Investigating the mechanism of cornel iridoid glycosides on type 2 diabetes mellitus using serum and urine metabolites in rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Cornel iridoid glycosides (CIG) are extracted from Corni fructus, a herbal medicine used in traditional Chinese medicine to treat diabetes. However, the antidiabetic effects of CIG and the underlying metabolic mechanisms require further exploration. AIM OF THE STUDY: This study aimed to assess the antidiabetic effects and metabolic mechanism of CIG by performing metabolomic analyses of serum and urine samples of rats. MATERIALS AND METHODS: A rat model of type 2 diabetes mellitus (T2DM) was established by administering a low dose of streptozotocin (30 mg/kg) intraperitoneally after 4 weeks of feeding a high-fat diet. The model was evaluated based on several parameters, including fasting blood glucose (FBG), random blood glucose (RBG), urine volume, liver index, body weight, histopathological sections, and serum biochemical parameters. Subsequently, serum and urine metabolomics were analyzed using ultra-high-pressure liquid chromatography coupled with linear ion trap-Orbitrap tandem mass spectrometry (UHPLC-LTQ-Orbitrap-MS). Data were analyzed using unsupervised principal component analysis (PCA) and supervised orthogonal partial least squares discriminant analysis (OPLS-DA). Differential metabolites were examined by the Kyoto Encyclopedia of Genes and Genomes (KEGG) metabolic pathways to explore the underlying mechanisms. RESULTS: After 4 weeks of treatment with different doses of CIG, varying degrees of antidiabetic effects were observed, along with reduced liver and pancreatic injury, and improved oxidative stress levels. Compared with the T2DM group, 19 and 23 differential metabolites were detected in the serum and urine of the CIG treatment group, respectively. The key metabolites involved in pathway regulation include taurine, chenodeoxycholic acid, glycocholic acid, and L-tyrosine in the serum and glycine, hippuric acid, phenylacetylglycine, citric acid, and D-glucuronic acid in the urine, which are related to lipid, amino acid, energy, and carbohydrate metabolism. CONCLUSIONS: This study confirmed the antidiabetic effects of CIG and revealed that CIG effectively controlled metabolic disorders in T2DM rats. This seems to be meaningful for the clinical application of CIG, and can benefit further studies on CIG mechanism.

Cornel Iridoid Glycoside Alleviates Microglia-Mediated Inflammatory Response via the NLRP3/Calpain Pathway.

Vascular dementia (VaD) is associated with cerebral hypoperfusion, which results in long-term cognitive impairment and memory loss. Cornel iridoid glycoside (CIG) is the major active constituent isolated from the ripe fruit of Cornus officinalis. Previous studies have shown that CIG enhances neurological function in VaD rats. In the present research, we attempted to clarify the molecular processes underlying the role of CIG in neuroinflammation in VaD. We created a chronic cerebral ischemia rat model by ligation of the bilateral common carotid arteries (2VO) and then treated rats with different concentrations of CIG. Comprehensive analyses revealed that CIG ameliorated myelin integrity and neuronal loss. Furthermore, we also found that CIG inhibited polarized microglia activation and attenuated inflammasome-mediated production of proinflammatory cytokines in BV2 microglia cells induced by LPS/IFN-γ and in the brains of 2VO rats. To further elucidate the role of CIG in microglia-mediated inflammatory response, we investigated the expression and activity of calpain. CIG inhibited the expression and activity of calpain 1/2, which was characterized by decreased calpastatin and spectrin αII expression. In particular, intra- and extracellular calpain 1 levels were reduced by CIG. However, CIG showed weak interaction with calpain 1. In addition, we found that CG administration significantly repressed the assembly of the NOD-like receptor protein 3 (NLRP3) inflammasome, including NLRP3, ASC, and caspase-1. In conclusion, our knowledge of the mechanisms by which CIG regulates NLRP3/calpain signaling to influence inflammatory responses offers further insights into potential therapeutic strategies to treat VaD.

Network pharmacology of iridoid glycosides from Eucommia ulmoides Oliver against osteoporosis.

Eucommia ulmoides Oliver is one of the commonly used traditional Chinese medicines for the treatment of osteoporosis, and iridoid glycosides are considered to be its active ingredients against osteoporosis. This study aims to clarify the chemical components and molecular mechanism of iridoid glycosides of Eucommia ulmoides Oliver in the treatment of osteoporosis by integrating network pharmacology and molecular simulations. The active iridoid glycosides and their potential targets were retrieved from text mining as well as Swiss Target Prediction, TargetNet database, and STITCH databases. At the same time, DisGeNET, GeneCards, and Therapeutic Target Database were used to search for the targets associated with osteoporosis. A protein-protein interaction network was built to analyze the interactions between targets. Then, DAVID bioinformatics resources and R 3.6.3 project were used to carry out Gene Ontology enrichment analysis and Kyoto Encyclopedia of Genes and Genomes pathway analysis. Moreover, interactions between active compounds and potential targets were investigated through molecular docking, molecular dynamic simulation, and binding free energy analysis. The results showed that a total of 12 iridoid glycosides were identified as the active iridoid glycosides of Eucommia ulmoides Oliver in the treatment of osteoporosis. Among them, aucubin, reptoside, geniposide and ajugoside were the core compounds. The enrichment analysis suggested iridoid glycosides of Eucommia ulmoides Oliver prevented osteoporosis mainly through PI3K-Akt signaling pathway, MAPK signaling pathway and Estrogen signaling pathway. Molecular docking results indicated that the 12 iridoid glycosides had good binding ability with 25 hub target proteins, which played a critical role in the treatment of osteoporosis. Molecular dynamic and molecular mechanics Poisson-Boltzmann surface area results revealed these compounds showed stable binding to the active sites of the target proteins during the simulations. In conclusion, our research demonstrated that iridoid glycosides of Eucommia ulmoides Oliver in the treatment of osteoporosis involved a multi-component, multi-target and multi-pathway mechanism, which provided new suggestions and theoretical support for treating osteoporosis.

Swertiamarin, an active iridoid glycoside from Swertia pseudochinensis H. Hara, protects against alpha-naphthylisothiocyanate-induced cholestasis by activating the farnesoid X receptor and bile acid excretion pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: Swertiamarin (SW), which belongs to iridoid glycosides, is one of the main components of Swertia plants in Gentianaceae family, including Swertia pseudochinensis H. Hara and Swertia mileensis T. N. Ho et W. L. Shi. There are mainly used in traditional Chinese medicine for the treatment of hepatic and biliary disease such as jaundice. AIM OF THIS STUDY: This experiment aimed to explore the protective mechanism of SW on cholestasis induced by alpha-naphthylisothiocyanate in rats. MATERIALS AND METHODS: Healthy rats were randomly divided into the control, model (ANIT, 50 mg/kg), ursodeoxycholic acid (UDCA, 80 mg/kg), and low-dose (SW, 80 mg/kg), medium-dose (SW, 100 mg/kg), and high-dose (SW, 150 mg/kg) groups. The hepatic protective effect of SW was preliminarily evaluated by measurement of serum biochemical indicators and liver morphological evaluation. Moreover, metabolomics and proteomics analysis were used to explore the protective mechanism of SW on cholestasis. The expression of related proteins was determined by Western blot and polymerase chain reaction, and the important proteins were verified by cell experiments in vitro. RESULTS: SW (100 mg/kg) can reduce the serum levels of the model group. The hepatocyte of the medium-dose treatment group was arranged neatly without evident inflammation. SW can partially reverse the changes in cholestasis metabolites, such as taurocholic acid, SM (d18:1/16:0), all-trans-retinoic acid and other products of rats. The main metabolic pathways affected were primary bile acid synthesis, glycerophospholipid metabolism, sphingolipid metabolism and retinol metabolism. SW medium-dose treatment group showed effective reversal of 25 related proteins and it can remarkably reduce the contents of NTCP and CYP27A1 in rat liver and increase the protein expressions of CYP7A1, CYP8B1, bile salt export pump, multidrug resistance-associated protein and FXR. CONCLUSIONS: SW can alleviate ANIT-induced cholestasis, which by activating the farnesoid X receptor and bile acid excretion pathway.

Ajugol enhances TFEB-mediated lysosome biogenesis and lipophagy to alleviate non-alcoholic fatty liver disease.

Lipophagy is the autophagic degradation of lipid droplets. Dysregulated lipophagy has been implicated in the development of non-alcoholic fatty liver disease (NAFLD). Ajugol is an active alkaloid isolated from the root of Rehmannia glutinosa which is commonly used to treat various inflammatory and metabolic diseases. This study aimed to investigate the effect of ajugol on alleviating hepatic steatosis and sought to determine whether its potential mechanism via the key lysosome-mediated process of lipophagy. Our findings showed that ajugol significantly improved high-fat diet-induced hepatic steatosis in mice and inhibited palmitate-induced lipid accumulation in hepatocytes. Further analysis found that hepatic steatosis promoted the expression of LC3-II, an autophagosome marker, but led to autophagic flux blockade due to a lack of lysosomes. Ajugol also enhanced lysosomal biogenesis and promoted the fusion of autophagosome and lysosome to improve impaired autophagic flux and hepatosteatosis. Mechanistically, ajugol inactivated mammalian target of rapamycin and induced nuclear translocation of the transcription factor EB (TFEB), an essential regulator of lysosomal biogenesis. siRNA-mediated knockdown of TFEB significantly abrogated ajugol-induced lysosomal biogenesis as well as autophagosome-lysosome fusion and lipophagy. We conclude that lysosomal deficit is a critical mediator of hepatic steatosis, and ajugol may alleviate NAFLD via promoting the TFEB-mediated autophagy-lysosomal pathway and lipophagy.

Harpagide exerts a neuroprotective effect by inhibiting endoplasmic reticulum stress via SERCA following oxygen-glucose deprivation/reoxygenation injury.

Cerebrovascular diseases endanger human health, and the physiological and pathological processes of cerebral ischemia/reperfusion injury (CIRI) are critical for the occurrence of these diseases and as targets for their treatment. Here, we evaluated the effects of harpagide-mediated pharmacological and genetic inhibition of sarco-endoplasmic reticulum Ca2+-ATPase (SERCA) in vitro in PC12 cells. The molecular mechanism by which harpagide protects PC12 cells against oxygen-glucose deprivation/reoxygenation (OGD/R) injury was investigated by evaluating the cell survival rate with the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay, assessing apoptosis by flow cytometry, determining the intracellular Ca2+ concentration ([Ca2+]i) by laser scanning confocal microscopy (LSCM), and measuring the expression of proteins related to SERCA and endoplasmic reticulum stress (ERS) by Western blotting. The results revealed that harpagide significantly decreased thapsigargin (TG)-induced apoptosis of PC12 cells, downregulated the expression of ERS-related markers, considerably improved the TG-induced expression of SERCA-related proteins and reduced the [Ca2+]i, suggesting that harpagide effectively inhibited ERS directly. Moreover, harpagide did not significantly reduce OGD/R-induced apoptosis but increased the expression of ERS markers in PC12/SERCA- cells, indicating that harpagide targets SERCA to protect against CIRI by suppressing ERS-mediated apoptosis.

8-O-(E-p-methoxycinnamoyl)harpagide Inhibits Influenza A Virus Infection by Suppressing Intracellular Calcium.

Calcium (Ca2+) dependent signaling circuit plays a critical role in influenza A virus (IAV) infection. The 8-O-(E-p-methoxycinnamoyl)harpagide (MCH) exhibits pharmacological activities that exert neuroprotective, hepatoprotective, anti-inflammatory and other biological effects. However, not have reports of antiviral effects. To investigate the antiviral activity of MCH on IAV-infected human lung cells mediated by calcium regulation. We examined the inhibitory effect of MCH on IAV infections and measured the level of viral proteins upon MCH treatment using Western blotting. We also performed molecular docking simulation with MCH and IAV M2 protein. Finally, we analyzed MCH's suppression of intracellular calcium and ROS (reactive oxygen species) in IAV-infected human lung cells using a flow cytometer. The results shown that MCH inhibited the infection of IAV and increased the survival of the infected human lung cells. The levels of IAV protein M1, M2, NS1 and PA were inhibited in MCH-treated human lung cells compared to that in infected and untreated cells. Also, docking simulation suggest that MCH interacted with M2 on its hydrophobic wall (L40 and I42) and polar amino acids (D44 and R45), which formed intermolecular contacts and were a crucial part of the channel gate along with W41. Lastly, MCH inhibited IAV infection by reducing intracellular calcium and mitochondrial Ca2+/ROS levels in infected human lung cells. Taken together, these data suggest that MCH inhibits IAV infection and increases the survival of infected human lung cells by suppressing calcium levels. These results indicate that MCH is useful for developing IAV treatments.

Dual Functional Eudragit® S100/L30D-55 and PLGA Colon-Targeted Nanoparticles of Iridoid Glycoside for Improved Treatment of Induced Ulcerative Colitis.

AIM: Iridoid glycosides (IG) as the major active fraction of Syringa oblata Lindl. has a proven anti-inflammatory effect for ulcerative colitis (UC). However, its current commercial formulations are hampered by low bioavailability and unable to reach inflamed colon. To overcome the limitation, dual functional IG-loaded nanoparticles (DFNPs) were prepared to increase the residence time of IG in colon. The protective mechanism of DFNPs on DSS-induced colonic injury was evaluated in rats. MATERIALS AND METHODS: We prepared DFNPs using the oil-in-water emulsion method. PLGA was selected as sustained-release polymer, and ES100 and EL30D-55 as pH-responsive polymers. The morphology and size distribution of NPs were measured by SEM and DLS technique. To evaluate colon targeting of DFNPs, DiR, was encapsulated as a fluorescent probe into NPs. Fluorescent distribution of NPs were investigated. The therapeutic potential and in vivo transportation of NPs in gastrointestinal tract were evaluated in a colitis model. RESULTS: SEM images and zeta data indicated the successful preparation of DFNPs. This formulation exhibited high loading capacity. Drug release results suggested DFNPs released less than 20% at the first 6 h in simulated gastric fluid (pH1.2) and simulated small intestine fluid (pH6.8). A high amount of 84.7% sustained release from NPs in simulated colonic fluid (pH7.4) was beyond 24 h. DiR-loaded NPs demonstrated a much higher colon accumulation, suggesting effective targeting due to functionalization with pH and time-dependent polymers. DFNPs could significantly ameliorate the colonic damage by reducing DAI, macroscopic score, histological damage and cell apoptosis. Our results also proved that the potent anti-inflammatory effect of DFNPs is contributed by decrease of NADPH, gene expression of COX-2 and MMP-9 and the production of TNF-α, IL-17, IL-23 and PGE2. CONCLUSION: We confirm that DFNPs exert protective effects through inhibiting the inflammatory response, which could be developed as a potential colon-targeted system.

Antiviral activity of iridoid glycosides extracted from Fructus Gardeniae against influenza A virus by PACT-dependent suppression of viral RNA replication.

Epidemic and pandemic influenza A virus (IAV) poses a significant threat to human populations worldwide. Iridoid glycosides are principal bioactive components from the Gardenia jasminoides J. Ellis fruit that exhibit antiviral activity against several strains of IAV. In the present study, we evaluated the protective effect of Fructus Gardeniae iridoid glycoside extracts (IGEs) against IAV by cytopathogenic effect(CPE), MTT and a plaque formation assay in vitro and examined the reduction in the pulmonary index (PI), restoration of body weight, reduction in mortality and increases in survival time in vivo. As a host factor, PACT provides protection against the pathogenic influenza A virus by interacting with IAV polymerase and activating the IFN-I response. To verify the whether IGEs suppress IAV replication in a PACT-dependent manner, IAV RNA replication, expression of PACT and the phosphorylation of eIF2α in A549 cells were detected; the levels of IFNß, PACT and PKR in mouse lung tissues were determined; and the activity of IAV polymerase was evaluated in PACT-compromised cells. The results indicated that IGEs sufficiently alleviated cell damage and suppressed IAV replication in vitro, protecting mice from IAV-induced injury and lethal IAV infection. These anti-IAV effects might be related to disrupted interplay between IVA polymerase and PACT and/or prevention of a PACT-dependent overactivated IFN-I antiviral response. Taken together, our findings reveal a new facet of the mechanisms by which IGEs fight the influenza A virus in a PACT-dependent manner.

Protective effects of iridoid glycosides on acute colitis via inhibition of the inflammatory response mediated by the STAT3/NF-кB pathway.

Morroniside and loganin are iridoid glycosides extracted from Cornus officinalis, a plant species widely used in traditional Chinese medicine. However, the anti-inflammatory effects of morroniside and loganin in colitis are barely understood. The aim of the present study was to explore the effects of morroniside and loganin on the dextran sodium sulfate (DSS)-induced murine model of colitis and an LPS-induced colorectal cancer (CRC) cell inflammation model, and to clarify the underlying mechanisms. We found that morroniside and loganin were able to ameliorate clinical features, including disease activity index (DAI), histological inflammation score and periodic acid-Schiff staining (PAS). In the mouse model, morroniside and loganin treatment increased expression of tight junction proteins (TJs) and decreased pro-inflammatory cytokine production. Moreover, our findings showed that the expression of p-STAT3 and p-p65 were suppressed compared to the disease group. In in vitro experiments, treatment with morroniside and loganin had no obvious effects on proliferative activity in HCT116 cells and HIEC-6 cells. Expression of pro-inflammatory cytokines was inhibited by morroniside and loganin treatment in comparison with the LPS-treated group. Taken together, morroniside and loganin have beneficial effects on colitis in vivo and are anti-inflammatory in vitro. Possible mechanisms of the anti-inflammatory response may include blockade of the STAT3/NF-κB pathway.

Antihyperlipidemic effect of iridoid glycoside deacetylasperulosidic acid isolated from the seeds of Spermacoce hispida L. - A traditional antiobesity herb.

ETHNOBOTANICAL RELEVANCE: The interest on herbal health supplements for obesity is increasing globally. Our previous ethnobotanical survey in Tiruvallur district, Tamil Nadu, India indicated the use of Spermacoce hispida L. seeds for the treatment of obesity. AIM OF THE STUDY: This study was aimed to validate the traditional claim and to identify the antihyperlipidemic principle in the seeds of Spermacoce hispida using bioassay guided fractionation method. METHODS: Bioassay monitored fractionation of the aqueous extract from Spermacoce hispida seeds was carried out using triton WR 1339 induced hyperlipidemic animals. It yielded deacetylasperulosidic acid (DAA) as the active ingredient. Pharmacokinetic properties of DAA were predicted using DataWarrior and SwissADME tools. In vitro antiobesity and antihyperlipidemic effects of DAA were evaluated in 3T3L1 preadipocytes and HepG2 cells, respectively. The chronic antihyperlipidemic efficacy of DAA was evaluated in high fat diet fed rats. RESULTS: DAA did not show any mutagenic and tumorigenic properties. It bound with PPARα with comparable ligand efficiency as fenofibrate. The treatment with DAA significantly lowered the proliferation of matured adipocytes, but not preadipocytes. The treatment of steatotic HepG2 cells with DAA significantly decreased the LDH leakage by 43.03% (P < 0.05) at 50 µM concentration. In triton WR 1339 induced hyperlipidemic animals, the treatment with 50 mg/kg dose significantly lowered the TC, TG and LDL-c levels by 40.27, 46.00 and 63.65% respectively. In HFD fed animals, the treatment at 10 mg/kg decreased BMI and AC/TC ratio without altering SRBG. It also improved serum lipid, transaminases and phosphatases levels of HFD fed animals. The treatment lowered adipocyte hypertrophy and steatosis of hepatocytes. CONCLUSION: This preliminary report supported the traditional use of Spermacoce hispida for the treatment of obesity. Further detailed investigations on the long term safety, efficacy and molecular mode of action of Spermacoce hispida and DAA will throw more light on their usefulness for the management of obesity.

Effect of cornel iridoid glycoside on microglia activation through suppression of the JAK/STAT signalling pathway.

The effect of cornel iridoid glycoside (CIG), main component extracted from Cornus officinalis, on microglia activation has not been elucidated so far. We induced a mouse model of multiple sclerosis (MS), namely, the experimental autoimmune encephalomyelitis (EAE) model by immunization subcutaneously with the MOG35-55 peptide, which causes neuroinflammation and microglia activation. Our data demonstrated that CIG delayed the onset of the EAE, ameliorated the severity of the symptoms and inhibited the activation of microglia in different brain regions. In addition, we also found that CIG has therapeutic potential by modulating microglia polarization by reducing the expression and release of proinflammatory cytokines, chemokines and inhibiting phosphorylation in the JAK/STAT cell signalling pathway. Based on our findings, CIG might be a promising candidate for the prevention of neurological disorders such as multiple sclerosis (MS).

Shufeng Jiedu Capsules Alleviate Lipopolysaccharide-Induced Acute Lung Inflammatory Injury via Activation of GPR18 by Verbenalin.

BACKGROUND/AIMS: Acute respiratory tract infection (ARTI) is the most common reason for outpatient physician office visits. Although powerful and significant in the treatment of infections, antibiotics used for ARTI inappropriately have been an important contributor to antibiotic resistance. We previously reported that Shufeng Jiedu Capsule (SJC) can effectively amplify anti-inflammatory signaling during infection. In this study, we aimed to systematically explore its composition and the mechanism of its effects in ARTI. METHODS: Pseudomonas aeruginosa (PAK) strain was used to generate a mouse model of ARTI, which were then treated with different drugs or compounds to determine the corresponding anti-inflammatory roles. High-performance liquid chromatography-quadrupole time of flight-tandem mass spectrometry. was conducted to detect the chemical compounds in SJC. RNAs from the lung tissues of mice were prepared for microarray analysis to reveal globally altered genes and the pathways involved after SJC treatment. RESULTS: SJC significantly inhibited the expression and secretion of inflammatory factors from PAK-induced mouse lung tissues or lipopolysaccharide-induced peritoneal macrophages. Verbenalin, one of the bioactive compounds identified in SJC, also showed notable anti-inflammatory effects. Microarray data revealed numerous differentially expressed genes among the different treatment groups; here, we focused on studying the role of GPR18. We found that the anti-inflammatory role of verbenalin was attenuated in GPR18 knockout mice compared with wild-type mice, although no statistically significant difference was observed in the untreated PAK-induced mice types. CONCLUSION: Our data not only showed the chemical composition of SJC, but also demonstrated that verbenalin was a significant anti-inflammatory compound, which may function through GPR18.

Protective Effects of Cornel Iridoid Glycoside in Rats After Traumatic Brain Injury.

Cornel iridoid glycoside (CIG) is the active ingredient extracted from Cornus officinalis. Our previous studies showed that CIG had protective effects on several brain injury models. In the present study, we aimed to examine the effects and elucidate the mechanisms of CIG against traumatic brain injury (TBI). TBI was induced in the right cerebral cortex of male adult rats. The neurological and cognitive functions were evaluated by modified neurological severity score (mNSS) and object recognition test (ORT), respectively. The level of serum S100ß was measured by an ELISA method. Nissl staining was used to estimate the neuron survival in the brain. The expression of proteins was determined by western blot and/or immunohistochemical staining. We found that intragastric administration of CIG in TBI rats ameliorated the neurological defects and cognitive impairment, and alleviated the neuronal loss in the injured brain. In the acute stage of TBI (24-72 h), CIG decreased the level of S100ß in the serum and brain, increased the ratio of Bcl-2/Bax and decreased the expression of caspase-3 in the injured cortex. Moreover, the treatment with CIG for 30 days increased the levels of nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF), enhanced the expression of synapsin I, synaptophysin and postsynaptic density protein 95 (PSD-95), and inhibited the apoptosis-regulating factors in the chronic stage of TBI. The present study demonstrated that CIG had neuroprotective effects against TBI through inhibiting apoptosis in the acute stage and promoting neurorestoration in the chronic stage. The results suggest that CIG may be beneficial to TBI therapy.

Preventive effect of Agnucastoside C against Isoproterenol-induced myocardial injury.

An iridoid glycoside, agnucastoside C (ACC) was isolated from the leaves of Moringa oliefera and its cardio protective potential was investigated in adult rats by examining the effects of this test compound, ACC at 30 mg/kg for 14 days in isoproterenol (100 mg/kg)-induced myocardial injury. Isoproterenol (ISO) administration induced the myocardial injury as evidenced by the altered ECG pattern with ST-segment elevation and an increase in the levels of cardiac injury markers including troponin-I, creatine kinase-MB, alanine transaminase, aspartate transaminase, lactate dehydrogenase; inflammatory markers, interleukine-6 and tumor necrosis factor. In this group, there was also an increase in cardiac lipid peroxidation and a decrease in cellular antioxidants. However, pretreatment with ACC maintained the normal ECG pattern and nearly normal levels of all the cardiac markers in ISO-induced animals. Electron microscopic and histological studies also showed marked reduction in ISO-induced cardiac damages including infarct size by ACC. Analysis by 2-DE revealed the involvement of 19 different cardiac proteins, associated with energy metabolism, oxidative stress and maintenance of cytoskeleton. The expression of those proteins were altered by ISO, but maintained in ACC pretreated rats. Our findings reveal the potential of isolated ACC in the prevention of myocardial damage.

Cornin increases angiogenesis and improves functional recovery after stroke via the Ang1/Tie2 axis and the Wnt/ß-catenin pathway.

We investigated whether cornin, an iridoid glycoside isolated from fruits of Verbena officinalis L., regulated angiogenesis and thereby improved functional outcomes after stroke and discovered a potential mechanism. The effects of cornin on proliferation of rat artery smooth muscle cell (RASMC) and signalling was investigated in vitro. Adult male rats were subjected to 1 h of middle cerebral artery occlusion (MCAO) and reperfusion and treated with or without 25 mg/kg of cornin, starting 24 h after ischemia and reperfusion, by continuous intravenous injection daily for 14 days. Neurological functional tests were performed and cerebral Evans blue extravasation was measured. Angiogenesis and angiogenic factor expressions were measured by immunohistochemistry and Western blotting, respectively. Cornin increased the proliferation of RASMC and enhanced the expression of Wnt5a, ß-catenin, cyclin D1 and angiopoietin-1 (Ang1). Cornin treatment promoted angiogenesis in the ischemic brain core and improved functional outcomes after stroke. Cornin-treated MCAO rats showed significant increase in vascularization and expression of vascular endothelial growth factor and Ang1 and phosphorylation of Tie2 and Akt compared with vehicle-treated MCAO rats. The Ang1/Tie2 axis and Wnt/ß-catenin pathways appear to mediate cornin-induced angiogenesis.

Anti-osteoporotic activity of harpagide by regulation of bone formation in osteoblast cell culture and ovariectomy-induced bone loss mouse models.

ETHNOPHARMACOLOGICAL RELEVANCE: Harpagide, an iridoid glucoside, is a constituent of the root of Harpagophytum procumbens var. sublobatum (Engl.) Stapf, Devil's claw which has been used in patients with osteoarthritis (OA). In the present study, we investigated the anti-osteoporotic potential of harpagide and its underlying mechanism of action in in vitro cell culture and in vivo bone loss animal models. MATERIAL AND METHODS: Harpagide was obtained from the alkalic hydrolysis of harpagoside, a major constituent of H. procumbens var. sublobatum Analysis of biomarkers for bone formation in osteoblastic MC3T3-E1 cells and bone resorption in osteoclast cells derived from mouse bone marrow cells was performed to evaluate the mechanism of action. The protective activity of harpagide against bone loss was also evaluated in ovariectomized (OVX) mouse model. RESULTS: Harpagide improved bone properties by stimulating the process of differentiation and maturation of osteoblast cells and suppressing the process of RANKL-induced differentiation of osteoclast cells. In OVX-induced bone loss mouse model, oral administration of harpagide significantly improved recovery of bone mineral density, trabecular bone volume, and trabecular number in the femur. Harpagide also prevented increase of trabecular separation and structure model index induced by OVX. Harpagide effectively inhibited the serum levels of biochemical markers of bone loss, including alkaline phosphatase, osteocalcin, C-terminal telopeptide, and tartrate-resistant acid phosphatase. CONCLUSION: Taken together, the present study demonstrates that harpagide has a potential for prevention of bone loss in OVX mice by regulating the stimulation of osteoblast differentiation and the suppression of osteoclast formation. Therefore, these findings suggest that harpagide might serve as a bioactive compound derived from H. procumbens var. sublobatum for improvement of age-dependent bone destruction disease.

Hepatoprotective activity of total iridoid glycosides isolated from Paederia scandens (lour.) Merr. var. tomentosa.

ETHNOPHARMACOLOGICAL RELEVANCE: Currently, human liver is susceptible to injury caused by alcohol and virus infiltration, resulting in hepatitis, cirrhosis, and even hepatocellular carcinoma. Paederia scandens (Lour.) Merr. var. tomentosa (Rubiaceae) has been used as traditional medicine in Asian countries to treat jaundice, dysentery, and abdominal mass. Furthermore, the abundance of iridoid glycosides in Paederia species indicates their notable hepatoprotective potential. MATERIALS AND METHODS: Total iridoid glycosides (TG) was prepared, and constituents of TG were analyzed by HPLC. TG and silymarin (positive) were orally administered for 15 days. Then, acute liver injury rats was induced by intraperitoneally injection (i.p.) of 10% CCl4 (0.12%, v/v, dissolved in olive oil, 10 mL/kg, body weight). Rats were sacrificed at 16 h after CCl4 injection. Liver tissues and blood were collected. Serum samples were prepared to determine the activities of alanine transaminase (ALT) and aspartate transaminase (AST), whereas liver tissue sections were prepared for the purpose of examining possible liver histopathological changes. In addition, antioxidant enzyme activities in liver tissues were also evaluated. RESULTS: Our results demonstrated that TG significantly decreased the levels of AST and ALT, compared with those in control rats. In addition, pre-treatment of the rats with TG clearly alleviated their liver tissue injuries. What's more, the activities of GSH, GAT and SOD in the groups of TG-treated rats were significantly increased compared with those of rats in the control group, whereas the levels of MDA were decreased. CONCLUSIONS: Our present research indicated that TG possessed notable hepatoprotective activity via decreasing oxidative stress level in liver tissues.

Analgesic effects and possible mechanisms of iridoid glycosides from Lamiophlomis rotata (Benth.) Kudo in rats with spared nerve injury.

ETHNOPHARMACOLOGICAL RELEVANCE: Lamiophlomis rotata (Benth.) Kudo (L. rotata) is a medical plant that has been traditionally used for centuries for the treatment of pain, such as bone and muscle pain, joint pain and dysmenorrhea. Although iridoid glycosides of L. rotata (IGLR) are the major active components of it according to reports, it still remains poorly understood about the molecular mechanisms underlying analgesic effects of IGLR. The aim of the present study was to investigate the analgesic effect of IGLR on a spared nerve injury (SNI) model of neuropathic pain. MATERIALS AND METHODS: The SNI model in rats was established by complete transection of the common peroneal and tibial distal branches of the sciatic nerve, leaving the sural branch intact. Then SNI rats were treated with IGLR for 14 days, using normal saline as the negative control. The paw withdrawal mechanical threshold (PMWT) in response to mechanical stimulation was measured by von Frey filaments on day 1 before operation and on days 1, 3, 5, 7, 9, 11, 13 and 14 after operation, respectively. After 14 days, the levels of nitric oxide (NO), nitric oxide synthase (NOS), tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß), interleukin-10 (IL-10) and cyclic guanosine monophosphate (cGMP) in the spinal dorsal horn were measured by the corresponding kits, mRNA expression of inducible NOS (iNOS) and protein kinase G type I (PKGI) of spinal cord were analyzed by reverse-transcription polymerase chain reaction (RT-PCR). The expression of N-methyl-D-aspartate receptor (NMDAR) and protein kinase C (PKCγ) of the spinal dorsal horn was performed by Western blot. Before all the experiments, motor coordination performance and locomotor activity had been tested. RESULTS: Our results showed that remarkable mechanical allodynia was observed on day 1 after operation in the SNI model, which was accompanied by a decrease in PMWT. Treatment with IGLR (200, 400, 800mg/kg) significantly alleviated SNI-induced mechanical allodynia, markedly decreased the levels of NO, NOS, TNF-α, IL-1ß and cGMP, and increased the level of IL-10. Meanwhile, IGLR (200, 400, 800mg/kg) also inhibited the protein expression of NMDAR, PKCγ and the mRNA expression of iNOS and PKGΙ in the spinal cord. In addition, gavage with the IGLR aqueous extract (800mg/kg) did not signifiantly alter motor coordination or locomotor activity. CONCLUSIONS: These results indicated IGLR could produce an anti-neuropathic pain effect that might partly be related to the inhibition of the NO/cGMP/PKG and NMDAR/PKC pathways and the level of TNF-α, IL-1ß as well as to the increase of the level of IL-10 in spinal cord.

Nyctanthes arbor-tristis positively affects immunopathology of malaria-infected mice prolonging its survival.

In order to search for new products that display antimalarial and immunomodulatory mechanisms that complement direct antiparasitic activity, a set of in vitro and in vivo experiments were designed to evaluate the effect of Nyctanthes arbor-tristis in Plasmodium berghei infected mice. Three extracts of N. arbor-tristis leaves from varying concentrations of alcohol and water were considered for their potential to suppress expression of pro-inflammatory mediators from macrophages primed with lipopolysaccharide. The ethanolic extract, which lowered the pro-inflammatory mediators [tumour necrosis factor (TNF), 13.52-55.83 %; interleukin-6 (IL-6), 0-17.29 %; and NO, 39.37-81.63 %], was selected to be examined in malaria (P. berghei) infected mice. Corroborating the in vitro results, it was observed that the extract could normalise the TNF (78 %) and IL-6 (70.35 %) optimally at 1 g/kg, thus retarding the pathological process in infected mice and increasing the mean survival time from 10.6 to 15.6 days. There were no signs of toxicity in the acute oral toxicity test up to 2 g/kg. (1)H NMR of the biologically active extract was obtained to ensure the presence of the compound of interest, i.e., iridoid glycoside. The quality and the reproducibility of results were ensured by means of achieving characteristic high-performance liquid chromatography fingerprint of the extract.