Thrombosis inhibited by Corydalis decumbens through regulating PI3K-Akt pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: Corydalis decumbens (Thunb.) Pers. was used as stasis-eliminating medicine traditionally to treat cardiovascular disease potentially attributed to its antithrombotic effect, but lack of pharmacological research on it. AIM OF THE STUDY: To investigate the antithrombotic effect of C. decumbens and its preliminary mechanism. MATERIALS AND METHODS: A carrageenan-induced mouse thrombus model and adenosine diphosphate stimulated platelet aggregation of rabbits were used to confirm the inhibitory effect of C. decumbens extract and compounds on thrombosis in vivo. Then, H2O2-induced human umbilical vein endothelial cells (HUVECs) injury model was further adopted to verify the effects of bioactive compounds in vitro. Moreover, in silico network pharmacology analyses and molecular docking were performed to predict the underlying mechanisms, targets, and pathways, and which were further confirmed through western blotting assay. RESULTS: The administration of total extract (TE), total alkaloids (TA) and tetrahydropalmatine (TET) resulted in a significant reduction in black tail thrombus and congestion, along with a decreasing in platelet aggregation of rabbits. A superior antithrombotic effect indicated the bioactive fraction, and then the isolated bioactive compounds, TET and protopine (PRO) increased cell survival, and decreased reactive oxygen species (ROS) and lactate dehydrogenase (LDH) release in H2O2-induced HUVECs injury model. Moreover, the two alkaloids targeted 33 major proteins and influenced 153 pathways in network pharmacology prediction. Among these, HSP90AA1, COX-2, NF-κB/p65, MMP1 and HIF-1α were the key proteins and PI3K-Akt emerged as the major signaling pathway. Further western blotting results supported that five key proteins were downregulated by the two bioactive compounds in H2O2-stimulated HUVECs model. CONCLUSION: C. decumbens exerted protective effect on thrombosis through inhibiting PI3K-Akt pathway and related key proteins, which supported the traditional use and presented potential antithrombotic alkaloids for further investigation.

Insights into the interaction and inhibitory action of palmatine on lysozyme fibrillogenesis: Spectroscopic and computational studies.

Interaction under amyloidogenic condition between naturally occurring protoberberine alkaloid palmatine and hen egg white lysozyme was executed by adopting spectrofluorometric and theoretical molecular docking and dynamic simulation analysis. In spetrofluorometric method, different types of experiments were performed to explore the overall mode and mechanism of interaction. Intrinsic fluorescence quenching of lysozyme (Trp residues) by palmatine showed effective binding interaction and also yielded different binding parameters like binding constant, quenching constant and number of binding sites. Synchronous fluorescence quenching and 3D fluorescence map revealed that palmatine was able to change the microenvironment of the interacting site. Fluorescence life time measurements strongly suggested that this interaction was basically static in nature. Molecular docking result matched with fluorimetric experimental data. Efficient drug like interaction of palmatine with lysozyme at low pH and high salt concentration prompted us to analyze its antifibrillation potential. Different assays and microscopic techniques were employed for detailed analysis of lysozyme amyloidosis.Thioflavin T(ThT) assay, Congo Red (CR) assay, 8-anilino-1-naphthalenesulfonic acid (ANS) assay, Nile Red (NR) assay, anisotropy and intrinsic fluorescence measurements confirmed that palmatine successfully retarded and reduced lysozyme fibrillation. Dynamic light scattering (DLS) and atomic force microscopy (AFM) further reiterated the excellent antiamyloidogenic potency of palmatine.

Palmatine improves cognitive dysfunction in Alzheimer's disease model rats through autophagy pathway and regulation of gut microbiota.

Alzheimer's disease (AD) is a primary degenerative encephalopathy that first appeared as a decline in memory and learning skills. Over time, the condition's severity grew. Palmatine (Pal) alleviates Alzheimer's disease symptoms, which has neuroprotective benefits. Numerous investigations have demonstrated a close relationship among AD and gut structure changes. The aim of the research was investigating whether the improvement of Pal on AD is linked to regulating gut flora and autophagy. First, we used Aß1-40 to induce apoptosis in HT22 cells. After Pal treatment, apoptosis can be improved. Then, We used bilateral intracranial hippocampal injection of Aß1-40 for establishing the AD model, after treatment with Pal, the morris water maze experiment and eight-arm maze test demonstrated that Pal enhanced the AD rats' capacity for learning and memory, HE staining illustrated that Pal improved the morphological abnormalities of brain cells and gut tissue damage. Pal reduced the death of hippocampus neurons, as shown by Nissl staining. Pal substantially reduced Tau hyperphosphorylation and Aß accumulation in the brain, according to immunohistochemical labelling. Pal improved the expression of LC3, Beclin 1, AMPK, and suppressed the expression of mTOR and P62, as validated by RT-qPCR and immunofluorescence labelling. This suggests that Pal's treatment of AD may be associated with the control of the AMPK/mTOR autophagy signalling system. 16S rRNA sequencing and short-chain fatty acids (SCFAs) content detection analysis illustrated that Pal has the potential to enhance the content of SCFAs, reverse the alterations in gut microorganisms. It has been showed by the study that Pal could improve AD by activating autophagy signaling pathway and improving gut barrier changes.

Protopine protects chondrocytes from undergoing ferroptosis by activating Nrf2 pathway.

Osteoarthritis is a highly prevalent joint disease; however, effective treatments are lacking. Protopine (PTP) is an isoquinoline alkaloid with potent anti-inflammatory and antioxidant properties; however, it has not been studied in osteoarthritis. This study aimed to investigate whether PTP can effectively protect chondrocytes from ferroptosis. Primary mouse chondrocytes were treated with tert-butyl hydroperoxide (TBHP) to simulate oxidative stress in an in vitro model of osteoarthritis. Two concentrations of PTP (10 and 20 µg/mL) were validated for in vitro experiments. Cellular inflammation and metabolism were detected using RT-qPCR and western blotting (WB). Ferroptosis was assessed via WB, qPCR, reactive oxygen species (ROS) levels, lipid ROS, and immunofluorescence staining. In vitro, PTP significantly ameliorated chondrocyte inflammation and cytolytic metabolism and significantly suppressed chondrocyte ferroptosis through the activation of the Nrf2 pathway. The anterior cruciate ligament transection (ACLT) mouse model was used to validate the in vivo effects of PTP. The joint cartilage was assessed using the Osteoarthritis Research Society International (OARSI) score, Safranin O staining, and immunohistochemistry. The intra-articular administration of PTP alleviated cartilage inflammation and ferroptosis, as evidenced by the expression of MMP3, MMP13, COL2A1, GPX4, and Nrf2. Overall, we find that PTP exerted anti-ferroptosis and anti-inflammatory effects on chondrocytes to protect the articular cartilage.

Palmatine inhibits expression fat mass and obesity associated protein (FTO) and exhibits a curative effect in dextran sulfate sodium (DSS)-induced experimental colitis.

BACKGROUND: Ulcerative colitis (UC) is an inflammatory disease whose pathogenesis and mechanisms have not been fully described. The m6A methylation modification is a general mRNA modification in mammalian cells and is closely associated with the onset and progression of inflammatory bowel disease (IBD). Palmatine (PAL) is a biologically active alkaloid with anti-inflammatory and protective effects in animal models of colitis. Accordingly, we examined the role of PAL on colitis by regulating N6-methyladenosine (m6A) methylation. METHODS: A rat experimental colitis model was established by 5 % dextran sulfate sodium (DSS) in drinking water for seven days, then PAL treatment was administered for seven days. The colonic tissue pathology was assessed using hematoxylin-eosin (HE) and disease activity index (DAI). In in vitro studies, a human, spontaneously immortalized non-cancerous colon mucosal epithelial cell line (NCM460) was exposed to 2 % DSS and treated with PAL and cell viability was assayed using Cell Counting Kit-8 (CCK-8). The levels of tumor necrosis factor α (TNF-α), interleukin (IL)-1ß, IL-6, and IL-8 were detected by enzyme-linked immunosorbent assay (ELISA) kits. The level of Zonula occludens-1 (ZO-1) was dectected by immunofluorescence. Transepithelial electrical resistance (TEER) of cells was also assessed. The methyltransferase-like 3 (METTL3), METTL14, AlkB homologate 5 (ALKBH5), and fat mass and obesity-associated protein (FTO) expression levels were assessed by western blotting. The localized expression of m6A was measured by immunofluorescence. RESULTS: PAL significantly prevented bodyweight loss and shortening of the colon in experimental colitis rats, as well as decreasing the DAI and histological damage scores. Furthermore, PAL inhibited the levels of inflammatory factors (TNF-α, IL-6, IL-8, and IL-1ß) in both DSS treated rats and NCM460 cells. In addition, PAL enhanced the expression level of ZO-1, and increased the transepithelial electrical resistance to repaire intestinal barrier dysfunction. Colitis occurred due to decreased m6A levels, and the increased FTO expression led to a colitis phenotype. PAL markedly enhanced the METTL3 and METTL14 expression levels while decreasing ALKBH5 and FTO expression levels. CONCLUSIONS: The findings demonstrated that PAL improved DSS-induced experimental colitis. This effect was associated with inhibiting FTO expression and regulating m6A methylation.

Protoberberine alkaloids: A review of the gastroprotective effects, pharmacokinetics, and toxicity.

BACKGROUND: Stomach diseases have become global health concerns. Protoberberine alkaloids (PBAs) are a group of quaternary isoquinoline alkaloids from abundant natural sources and have been shown to improve gastric disorders in preclinical and clinical studies. The finding that PBAs exhibit low oral bioavailability but potent pharmacological activity has attracted great interest. PURPOSE: This review aims to provide a systematic review of the molecular mechanisms of PBAs in the treatment of gastric disorders and to discuss the current understanding of the pharmacokinetics and toxicity of PBAs. METHODS: The articles related to PBAs were collected from the Web of Science, Pubmed, and China National Knowledge Infrastructure databases using relevant keywords. The collected articles were screened and categorized according to their research content to focus on the gastroprotective effects, pharmacokinetics, and toxicity of PBAs. RESULTS: Based on the results of preclinical studies, PBAs have demonstrated therapeutic effects on chronic atrophic gastritis and gastric cancer by activating interleukin-4 (IL-4)/signal transducer and activator of transcription 6 (STAT6) pathway and suppressing transforming growth factor-beta 1 (TGF-ß1)/phosphoinositide 3-kinase (PI3K), Janus kinase-2 (JAK2)/signal transducers and activators of transcription 3 (STAT3), and mitogen-activated protein kinase (MAPK) pathways. The major PBAs exhibit similar pharmacokinetic properties, including rapid absorption, slow elimination, and low bioavailability. Notably, the natural organ-targeting property of PBAs may account for the finding of their low blood levels and high pharmacological activity. PBAs interact with other compounds, including conventional drugs and natural products, by modulation of metabolic enzymes and transporters. The potential tissue toxicity of PBAs should be emphasized due to their high tissue accumulation. CONCLUSION: This review highlights the gastroprotective effects, pharmacokinetics, and toxicity of PBAs and will contribute to the evaluation of drug properties and clinical translational studies of PBAs, accelerating their transfer from the laboratory to the bedside.

Studies on crystal structures, optical, dyeing and biological properties of protoberberine alkaloids and their supramolecular salts.

The novel Palmatine (PLT)-based supramolecular salt palmatine-sulfosalicylic acid (PLT-SSA) was designed and synthesized, and its structures was determined by the single crystal X-ray diffraction. It is found that PLT-SSA exhibited enhancing thermodynamic stability, fluorescence intensity and emission lifetime in crystal state, which indicated that these structures and aromatic rings may give more overlap between the host-guest units and give rise to a long-lived charge-separated state. In addition, the dyeing properties and toxicity of these protoberberine alkaloid (BBC and PLTCl) and their supramolecular salts will be developed in this work used as yellow dyes for development multifunctional fabrics.

Discovery and development of palmatine analogues as anti-NASH agents by activating farnesoid X receptor (FXR).

Sixty-one palmatine (PMT) derivatives, of which twenty-eight were new, were synthesized and evaluated for their anti-fibrogenic activities via collagen type I α 1 (COL1A1)-promoter based luciferase model in LX-2 cells, taking 2,3,10-trimethoxy-9-p-isopropyloxyprotopalmatine bromide (1) as the lead. Among them, compound 3a exerted the highest potency with the IC50 value of 8.19 µmol/L and SI value of 8.59, and reduced the expressions of multiple fibrogenic biomarkers, including COL1A1, TGF-ß1, α-SMA and TIMP1 in a dose-dependent manner. In addition, it significantly reduced liver steatosis and inflammation, and especially attenuated the degree of liver fibrosis in choline-deficient, l-amino acid-defined, high-fat diet (CDAHFD)-induced NASH mice model in vivo. Mechanism study indicated that it significantly ameliorated liver injury by activating farnesoid X receptor (FXR). BDL-induced fibrosis rats model further verified its liver-protective and anti-fibrosis activities. Therefore, PMT derivatives constituted a new family of non-steroidal FXR agonists as anti-NASH candidates, with the advantage of good safety profile, and are worthy for further investigation.

Isoquinoline Alkaloids from Coptis chinensis Franch: Focus on Coptisine as a Potential Therapeutic Candidate against Gastric Cancer Cells.

Gastric cancer (GC) has high incidence rates and constitutes a common cause of cancer mortality. Despite advances in treatment, GC remains a challenge in cancer therapy which is why novel treatment strategies are needed. The interest in natural compounds has increased significantly in recent years because of their numerous biological activities, including anti-cancer action. The isolation of the bioactive compounds from Coptis chinensis Franch was carried out with the Centrifugal Partition Chromatography (CPC) technique, using a biphasic solvent system composed of chloroform (CHCl3)-methanol (MeOH)-water (H2O) (4:3:3, v/v) with an addition of hydrochloric acid and trietylamine. The identity of the isolated alkaloids was confirmed using a high resolution HPLC-MS chromatograph. The phytochemical constituents of Coptis chinensis such as berberine, jatrorrhizine, palmatine and coptisine significantly inhibited the viability and growth of gastric cancer cell lines ACC-201 and NCI-N87 in a dose-dependent manner, with coptisine showing the highest efficacy as revealed using MTT and BrdU assays, respectively. Flow cytometry analysis confirmed the coptisine-induced population of gastric cancer cells in sub-G1 phase and apoptosis. The combination of coptisine with cisplatin at the fixed-ratio of 1:1 exerted synergistic and additive interactions in ACC-201 and NCI-N87, respectively, as determined by means of isobolographic analysis. In in vivo assay, coptisine was safe for developing zebrafish at the dose equivalent to the highest dose active in vitro, but higher doses (greater than 10 times) caused morphological abnormalities in larvae. Our findings provide a theoretical foundation to further studies on more detailed mechanisms of the bioactive compounds from Coptis chinensis Franch anti-cancer action that inhibit GC cell survival in in vitro settings.

Berberine alkaloids inhibit the proliferation and metastasis of breast carcinoma cells involving Wnt/ß-catenin signaling and EMT.

Berberine alkaloids belong to the class of isoquinoline alkaloids that have been shown to possess anticancer potential, berberine exhibits inhibitory effects on breast cancer development. However, the exact mechanisms of action for anti-breast carcinoma of the alkaloids, including epiberberine, berberrubine and dihydroberberine are still unclear. MTT assay, colony formation, wound healing and transwell invasion assays detected these alkaloids suppressed proliferation, migration and invasion of breast cancer cells. Hoechst and Annexin V-FITC/PI staining were used to analyze the apoptosis of breast cancer cells. Western blotting investigated the changes noted in the expression levels of the key proteins involved in the Wnt/ß-catenin signaling pathway and epithelial to mesenchymal transition (EMT). The results showed that inhibited the proliferation of breast cancer cells. Berberine alkaloids inhibited the cell cycle at G2/M phase in MCF-7 cells, but in MDA-MB-231 cells berberine alkaloids arrested the cell cycle in G0/G1 and G2/M phases. By decreasing ß-catenin expression, increasing GSK-3ß expression and decreasing N-cadherin expression, increasing E-cadherin expression, which proved that epiberberine, berberrubine and dihydroberberine inhibited of metastasis of breast cancer cells through Wnt signaling pathway and reversed EMT except berberine. Furthermore, berberine alkaloids exert their anti-breast cancer effects through the synergistic action of intrinsic and extrinsic pathways of apoptosis. These findings highlight the different effects of different berberine alkaloids on breast cancer cells and confirm that berberine alkaloids may be potentially used in the treatment of breast cancer.

The phytochemical, corynoline, diminishes Aurora kinase B activity to induce mitotic defect and polyploidy.

Plants are a rich source for bioactive compounds. However, plant extracts can harbor a mixture of bioactive molecules that promote divergent phenotypes and potentially have confounding effects in bioassays. Even with further purification and identification, target deconvolution can be challenging. Corynoline and acetylcorynoline, are phytochemicals that were previously isolated through a screen for compounds able to induce mitotic arrest and polyploidy in oncogene expressing retinal pigment epithelial (RPE) cells. Here, we shed light on the mechanism by which these phytochemicals can attack human cancer cells. Mitotic arrest was coincident to the induction of centrosome amplification and declustering, causing multi-polar spindle formation. Corynoline was demonstrated to have true centrosome declustering activity in a model where A549 cells were chemically induced to have more than a regular complement of centrosomes. Corynoline could inhibit the centrosome clustering required for pseudo-bipolar spindle formation in these cells. The activity of AURKB, but not AURKA or polo-like kinase 4, was diminished by corynoline. It only partially inhibited AURKB, so it may be a partial antagonist or corynoline may work upstream on an unknown regulator of AURKB activity or localization. Nonetheless, corynoline and acetylcorynoline inhibited the viability of a variety of human cancer derived cell lines. These phytochemicals could serve as prototypes for a next-generation analog with improved potency, selectivity or in vivo bioavailability. Such an analog could be useful as a non-toxic component of combination therapies where inhibiting the chromosomal passenger protein complex is desired.

13-Methyl-palmatrubine shows an anti-tumor role in non-small cell lung cancer via shifting M2 to M1 polarization of tumor macrophages.

BACKGROUND: Previous studies have substantiated that M2-activated tumor-associated macrophages (M2-TAMs) are involved in multiple malignancies. Presently, we probe the impact and related mechanisms of 13-methyl-palmatrubine (13MP), the Corydalis yanhusuo extract, on M2-TAM-mediated non-small cell lung cancer (NSCLC) development. METHODS: IL-4 and IL-13 were adopted to induce M2-TAMs. The polarization state of TAMs was evaluated by quantitative reverse transcription PCR (qRT-PCR), Western blot (WB) and cellular immunofluorescence. NSCLC cells (A549 and NCL-H1975) were co-cultured with the conditioned medium (CM) of M2-TAMs. Followed by 13MP treatment, cell viability, proliferation, invasion, epithelial-mesenchymal transition (EMT), and in-vivo growth of NSCLC cells were determined. Additionally, human umbilical vein endothelial cells (HUVECs) were co-cultured with the CM of M2-TAMs. The tube formation assay was made to test the tube formation capacity of HUVECs, and the expression of MMP3, MMP9, and VEGF was assessed by WB in the co-culture model. Mechanistically, WB was performed to validate the expression of the PI3K/AKT and JAK/STAT3 pathways in NSCLC cells (A549 and NCL-H1975) as well as in endothelial cell lines co-cultured with M2-TAMs. RESULTS: 13MP inhibited the proliferation, invasion, EMT, growth and enhanced apoptosis of NSCLC cells. 13MP dose-dependently boosted the polarization of TAM from M2 to M1 state. M2-TAMs enhanced the malignant behaviors of NSCLC cells, whereas 13MP hindered M2-TAM-mediated NSCLC cell proliferation and invasion. Meanwhile, 13MP weakened the M2-TAM-mediated angiogenesis. Moreover, 13MP inactivated the PI3K/AKT and JAK/STAT3 signaling in A549 cells, NCL-H1975 cells and HUVECs. CONCLUSION: 13MP suppresses TAM-mediated NSCLC progression via transforming the polarization of TAM from M2 to M1.

Spatial Distribution and Stability of Cholinesterase Inhibitory Protoberberine Alkaloids from Papaver setiferum.

During a research program to identify new cholinesterase inhibitors of natural origin, two new 7,8-didehydroprotoberberine alkaloids (1 and 2) and nine known compounds (3-11) were isolated from the capsules of the common ornamental poppy, Papaver setiferum (previously P. pseudo-orientale). Despite their reported instability, the 7,8-didehydroprotoberberines isolated herein appeared relatively stable, particularly as their trifluoroacetic acid salts. The spatial distributions of the isolated alkaloids were also analyzed using desorption electrospray ionization imaging mass spectrometry. The alkaloids were localized predominantly within the walls and vascular bundles of the capsules, with the highest relative abundances occurring in the lower half of the capsules toward the peduncle. The relative abundances of the alkaloids were also compared across plant development stages. Although most alkaloids did not show clear patterns in their concentration across development stages, the concentration of suspected oxidation products clearly spiked upon plant death. Finally, all isolated natural products were screened for inhibitory activities against a panel of cholinesterases, from both human and animal sources. These studies identified several competitive inhibitors of cholinesterases with potency in the low micromolar range (1-4, 6, 7), offering new lead compounds for the development of cholinesterase inhibitory drugs.

Biological Response Profiling Reveals the Functional Differences of Main Alkaloids in Rhizoma Coptidis.

Rhizoma Coptidis (RC) is a widely used traditional Chinese medicine. Although modern research has found that some alkaloids from RC are the pharmacologically active constituents, the differences in their biological effects are not completely clear. This study analyzed the differences in the typical alkaloids in RC at a systematic level and provided comprehensive information on the pharmaceutical mechanisms of the different alkaloids. The ethanol RC extract (RCE) was characterized using HPLC assay. HepG2, 3T3-L1, and RAW264.7 cells were used to detect the cytotoxicity of alkaloids. Transcriptome analyses were performed to elucidate the cellular pathways affected by RCE and alkaloids. HPLC analysis revealed that the typical alkaloids of RCE were berberine, coptisine, and palmatine. Coptisine and berberine displayed a stronger inhibitory effect on cell proliferation than palmatine. The overlapping ratios of differentially expressed genes between RCE and berberine, coptisine, and palmatine were 70.8%, 52.6%, and 42.1%, respectively. Pathway clustering analysis indicated that berberine and coptisine possessed a certain similarity to RCE, and both compounds affected the cell cycle pathway; moreover, some pathways were uniquely enriched by berberine or coptisine. Berberine and coptisine had different regulatory effects on genes involved in lipid metabolism. These results provide comprehensive information on the pharmaceutical mechanisms of the different RC alkaloids and insights into their better combinatory use for the treatment of diseases.

Opposing Effects of Chelidonine on Tyrosine and Serine Phosphorylation of STAT3 in Human Uveal Melanoma Cells.

STAT3 is a transcription factor that regulates various cellular processes with oncogenic potential, thereby promoting tumorigenesis when activated uncontrolled. STAT3 activation is mediated by its tyrosine phosphorylation, triggering dimerization and nuclear translocation. STAT3 also contains a serine phosphorylation site, with a postulated regulatory role in STAT3 activation and G2/M transition. Interleukin-6, a major activator of STAT3, is present in elevated concentrations in uveal melanomas, suggesting contribution of dysregulated STAT3 activation to their pathogenesis. Here, we studied the impact of chelidonine on STAT3 signaling in human uveal melanoma cells. Chelidonine, an alkaloid isolated from Chelidonium majus, disrupts microtubules, causes mitotic arrest and provokes cell death in numerous tumor cells. According to our flow cytometry and confocal microscopy data, chelidonine abrogated IL-6-induced activation and nuclear translocation, but amplified constitutive serine phosphorylation of STAT3. Both effects were restricted to a fraction of cells only, in an all-or-none fashion. A partial overlap could be observed between the affected subpopulations; however, no direct connection could be proven. This study is the first proof on a cell-by-cell basis for the opposing effects of a microtubule-targeting agent on the two types of STAT3 phosphorylation.

Palmatine, a Bioactive Protoberberine Alkaloid Isolated from Berberis cretica, Inhibits the Growth of Human Estrogen Receptor-Positive Breast Cancer Cells and Acts Synergistically and Additively with Doxorubicin.

Palmatine (PLT) is a natural isoquinoline alkaloid that belongs to the class of protoberberines and exhibits a wide spectrum of pharmacological and biological properties, including anti-cancer activity. The aim of our study was to isolate PLT from the roots of Berberis cretica and investigate its cytotoxic and anti-proliferative effects in vitro alone and in combination with doxorubicine (DOX) using human ER+/HER2- breast cancer cell lines. The alkaloid was purified by column chromatography filled with silica gel NP and Sephadex LH-20 resin developed in the mixture of methanol: water (50:50 v/v) that provided high-purity alkaloid for bioactivity studies. The purity of the alkaloid was confirmed by high resolution mass measurement and MS/MS fragmentation analysis in the HPLC-ESI-QTOF-MS/MS-based analysis. It was found that PLT treatment inhibited the viability and proliferation of breast cancer cells in a dose-dependent manner as demonstrated by MTT and BrdU assays. PLT showed a quite similar growth inhibition on breast cancer cells with IC50 values ranging from 5.126 to 5.805 µg/mL. In contrast, growth of normal human breast epithelial cells was not affected by PLT. The growth inhibitory activity of PLT was related to the induction of apoptosis, as determined by Annexin V/PI staining. Moreover, PLT sensitized breast cancer cells to DOX. Isobolographic analysis revealed synergistic and additive interactions between studied agents. Our studies suggest that PLT can be a potential candidate agent for preventing and treating breast cancer.

Neuroprotective Effects of Palmatine via the Enhancement of Antioxidant Defense and Small Heat Shock Protein Expression in Aß-Transgenic Caenorhabditis elegans.

Palmatine is a naturally occurring isoquinoline alkaloid that has been reported to display neuroprotective effects against amyloid-ß- (Aß-) induced neurotoxicity. However, the mechanisms underlying the neuroprotective activities of palmatine remain poorly characterized in vivo. We employed transgenic Caenorhabditis elegans models containing human Aß 1-42 to investigate the effects and possible mechanisms of palmatine-mediated neuroprotection. Treatment with palmatine significantly delayed the paralytic process and reduced the elevated reactive oxygen species levels in Aß-transgenic C. elegans. In addition, it increased oxidative stress resistance without affecting the lifespan of wild-type C. elegans. Pathway analysis suggested that the differentially expressed genes were related mainly to aging, detoxification, and lipid metabolism. Real-time PCR indicated that resistance-related genes such as sod-3 and shsp were significantly upregulated, while the lipid metabolism-related gene fat-5 was downregulated. Further studies demonstrated that the inhibitory effects of palmatine on Aß toxicity were attributable to the free radical-scavenging capacity and that the upregulated expression of resistance-related genes, especially shsp, whose expression was regulated by HSF-1, played crucial roles in protecting cells from Aß-induced toxicity. The research showed that there were significantly fewer Aß deposits in transgenic CL2006 nematodes treated with palmatine than in control nematodes. In addition, our study found that Aß-induced toxicity was accompanied by dysregulation of lipid metabolism, leading to excessive fat accumulation in Aß-transgenic CL4176 nematodes. The alleviation of lipid disorder by palmatine should be attributed not only to the reduction in fat synthesis but also to the inhibition of Aß aggregation and toxicity, which jointly maintained metabolic homeostasis. This study provides new insights into the in vivo neuroprotective effects of palmatine against Aß aggregation and toxicity and provides valuable targets for the prevention and treatment of AD.

Tetrahydropalmatine attenuates MSU crystal-induced gouty arthritis by inhibiting ROS-mediated NLRP3 inflammasome activation.

Activation of NACHT, LRR, and PYD domains-containing protein 3 (NLRP3) inflammasome plays a crucial role in the inflammatory responses of monosodium urate (MSU) crystal-induced gouty arthritis. Therefore, the molecular basis of NLRP3 inflammasome is very valuable in developing potential therapeutic drugs for gout. Tetrahydropalmatine (THP), the main active component of the traditional Chinese medicinal herb Corydalis yanhusuo, has shown prominent anti-inflammatory and analgesic activities, but to date, these effects have not been investigated exhaustively on gout. This study indicated that THP attenuated pain and swelling in an MSU-induced acute gout model by decreasing pro-inflammatory cytokine production and inflammatory cell infiltration. THP exerted its actions by suppressing NLRP3 inflammasome activation and subsequent formation of caspase-1. Furthermore, results showed that THP alleviated MSU-induced reactive oxygen species (ROS) generation, upstream of NLRP3 inflammasome activation, by an increase in the activities of antioxidant enzymes both in vitro and in vivo. In conclusion, our study suggests that THP suppressed ROS-mediated NLRP3 inflammasome activation in MSU-induced inflammatory responses, which highlights its therapeutic potential in gouty arthritis.

Tetrahydropalmatine exerts analgesic effects by promoting apoptosis and inhibiting the activation of glial cells in rats with inflammatory pain.

BACKGROUND: Pain is an unpleasant sensory experience that usually plays a protective role. Inflammatory pain is often severe and stubborn, which has a great impact on the quality of life of patients. However, there has been no breakthrough in the treatment strategy and mechanism of inflammatory pain. METHODS: This study investigated the analgesic effect of tetrahydropalmatine (THP) in rats injected with complete Freund's adjuvant (CFA)-induced inflammatory pain. Allodynia and gait analysis of rats were used to evaluate the analgesic effect at different time points before and after operation. THP (2.5, 5, and 10 mg/kg) was administered intraperitoneally once daily for 7 days post Day 3. The expression levels of TNF-α and IL-1ß in the spinal cord were measured by enzyme-linked immunosorbent assay. The activation of astrocytes and microglial cells in the spinal cord was tested by western blot before and after THP treatment. The apoptosis of glial cells was tested by flow cytometry after treatment with THP in the primary cultured glial cell model. RESULTS: CFA treatment induced significant allodynia and caused abnormal gait in rats. Administration of THP at 10 mg/kg significantly alleviated CFA-induced inflammatory pain behaviors. Moreover, CFA-induced activation of glial cells and the increased levels of TNF-α and IL-1ß were inhibited by THP administration. In addition, THP promotes apoptosis in primary cultured glial cells. This study suggests the possible clinical utility of THP in the treatment of inflammatory pain. CONCLUSION: THP plays an analgesic role by inhibiting the activation of glial cells and promoting apoptosis.