyopathy, ischemia/reperfusion injury, myocardial infarction, and cardiotoxicity. Nuclear factor E2-related factor 2 (Nrf2) activity is crucial for cell survival in response to oxidative stress. H₂ S up-regulates Nrf2 expression and its related signaling pathway in myocytes. H₂ S also suppresses the expression and activity of ER stress-related proteins. H₂ S has been reported to improve various cardiac conditions through antioxidant and anti-ER stress-related activities.

Anti-oxidant, anti-inflammatory and anti-fibrosis effects of ganoderic acid A on carbon tetrachloride induced nephrotoxicity by regulating the Trx/TrxR and JAK/ROCK pathway

Ganoderic acid A (GAA), one of the major triterpenoid components extracted from Ganoderma mushroom has been shown to possess numerous important pharmacological activities. The present study was aimed to investigate the mechanisms of GAA on carbon tetrachloride (CCl4)-induced kidney inflammation, fibrosis and oxidative stress in mice. The male mice were treated with 25 and 50 mg/mg GAA after stimulated with CCl4. Our results showed that GAA improved renal damage by decreasing the serum levels of creatinine, urea, uric acid and alleviating kidney fibrosis. GAA ameliorated CCl4-induced indices of inflammation. GAA suppressed oxidative stress by regulating the glutathione antioxidant system and the thioredoxin antioxidant system. GAA increased the activations of thioredoxin reductase (TrxR), Trx, GSH, SOD, GPx. Furthermore, GAA supplementation inhibited the JAK and STAT3 pathway. GAA inhibited the activations of RhoA, ROCK, NF-κB, TGF-β and Smad3. Thus, this study demonstrated that GAA possesses immune-protective properties through regulating the Trx/TrxR, JAK2/STAT3 and RhoA/ROCK pathways.

Mechanisms and Efficacy of Chinese Herbal Medicines in Chronic Kidney Disease

As the current treatment of chronic kidney disease (CKD) is limited, it is necessary to seek more effective and safer treatment methods, such as Chinese herbal medicines (CHMs). In order to clarify the modern theoretical basis and molecular mechanisms of CHMs, we reviewed the knowledge based on publications in peer-reviewed English-language journals, focusing on the anti-inflammatory, antioxidative, anti-apoptotic, autophagy-mediated and antifibrotic effects of CHMs commonly used in kidney disease. We also discussed recently published clinical trials and meta-analyses in this field. Based on recent studies regarding the mechanisms of kidney disease in vivo and in vitro, CHMs have anti-inflammatory, antioxidative, anti-apoptotic, autophagy-mediated, and antifibrotic effects. Several well-designed randomized controlled trials (RCTs) and meta-analyses demonstrated that the use of CHMs as an adjuvant to conventional medicines may benefit patients with CKD. Unknown active ingredients, low quality and small sample sizes of some clinical trials, and the safety of CHMs have restricted the development of CHMs. CHMs is a potential method in the treatment of CKD. Further study on the mechanism and well-conducted RCTs are urgently needed to evaluate the efficacy and safety of CHMs.

Nephroprotective effect of gastrodin against lead-induced oxidative stress and inflammation in mice by the GSH, Trx, Nrf2 antioxidant system, and the HMGB1 pathway

Gastrodin (GAS), the main phenolic glycoside derivative from Gastrodiaelata Blume, has several bio-activities. However, the molecular mechanisms of these protective actions currently remain unclear. This study aimed to investigate the mechanisms of GAS on lead (Pb)-induced oxidative stress and inflammation in the kidneys and primary kidney mesangial cells. Results indicated that GAS improved Pb-induced renal dysfunction and morphological changes in mice. GAS ameliorated Pb-induced inflammation in kidneys by reducing the TNF-α and IL-6 levels. GAS inhibited Pb-induced oxidative stress by regulating the glutathione, thioredoxin (Trx), and Nrf2 antioxidant systems. Furthermore, GAS supplementation increased the activation of SOD, GPx, HO-1, and NQO1 in the kidneys. GAS decreased the expression levels of HMGB1, TLR4, RAGE, MyD88, and NF-κB. These results were further confirmed in primary kidney mesangial cells. Collectively, this study demonstrated that GAS alleviated Pb-induced kidney oxidative stress and inflammation by regulating the antioxidant systems and the Nrf2 signaling pathway. Highlights Gastrodin ameliorated Pb-induced kidney injury in mice.Gastrodin inhibited oxidative stress and inflammation in kidneys.Gastrodin activated the GSH, Trx and Nrf2 antioxidant system in kidneys.Gastrodin inhibited the activities of HMGB1. RAGE, TLR4, and MyD88.

NLRP3 inflammasome is involved in the mechanism of mitigative effect of selenium on lead-induced inflammatory damage in chicken kidneys

Lead (Pb) is a kind of widespread toxic environmental pollutant which can cause harm to organisms. Selenium (Se) has the property of mitigating Pb toxicity through decreasing oxidative stress and inflammation caused by Pb. Nucleotide-binding domain, leucine-rich-containing family, and pyrin-domain containing-3 (NLRP3) inflammasome involve in inflammation process. However, the effect of NLRP3 inflammasome in heavy metal-caused animal damage remains unknown. This research aimed to explore the mechanism of mitigative role of Se on Pb-caused renal inflammatory injury in chickens. One-week-old male chickens were provided a standard diet and drinking water, a standard diet added with 1 mg kg^-1 of Se and drinking water, a standard diet and drinking water added with 350 mg L^-1 Pb, and a standard diet added with 1 mg kg^-1 Se and drinking water added with 350 mg L^-1 Pb. On the 4th, 8th, and 12th weeks, serum was used to measure creatinine (CREA) and uric acid (UA) contents, and kidneys were used to measure Se and Pb concentrations, histological structure, oxidative stress indicators, relative expressions of cytokines, and inflammatory factors. The results showed that Pb accumulated, Se concentration decreased, CREA and UA contents increased, and renal injury occurred in Pb-treated chicken kidneys. Excess Pb increased MDA content and the expressions of IL-1β, IL-6, IL-17, NLRP3, caspase-1, NF-κB, COX-2, TNF-α, and PTGEs and decreased GSH content, GPx and SOD activities, and IFN-γ expression in the chicken kidneys. Se administration alleviated the aforementioned changes. In addition, toxic effect of Pb on the chicken kidneys was time-dependent. NLRP3 inflammasome, caspase-1, and IL-1β may be sensitive indicators in Pb-induced chicken kidney inflammatory damage. In conclusion, NLRP3 inflammasome took part in antagonistic role of Se against Pb-caused inflammation via changing oxidative stress indicators, cytokines, and inflammation-related genes in the chicken kidneys.

Paeonol derivative-6 attenuates inflammation by activating ZEB2 in acute liver injury

Paeonol is a natural phenolic compound and isolated as an active ingredient from Moutan Cortex. Paeonol derivative-6 (DPF-6) is a derivative of paeonol improved in water solubility and bioavailability. Previous studies have reported that paeonol possesses a variety of pharmacological activities, such as antioxidant and anti-inflammatory properties. Moreover, we have previously verified that DPF-6 has anti-inflammatory effects. However, the role and fundamental mechanism of DPF-6 in acute liver injury (ALI) was still unclear. In this study, we indicated that DPF-6 inhibited inflammation and the expression of TNF-α, IL-6 and IL-1β in liver tissues and LPS-mediated L-02 cells, concomitant with the upregulated expression of ZEB2. More importantly, it was demonstrated that overexpression of ZEB2 inhibited the expression level of TNF-α, IL-6 and IL-1β in LPS-mediated L-02 cells. In contrast, knockdown of ZEB2 increased the expression level of TNF-α, IL-6 and IL-1β in LPS-mediated L-02 cells. Further studies showed that ZEB2 inhibited the inflammation cytokine secretion via JNK signaling pathway in L-02 cells. Taken together, all the above results indicate that DPF-6 increased the expression of ZEB2, consequently inhibited inflammation cytokine secretion through JNK signaling pathway, which may be utilized as a potential anti-inflammation monomeric compound in the treatment of ALI.

Effects of dibutyl phthalate on lipid metabolism in liver and hepatocytes based on PPARα/SREBP-1c/FAS/GPAT/AMPK signal pathway

Phateacid esters (PAEs), such as dibutyl phthalate (DBP), have been widely used and human exposure results into serious toxic effects; such as the development of fatty liver disease. In the present study, SD rat models for in vivo study (normal and fatty liver model group) and hepatocytes for in vitro study (normal and abnormal lipid metabolism model group) were established to determine the effects of DBP on liver function and discover the possible mechanisms. Meanwhile, the peroxisome proliferator activated receptor (PPARα) blocker, GW6471, with the Adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK) activator, AICAR, were applied in vitro study to clarify the role of PPARα/SREBP-1c/FAS/GPAT/AMPK signal pathway in the process. Results suggested that DBP could activate PPARα signaling pathway and affected the protein expression of SREBP, FAS and GPAT to cause hyperlipidemia and abnormal liver function. DBP also could inhibit the phosphorylation and activation of AMPK to inhibit the decomposition and metabolism of lipids. Interestingly, the effects of DBP could be alleviated by GW6471 and AICAR. Our experimental results provide reliable evidence that DBP exposure could further induce liver lipid metabolism disorder and other hepatic toxicity through PPARα/SREBP-1c/FAS/GPAT/AMPK signal pathway.

Paeonol protects melanocytes against hydrogen peroxide-induced oxidative stress through activation of Nrf2 signaling pathway

Oxidative stress plays a pivotal role in the pathogenesis of vitiligo. Paeonol, a phenolic compound found in the root bark of Cortex Moutan, has been suggested to have therapeutic effects on various diseases through nuclear factor Nrf2 mediated antioxidant pathways. However, the therapeutic effects of paeonol on vitiligo have not been investigated. In this study, we investigated whether paeonol could protect melanocytes against oxidative stress through Nrf2 activation. Hydrogen peroxide (H₂ O₂ ) was used to mimic the oxidative stress. PIG1 cells were pretreated with paeonol for 24 h, and then were treated with H₂ O₂ for 24 h. To detect the role of Nrf2, siRNA method was used to knockdown the Nrf2 expression. After that, cell viability, melanin content, tyrosinase activity, intracellular reactive oxygen species, antioxidant enzymes activities, nuclear translocation of Nrf2, and mRNA expression of Nrf2 downstream antioxidant genes were detected. Paeonol improved cell viability and melanogenesis in PIG1 cells treated with H₂ O₂ . Paeonol also alleviated oxidative stress by restoring the activities of superoxide dismutase, catalase, and glutathione peroxidase. Paeonol promoted Nrf2 nuclear translocation and the expression of its downstream-regulated antioxidative genes under oxidative stress. Furthermore, Nrf2 knockdown by siRNA abolished the protective effects of paeonol on PIG1 cells against oxidative damage. Paeonol protected melanocytes against H₂ O₂ -induced oxidative stress by Nrf2 mediated antioxidant pathways. Paeonol is a potential therapeutic drug for vitiligo.

Bixin attenuates carbon tetrachloride induced oxidative stress, inflammation and fibrosis in kidney by regulating the Nrf2/TLR4/MyD88 and PPAR-γ/TGF-β1/Smad3 pathway

Bixin, an natural carotenoid extracted from the seeds of the Bixa orellana has been shown to possess numerous important pharmacological activities. The present study was aimed to investigate the mechanisms of Bixin on carbon tetrachloride (CCl4)-induced kidney inflammation, fibrosis and oxidative stress in mice. Our results showed that Bixin improved renal damage by decreasing the serum levels of creatinine, urea, uric acid and alleviating kidney fibrosis. Bixin ameliorated CCl4-induced inflammation in kidneys by reducing the levels of TNF-α and IL-1β. Bixin suppressed oxidative stress by decreasing the MDA level and increasing the activation of SOD, CAT and GPx. Furthermore, Bixin increased the levels of PPAR-γ, NQO1, HO-1 and the nuclear translocation of Nrf2 in the kidneys of mice. Bixin supplementation inhibited the activation of TLR4, MyD88, NF-κB, TGF-β and Smad3. Thus, this study demonstrated that Bixin possesses anti-oxidant, anti-inflammatory and anti-fibrosis properties through regulating the Nrf2/TLR4/MyD88 and PPAR-γ/TGF-β1/Smad3 pathways.

Total Glucosides of Peony Protect Cardiomyocytes against Oxidative Stress and Inflammation by Reversing Mitochondrial Dynamics and Bioenergetics

Total glucosides of peony (TGP) are used to treat rheumatoid arthritis and systemic lupus erythematosus. We explored the protective effects of TGP on cardiomyocyte oxidative stress and inflammation in the presence of hydrogen peroxide by focusing on mitochondrial dynamics and bioenergetics. Our study demonstrated that hydrogen peroxide significantly repressed cardiomyocyte viability and promoted cell apoptosis through induction of the mitochondrial death pathway. TGP treatment sustained cardiomyocyte viability, reduced cardiomyocyte apoptosis, and decreased inflammation and oxidative stress. Molecular investigation indicated that hydrogen peroxide caused mitochondrial dynamics disruption and bioenergetics reduction in cardiomyocytes, but this alteration could be normalized by TGP. We found that disruption of mitochondrial dynamics abolished the regulatory effects of TGP on mitochondrial bioenergetics; TGP modulated mitochondrial dynamics through the AMP-activated protein kinase (AMPK) pathway; and inhibition of AMPK alleviated the protective effects of TGP on mitochondria. Our results showed that TGP treatment reduces cardiomyocyte oxidative stress and inflammation in the presence of hydrogen peroxide by correcting mitochondrial dynamics and enhancing mitochondrial bioenergetics. Additionally, the regulatory effects of TGP on mitochondrial function seem to be mediated through the AMPK pathway. These findings are promising for myocardial injury in patients with rheumatoid arthritis and systemic lupus erythematosus.

The role of endoplasmic reticulum stress in lead (Pb)-induced mitophagy of HEK293 cells

It is well-documented that lead (Pb) toxicity can affect almost all systems in living organisms. It can induce selective autophagy of mitochondria (mitophagy) by triggering reactive oxygen species production. Emerging evidence has suggested that Pb-induced autophagy can also be activated by the endoplasmic reticulum (ER) stress pathway. However, the interplay between ER stress and mitophagy remains to be elucidated. In this study, human embryonic kidney HEK293 cells were employed to investigate the role of ER stress in Pb-induced mitophagy. The results showed that the cell viability was decreased and cell damage was induced after exposure to Pb (0, 0.5, 1, 2, and 4 mM) for 24 h in a dose-dependent manner. Moreover, the expression of LC3-Ⅱ was significantly increased, and the expression of HSP60 was dramatically decreased after exposure to 1 mM and 2 mM Pb, indicating the induction of mitophagy following Pb exposure. Meanwhile, the expressions of activating transcription factor 6, inositol-requiring protein-1α, CCAAT/enhancer binding protein homologous protein, and glucose-regulated protein 78 were dramatically increased after Pb treatment, signifying the initiation of ER stress. Notably, the mitophagic effect was significantly compromised when ER stress was inhibited by 0.5 mM 4-phenylbutyrate, which was evidenced by lesser decreases in HSP60 expression and level of LC3-Ⅱ, suggesting Pb-induced mitophagy may be activated by the ER stress. Taken together, these findings provide a better understanding of Pb toxicity and suggest that Pb-induced ER stress may play a regulatory role in the upstream of mitophagy.

Cynanchum paniculatum and Its Major Active Constituents for Inflammatory-Related Diseases: A Review of Traditional Use, Multiple Pathway Modulations, and Clinical Applications

Cynanchum paniculatum Radix, known as Xuchangqing in Chinese, is commonly prescribed in Chinese Medicine (CM) for the treatment of various inflammatory diseases. The anti-inflammatory property of Cynanchum paniculatum can be traced from its wind-damp removing, collaterals' obstruction relieving, and toxins counteracting effects as folk medicine in CM. This paper systematically reviewed the research advancement of the pharmacological effects of Cynanchum paniculatum among a variety of human diseases, including diseases of the respiratory, circulatory, digestive, urogenital, hematopoietic, endocrine and metabolomic, neurological, skeletal, and rheumatological systems and malignant diseases. This review aims to link the long history of clinical applications of Cynanchum paniculatum in CM with recent biomedical investigations. The major bioactive chemical compositions of Cynanchum paniculatum and their associated action mechanism unveiled by biomedical investigations as well as the present clinical applications and future perspectives are discussed. The major focuses of this review are on the diverse mechanisms of Cynanchum paniculatum and the role of its active components in inflammatory diseases.

Endoplasmic Reticulum Stress Induced by Toxic Elements-a Review of Recent Developments

Endoplasmic reticulum of all eukaryotic cells is a membrane-bound organelle. Under electron microscope it appears as parallel arrays of "rough membranes" and a maze of "smooth vesicles" respectively. It performs various functions in cell, i.e., synthesis of proteins to degradation of xenobiotics. Bioaccumulation of drugs/chemicals/xenobiotics in the cytosol can trigger ER stress. It is recognized by the accumulation of unfolded or misfolded proteins in the lumen of ER. Present review summarizes the present status of knowledge on ER stress caused by toxic elements, viz arsenic, cadmium, lead, mercury, copper, chromium, and nickel. While inorganic arsenic may induce various glucose-related proteins, i.e., GRP78, GRP94 and CHOP, XBP1, and calpains, cadmium upregulates GRP78. Antioxidants like ascorbic acid, NAC, and Se inhibit the expression of UPR. Exposure to lead also changes ER stress related genes, i.e., GRP 78, GRP 94, ATF4, and ATF6. Mercury too upregulates these genes. Nickel, a carcinogenic element upregulates the expression of Bak, cytochrome C, caspase-3, caspase-9, caspase-12, and GADD 153. Much is not known on ER stress caused by nanoparticles. The review describes inter-organelle association between mitochondria and ER. It also discusses the interdependence between oxidative stress and ER stress. A cross talk amongst different cellular components appears essential to disturb pathways leading to cell death. However, these molecular switches within the signaling network used by toxic elements need to be identified. Nevertheless, ER stress especially caused by toxic elements still remains to be an engaging issue.

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.

Ameliorative effect of curcumin against lead acetate-induced hemato-biochemical alterations, hepatotoxicity, and testicular oxidative damage in rats

Lead, toxic heavy metal of global concern, induces toxicity in various organs via oxidative stress. Thereby, in this study, the protective role of curcumin against lead acetate-induced toxicity was evaluated. Thirty-two male albino rats were allocated equally into four groups and orally administered with corn oil as a vehicle (Cont.), curcumin (CUR) (400 mg/kg bw), lead acetate (LA) (100 mg/kg bw), and lead acetate plus curcumin (LA + CUR). All rats had received their treatments daily for 4 weeks. The results revealed that LA toxicity induced normocytic normochromic anemia with significant leukocytosis and lymphocytosis. Moreover, LA-intoxicated rats showed a marked elevation in the liver enzyme activities, serum cholesterol, and triglyceride levels. In contrast, sero-immunological parameters, total protein, albumin, globulin, and testosterone levels were significantly reduced compared to the control rats. Additionally, LA-induced hepatic and testicular oxidative damage revealed by marked increased in MDA level with prominent reduction in the antioxidant system. The gene expression of the hepatic pro-inflammatory markers and testicular steroidogenic biomarkers including LHR and aromatase were significantly upregulated; meanwhile, the expressions of testicular StAR, CYP17a, 3B-HDS, SR-B1, and P450SCC were significantly downregulated in the LA-intoxicated group. Curcumin treatment could partially improve the hematological, biochemical, and histopathological alterations induced by LA. Also, it was observed that curcumin significantly restored hepatic pro-inflammatory markers and testicular steroidogenic enzymes. In conclusion, curcumin has antioxidant, anti-inflammatory, and immunomodulatory effects and is able to minimize the LA-induced oxidative damage in rats.

Chemistry, pharmacokinetics, pharmacology and recent novel drug delivery systems of paeonol

Paeonol is a bioactive phenol present in Dioscorea japonica, Paeonia suffruticosa and Paeonia lactiflora. It is reported for various pharmacological activities.

AIM

To review chemistry, pharmacokinetics, pharmacological activities as well as various formulations of paeonol.

MATERIALS AND METHODS

A literature search was done using different search terms for paeonol by using different scientific databases like PubMed, Scopus and ProQuest. Scientific papers published during the period 1969 to 2019 were comprehensively reviewed.

KEY FINDINGS

Researchers have synthesized methoxy, ethoxy, piperazine, chromonylthiazolidine, phenol-phenylsulfonyl, alkyl ether, aminothiazole, tryptamine hybrids and paeononlsilatie derivatives to enhance the stability of paeonol. These derivatives were synthesized and evaluated for in vitro series of biological activities like anti-inflammatory, tyrosinase inhibitory, neuroprotective, anticancer and antiviral activity. Regardless of valuable therapeutic potential, the clinical use of paeonol is restricted due to poor water solubility, low oral bioavailability, low stability and high volatility at room temperature. To enhance the bioavailability of paeonol various formulations are prepared and evaluated for its activity. Paeonol formulations can be categorized as conventional-tablets, topical gel and hydrogel; polymeric delivery system-microparticles, microsponges, dendrimers, nanocapsules, polymeric nanoparticles, nanospheres; lipid-based delivery systems-microemulsion, self-micro-emulsifying drug delivery, liposome, transethosomes, ethosomes, niosomes, proniosomes, lipid-based nanoparticles and nanoemulsion of paeonol.

SIGNIFICANCE

Paeonol has a potential to be developed as a techno-commercial product with respect to its multi-faceted pharmacological properties. Even though in vitro and in vivo studies have been reported the important activities of paeonol, its commercial utilization requires extensive safety and efficacy data.

Paeonol alleviates primary dysmenorrhea in mice via activating CB2R in the uterus

BACKGROUND AND PURPOSE

Primary dysmenorrhea is the most common gynaecologic problem in menstruating women and is characterized by spasmodic uterine contraction and pain symptoms associated with inflammatory disturbances. Paeonol is an active phytochemical component that has shown anti-inflammatory and analgesic effects in several animal models. The aim of this study was to explore whether paeonol is effective against dysmenorrhea and to investigate the potential mechanism of cannabinoid receptor signalling.

EXPERIMENTAL APPROACH

Dysmenorrhea was established by injecting oestradiol benzoate into female mice. The effects of paeonol on writhing time and latency, uterine pathology and inflammatory mediators were explored. Isolated uterine smooth muscle was used to evaluate the direct effect of paeonol on uterine contraction.

KEY RESULTS

The oral administration of paeonol reduced dysmenorrhea pain and PGE2 and TNF-α expression in the uterine tissues of mice, and paeonol was found to be distributed in lesions of the uterus. Paeonol almost completely inhibited oxytocin-, high potassium- and Ca²⁺-induced contractions in isolated uteri. Antagonists of CB2R (AM630) and the MAPK pathway (U0126), but not of CB1R (AM251), reversed the inhibitory effect of paeonol on uterine contraction. Paeonol significantly blocked L-type Ca²⁺ channels and calcium influx in uterine smooth muscle cells via CB2R. Molecular docking results showed that paeonol fits well with the binding site of CB2R.

CONCLUSIONS AND IMPLICATIONS

Paeonol partially acts through CB2R to restrain calcium influx and uterine contraction to alleviate dysmenorrhea in mice. These results suggest that paeonol has therapeutic potential for the treatment of dysmenorrhea.

Effects of gastrodin against carbon tetrachloride induced kidney inflammation and fibrosis in mice associated with the AMPK/Nrf2/HMGB1 pathway

Gastrodin (GAS), the main phenolic glycoside extracted from Gastrodia elata Blume, exhibits potential renoprotective properties.

The remedial effect of Thymus vulgaris extract against lead toxicity-induced oxidative stress, hepatorenal damage, immunosuppression, and hematological disorders in rats

The Thymus vulgaris (T. vulgaris) has been used in foods for the flavor, aroma, and preservation and in folk medicines. The objective of the present work was to determine the antioxidant and protective effects of T. vulgaris extract against lead (Pb)-intoxicated rats. A thirty-two male Sprague-Dawley were randomly assigned into 4 equal groups and treated for six weeks as follows: group I (GP-I), served as negative control; GP-II, -III, and -IV received either Pb acetate in drinking water (500 mg/L), T. vulgaris extract (500 mg/kg/day) by oral gavage or Pb acetate with T. vulgaris extract, respectively. Blood samples were collected at the end of the study week 6 to measure the hepatic and renal biochemical markers, complete blood count alongside the serum levels of interleukin (IL)-1β, IL-6, IL-10, tumor necrosis (TNF)-α, and interferon (IFN)-γ. Additionally, liver and kidney tissue specimens were collected for histopathology as well as to measure the antioxidant-reduced glutathione (GSH), glutathione peroxidase (GPx), catalase (CAT), and superoxide dismutase (SOD) alongside the lipid peroxidation marker, malonaldehyde (MDA). The results indicated that Pb toxicity increased the serum levels of IL-1β, IL-6, and TNF-α, whereas IL-10 and IFN-γ were reduced. The results showed disturbed liver and renal functions; increased serum levels of ALT, AST, ALP, total bilirubin, creatinine, and urea; and decreased total protein, albumin, and calcium. The GSH, Gpx, and CAT levels were significantly decreased in the Pb-administrated group, while MDA was increased. However, regarding the hepatorenal markers, those animals treated with T. vulgaris alone did not induce any significant changes. Moreover, the combined treatment with T. vulgaris extract together with Pb showed significant improvement in Pb-induced toxicity in all the tested parameters compared to the negative control group. We investigated the potential protective effects of the medicinal plant T. vulgaris in vivo, since there are no publications that address the potential protective effect of this leaf extract against Pb-induced hepatorenal toxicity. Our studies concluded that the T. vulgaris extract reduces Pb overload in hepatorenal tissues, and that this has a potential immunomodulatory role, antioxidant activity, and a protective effect against Pb toxicity.

Paeonol: pharmacological effects and mechanisms of action

Paeonia suffruticosa possesses various medicinal benefits and has been used extensively in traditional oriental medicine for thousands of years. Paeonol is the main component isolated from the root bark of Paeonia suffruticosa. The pharmacological effects of Paeonia suffruticosa are mostly attributed to paeonol. Paeonol injection has been successfully applied in China for nearly 50 years for inflammation/pain-related indications. Currently, the dosage forms of paeonol approved by China Food and Drug Administration include tablet, injection, and external preparations such as ointment and adhesive plaster. So far, the clinical applications of paeonol are mainly focusing on the anti-inflammatory activity. Studies of other pharmacological activities of paeonol are developing rapidly, and which may play an important role in the future. Besides, substantial mechanisms of pharmacological action of paeonol have been clarified in recent years. In this review, we summarize the pharmacological effects anti-inflammatory, neuroprotective, anti-tumor, anti-cardiovascular diseases and associated mechanisms of action of paeonol up to date.

Paeonol inhibits the development of 1‑chloro‑2,4‑dinitrobenzene‑induced atopic dermatitis via mast and T cells in BALB/c mice

Our previous studies suggested that paeonol, the active constituent of the traditional Chinese medicine Cortex Moutan, may be an effective treatment for inflammatory disorders. In the present study, the therapeutic potential of paeonol on atopic dermatitis (AD) was investigated using animal and cell experiments. AD‑like lesions were induced by repeated application of 1‑chloro‑2,4‑dinitrobenzene (DNCB) to the shaved dorsal skin of BALB/c mice, and P815 cells were used for in vitro assays. The skin lesions, serum and spleens of the mice were analyzed using lesion severity scoring, histological analysis, flow cytometry, reverse transcription‑quantitative polymerase chain reaction, western blotting and ELISA, in order to investigate the anti‑AD effects of paeonol. In addition, western blotting and ELISA were conducted for in vitro analysis of P815 cells. The results demonstrated that oral administration of paeonol inhibited the development of DNCB‑induced AD‑like lesions in the BALB/c mice by reducing severity of the lesions, epidermal thickness and mast cell infiltration; this was accompanied by reduced levels of immunoglobulin E and inflammatory cytokines [interleukin (IL)‑4, histamine, IL‑13, IL‑31 and thymic stromal lymphopoietin], along with regulation of the T helper (Th) cell subset (Th1/Th2) ratio. Application of paeonol also reduced the protein expression levels of phosphorylated (p)‑p38 and p‑extracellular signal‑regulated kinase (ERK) in skin lesions. In vitro, paeonol reduced the expression levels of tumor necrosis factor‑α and histamine in P815 cells, and inhibited p38/ERK/mitogen‑activated protein kinase signaling. The present findings indicated that paeonol may relieve dermatitis by acting on cluster of differentiation 4+ T and mast cells; therefore, paeonol may represent a potential therapeutic strategy for the treatment of allergic inflammatory conditions via immunoregulation.