Paeoniflorin protects human EA.hy926 endothelial cells against gamma-radiation induced oxidative injury by activating the NF-E2-related factor 2/heme oxygenase-1 pathway

Antioxidant effects of Paeoniflorin and relevant molecular mechanisms as related to a variety of diseases: A review

Paeoniflorin (PF), which is the main component of the Paeonia lactiflora Pall extract, is one of the traditional Chinese medicines. The pharmacological effects associated with PF include antioxidant, immunomodulatory, anti-inflammatory, anticancer, antidepressant-like and neuroprotective effects. Our previous studies had revealed that PF protected melanocytes and inhibited photodamage through the suppression of oxidative stress (OS). As OS plays a vital role in the progression of a variety of diseases, the capacity for PF to suppress OS may exert important effects upon them. However, no review exists on these antioxidant effects of PF as related to various diseases. Therefore, in this review we summarized studies involved with examining the antioxidant effects and molecular mechanisms of PF. Through its capacity to inhibit OS, PF has been shown to exert beneficial effects upon several systems including nervous, cardiac/vascular, digestive, and respiratory as well as specific diseases such as diabetes, autoimmune, pregnancy related, ocular, kidney, dermatology, along with suppression of distal flap necrosis, postoperative adhesions, and hearing loss. Such findings provide new insights and directions for future research directed at the development of PF as a natural antioxidant for the treatment of clinical diseases.

Naoxintong capsule for treating cardiovascular and cerebrovascular diseases: from bench to bedside

Naoxintong Capsule (NXT), a renowned traditional Chinese medicine (TCM) formulation, has been broadly applied in China for more than 30 years. Over decades, accumulating evidences have proven satisfactory efficacy and safety of NXT in treating cardiovascular and cerebrovascular diseases (CCVD). Studies have been conducted unceasingly, while this growing latest knowledge of NXT has not yet been interpreted properly and summarized comprehensively. Hence, we systematically review the advancements in NXT research, from its chemical constituents, quality control, pharmacokinetics, to its profound pharmacological activities as well as its clinical applications in CCVD. Moreover, we further propose specific challenges for its future perspectives: 1) to precisely clarify bioactivities of single compound in complicated mixtures; 2) to evaluate the pharmacokinetic behaviors of NXT feature components in clinical studies, especially drug-drug interactions in CCVD patients; 3) to explore and validate its multi-target mechanisms by integrating multi-omics technologies; 4) to re-evaluate the safety and efficacy of NXT by carrying out large-scale, multicenter randomized controlled trials. In brief, this review aims to straighten out a paradigm for TCM modernization, which help to contribute NXT as a piece of Chinese Wisdom into the advanced intervention strategy for CCVD therapy.

Combination of total glucosides of paeony, narrow-band ultraviolet B, and oral corticosteroid mini-pulse therapy for nonsegmental vitiligo: A retrospective study

BACKGROUND

The total glucoside of paeony (TGP) is recognized for its immunomodulatory properties and anti-inflammatory effects. This study evaluates the efficacy of TGP combined with oral mini-pulse therapy (OMP) and narrow-band ultraviolet B (NB-UVB) in treating active nonsegmental vitiligo (NSV).

MATERIALS AND METHODS

The combination therapy was contrasted against those from a group treated solely with OMP and NB-UVB. Data from 62 patients undergoing TGP combination treatment and 55 without were analyzed over a 3-month period. After 6 months, the differences in recurrence rate were investigated by follow-up.

RESULTS

The findings indicate that integrating TGP may yield superior outcomes compared to OMP + NB-UVB alone. Moreover, the patient's oxidative stress makers were significantly reduced after the treatment. The majority of patients in the TGP cohort exhibited enhanced skin pigmentation over the duration. Notably, no increase in side effects or recurrence was observed in this group. Especially, patients with vitiligo on their head and neck experienced pronounced improvements.

CONCLUSION

The efficacy of the combination treatment group was better than that of the control group at 2 and 3 months, and there was no difference in recurrence rate and side effects, suggesting that TGP may continue to show efficacy in NSV for a longer period of time by reducing the level of oxidative stress, and is especially suitable for patients with head and neck lesions.

Traditional Chinese medicines treat ischemic stroke and their main bioactive constituents and mechanisms

Ischemic stroke (IS) remains one of the leading causes of death and disability in humans. Unfortunately, none of the treatments effectively provide functional benefits to patients with IS, although many do so by targeting different aspects of the ischemic cascade response. The advantages of traditional Chinese medicine (TCM) in preventing and treating IS are obvious in terms of early treatment and global coordination. The efficacy of TCM and its bioactive constituents has been scientifically proven over the past decades. Based on clinical trials, this article provides a review of commonly used TCM patent medicines and herbal decoctions indicated for IS. In addition, this paper also reviews the mechanisms of bioactive constituents in TCM for the treatment of IS in recent years, both domestically and internationally. A comprehensive review of preclinical and clinical studies will hopefully provide new ideas to address the threat of IS.

Paeoniflorin alleviates hypoxia/reoxygenation injury in HK-2 cells by inhibiting apoptosis and repressing oxidative damage via Keap1/Nrf2/HO-1 pathway

Acute kidney injury (AKI) is a serious disorder associated with significant morbidity and mortality. AKI and ischemia/reperfusion (hypoxia/reoxygenation, H/R) injury can be induced due to several reasons. Paeoniflorin (PF) is a traditional herbal medicine derived from Paeonia lactiflora Pall. It exerts diverse therapeutic effects, including anti-inflammatory, antioxidative, antiapoptotic, and immunomodulatory properties; thus, it is considered valuable for treating several diseases. However, the effects of PF on H/R injury-induced AKI remain unknown. In this study, we established an in vitro H/R model using COCL2 and investigated the functions and underlying mechanisms of PF on H/R injury in HK-2 cells. The cell vitality was evaluated using the cell count kit-8 assay. The DCFH-DA fluorescence probe was used to measure the levels of reactive oxygen species (ROS). Oxidative damage was detected using superoxide dismutase (SOD) and malondialdehyde (MDA) assay kits. Apoptotic relative protein and Keap1/Nrf2/HO-1 signaling were evaluated by Western blotting. Our results indicated that PF increased cell viability and SOD activity and decreased the ROS and MDA levels in HK-2 cells with H/R injury. PF inhibits apoptosis by increasing Bcl-2 and decreasing Bax. Furthermore, PF significantly upregulated the expression of HO-1 and Nrf2, but downregulated the expression of HIF-1α and Keap1. PF considerably increased Nrf2 nuclear translocation and unregulated the HO-1 expression. The Nrf2 inhibitor (ML385) could reverse the abovementioned protective effects of PF, suggesting that Nrf2 can be a critical target of PF. To conclude, we found that PF attenuates H/R injury-induced AKI by decreasing the oxidative damage via the Nrf2/HO-1 pathway and inhibiting apoptosis.

Research on Mechanisms of Chinese Medicines in Prevention and Treatment of Postoperative Adhesion

Postoperative adhesion (PA) is currently one of the most unpleasant complications following surgical procedures. Researchers have developed several new strategies to alleviate the formation of PA to a great extent, but so far, no single measure or treatment can meet the expectations and requirements of clinical patients needing complete PA prevention. Chinese medicine (CM) has been widely used for thousands of years based on its remarkable efficacy and indispensable advantages CM treatments are gradually being accepted by modern medicine. Therefore, this review summarizes the formating process of PA and the efficacy and action mechanism of CM treatments, including their pharmacological effects, therapeutic mechanisms and advantages in PA prevention. We aim to improve the understanding of clinicians and researchers on CM prevention in the development of PA and promote the in-depth development and industrialization process of related drugs.

AP2a-Mediated Upregulation of miR-125a-5p Ameliorates Radiation-Induced Oxidative Stress Injury via BRD4/Nrf2/HO-1 Signaling

Radiation therapy is widely used to restrain tumor progression, but it is always accompanied by damage to healthy tissues. We aimed to probe the impact and mechanism of activator protein 2a (AP2a) and miR-125a-5p in radiation-induced oxidative stress injury. Human umbilical vein endothelial cells (HUVECs) were treated with X rays to induce radiation injury in vitro. Cell viability was measured using MTT assays. Flow cytometry assay was employed to detect the apoptosis rate. Oxidative stress markers were evaluated by detection kits. Gene or protein levels were determined by RT-qPCR or Western blotting. Validation of the interaction of miR-125a-5p with BRD4 and AP2a was conducted by dual luciferase assay or ChIP. MiR-125a-5p and AP2a were decreased in irradiated HUVECs, whereas BRD4 was increased. MiR-125a-5p overexpression or BRD4 silencing alleviated the cell viability decline, apoptosis, and oxidative stress injury caused by radiation treatment. MiR-125a-5p repressed the BRD4 level. The protective effects of miR-125a-5p overexpression in the radiation-induced oxidative injury were impeded by BRD4 overexpression. Moreover, AP2a bound to the promoter of miR-125a-5p. MiR-125a-5p inhibition reversed the effects of AP2a overexpression on radiational oxidative injury by modulating Nrf2/HO-1 signaling. AP2a transcriptionally activated miR-125a-5p ameliorated oxidative stress injury of HUVECs caused by radiation through Nrf2/HO-1 signaling.

Therapeutic potential of paeoniflorin in atherosclerosis: A cellular action and mechanism-based perspective

Epidemiological studies have shown that the incidence, prevalence and mortality of atherosclerotic cardiovascular disease (ASCVD) are increasing globally. Atherosclerosis is characterized as a chronic inflammatory disease which involves inflammation and immune dysfunction. P. lactiflora Pall. is a plant origin traditional medicine that has been widely used for the treatment of various diseases for more than a millennium in China, Japan and Korean. Paeoniflorin is a bioactive monomer extracted from P. lactiflora Pall. with anti-atherosclerosis effects. In this article, we comprehensively reviewed the potential therapeutic effects and molecular mechanism whereby paeoniflorin protects against atherosclerosis from the unique angle of inflammation and immune-related pathway dysfunction in vascular endothelial cells, smooth muscle cells, monocytes, macrophages, platelets and mast cells. Paeoniflorin, with multiple protective effects in atherosclerosis, has the potential to be used as a promising therapeutic agent for the treatment of atherosclerosis and its complications. We conclude with a detailed discussion of the challenges and future perspective of paeoniflorin in translational cardiovascular medicine.

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

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

The inhibitory effect of paeoniflorin on reactive oxygen species alleviates the activation of NF-κB and MAPK signalling pathways in macrophages

Paeoniflorin (PF) has been proven to possess a protective effect in some inflammatory diseases, but the underlying mechanism remains unclear. Macrophages play central roles in inflammatory responses and LPS-stimulated RAW264.7 macrophage is an ideal model for studying the anti-inflammatory effects and mechanisms of drugs. Thus, it was used to explore the anti-inflammatory mechanism of PF in this study. The results showed that PF markedly attenuated the activation of NF-κB, extracellular signal-regulated kinase (ERK1/2) and p38 mitogen activated protein kinase (p38) signalling pathways induced by LPS exposure. In addition, PF pretreatment dose-dependently suppressed the production of cytokines and the expressions of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS). Concomitantly, PF pretreatment dramatically inhibited the accumulation of intracellular reactive oxygen species (ROS) without affecting the phagocytosis of macrophages. Furthermore, it has proved the scavenging effect of PF on ROS was involved in the anti-inflammatory process. This study provides a novel aspect to the understanding of the anti-inflammatory mechanism of PF.

Effect of Dietary Paeoniae Radix Alba Extract on the Growth Performance, Nutrient Digestibility and Metabolism, Serum Biochemistry, and Small Intestine Histomorphology of Raccoon Dog During the Growing Period

Paeoniae radix alba extract (PRA extract) has the functions of regulating immunity, resisting inflammation, and has antioxidant properties. However, current recommendations of dietary PRA extract levels for raccoon dogs were inadequate. The purpose of this experimental study was to gain information allowing for better estimating the effects of PRA extract on raccoon dogs, and their PRA requirements. Fifty healthy male raccoon dogs of (120 ± 5) days old were randomly divided into 5 groups (group PRA0, PRA1, PRA2, PRA4, PRA8) with 10 animals in each group and 1 in each replicate. Five kinds of experimental diets were prepared with five levels of Paeoniae radix alba extract (0, 1, 2, 4, 8 g/kg) in the basic diet. The prefeeding period was 7 days and the experimental period was 40 days. The results showed that the average daily feed intake in group PRA1 and PRA2 was significantly higher than that in other groups (P < 0.01). The dry matter excretion in group PRA8 was significantly higher than that in other groups (P < 0.01), while the dry matter digestibility and protein digestibility in group PRA8 were significantly lower than those in other groups (P < 0.01). Nitrogen retention in group PRA1 and PRA2 was significantly higher than that in group PRA8 (P < 0.05). With the increase of the content of Paeoniae radix alba extract in diet, the activity of alkaline phosphatase in group PRA2 was significantly higher than that in group PRA0 (P < 0.05); The activity of serum SOD in group PRA4 was significantly higher than that in other groups (P < 0.01). The content of serum IgA in group PRA2 was significantly higher than that in other groups (P < 0.05). The content of TNF-α in intestinal mucosa in group PRA1 and group PRA2 was significantly lower than that in group PRA0 (P < 0.05). In conclusion, we found that dietary Paeoniae radix alba extract intake significantly improved the feed intake and nitrogen deposition of Ussuri raccoon dog, increased the content of serum IgA and reduced the content of TNF-α in the small intestinal mucosa. We suggest that an estimated dietary Paeoniae radix alba extract level of 1 to 2 g/kg could be used as a guide to achieve the optimal performance of raccoon dogs.

Paeoniflorin alleviates NG-nitro-L-arginine methyl ester (L-NAME)-induced gestational hypertension and upregulates silent information regulator 2 related enzyme 1 (SIRT1) to reduce H2O2-induced endothelial cell damage

Pregnancy-induced hypertension (PIH) is a leading cause of maternal mortality. Paeoniflorin has been reported to alleviate hypertension, thus relieving the injury of target organ. This study aimed to investigate the role of paeoniflorin in PIH development by regulating SIRT1 in rats. The mean arterial pressure (MAP), urine protein and histopathological damage of placenta in gestational hypertension rats were, respectively, detected by noninvasive tail-artery pressure measuring instrument, BCA method and H&E staining. The viability of human umbilical vein endothelial cells (HUVECs) treated with paeoniflorin or/and H₂O₂ was observed by CCK-8 assay. SIRT1 protein expression in HUVECs treated with paeoniflorin or/and H₂O₂ was analyzed by Western blot. Tunel assay, wound healing assay and tube formation assay were used to detect the apoptosis, migration and tube formation of HUVECs administrated with paeoniflorin or/and H₂O₂ or/and EX527 (SIRT1 inhibitor). As a result, MAP, urine protein and histopathological damage of placenta were enhanced in PIH rats, which were then alleviated by paeoniflorin. Paeoniflorin decreased the levels of sFlt-1, PlGF and VEGF in serum and placental tissues of gestational hypertension rats as well as the inflammatory response and oxidative stress. In addition, paeoniflorin promoted the expressions of SIRT1 and NO/eNOS and inhibited the production of iNOS in gestational hypertension rats to improve vascular endothelial cell injury. However, SIRT1 inhibition could suppress the protective effects of paeoniflorin on endothelial dysfunction of H₂O₂-induced HUVECs. In conclusion, paeoniflorin could improve gestational hypertension development by upregulating SIRT1.

Effect of paeoniflorin on acute lung injury induced by influenza A virus in mice. Evidences of its mechanism of action

BACKGROUND

Influenza often leads to acute lung injury (ALI). Few therapeutics options such as vaccines and other antiviral drugs are available. Paeoniflorin is a monoterpene glucoside isolated from the roots of Paeonia lactiflora Pall. that has showed good anti-inflammatory and anti-fibrotic effects. However, it is not known whether paeoniflorin has an effect on influenza virus-induced ALI.

PURPOSE

To investigative the protective effect and potential mechanism of paeoniflorin on ALI induced by influenza A virus (IAV).

STUDY DESIGN AND METHODS

The anti-influenza activity of paeoniflorin in vitro was investigated. Influenza virus A/FM/1/47 was intranasally infected in mice to induce ALI, and paeoniflorin (50 and 100 mg/kg) was given orally to mice during 5 days, beginning 2 h after infection. On day 6 post-infection, body and lung weights, histology and survival were observed, and the lungs were examined for viral load, cytokine and cellular pathway protein expression.

RESULTS

Results showed that paeoniflorin (50 and 100 mg/kg) reduced IAV-induced ALI. It reduces pulmonary oedema and improves histopathological changes in the lung, and also diminishes the accumulation of inflammatory cells in the lung. It was shown that paeoniflorin (50 and 100 mg/kg) alleviated IAV-induced ALI, as evidenced by improved survival in infected mice (40% and 50%, respectively), reduced viral titer in lung tissue, improved histological changes, and reduced lung inflammation. Paeoniflorin also improves pulmonary fibrosis by reducing the levels of pulmonary fibrotic markers (collagen type IV, alpha-smooth muscle actin, hyaluronic acid, laminin, and procollagen type III) and downregulating the expression levels of type I collagen (Col I) and type III collagen (Col III) in the lung tissues. Additionally, paeoniflorin inhibits the expression of αvβ3, TGF-β1, Smad2, NF-κB, and p38MAPK in the lung tissues.

CONCLUSION

The results showed that paeoniflorin (50 and 100 mg/kg) protected against IAV-induced ALI, and the underlying mechanism may be related to the reduction of pro-inflammatory cytokine production and lung collagen deposition through down-regulation of activation of αvβ3/TGF-β1 pathway in lung tissue.

Mangiferin attenuates cigarette smoke-induced chronic obstructive pulmonary disease in male albino rats

We analyzed the ability of mangiferin to suppress cigarette smoke-induced chronic obstructive pulmonary disease. Control rats showed a marked decrease in the ratio of the forced expiratory volume at 0.1 s to forced vital capacity. The decreases in the peak expiratory flow and maximal mid-expiratory flow indicated airway remodeling and enlargement. The expression levels of superoxide dismutase (SOD), heme oxygenase-1 (HO-1), γ-glutamylcysteine synthetase, nuclear factor erythroid 2-related factor 2, and activating transcription factor 4 were increased in the control rats. The levels of oxidative stress, malondialdehyde, and reactive oxygen species peaked after 24 weeks, whereas the SOD and HO-1 levels and the total antioxidant capacity were reduced in control rats. Mangiferin restored the levels of reactive oxygen species, malondialdehyde, SOD, HO-1, and T-AOC to near normal. Increased numbers of infiltrating inflammatory cells were observed in control rats but were significantly reduced by mangiferin. In addition, edema and airway inflammation were reduced by mangiferin.

Recent Insights Into the Protective Mechanisms of Paeoniflorin in Neurological, Cardiovascular, and Renal Diseases

ABSTRACT

The monoterpene glycoside paeoniflorin (PF) is the principal active constituent of the traditional Chinese herbal medicines, Radix Paeoniae Alba and Radix Paeoniae Rubra, which have been used for millennia to treat cardiovascular diseases (eg, hypertension, bleeding, and atherosclerosis) and neurological ailments (eg, headaches, vertigo, dementia, and pain). Recent evidence has revealed that PF exerts inhibitory effects on inflammation, fibrosis, and apoptosis by targeting several intracellular signaling cascades. In this review, we address the current knowledge about the pharmacokinetic properties of PF and its molecular mechanisms of action. We also present results from recent preclinical studies supporting the utility of PF for the treatment of pain, cerebral ischemic injury, and neurodegenerative diseases, such as Alzheimer's and Parkinson's diseases. Moreover, new evidence suggests a general protective role of PF in heart attack, diabetic kidney, and atherosclerosis. Mechanistically, PF exerts multiple anti-inflammatory actions by targeting toll-like receptor-mediated signaling in both parenchymal and immune cells (in particular, macrophages and dendritic cells). A better understanding of the molecular actions of PF may lead to the expansion of its therapeutic uses.

Review of the Efficacy and Mechanisms of Traditional Chinese Medicines as a Therapeutic Option for Ionizing Radiation Induced Damage

Ionizing radiation damage refers to acute, delayed, or chronic tissue damage associated with ionizing radiation. Specific or effective therapeutic options for systemic injuries induced by ionizing radiation have not been developed. Studies have shown that Chinese herbal Medicine or Chinese Herbal Prescription exhibit preventive properties against radiation damage. These medicines inhibit tissue injuries and promote repair with very minimal side effects. This study reviews traditional Chinese herbal medicines and prescriptions with radiation protective effects as well as their mechanisms of action. The information obtained will guide the development of alternative radioprotectants.

Paeoniflorin modulates oxidative stress, inflammation and hepatic stellate cells activation to alleviate CCl4-induced hepatic fibrosis by upregulation of heme oxygenase-1 in mice

OBJECTIVES

The role of Paeoniflorin on hepatic fibrosis and the specific mechanisms has not yet been elucidated. Therefore, we explored whether Paeoniflorin exerted protective effects on carbon tetrachloride (CCl4)-induced hepatic fibrosis and the underlying mechanisms.

METHODS

A model of hepatic fibrosis was induced by intraperitoneally injecting with CCl4 (10% 5 μl/g) twice a week for 7 weeks. To explore the effects of Paeoniflorin, mice were treated with Paeoniflorin (100 mg/kg) by gavage once a day at 1 week after modeling until they were sacrificed.

KEY FINDINGS

Paeoniflorin remarkably improved liver function and histopathological changes of hepatic tissues in CCl4-induced liver injury. Besides, the serum MAO enzyme activity and hydroxyproline contents were notably decreased following the intervention of Paeoniflorin. The decreased expression of Vimentin, α-SMA, Col1a and Desmin manifested the inhibition of the hepatic stellate cells (HSCs) activation. Interestingly, Paeoniflorin intervention significantly upregulated the expression of heme oxygenase-1, and attenuated the inflammatory cytokines production as well as the CCl4-induced oxidative stress imbalance.

CONCLUSIONS

Paeoniflorin could effectively alleviate CCl4-induced hepatic fibrosis by upregulation of heme oxygenase-1, and it might be a new effective option for the comprehensive treatment of hepatic fibrosis.

High-throughput preparation of radioprotective polymers via Hantzsch's reaction for in vivo X-ray damage determination

Radioprotectors for acute injuries caused by large doses of ionizing radiation are vital to national security, public health and future development of humankind. Here, we develop a strategy to explore safe and efficient radioprotectors by combining Hantzsch's reaction, high-throughput methods and polymer chemistry. A water-soluble polymer with low-cytotoxicity and an excellent anti-radiation capability has been achieved. In in vivo experiments, this polymer is even better than amifostine, which is the only approved radioprotector for clinical applications, in effectively protecting zebrafish embryos from fatally large doses of ionizing radiation (80 Gy X-ray). A mechanistic study also reveals that the radioprotective ability of this polymer originates from its ability to efficiently prevent DNA damage due to high doses of radiation. This is an initial attempt to explore polymer radioprotectors via a multi-component reaction. It allows exploiting functional polymers and provides the underlying insights to guide the design of radioprotective polymers.

Total glucosides of paeony: A review of its phytochemistry, role in autoimmune diseases, and mechanisms of action

ETHNOPHARMACOLOGICAL RELEVANCE

Paeoniae Radix Alba (PRA, called baishao in China), the root of Paeonia lactiflora Pall., has shown a rich medicinal value for more than 2000 years. PRA is used in local medicine and traditional medicine for autoimmune diseases associated with inflammation. At present, total glucosides of paeony (TGP), the main active ingredient of PRA, has been developed into a preparation for the treatment of autoimmune diseases, as TGP exhibits the effect of regulating immunity, anti-inflammatory, and analgesic effects.

AIM OF THE REVIEW

TGP was developed and applied to inflammation-related autoimmune diseases in modern clinical practice. Based on its application in traditional prescriptions, this article reviews PRA's botany and phytochemistry (including its extraction process and quality control), and discusses the clinical application and pharmacological research of TGP as an anti-inflammatory drug from the perspective of ethnopharmacology. Additionally, we review modern pharmacological and molecular-target research on TGP and discuss the mechanisms of TGP in treating autoimmune diseases. Through a systematic literature review, we also highlight the clinical efficacy of TGP in the treatment of immune diseases, and provide a reference for the continued scientific development and quality control of TGP so that its wider application and clinical value can be fully realized.

MATERIALS AND METHODS

Literature search was conducted through the Web of Science, Baidu Scholar, ScienceDirect, PubMed, CNKI, and WanFang DATA using the keywords "Total glucosides of paeony", "Paeonia lactiflora Pall. ", "Paeonia veitchii Lynch", "Paeoniae Radix Alba or white peony", "Paeoniae Radix Rubra or red peony", "Paeoniflorin", "Albiflorin", "Autoimmune diseases", and their combinations. In addition, information was collected from relevant textbooks, reviews, and documents.

RESULTS

Approximately 15 compounds have been identified in TGP, of which paeoniflorin and albiflorin are the most common constituents. In recent years, studies have found that TGP and its main chemical components are effective in the treatment of autoimmune diseases, such as rheumatoid arthritis, psoriasis, oral lichen planus, and Sjogren's syndrome. TGP has a variety of pharmacological effects related to PRA traditional effects, including anti-organ-damage, anti-inflammatory, analgesic, antioxidant, cardiovascular, and nervous-system protection. Previously published reports on TGP treatment of autoimmune diseases have shown that TGP regulates intracellular pathways, such as the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), mitogen-activated protein kinase (MAPK), and phosphatidylinositol 3-kinase/protein kinase B (PI3K/Akt) signaling pathways. However, there is no standardized preparation method for TGP, and there is insufficient quality control of formulations. Many related pharmacological studies have not tested TGP components, and the validity of such pharmacological results requires further verification.

CONCLUSIONS

Modern pharmacological research on TGP is based on the traditional usage of PRA, and its folk medicinal value in the treatment of autoimmune diseases has now been verified. In particular, TGP has been developed into a formulation used clinically for the treatment of autoimmune diseases. The combination of TGP capsules and chemicals to treat autoimmune diseases has the effect of increasing efficacy and reducing toxicity. Based on further research on its preparation, quality control, and mechanisms of action, TGP is expected to eventually play a greater role in the treatment of autoimmune diseases.

UVA Induced Oxidative Stress Was Inhibited by Paeoniflorin/Nrf2 Signaling or PLIN2

Photodamages caused by UVA radiation induced oxidative injuries are closely related to photoaging and skin cancer. Paeoniflorin (PF), extracted from the root of Paeonia lactiflora, has been reported to be an effective antioxidant. PLIN2, known as adipose differentiation-related protein, has been previously involved in the regulation of oxidative stress. In this study, we were sought to investigate the photo-protective property of PF and PLIN2 in UVA-radiated human dermal fibroblasts (HDFs). HDFs were pre-treated with PF (800 μM) followed by UVA radiation (22.5 J/cm2). MTS activity, cell apoptosis, ROS, MDA, and SOD were detected, respectively. The expressions of Nrf2, HO-1, NQ-O1, and PLIN2 were determined using RT-qPCR or western blot. Nrf2 was silenced by siRNA, and PLIN2 was overexpressed via lentiviral transduction. Comparing to the UVA radiation, PF pre-treatment could prominently increase the MTS activity, decrease cell apoptosis, reduce the generations of ROS and MDA, increase the activity of SOD and increase the expression of Nrf2 and its target genes HO-1 and NQ-O1. When Nrf2 was knocked down, PF lost above protective properties. In addition, UVA induced oxidative stress led to upregulation of PLIN2 and the latter could be decreased by PF. Overexpression of PLIN2 improved MTS activity and reduced MDA level in HDFs. The combination of PLIN2 overexpression and PF pre-treatment corporately inhibited UVA-induced injury. Besides, we also found that PF and PLIN2 had a compensatory protection against UVA induced oxidative stress. In conclusion, our study demonstrated that UVA induced photodamages could be inhibited by PF via Nrf2/HO-1/NQ-O1 signaling pathway or by PLIN2, and the combination of PLIN2 overexpression and PF played additive effects against UVA-related oxidative stress.

Paeoniflorin Resists H2O2-Induced Oxidative Stress in Melanocytes by JNK/Nrf2/HO-1 Pathway

Paeoniflorin (PF) possesses multiple biological functions including anti-oxidization. PF is the major bioactive ingredient of total glycosides of paeony (TGP), which could promote re-pigmentation of vitiligo. The study was sought to investigate the effects and potential signaling pathways of PF on hydrogen peroxide (H₂O₂)-induced oxidative stress in melanocytes. The results showed that pretreatment with 50 µM PF significantly inhibited cell apoptosis, enhanced cell viability, and suppressed reactive oxygen species (ROS) accumulation by enhancing the productions of superoxide dismutase (SOD) and antioxidant enzymes catalase (CAT). Furthermore, PF activated c-Jun amino terminal kinase (JNK) and the nuclear factor E2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) pathway to counteract H₂O₂-induced oxidative damage in PIG1 and PIG3V. Taken together, our study firstly demonstrates that PF resists H₂O₂-induced oxidative stress in melanocytes probably by activating JNK/Nrf2/HO-1 signaling, suggesting a potential therapeutic application of PF on vitiligo.

Shaoyao Gancao Tang (SG-Tang), a formulated Chinese medicine, reduces aggregation and exerts neuroprotection in spinocerebellar ataxia type 17 (SCA17) cell and mouse models

Spinocerebellar ataxia (SCA) type 17 is an autosomal dominant ataxia caused by expanded polyglutamine (polyQ) tract in the TATA-box binding protein (TBP). Substantial studies have shown involvement of compromised mitochondria biogenesis regulator peroxisome proliferator-activated receptor gamma-coactivator 1 alpha (PGC-1α), nuclear factor erythroid 2-related factor 2 (NRF2), nuclear factor-Y subunit A (NFYA), and their downstream target genes in the pathogenesis of polyQ-expansion diseases. The extracts of Paeonia lactiflora (P. lactiflora) and Glycyrrhiza uralensis (G. uralensis) have long been used as a Chinese herbal medicine (CHM). Shaoyao Gancao Tang (SG-Tang) is a formulated CHM made of P. lactiflora and G. uralensis at a 1:1 ratio. In the present study, we demonstrated the aggregate-inhibitory and anti-oxidative effect of SG-Tang in 293 TBP/Q₇₉ cells. We then showed that SG-Tang reduced the aggregates and ameliorated the neurite outgrowth deficits in TBP/Q₇₉ SH-SY5Y cells. SG-Tang upregulated expression levels of NFYA, PGC-1α, NRF2, and their downstream target genes in TBP/Q₇₉ SH-SY5Y cells. Knock down of NFYA, PGC-1α, and NRF2 attenuated the neurite outgrowth promoting effect of SG-Tang on TBP/Q₇₉ SH-SY5Y cells. Furthermore, SG-Tang inhibited aggregation and rescued motor-deficits in SCA17 mouse model. The study results suggest the potential of SG-Tang in treating SCA17 and probable other polyQ diseases.

Paeoniflorin Ameliorates Chronic Hypoxia/SU5416-Induced Pulmonary Arterial Hypertension by Inhibiting Endothelial-to-Mesenchymal Transition

Background

Endothelial cells dysfunction is one of the hallmark pathogenic features of pulmonary arterial hypertension (PAH). Paeoniflorin (PF) is a monoterpene glycoside with endothelial protection, vasodilation, antifibrotic, anti–inflammatory and antioxidative properties. However, the effects of PF on PAH remain unknown.

Methods

Here, we investigated the efficacy of PF in the SU5416/hypoxia (SuHx) rat model of PAH. Human pulmonary arterial endothelial cells (HPAECs) were exposed to 1% O₂ with or without PF treatment.

Results

Hemodynamics analysis showed that prophylactic treatment with PF (300 mg/kg i.g. daily for 21 days) significantly inhibited chronic hypoxia/SU5416-induced elevations of right ventricular systolic pressure (RVSP) and right ventricular hypertrophy index in rats. Meanwhile, PF significantly reduced pulmonary vascular remodeling, as well as alleviated collagen deposition in lungs and right ventricles in SuHx rats. Additionally, PF inhibited SuHx–induced down-regulation of endothelial marker (vascular endothelial cadherin) and up-regulation of mesenchymal markers (fibronectin and vimentin) in lung, suggesting that PF could inhibit SuHx–induced endothelial-to-mesenchymal transition (EndMT) in lung. Further in vitro studies confirmed that PF treatment suppressed hypoxia-induced EndMT in HPAECs, which was abolished by the knockdown of bone morphogenetic protein receptor type 2 (BMPR2) in HPAECs.

Conclusion

Taken together, our findings suggest that PF ameliorates BMPR2 down-regulation-mediated EndMT and thereafter alleviates SuHx–induced PAH in rats.

Gamma Radiation-Induced Disruption of Cellular Junctions in HUVECs Is Mediated through Affecting MAPK/NF-κB Inflammatory Pathways

Ionizing radiation-induced cardiovascular diseases (CVDs) have been well documented. However, the mechanisms of CVD genesis are still not fully understood. In this study, human umbilical vein endothelial cells (HUVECs) were exposed to gamma irradiation at different doses ranging from 0.2 Gy to 5 Gy. Cell viability, migration ability, permeability, oxidative and nitrosative stresses, inflammation, and nuclear factor kappa-light-chain-enhancer of activated B cell (NF-κB) pathway activation were evaluated postirradiation. It was found that gamma irradiation at doses ranging from 0.5 Gy to 5 Gy inhibited the migration ability of HUVECs without any significant effects on cell viability at 6 h and 24 h postirradiation. The decreased transendothelial electrical resistance (TEER), increased permeability, and disruption of cellular junctions were observed in HUVECs after gamma irradiation accompanied by the lower levels of junction-related proteins such as ZO-1, occludin, vascular endothelial- (VE-) cadherin, and connexin 40. The enhanced oxidative and nitrosative stresses, e.g., ROS and NO₂ ^- levels and inflammatory cytokines IL-6 and TNF-α were demonstrated in HUVECs after gamma irradiation. Western blot results showed that protein levels of mitogen-activated protein kinase (MAPK) pathway molecules p38, p53, p21, and p27 increased after gamma irradiation, which further induced the activation of the NF-κB pathway. BAY 11-7085, an inhibitor of NF-κB activation, was demonstrated to partially block the effects of gamma radiation in HUVECs examined by TEER and FITC-dextran permeability assay. We therefore concluded that the gamma irradiation-induced disruption of cellular junctions in HUVECs was through the inflammatory MAPK/NF-κB signaling pathway.

Paeoniflorin protects spiral ganglion neurons from cisplatin-induced ototoxicity: Possible relation to PINK1/BAD pathway

The objective of this study was to elucidate whether paeoniflorin (PF) exerted an effect on cisplatin‐induced spiral ganglion neuron (SGN) damage, with special attention given to the role of PINK1/BAD pathway in this process. Middle cochlear turn culture and C57BL/6 mice were utilized to identify the character of PF in vitro and in vivo. We found that cisplatin treatment led to SGN damage, in which reactive oxygen species (ROS) generation increased, PINK1 expression decreased, BAD accumulation on mitochondria raised and mitochondrial apoptotic pathway activated. Conversely, we demonstrated that PF pre‐treatment obviously mitigated cisplatin‐induced SGN damage. Mechanistic studies showed that PF could reduce ROS levels, increase PINK1 expression, decrease the BAD accumulation on mitochondria and, thus, alleviate the activated mitochondrial apoptosis in SGNs caused by cisplatin. Overall, the findings from this work reveal the important role of PF and provide another strategy against cisplatin‐induced ototoxicity.

Ferroptosis inhibitor alleviates Radiation-induced lung fibrosis (RILF) via down-regulation of TGF-β1

Background

Radiation-induced lung fibrosis (RILF) is a severe and life-threatening complication of thoracic radiotherapy. Cell death is the key issue in RILF. Ferroptosis is a form programmed cell death implicated in the pathologies of inflammation. This study aimed to investigate the role of ferroptosis in RILF, and the effectiveness and the potential underlying mechanism of ferroptosis inhibitor on RILF.

Methods

Immunofluorescence, western blot and RT-PCR assays were performed to examine the ferroptosis maker glutathione peroxidase 4 (GPX4) in a mice RILF model. The lung tissue sections were stained with hematoxylin and eosin (H&E), Masson trichrome staining and Sirius-Red staining to evaluate the histopathological changes in RILF mice. Reactive oxygen species (ROS) and hydroxyproline (HYP) in lungs were measured by the relevant kits. The serum levels of inflammatory cytokines (TNF-α, IL-6, IL-10, and TGF-β1) were measured with Elisa. The protein and mRNA levels of GPX4, nuclear factor (erythroid-derived 2)-like 2 (Nrf2), hemeoxygenase-1 (HO1) and quinone oxidoreductase 1 (NQO1) in lungs were examined by western blot and RT-PCR.

Results

GPX4 levels of the irradiated lungs were significantly down-regulated than the groups with no irradiation, and the ferroptosis inhibitor, liproxstatin-1, increased GPX4 levels significantly in RILF mice. Treatment with liproxstatin-1 lowered the Szapiel and Ashcroft scores significantly, down-regulated the levels of ROS and HYP in lungs and reduced the serum inflammatory cytokines levels in RILF mice. The protein and the mRNA levels of Nrf2, HO1 and NQO1 were up-regulated by liproxsratin-1 in RILF.

Conclusions

Our data suggested that ferroptosis played a critical role in RILF, ferroptosis inhibitor liproxstatin-1 alleviated RILF via down-regulation of TGF-β1 by the activation of Nrf2 pathway. The effectiveness of ferroptosis inhibition on RILF provides a novel therapeutic target for RILF.

Protective Effect of Phloroglucinol on Oxidative Stress-Induced DNA Damage and Apoptosis through Activation of the Nrf2/HO-1 Signaling Pathway in HaCaT Human Keratinocytes

Phloroglucinol (PG) is a component of phlorotannins, which are abundant in marine brown alga species. Recent studies have shown that PG is beneficial in protecting cells from oxidative stress. In this study, we evaluated the protective efficacy of PG in HaCaT human skin keratinocytes stimulated with oxidative stress (hydrogen peroxide, H₂O₂). The results showed that PG significantly inhibited the H₂O₂-induced growth inhibition in HaCaT cells, which was associated with increased expression of heme oxygenase-1 (HO-1) by the activation of nuclear factor erythroid 2-related factor-2 (Nrf2). PG remarkably reversed H₂O₂-induced excessive ROS production, DNA damage, and apoptosis. Additionally, H₂O₂-induced mitochondrial dysfunction was related to a decrease in ATP levels, and in the presence of PG, these changes were significantly impaired. Furthermore, the increases of cytosolic release of cytochrome c and ratio of Bax to Bcl-2, and the activation of caspase-9 and caspase-3 by the H₂O₂ were markedly abolished under the condition of PG pretreatment. However, the inhibition of HO-1 function using zinc protoporphyrin, a HO-1 inhibitor, markedly attenuated these protective effects of PG against H₂O₂. Overall, our results suggest that PG is able to protect HaCaT keratinocytes against oxidative stress-induced DNA damage and apoptosis through activating the Nrf2/HO-1 signaling pathway.

Protective Effect of Glutathione against Oxidative Stress-induced Cytotoxicity in RAW 264.7 Macrophages through Activating the Nuclear Factor Erythroid 2-Related Factor-2/Heme Oxygenase-1 Pathway

Reactive oxygen species (ROS), products of oxidative stress, contribute to the initiation and progression of the pathogenesis of various diseases. Glutathione is a major antioxidant that can help prevent the process through the removal of ROS. The aim of this study was to evaluate the protective effect of glutathione on ROS-mediated DNA damage and apoptosis caused by hydrogen peroxide, H₂O₂, in RAW 264.7 macrophages and to investigate the role of the nuclear factor erythroid 2-related factor-2 (Nrf2)/heme oxygenase-1 (HO-1) signaling pathway. The results showed that the decrease in the survival rate of RAW 264.7 cells treated with H₂O₂ was due to the induction of DNA damage and apoptosis accompanied by the increased production of ROS. However, H₂O₂-induced cytotoxicity and ROS generation were significantly reversed by glutathione. In addition, the H₂O₂-induced loss of mitochondrial membrane potential was related to a decrease in adenosine triphosphate (ATP) levels, and these changes were also significantly attenuated in the presence of glutathione. These protective actions were accompanied by a increase in the expression rate of B-cell lymphoma-2 (Bcl-2)/Bcl-2-associated X protein (Bax) and poly(ADP-ribose) polymerase cleavage by the inactivation of caspase-3. Moreover, glutathione-mediated cytoprotective properties were associated with an increased activation of Nrf2 and expression of HO-1; however, the inhibition of the HO-1 function using an HO-1 specific inhibitor, zinc protoporphyrin IX, significantly weakened the cytoprotective effects of glutathione. Collectively, the results demonstrate that the exogenous administration of glutathione is able to protect RAW 264.7 cells against oxidative stress-induced mitochondria-mediated apoptosis along with the activity of the Nrf2/HO-1 signaling pathway.

Thalidomide (THD) alleviates radiation induced lung fibrosis (RILF) via down-regulation of TGF-β/Smad3 signaling pathway in an Nrf2-dependent manner

Radiation-induced lung fibrosis (RILF) is a complication of radiotherapy in thoracic cancer patients. Thalidomide (THD) has a therapeutic effect on fibrotic and inflammatory disorders. The purpose of the current study was to investigate the therapeutic effect of THD on RILF in mice and better understand the underlying regulatory mechanisms of the therapeutic effect. We found that THD mitigated the fibrosis caused by irradiation in mice. The action of THD on RILF was related to the elevation of low levels reactive oxygen species (ROS), which inhibited the transforming growth factor‑β (TGF‑β)/Smad3 signaling pathway through activation of nuclear factor (erythroid-derived 2)-like 2 (Nrf2). Analysis of the therapeutic effect of THD using Nrf2-/- mouse model confirmed the role of Nrf2 in vivo. In addition, no radioprotective effect of THD on thoracic cancer cell lines was observed. In conclusion, these data showed that THD attenuated RILF in mice, which was mediated by Nrf2-dependent down-regulation of the TGF-β/Smad3 pathway, suggesting THD as a potential novel agent for RILF prevention.

Protective Role of Nuclear Factor-Erythroid 2-Related Factor 2 Against Radiation-Induced Lung Injury and Inflammation

Radiation-induced lung injury (RILI) is one of the most common and fatal complications of thoracic radiotherapy. Inflammatory cell infiltration, imbalance of inflammatory cytokines, and oxidative damage were reported to be involved during RILI pathogenesis, especially in the early phase of RILI. Nuclear factor-erythroid 2-related factor 2 (Nrf2) is a key transcriptional regulator of antioxidative cascades, and regulates life span of mice after administration of thoracic irradiation. We investigated the effects of Nrf2 on RILI and inflammation using Nrf2-knockout, Nrf2-overexpression and wild-type mice with or without 15 Gy ionizing radiation to thorax. Our results showed that Nrf2 deficiency aggravated radiation-induced histopathological changes, macrophage and neutrophil infiltration, serum levels of pro-inflammatory cytokines (IL-6, MCP-1, IFN-γ, TNF, and IL-12p70), and the levels of peroxidation products in the mouse lung. Moreover, loss of Nrf2 reduced radiation-induced serum levels of anti-inflammatory cytokine, IL-10, and antioxidative proteins. Nrf2 overexpression significantly alleviated radiation-induced histopathological changes, macrophages and neutrophils infiltration, serum levels of pro-inflammatory cytokines, and the levels of peroxidation products in lung tissues. Nrf2 overexpression also increased the serum levels of IL-10 and antioxidative proteins. These results indicated that Nrf2 had a protective role against radiation-induced acute lung injury and inflammation, and that antioxidative therapy might be a promising treatment for RILI.

Total C-21 steroidal glycosides, isolated from the root tuber of Cynanchum auriculatum Royle ex Wight, attenuate hydrogen peroxide-induced oxidative injury and inflammation in L02 cells

Oxidative stress plays an important role in the pathology of liver disorders. Total C-21 steroidal glycosides (TCSGs), isolated from the root tuber of Cynanchum auriculatum Royle ex Wight, have been reported to exert numerous effects, including liver protective and antioxidant effects. In order to investigate the potential mechanisms underlying the protective effects of TCSGs on liver function, the present study used the human normal liver cell line, L02, to evaluate the effects of TCSGs on hydrogen peroxide (H₂O₂)-induced oxidative injury and inflammatory responses. The L02 cells were pretreated with various concentrations of TCSGs, followed by exposure to 1.5 mM H₂O₂. Cell viability was determined by a 3-(4,5-dimethylthiazol-2-yl)-2,5-di-phenyltetrazolium bromide (MTT) assay. The levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), lactate dehydrogenase (LDH) and nitric oxide (NO) were measured using colorimetric assays. The activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px) and the production of malondialdehyde (MDA) were also determined. Intracellular reactive oxygen species (ROS) levels were detected using a fluorescent probe. H₂O₂-induced oxidative toxicity was attenuated following treatment with TCSGs, as indicated by the increase in cell viability, the decreased levels of ALT, AST, LDH, NO, MDA and ROS, and the increased activities of SOD, CAT and GSH-Px. To further explore the possible mechanisms of action of TCSGs, the nuclear factor erythroid 2-related factor 2 (Nrf2) and nuclear factor-κB (NF)-κB pathways were examined. The results revealed that treatment with TCSGs markedly induced Nrf2 nuclear translocation and upregulated the expression of heme oxygenase-1 (HO-1) in the L02 cells damaged by H₂O₂. In addition, pretreatment with TCSGs inhibited the NF-κB signaling pathway by blocking the degradation of the inhibitor of nuclear factor κBα (IκBα), thereby reducing the expression and nuclear translocation of NF-κB, as well as reducing the expression of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), inducible nitric oxide synthase (iNOS) and cyclooxygenase 2 (COX-2). On the whole, the findings of this study demonstrate that TCSGs can protect L02 cells against H₂O₂-induced oxidative toxicity and inflammatory injury by increasing the expression of Nrf2 and HO-1, mediated by the NF-κB signaling pathway.

Protective effects of celastrol against γ irradiation-induced oxidative stress in human umbilical vein endothelial cells

High-dose ionizing radiation can cause harmful effects on the cardiovascular system. Notably, endothelial cells are critical targets in radiation-induced damage. γ radiation exerts its biological effects through the radiolysis of water, which further generates ROS and induces lipid peroxidation and DNA damage. The present study aimed to evaluate the potential protective effects of celastrol against γ radiation-induced oxidative stress in human umbilical vein endothelial cells (HUVECs). HUVECs were exposed to γ radiation at different doses with or without celastrol treatment. Cell viability and cytotoxicity, migratory ability, ROS production, lipid peroxidation, oxidative DNA damage and antioxidative enzyme levels were evaluated in HUVECs at 24 h post-irradiation. It was observed that HUVECs exhibited decreased cell viability, increased cytotoxicity and a decreased migratory ability after exposure to 20-Gy γ radiation. Celastrol treatment concentration-dependently reversed these effects. γ irradiation was also demonstrated to increase the production of ROS, enhance lipid peroxidation and oxidative DNA damage and decrease the levels of SOD, catalase, GST and GPx in HUVECs. These detrimental effects were blocked by treatment with celastrol for 24 h. These data suggested that celastrol not only attenuated γ radiation-induced cytotoxicity, but also effectively blocked oxidative stress in HUVECs. As an antioxidant agent, celastrol may have potential protective effects in HUVECs against γ irradiation-induced injury.

Dihydromyricetin protects human umbilical vein endothelial cells from injury through ERK and Akt mediated Nrf2/HO-1 signaling pathway

Atherosclerosis-related cardiovascular disease is the predominant cause of death worldwide. Ox-LDL-induced vascular endothelial cell injury is a major factor in the pathogenesis of atherosclerosis. Dihydromyricetin (DMY) is a flavonoid extracted from vine tea that exerts multiple pharmacological activities, including cardio-protective, anti-tumor, and anti-oxidative effects. However, it is unreported that DMY shows protective effects on ox-LDL-induced endothelial cell injury. In this study, we used an ox-LDL injured human umbilical vein endothelial cell (HUVEC) in vitro model to explore the protective effects and mechanism of DMY. HUVECs were pretreatment with DMY and then exposed to ox-LDL, the cell viability was measured. Then, the anti-oxidative enzymes were tested by commercial kits and intracellular reactive oxygen species (ROS) was measured by flow cytometry, cell apoptosis was determined by Annexin-V/PI assay and apoptosis-related proteins were detected by western blot. Our results showed that DMY pretreatment provided cytoprotective effects by suppressing ox-LDL-induced endothelial cell apoptosis, mitochondrial membrane depolarization, caspase-3 activation, and modulation of oxidative enzymes, thereby inhibiting ROS generation. The anti-oxidative and anti-apoptotic effects of DMY were abrogated by the transfection of Nrf2 siRNAs and HO-1 inhibitor ZnPP. Furthermore, DMY might activate the Nrf2/HO-1 pathway through activation of the Akt and ERK1/2 pathways, as shown by the inhibition of Nrf2/HO-1 signaling by the inhibitors PD98059 or LY294002 and the transfection of ERK, Akt siRNAs. In this study, DMY protects HUVECs from ox-LDL-induced oxidative injury by activating Akt and ERK1/2, which subsequently activates Nrf2/HO-1 signaling, thereby up-regulating antioxidant enzymes and anti-apoptotic proteins.

[Protective effect of paeoniflorin against PM2.5-induced damage in BEAS-2B cells]

OBJECTIVE

To investigate the protective effects of paeoniflorin against PM2.5-induced damage in BEAS-2B cells and explore the possible mechanism.

METHODS

With a factorial design, this study was performed to observe the protective effects of different doses of paeoniflorin against PM2.5-induced BEAS-2B cell growth inhibition and the effects of paeoniflorin on the contents of malondialdehyde (MDA) and intracellular reactive oxygen species (ROS) in the cell cultures.

RESULTS

Exposure to increased PM2.5 concentrations caused significant decrease in the cell survival rate (P<0.05) with a clear dose-response relationship (r=-0.759, P<0.05). Treatment of the cells with paeoniflorin significantly attenuated PM2.5-induced inhibition of BEAS-2B cell survival (P<0.05), but the effect of paeoniflorin was not dose-dependent (P>0.05). PM2.5 exposure also significantly increased the contents of MDA and intracellular ROS (P<0.05), and paeoniflorin obviously antagonized these effects of PM2.5.

CONCLUSION

Paeoniflorin can protect BEAS-2B cells from PM2.5-induced growth inhibition, and the mechanism might be related to the anti-oxidant effects of paeoniflorin.

Paeoniflorin reduces neomycin-induced ototoxicity in hair cells by suppression of reactive oxygen species generation and extracellularly regulated kinase signalization

The present study was designed to investigate the effect of paeoniflorin (PF) on neomycin-induced ototoxicity in hair cells (HCs). Here, we took advantage of C57BL/6 mice and cochlear explants culture to determine the role of PF in vivo and in vitro. We demonstrated that neomycin exposure induced severe hearing loss and HC damage, which was mediated by activated mitochondrial apoptosis pathway, promoted extracellular signal-regulated kinase (ERK) signaling as well as enhanced reactive oxygen species (ROS) generation in HCs. Interestingly, we found that PF pretreatment significantly alleviated neomycin-induced hearing loss, attenuated HC injury and decreased HC apoptosis caused by neomycin. Mechanistic studies revealed that PF could decrease cellular ROS levels, suppress the activation of ERK signaling and, subsequently, mitigate the imbalance of mitochondrial apoptotic pathway, thus protecting HCs from neomycin-induced apoptosis. This study indicates that PF may serve as an antioxidative and anti-apoptotic agent to prevent hearing loss caused by neomycin.

Effects of bergenin on methylglyoxal-induced damage in osteoblastic MC3T3-E1 cells

Bergenin is the main chemical constituent of plants in the genus Bergenia, which are used in traditional medicines. Methylglyoxal (MG), a highly reactive dicarbonyl compound, is the major precursor for forming advanced glycation end products (AGEs). Pretreating MC3T3-E1 cells with bergenin prevented MG-induced protein adduct formation. Bergenin inhibited the MG-induced soluble receptor for AGE (sRAGE), interleukin, reactive oxygen species and mitochondrial superoxide production. Additionally bergenin increased glyoxalase I activity, glutathione, heme oxygenase-1 and nuclear factor erythroid 2-related factor 2 levels in the presence of MG. Pretreatment with bergenin before MG exposure reduced MG-induced mitochondrial dysfunction by preventing mitochondrial membrane potential dissipation, loss of adenosine triphosphate and reduced adenosine monophosphate-activated protein kinase. These results demonstrate that bergenin may prevent the development of diabetic osteopathy.

Paeoniflorin inhibits VSMCs proliferation and migration by arresting cell cycle and activating HO-1 through MAPKs and NF-κB pathway

The proliferation, migration and inflammation of vascular smooth muscle cells (VSMCs) contributes to the pathogenesis and progression of atherosclerosis. Paeoniflorin (PF) as active compound in the Rhizoma Atractylodes macrocephala has been used for various diseases like cancer, splenic asthenia, anaphylaxis and anorexia. This study aimed to explore whether and how PF regulated the inflammation, proliferation and migration of VSMCs under ox-LDL stimulation. Here, we found that PF dose-dependently inhibited ox-LDL-induced VSMCs proliferation and migration, and decreased inflammatory cytokines and chemokine overexpression. Mechanistically, PF prevented p38, ERK1/2 and NF-κB phosphorylation, and arrested cell cycle in S phase. Meanwhile, PF regulated the HO-1 and PCNA expression. Furthermore, PF blocked the foam cell formation in macrophages induced by ox-LDL. These results indicate that PF antagonizes the ox-LDL-induced VSMCs proliferation, migration and inflammation through activation of HO-1, cell cycle arrest and then suppression of p38, ERK1/2/MAPK and NF-κB signaling pathways.

Protective effects of Paeoniflorin against AOPP-induced oxidative injury in HUVECs by blocking the ROS-HIF-1α/VEGF pathway

BACKGROUND

Paeoniflorin, a monoterpene glycoside, exerts protective vascular effects, showing good antioxidant properties. However, whether Paeoniflorin has protective effect against the oxidative damage induced by advanced oxidation protein products (AOPPs) in Human umbilical vein endothelial cells (HUVECs) is unknown, as is the underlying mechanism.

PURPOSE

The present study was designed to investigate the effect of Paeoniflorin on oxidative damage of HUVECs and elucidate its underlying molecular mechanisms.

METHODS

The fluorescence intensity of 2', 7'-dichlorofluorescein-diacetate (DCFH-DA) staining was detected for intracellular reactive oxygen species (ROS) production. The increases mitochondrial membrane potential (MMP) was measured via flow cytometry and confocal microscopy using MitoTracker® Deep Red/ MitoTracker® Green staining. The intracellular adenosine triphosphate (ATP) was measured by ATP Determination Kit according to the manufacturer's protocol. Nox2, Nox4, hypoxia inducible factor-1α (HIF-1α), vascular endothelial growth factor (VEGF) and nuclear factor-κB (NF-κB) p65 expressions were detected by western blot.

RESULTS

Our results showed that Paeoniflorin increases MMP and ATP levels of HUVECs induced by AOPPs, and attenuates NF-κB p65 expression on HUVECs might mainly result from its antioxidant capability by suppressing ROS production. Moreover, we also found that Paeoniflorin can suppress HIF-1α and VEGF protein expression through a decrease of ROS production via down-regulation of Nox2/Nox4 expression in HUVECs. AOPP-induced RAGE mRNA up-regulation was blocked by Paeoniflorin treatment in HUVECs.

CONCLUSION

Our results provided the first experimental that Paeoniflorin protects against AOPP-induced oxidative damage in HUVECs, mainly through a mechanism involving a decrease in ROS production by the inhibition of Nox2/Nox4 and RAGE expression; restored ATP depletion and mitochondria dysfunction via ROS suppression; and down-regulated HIF-1α/VEGF, possibly via the ROS-NF-κB axis.

Paeoniflorin prevents postoperative peritoneal adhesion formation in an experimental rat model

Although materials and modern surgical techniques have been developed to suppress postoperative adhesions, adhesion formation can still occur, and thus, a novel effective anti-adhesion drug is greatly needed. In the present study, we explored the efficacy of paeoniflorin treatment against postoperative peritoneal adhesions and examined the anti-oxidative stress and anti-inflammatory properties of PE. Forty-eight male Sprague-Dawley rats were randomly divided into 6 groups for the study: the sham, control, hyaluronan and three concentrations (10, 20 and 40 mg/kg/d) paeoniflorin groups. Abdominal adhesions were created by abrasion of the caecum and its opposite abdominal wall. In the paeoniflorin groups, the rats were administered daily oral doses of paeoniflorin for 7 days. The abdominal cavities of the rats were reopened with a U-shaped incision to macroscopically grade the adhesions. Histologic analysis was performed, and oxidative stress, inflammatory cytokine, collagen fiber degradation and cytokeratin levels were measured. Macroscopic and histopathological measurements revealed that paeoniflorin reduced peritoneal adhesion and inflammation. Notably, treatment with paeoniflorin reduced the protein levels of TGF-β1, IL-6 and COX-2. The collagen fiber fractions were distinctly lower in the PE groups than in the control group. Western blotting analyses showed that paeoniflorin increased MMP-9 and superoxide dismutase-2 protein expression and sharply reduced α-SMA and COX-2 protein expression. Peritoneal mesothelium cells were more continuous and complete in animals treated with paeoniflorin. Our study suggests that paeoniflorin can be used to ameliorate peritoneal adhesions via anti-oxidative stress and anti-inflammatory actions during the postoperative period.

Liuwei Dihuang soft capsules attenuates endothelial cell apoptosis to prevent atherosclerosis through GPR30-mediated regulation in ovariectomized ApoE-deficient mice

ETHNOPHARMACOLOGICAL RELEVANCE

Liuwei Dihuang (LWDH), a classical traditional Chinese medicine prescription, has been widely used to prevent and to treat various diseases with symptoms of 'Kidney-Yin' deficiency syndrome for over 1000 years in China. It is commonly used to treat functional decline associated with senile disease and menopausal syndrome, especially memory decline, insomnia, diabetes and osteoporosis. Modern experimental pharmacological studies indicated that the mechanism of LWDH treatment of menopausal syndrome may be associated with enhanced estrogenic effects. However, little attention has been paid to the potential impact of LWDH on atherosclerosis (AS) associated with female menopause. The aim of this study was to evaluate the preventive effects of LWDH intake on an animal model of female menopause AS and to explore the underlying molecular mechanism.

MATERIALS AND METHODS

ApoE^-/- mice were randomly divided into 4 groups, with C57BN/L6 mice as the control group. All ApoE^-/- mice were ovariectomized (Ovx) one week prior to oral administration and initiation of high-fat diet. C57BL/6 mice were given sham operation and maintained on normal diet. The three administered groups were given simvastatin (4mg/kg via i.g.) and LWDH (4.5, 9.0g/kg via i.g.) every day for 14 weeks. Atherosclerotic lesions in the aortic root were determined by oil red O staining and hematoxylin-eosin staining. α-Actin and CD68 in atherosclerotic lesions were detected by immunohistological assay. Serum lipids and homocysteine (Hcy) levels were measured in the 14th week. The cleaved caspase-3, C/EBP homologous protein (CHOP) and G protein coupled estrogen receptor 30 (GPR30) expressions in the aortic arch endothelium were determined by immunohistochemistry and Western blot. The inhibitory effect of LWDH-medicated (20%, 12h) on Hcy (20%, 24h)-induced apoptosis of human umbilical vein endothelial cells (HUVECs) was examined by flow cytometry and Hoechst 33258 staining. Intracellular ROS production, nitric oxide release, and endothelial NO synthase (eNOS) activity were measured with or without LWDH-medicated serum pretreatment. In addition, CHOP, glucose-regulated protein GPR30, 78 (Grp78), Bcl-2, Bax and cleaved caspase-3 were analyzed by Western blot. Finally, the influence of G15, a specific antagonist of GPR30, on the protective effect of LWDH on endothelial cells was investigated.

RESULTS

In vivo administration of LWDH prevented plaque formation and reduced plasma lipid and Hcy levels. LWDH inhibited CHOP and cleaved caspase-3 expression in vivo and in vitro while maintaining GPR30 expression. In vitro study showed that Hcy-induced HUVECs apoptosis was weakened by LWDH-medicated serum pretreatment. Treatment with LWDH-medicated serum significantly upregulated NO release and eNOS activity in HUVECs. In addition, LWDH-medicated serum treatment optimized the balance between Bax and Bcl-2, and attenuated intracellular ROS production. G15 reversed the protective effect of LWDH on endothelial cells and the changes of apoptosis-related proteins.

CONCLUSIONS

LWDH treatment can significantly reduce plaque formation in an animal model of menopausal AS. The mechanism may be inhibition of Hcy-induced endothelial cell apoptosis by modulating GPR30. Hence, LWDH can potentially be used to prevent AS-related vascular disease in menopausal women.

Protective effects of paeoniflorin on TNBS-induced ulcerative colitis through inhibiting NF-kappaB pathway and apoptosis in mice

Paeoniflorin is traditionally used to treat inflammatory disorders. In our laboratory, we have scientifically validated the anti-inflammatory effect of paeoniflorin. In this study, it has been aimed to evaluate in vivo anti-inflammatory effect of paeoniflorin isolated from the dried peeled root of Paeonia lactiflora Pall. It was further intended to find out the probable mechanism of anti-inflammatory effect of paeoniflorin. The anti-inflammatory effect of paeoniflorin (15, 30 and 45mg/kg) was measured employing TNBS-induced ulcerative colitis model of acute inflammation. The TNBS injection resulted significant colitis formation when compared with un-injected mice. The anti-inflammatory effects of paeoniflorin for ulcerative colitis were assessed by body weight, colonic weight and length, macroscopic scores, and histopathological examinations. In addition, the colonic tissue levels of inflammation markers, including myeloperoxidase (MPO), IL-2, IL-6, IL-10, IL-12, IL-1β, TNF-α and IFN-γ were also determined to assess the effect of paeoniflorin. In addition, western blot demonstrated that paeoniflorin inhibited NF-kappaB signaling pathway and apoptosis in TNBS-induced ulcerative colitis tissues. In conclusion, all the findings of this study suggested that paeoniflorin has the anti-inflammatory effect in ulcerative colitis via inhibiting MAPK/NF-kappaB pathway and apoptosis in mice.

Endothelial angiogenesis is directed by RUNX1T1-regulated VEGFA, BMP4 and TGF-β2 expression

Tissue angiogenesis is intimately regulated during embryogenesis and postnatal development. Defected angiogenesis contributes to aberrant development and is the main complication associated with ischemia-related diseases. We previously identified the increased expression of RUNX1T1 in umbilical cord blood-derived endothelial colony-forming cells (ECFCs) by gene expression microarray. However, the biological relevance of RUNX1T1 in endothelial lineage is not defined clearly. Here, we demonstrate RUNX1T1 regulates the survival, motility and tube forming capability of ECFCs and EA.hy926 endothelial cells by loss-and gain-of function assays, respectively. Second, embryonic vasculatures and quantity of bone marrow-derived angiogenic progenitors are found to be reduced in the established Runx1t1 heterozygous knockout mice. Finally, a central RUNX1T1-regulated signature is uncovered and VEGFA, BMP4 as well as TGF-β2 are demonstrated to mediate RUNX1T1-orchested angiogenic activities. Taken together, our results reveal that RUNX1T1 serves as a common angiogenic driver for vaculogenesis and functionality of endothelial lineage cells. Therefore, the discovery and application of pharmaceutical activators for RUNX1T1 will improve therapeutic efficacy toward ischemia by promoting neovascularization.

Heme Oxygenase-1, a Key Enzyme for the Cytoprotective Actions of Halophenols by Upregulating Nrf2 Expression via Activating Erk1/2 and PI3K/Akt in EA.hy926 Cells

Increasing evidence has demonstrated that heme oxygenase-1 (HO-1) is a key enzyme triggered by cellular stress, exhibiting cytoprotective, antioxidant, and anti-inflammatory abilities. Previously, we prepared a series of novel active halophenols possessing strong antioxidant activities in vitro and in vivo. In the present study, we demonstrated that these halophenols exhibited significant protective effects against H₂O₂-induced injury in EA.hy926 cells by inhibition of apoptosis and ROS and TNF-α production, as well as induction of the upregulation of HO-1, the magnitude of which correlated with their cytoprotective actions. Further experiments which aimed to determine the mechanistic basis of these actions indicated that the halophenols induced the activation of Nrf2, Erk1/2, and PI3K/Akt without obvious effects on the phosphorylation of p38, JNK, or the expression of PKC-δ. This was validated with the use of PD98059 and Wortmannin, specific inhibitors of Erk1/2 and PI3K, respectively. Overall, our study is the first to demonstrate that the cytoprotective actions of halophenols involve their antiapoptotic, antioxidant, and anti-inflammatory abilities, which are mediated by the upregulation of Nrf2-dependent HO-1 expression and reductions in ROS and TNF-α generation via the activation of Erk1/2 and PI3K/Akt in EA.hy926 cells. HO-1 may thus be an important potential target for further research into the cytoprotective actions of halophenols.

Origins, Phytochemistry, Pharmacology, Analytical Methods and Safety of Cortex Moutan (Paeonia suffruticosa Andrew): A Systematic Review

Cortex Moutan (CM), a well-known traditional Chinese medicine, is commonly used for treating various diseases in China and other eastern Asian countries. Recorded in Pharmacopeias of several countries, CM is now drawing increasing attention and under extensive studies in various fields. Phytochemical studies indicate that CM contains many valuable secondary metabolites, such as monoterpene glycosides and phenols. Ample evidence from pharmacological researches suggest that CM has a wide spectrum of activities, such as anti-inflammatory, anti-oxidant, anti-tumor, anti-diabetic, cardiovascular protective, neuroprotective, hepatoprotective effects. Moreover, various analytical methods were established for the quality evaluation and safety control of CM. This review synopsizes updated information concerning the origins, phytochemistry, pharmacology, analytical method and safety of CM, aiming to provide favorable references for modern CM research and application. In conclusion, continuing pharmacological investigations concerning CM should be conducted to unravel its pharmacological mechanisms. Further researches are necessary to obtain comprehensive and applicable analytical approach for quality evaluation and establish harmonized criteria of CM.

Research Progress on Signaling Pathway-Associated Oxidative Stress in Endothelial Cells

Studying the mechanisms of oxidative stress in endothelial cells is vital to the discovery of novel drugs for the treatment of cardiovascular disease. This article reviews the progress within the field of the role of oxidative responses in the physiology and growth of endothelial cells and emphasizes the effects of several main signal pathways involved in the oxidative stress of endothelial cells. Herein, we aim to provide scientific direction that can serve as a basis for researchers specializing in the signaling pathway of oxidative stress.

Paeoniflorin Attenuated Oxidative Stress in Rat COPD Model Induced by Cigarette Smoke

Paeoniflorin (PF), a monoterpene glucoside, might have an effect on the oxidative stress. However, the mechanism is still unknown. In this study, we made the COPD model in Sprague-Dawley (SD) rats by exposing them to the smoke of 20 cigarettes for 1 hour/day and 6 days/week, for 12 weeks, 24 weeks, or 36 weeks. Our findings suggested that smoke inhalation can trigger the oxidative stress from the very beginning. A 24-week treatment of PF especially in the dosage of 40 mg/kg·d can attenuate oxygen stress by partially quenching reactive oxygen species (ROS) and upregulating antioxidant enzymes via an Nrf2-dependent mechanism.