Evaluation of the in vitro and in vivo antimicrobial activity of alkaloids prepared from Chelidonium majus L. using MRSA- infected C. elegans as a model host.

Chelidonium majus L. contained alkaloids as its main component, exhibiting various biological activities, particularly antibacterial activity. This study aimed to extract alkaloids from C. majus L. (total alkaloids) and evaluate their antibacterial activity both in vitro and in vivo. Reflux extraction was carried out on C. majus L., and the extract was purified with HPD-600 macroporous resin and 732 cation exchange resin columns. Infection modeling of Caenorhabditis elegans (C. elegans) was established to investigate the impact of Methicillin-resistant Staphylococcus aureus (MRSA) and Methicillin-sensitive Staphylococcus aureus (MSSA) on the motility, longevity, and reactive oxygen species (ROS) levels of wild-type worms (N2 strain). The effects of total alkaloids on longevity and ROS were further evaluated in infected N2 worms. Additionally, the effect of total alkaloids on the stress resistance of C. elegans and the mechanism of action were investigated. By utilizing CB1370, DR26 and CF1038 transgenic strains of C. elegans to identify whether the antibacterial activity of total alkaloids was dependent on DAF-2/DAF-16 pathway. The results showed that total alkaloids exhibited a significant antibacterial activity against both MRSA and MSSA (MIC 31.25 µg/mL). Compared with MSSA, the MRSA exhibited a stronger inhibitory effect on the movement behavior and development of worms, along with faster pathogenicity and unique virulence factors. Total alkaloids also displayed the ability to extend the lifespan of C. elegans under oxidative stress and heat stress, and reduce the expression of ROS. The antibacterial activity of total alkaloids was primarily dependent on the DAF-2/DAF-16 pathway, and the presence of functional DAF-2 was deemed essential in total alkaloids mediated immune response against MRSA. Moreover, the antibacterial and anti-infection effects of total alkaloids were found to be associated with the daf-16 gene fragment.

Short-term and long-term effectiveness of acupuncture and Tuina on knee osteoarthritis: study protocol for a randomized controlled trial.

Background: The effectiveness of acupuncture and tuina in treating knee osteoarthritis (KOA) is still controversial, which limits their clinical application in practice. This study aims to evaluate the short-term and long-term effectiveness of acupuncture and tuina on KOA. Methods/design: This parallel-group, multicenter randomized clinical trial (RCT) will be conducted at the outpatient clinic of five traditional Chinese medicine hospitals in China. Three hundred and thirty participants with KOA will be randomly assigned to acupuncture, tuina, or home-based exercise group with a ratio of 1:1:1. The primary outcome is the proportion of participants achieving a minimal clinically important improvement defined as a ≥ 12% reduction on the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain dimension on short term (week 8) and long term (week 26) compared with baseline. Secondary outcomes are knee joint conditions (pain, function, and stiffness), self-efficacy of arthritis, quality of life, and psychological conditions, which will be evaluated by the WOMAC score and the Patient Global Assessment (PGA), and in addition, the respondents index of OMERACT-OARSI, Short Form 12 Health Survey (SF-12), arthritis self-efficacy scale, and European five-dimensional health scale (EQ-5D). Adverse events will be collected by self-reported questionnaires predefined. Clinical trial registration: https://www.chictr.org.cn.

A sustained-release phospholipid-based phase separation gel loaded with berberine for treating rheumatoid arthritis.

Berberine (BBR) has a long history of use in the treatment of Rheumatoid arthritis (RA) and is considered one of the most promising natural product for the treatment of RA. However, oral administration of berberine has low bioavailability and requires frequent administration, resulting in poor patient compliance. In this study, we developed a BBR-loaded phospholipid-based phase separation gel (BBR-PPSG) to achieve sustained drug release and long-term therapeutic effect. The stability of BBR-PPSG was verified and it was found that it can be stored for a long time. The pharmacokinetic study on rats and rabbits showed that BBR-PPSG not only achieved 1-month of sustained release, but also significantly increased the area under the curve (AUC) by nearly 9-fold and prolonged the half-life (t1/2) by 10-fold. By constructing rat and rabbit models of RA, we also proved that BBR-PPSG administration once a month effectively alleviated joint swelling, and significantly reduce TNF-α levels in AIA rats and OIA rabbits. Histopathological analysis of rabbit joint sections revealed that after intra-articular injection of BBR-PPSG, the synovial cell layer remained intact, while in the model group, the synovial cells were significantly reduced and exhibited necrosis. MicroCT data analysis showed that the values of Tb.N and Tb. Sp in the BBR-PPSG group were significantly better than those in the model group (p < 0.05). This study addressed the limitations of frequent administration of BBR by developing a phospholipid-based phase separation gel system for berberine delivery, achieving long-term sustained release. The BBR-PPSG demonstrated good biocompatibility, simple preparation and excellent stability, thus holding potential as a novel pharmaceutical formulation for RA treatment.

Comparative Transcriptome Analysis Provides Insights into the Molecular Mechanism Underlying the Effect of MeJA Treatment on the Biosynthesis of Saikosaponins in Bupleurum chinense DC.

Bupleurum chinense DC. is a well-known traditional Chinese medicinal plant that produces saikosaponins (SSs), which possess hepatoprotective, antipyretic, and anti-inflammatory activities. Methyl jasmonate (MeJA) is a signalling phytohormone that can increase the accumulation of SSs in the root of Bupleurum plants. However, the molecular understanding of MeJA-mediated SS biosynthesis is not clear. Therefore, it is necessary to explore the molecular mechanism underlying the response of B. chinense DC. to MeJA in roots. In this study, we performed comparative transcriptome analysis of B. chinense DC. roots with different MeJA treatment times. In total, 104,057 unigenes were identified, of which 4053 were differentially expressed genes (DEGs). Most of the DEGs were downregulated after MeJA treatment, and GO enrichment analysis showed that they were mainly related to biological processes involved in stress responses and development. A total of 88 DEGs encoding enzymes known to be involved in the SS synthesis pathway were found, and most were significantly downregulated within 24 h. Based on the DEGs, 99 transcription factors (TFs) belonging to the AP2/ERF, WRKY, bZIP, ZFP, and bHLH families with different expression patterns were also identified. Further integrated analysis indicated that 20 DEGs involved in the SS synthesis pathway and 12 DEGs encoding TFs presented strong correlations with the SS contents, and these DEGs may be critical for the biosynthesis and regulation of SSs. These findings will be critical for further study of the response of B. chinense DC. to MeJA for SS biosynthesis.

Molecular cloning, functional characterization and expression of the ß-amyrin synthase gene involved in saikosaponin biosynthesis in Bupleurum chinense DC.

Bupleurum chinense DC. is a commonly used plant in traditional Chinese medicine, and saikosaponins(SSs) are the main active oleanane-typetriterpene saponins in B. chinense. ß-Amyrin synthase (ß-AS) is an important enzyme in oleanane-type triterpenoid saponin synthesis, but its role in saikosaponin synthesis has rarely been studied. Here, the putative ß-AS gene BcBAS1(Accession No.ON890382) selected according to metabolomic and transcriptomic analyses was cloned and functionally characterized by heterologous expression in Escherichia coli and Pichia pastoris, and its subcellular localization and expression patterns were examined. The molecular weight of the BcBAS1 recombinant protein was approximately 87 kDa, and this protein could catalyse the production of ß-amyrin, the precursor of SSs. Furthermore, BcBAS1 was located in the cytosol, and relative expression in four tissues of the four genotypes was positively correlated with SSa and SSd contents. Our results indicate that BcBAS1 is a ß-AS gene and may play an important role in saikosaponin biosynthesis and regulation. This study sheds light on the role of ß-AS genes in the synthesis of SSs and provides insights for the metabolic engineering of SSs.

Biosynthesis of Melanin Nanoparticles for Photoacoustic Imaging Guided Photothermal Therapy.

Photothermal therapy (PTT) has attracted considerable attention in recent years due to their unique advantages in minimal invasiveness and spatiotemporal selectivity. However, the fabrication procedures of PTT agents frequently require complex chemical and/or physical methods that involves harsh and environmentally hazardous conditions. Here, a genetically engineered bacterium is developed to synthesize melanin nanoparticles under mild and environmentally friendly conditions. The biosynthetic melanin nanoparticles exhibit excellent biocompatibility, good stability, and negligible toxicity. In addition, the biosynthetic melanin nanoparticles have strong absorption at near-infrared (NIR) region and higher photothermal conversion efficiency (48.9%) than chemically synthesized melanin-like polydopamine nanoparticles under an 808 nm laser irradiation. Moreover, the results show that the biosynthetic melanin nanoparticles have excellent photoacoustic imaging (PAI) performance and can be used for PAI guided PTT in vivo. In conclusion, the study provides an alternative approach to synthesize PTT agents with broad application potential in the diagnosis and treatment of cancer.

Enhanced intrathalamic morphological connectivity in patients with chronic insomnia.

This study aimed to systematically investigate abnormal morphological connectivity in subregions of the thalamus and examine the clinical relevance of this connectivity in patients with chronic insomnia. One hundred and two patients with chronic insomnia (aged 45.50 [34.75 ~ 58.00] years; 24 men, 78 women) and one hundred and one healthy controls (aged 45.00 [34.00 ~ 55.00] years; 32 men, 69 women) were recruited. Intrathalamic and thalamocortical morphological connectivity in the thalamic subregions defined in the Human Brainnetome Atlas were computed and compared between the two groups. Spearman's correlation was used to estimate the association between thalamic morphological connectivity alterations and clinical variables. Compared with the control group, the insomnia group exhibited higher intrathalamic mean morphological connectivity than the control group, though no alterations in thalamocortical morphological connectivity were observed. However, no correlation was found between altered intrathalamic morphological connectivity and behavioral scales. In addition, alterations in morphological connectivity among thalamic subregions were found mainly in the left medial premotor thalamus, left medial prefrontal thalamus, and left sensory thalamus; however, these results were no longer significant after correction. Our findings suggest increased intrathalamic morphological connectivity in patients with chronic insomnia, thus enriching the understanding of morphological connectivity at the individual level and providing new perspectives for clinical interventions and diagnostic imaging.

Transcriptome Level Reveals the Triterpenoid Saponin Biosynthesis Pathway of Bupleurum falcatum L.

Bupleurum falcatum L. is frequently used in traditional herbal medicine in Asia. Saikosaponins (SSs) are the main bioactive ingredients of B. falcatum, but the biosynthetic pathway of SSs is unclear, and the biosynthesis of species-specific phytometabolites is little known. Here we resolved the transcriptome profiles of B. falcatum to identify candidate genes that might be involved in the biosynthesis of SSs. By isoform sequencing (Iso-Seq) analyses of the whole plant, a total of 26.98 Gb of nucleotides were obtained and 124,188 unigenes were identified, and 81,594 unigenes were successfully annotated. A total of 1033 unigenes of 20 families related to the mevalonate (MVA) pathway and methylerythritol phosphate (MEP) pathway of the SS biosynthetic pathway were identified. The WGCNA (weighted gene co-expression network analysis) of these unigenes revealed that only the co-expression module of MEmagenta, which contained 343 unigenes, was highly correlated with the biosynthesis of SSs. Comparing differentially expressed gene analysis and the WGCNA indicated that 130 out of 343 genes of the MEmagenta module exhibited differential expression levels, and genes with the most "hubness" within this module were predicted. Manipulation of these genes might improve the biosynthesis of SSs.

How different nitrogen fertilizers affect arsenic mobility in paddy soil after straw incorporation?

In straw return fields, nitrogen-fertilizers are added to mitigate microbial competition for nitrogen with plants. However, in arsenic (As)-contaminated paddy fields, the specific effects of different nitrogen fertilizers on As mobility after straw incorporation and the interactions among iron(Fe)/carbon(C)/nitrogen(N)/As are not well understood. In the reported microcosm experiment we monitored As-mobility as a function of different dosages of KNO3, NH4Cl and rice straw incorporation. Addition of both KNO3 and NH4Cl significantly inhibited the As mobilization induced by straw incorporation. Following the KNO3 addition, the As concentration in porewater dropped by 51-66% after 2 days of the incubation by restraining Fe reduction and enhancing Fe oxidation. High-dose NH4Cl addition reduced As in porewater by 22-43% throughout the incubation by decreasing porewater pH. High-throughput sequencing results demonstrated that KNO3 addition enriches both the denitrifying and Fe-oxidizing bacteria, while diminishing Fe-reducing bacteria; NH4Cl addition has the opposite effect on Fe-reducing bacteria. Network analysis revealed that As and Fe concentrations in porewater were positively correlated with the abundance of denitrifying and Fe-reducing bacteria. This study broadens our insight into the As biogeochemistry associated with the N/C/Fe balance in soil, which are of great significance for agronomic management and mitigation the risk of As-contaminated paddy fields.

Preparation, optimization and reusability of immobilized petroleum-degrading bacteria.

In the remediation of marine pollution, it is important to effectively degrade pollutants and reuse petroleum-degrading bacteria. In order to obtain more effective biodegradability and reusability, an immobilized bacteria combination with petroleum-degrading bacteria, sodium alginate (SA) and biochar by adsorption-embedding method was systematically analysed. The results indicated that the immobilized bacteria had good mechanical properties and the degradation rate was 51% when the straw (CS) was 3%, the SA and CaCl2 were 4.5% and 6%, respectively. Besides, SA-CS-DM-PVA has the highest degradation rate and the lowest broken rate, above 51% and below 6.1% respectively. The optimum dosage of the modified immobilized bacteria was 132, degradation time was 5d, and reuse frequency was 4 times. Moreover, immobilized bacteria characterized by scanning electron microscopy (SEM), results showed that there were more pores on the surface after degradation, and the carrier was exposed. Therefore, the modified immobilized bacteria with good degradability and reusability, have good application prospects in the treatment of marine oil pollution.

Floralozone Ameliorated Atherosclerosis in Experimental Atherosclerotic Rats Involved with Sphingosine 1-Phosphate 1 Enhancement.

Atherosclerosis (AS) is a chronical pathological process of the arterial narrows due to the AS plaque formation. The aim of this study was to explore the therapeutic effect and the underlying mechanism of Floralozone on experimental atherosclerotic model rats. Experimental atherosclerotic model rats were induced by the right carotid artery balloon injury and intraperitoneal injection of vitamin D3 in rats after 4 weeks high-fat diet. The results exhibited that Floralozone could ameliorate vascular injury and vasorelaxation of descending aortas and increase the superoxide dismutase activity and the expression of sphingosine 1-phosphate (S1P) 1 and reduce the intercellular cell adhesion molecule-1, vascular cell adhesion molecule-1, interleukin (IL)-1, IL-6 level, and the malondialdehyde activity in experimental atherosclerotic rats. However, Fingolimod, an S1P1 inhibitor, could reverse these Floralozone effects in experimental atherosclerotic rats. Our results indicated that Floralozone could inhibit the atherosclerotic plaque formation and improves arterial stenosis and reduces endothelial dysfunction in experimental atherosclerotic rats, which might be involved with S1P1 enhancement.

NH4H2PO4-extractable arsenic provides a reliable predictor for arsenic accumulation and speciation in pepper fruits (Capsicum annum L.).

Dietary arsenic (As) intake from food is of great concern, and developing a reliable model capable of predicting As concentrations in plant edible parts is desirable. In this study, pot experiments were performed with 16 Chinese upland soils spiked with arsenate [As(V)] to develop a predictive model for As concentrations in pepper fruits (Capsicum annum L.). Our results showed that after three months' aging, concentrations of bioavailable As (extracted by 0.05 M NH4H2PO4) in various soils varied widely, depending on soil total As concentrations and soil properties such as soil pH and amorphous iron (Fe) contents. Furthermore, both the bioconcentration factor (BCF, denoted as the ratio of fruit As to soil As) and total As concentrations in pepper fruits were largely determined by concentrations of bioavailable As, which explained 27% and 69% variations in the BCF and fruit As concentrations, respectively. Apart from bioavailable As, soil pH and Fe contents were another two important factors influencing As accumulation in pepper fruits. Taking the three factors into account, concentrations of fruit As can be well predicted using a stepwise multiple linear regression (SMLR) analysis (R2 = 0.80, RMSE = 0.17). Arsenic species in soils and edible parts were also analyzed. Although As(V) predominated in soils (>96%), As in pepper fruits presented as As(V) (46%) and arsenite [As(III)] (39%) with small amount of methylated As (<15%). Aggregated boosted tree (ABT) analysis revealed that inorganic As concentrations in pepper fruits were determined by concentrations of bioavailable As, phosphorus (P) and Fe in soils. In contrast to inorganic As, methylated As concentrations were not correlated with those factors in soils. Taken together, this study established an empirical model for predicting As concentrations in pepper fruits. The predictive model can be used for establishing the As threshold in fruit vegetable farming soils.

[Chemical constituents in chloroform fraction of Houttuynia cordata].

Nine compounds were isolated from chloroform fraction of Houttuynia cordata,and the isolates were identified as follows:( S)-5,6,6 a,7-tetrahydro-2,10-dimethoxy-4 H-dibenzo [DE,G] quinoline-1,9-diol( 1),( +)-isoboldine ß-N-oxide( 2),liriotulipiferine( 3),telitoxinone( 4),isoboldine( 5),(-)-clovane-2ß,9α-diol( 6),benzoic acid( 7),acantrifoside E( 8),and dibutyl phthalate( 9). Among them,compound 1 was new,and compounds 2-9 were reported from this species for the first time.

Puerarin inhibits vascular smooth muscle cells proliferation induced by fine particulate matter via suppressing of the p38 MAPK signaling pathway.

BACKGROUND: Fine particulate matter (PM2.5) is a major risk factor for the development and progression of atherosclerosis. Proliferation and infiltration of vascular smooth muscle cells (VSMCs) from the blood vessel media into the intima is a crucial step in the pathophysiology of atherosclerosis. Puerarin, a natural extract from Radix Puerariae, possesses significant anti-atherosclerosis properties. However, the underlying molecular mechanisms responsible for the effect of puerarin on the VSMCs proliferation induced by PM2.5 remain unclear. The present study was designed to examine the effect of puerarin on PM2.5-induced VSMCs proliferation, and to explore the p38 mitogen-activated protein kinase (p38 MAPK) signal mechanism involved. METHODS: VSMCs viability was measured by CCK-8 assay, VSMCs proliferation was assessed by BrdU immunofluorescence, the levels of superoxide dismutase (SOD) and malonaldehyde (MDA) were assayed by colorimetric assay kits, the levels of nitric oxide (NO) and endothelin-1 (ET-1) were determined by nitrate reductase method and radioimmunoassay, the levels of vascular cell adhesion molecule-1 (VCAM-1), interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α) were measured by ELISA. The protein expressions of phospho-p38 MAPK (p-p38 MAPK) and proliferating cell nuclear antigen (PCNA) in the VSMCs were subjected by Western blot. RESULTS: Compared to the PM2.5-treated cells, in addition to inhibiting the PM2.5-induced VSMCs proliferation, puerarin also down-regulated the protein expressions of p-p38 MAPK and PCNA, decreased the levels of ET-1, VCAM-1, IL-6, TNF-α and MDA, increased the levels of NO and SOD. Moreover, the anti-proliferative effects of puerarin were significantly enhanced by the co-incubation of puerarin with SB203580, a selective inhibitor of p38 MAPK, as compared to the puerarin-treated cells. CONCLUSION: These results suggest that puerarin might suppress the PM2.5-induced VSMCs proliferation via the inhibition of the p38 MAPK signaling pathway.

Suppressive effects of berberine on atherosclerosis via downregulating visfatin expression and attenuating visfatin-induced endothelial dysfunction.

Berberine (BBR) possesses significant anti-atherosclerosis properties. Visfatin is one of the most promising biomarkers of incoming atherosclerosis. However, research on the effect of BBR on regulating visfatin expression in atherogenesis remains largely unknown. In this study, we investigated the effects of BBR on visfatin expression and atherogenesis in apolipoprotein E knockout (ApoE-/-) mice. The effect of BBR on attenuating visfatin-induced endothelial dysfunction was also evaluated in cultured human umbilical vein endothelial cells (HUVECs). In vivo experiments showed that BBR treatment (5 mg/kg/day) significantly reduced the serum levels of visfatin, lipid, interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α), the protein expression of visfatin, p-p38 MAPK and p-c-Jun N-terminal kinase (JNK) in mice aorta and the distribution of visfatin in the atherosclerotic lesions in ApoE-/- mice fed with a Western diet. In addition, in vitro experiments indicated that visfatin (100 µg/l) significantly increased apoptosis, the contents of IL-6 and TNF-α, the protein levels of p-p38 MAPK, p-JNK and Bax in HUVECs, which were reversed by BBR administration (50 µmol/l). Our findings suggest that BBR significantly ameliorates Western diet-induced atherosclerosis in ApoE-/- mice via downregulating visfatin expression, which is related to the inhibition of p38 MAPK and JNK signaling pathways and subsequent suppression of visfatin-induced endothelial dysfunction.

Fractionation and Biological Activities of Water-Soluble Polysaccharides from Sclerotium of Tiger Milk Medicinal Mushroom, Lignosus rhinocerotis (Agaricomycetes).

This study investigated antioxidant and anti-inflammatory properties, and the direct cytotoxic effect of Lignosus rhinocerotis fractions, especially the polysaccharide fraction, on nasopharyngeal carcinoma cells. L. rhinocerotis crude extract was obtained through hot water extraction. The precipitate saturated with 30% ammonium sulfate was purified with ion-exchanged chromatography. Gel permeation chromatography multiangle laser light scattering analysis equipped with light scattering and UV signals revealed two district groups of polymers. A total of four peaks were observed in the total carbohydrate test. Fraction C, which was the second region of the second peak eluted with 0.3 M NaOH, showed the highest integrated molecular weight, whereas fraction E had the lowest integrated molecular weight of 19,790 Da. Fraction A contained the highest ß-D-glucan content. Enzymatic analysis showed that most of the polysaccharide fractions contained ß-1-3 and ß-1-6 skeletal backbones. The peak eluted with 0.6 M NaOH was separated in fraction D (flask 89-92) and fraction E (93-96). The results showed that fraction E expressed higher antioxidant activities than fraction D whereas fraction D expressed higher chelating activity than fraction E. The extract saturated with 30% ammonium sulfate exhibited higher reducing power than the extract saturated with 100% ammonium sulfate. Fractions D and E significantly inhibited the secretion of tumor necrosis factor-α in lipopolysaccharide-stimulated RAW 264.7 macrophages in a dose-dependent manner. There was no apparent difference in the viability of cells exposed or unexposed to L. rhinocerotis fractions.

Differential identification of mushrooms sclerotia by IR macro-fingerprint method.

Many macrofungus sclerotia are well-known medicinal herbs, health food and nutritional supplements. However, the prevalent adulterant commercial products are major hindrances to their incorporation into mainstream medical use in many countries. The mushroom sclerotia of Lignosus rhinocerotis, Poria cocos, Polyporus umbellatus, Pleurotus tuber-regium and Omphalia lapidescens are commonly used in traditional Chinese medicine. In this study, IR macro-fingerprint method was used in the identification of these sclerotia. The results showed that the spectrum of L. rhinocerotis (LR) was comparable with P. cocos with 94.4% correlation, except that the peak at 1543cm(-1) of LR appeared in lower intensity. The spectrum of P. umbellatus and P. tuber-regium was also correlated (91.5%), as both spectra could be clearly discriminated in that P. umbellatus spectrum has small base peaks located at the range of 1680-1500cm(-1). O. lapidescens was not comparable with all the other sclerotia as its spectrum was totally different. Its base peak was broad and derivated equally along the range. The first IR has revealed the dissimilarity among five mushrooms sclerotia. The second derivative and 2DIR further enhanced the identification in detail.

[Puerarin attenuates PM2.5-induced vascular endothelial cells injury via ERK1/2 signaling pathway].

To investigate the effect and the mechanism of puerarin in attenuating PM2.5-induced human umbilical vein endothelial cells (EA.hy926) injury, the samples of fine particulate matter (PM2.5) were collected and made into suspension. Different concentrations of PM2.5 (0,20, 200, 400 mg•L⁻¹) were used to contaminate EA.hy926 cells for 24 h. The cells survival rate was detected by MTT assay; cells apoptosis of EA.hy926cells was detected by flow cytometry; the protein levels of p-ERK1/2, Bax and Bcl-2 were detected by Western blot; the contents of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), malonaldehyde (MDA), and the activities of superoxide dismutase (SOD) and lactic dehydrogenase (LDH) were measured by ELISA. Puerarin at different concentrations (10, 50, 100 µmol•L⁻¹) or a specific inhibitor of ERK1/2 pathway PD98059 (20 µmol•L-1) was added into the EA.hy926 cells to observe the intervention effect and mechanism of puerarin. Compared with the control group, PM2.5 reduced the cells survival rate, up-regulatedp-ERK1/2 protein level and Bax/Bcl-2 ratio in a dose dependent manner to promote apoptosis; increased the contents of TNF-α, IL-6 and MDA, the activity of LDH, but decreased SOD activity in the EA.hy926 cells (P<0.05). Compared with PM2.5 group, puerarin increased the cells survival rate, down-regulated p-ERK1/2 protein level and Bax/Bcl-2 ratio in a dose dependent manner to inhibit the apoptosis; decreased the contents of TNF-α, IL-6 and MDA, the activity of LDH, but increased SOD activity in the EA.hy926 cells (P<0.05). The results indicated that puerarin could attenuate PM2.5-induced EA.hy926 cells injury via the inhibition of ERK1/2 pathway.