Fatty acid synthesis suppresses dietary polyunsaturated fatty acid use.

Dietary polyunsaturated fatty acids (PUFA) are increasingly recognized for their health benefits, whereas a high production of endogenous fatty acids - a process called de novo lipogenesis (DNL) - is closely linked to metabolic diseases. Determinants of PUFA incorporation into complex lipids are insufficiently understood and may influence the onset and progression of metabolic diseases. Here we show that fatty acid synthase (FASN), the key enzyme of DNL, critically determines the use of dietary PUFA in mice and humans. Moreover, the combination of FASN inhibition and PUFA-supplementation decreases liver triacylglycerols (TAG) in mice fed with high-fat diet. Mechanistically, FASN inhibition causes higher PUFA uptake via the lysophosphatidylcholine transporter MFSD2A, and a diacylglycerol O-acyltransferase 2 (DGAT2)-dependent incorporation of PUFA into TAG. Overall, the outcome of PUFA supplementation may depend on the degree of endogenous DNL and combining PUFA supplementation and FASN inhibition might be a promising approach to target metabolic disease.

"Corrigendum to Herbs and their bioactive ingredients in cardio-protection: Underlying molecular mechanisms and evidences from clinical studies".

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Herbs and their bioactive ingredients in cardio-protection: Underlying molecular mechanisms and evidences from clinical studies.

BACKGROUND: Medicinal plants or herbs produce a bounty of bioactive phytochemicals. These phytochemicals can influence a variety of physiological events related to cardiovascular health through multiple underlying mechanisms, such as their role as antioxidative, anti-ischemic, anti-proliferative, hypotensive, anti-thrombotic, and anti-hypercholesterolemic agents. PURPOSE: The purpose of this review is to summarize and connect evidences supporting the use of phytotherapy in the management of some of the most common cardiovascular impairments, molecular mechanisms underlying cardio-protection mediated by herbs, and clinical studies which are positively linked with the use of herbs in cardiovascular biology. Additionally, we also describe several adverse effects associated with some of the herbal plants and their products to provide a balanced set of studies in favor or against phytotherapy in cardiovascular health that may help global discourses on this matter. METHODS: Studies relating to the use of medicinal plants were mined by strategically searching scientific databases including Google Scholar, PubMed and Science Direct. Investigations involving approximately 175 articles including reviews, research articles, meta-analyses, and cross-sectional and observational studies were retrieved and analyzed in line with the stated purpose of this study. RESULTS: A positive correlation between the use of medicinal plants and cardiovascular health was observed. While maintaining cardiovascular physiology, medicinal plants and their derivatives seem to govern a variety of cellular mechanisms involved in vasoconstriction and vasorelaxation, which in turn, are important aspects of cardiovascular homeostasis. Furthermore, a variety of studies including clinical trials, cross-sectional studies, and meta-analyses have also supported the anti-hypertensive and thus, cardio-protective effects, of medicinal plants. Apart from this, evidence is also available for the potential drawbacks of several herbs and their products indicating that the unsupervised use of many herbs may lead to severe health issues. CONCLUSIONS: The cardio-protective outcomes of medicinal plants and their derivatives are supported by ever-increasing studies, while evidences exist for the potential drawbacks of some of the herbs. A balanced view about the use of medicinal plants and their derivative in cardiovascular biology thus needs to be outlined by researchers and the medical community. The novelty and exhaustiveness of the present manuscript is reflected by the detailed outline of the molecular basis of "herbal cardio-protection", active involvement of several herbs in ameliorating the cardiovascular status, adverse effects of medicinal plants, and the clinical studies considering the use of phytotherapy, all on a single platform.

Early initiation of prophylactic anticoagulation for prevention of COVID-19 mortality: a nationwide cohort study of hospitalized patients in the United States.

IMPORTANCE: Deaths among patients with coronavirus disease 2019 (COVID-19) are partially attributed to venous thromboembolism and arterial thromboses. Anticoagulants prevent thrombosis formation, possess anti-inflammatory and anti-viral properties, and may be particularly effective for treating patients with COVID-19. OBJECTIVE: To evaluate whether initiation of prophylactic anticoagulation within 24 hours of admission is associated with decreased risk of death among patients hospitalized with COVID-19. DESIGN: Observational cohort study. SETTING: Nationwide cohort of patients receiving care in the Department of Veterans Affairs, the largest integrated healthcare system in the United States. PARTICIPANTS: All patients hospitalized with laboratory-confirmed SARS-CoV-2 infection March 1 to July 31, 2020, without a history of therapeutic anticoagulation. EXPOSURES: Prophylactic doses of subcutaneous heparin, low-molecular-weight heparin, or direct oral anticoagulants. MAIN OUTCOMES AND MEASURES: 30-day mortality. Secondary outcomes: inpatient mortality and initiating therapeutic anticoagulation. RESULTS: Of 4,297 patients hospitalized with COVID-19, 3,627 (84.4%) received prophylactic anticoagulation within 24 hours of admission. More than 99% (n=3,600) received subcutaneous heparin or enoxaparin. We observed 622 deaths within 30 days of admission, 513 among those who received prophylactic anticoagulation. Most deaths (510/622, 82%) occurred during hospitalization. In inverse probability of treatment weighted analyses, cumulative adjusted incidence of mortality at 30 days was 14.3% (95% CI 13.1-15.5) among those receiving prophylactic anticoagulation and 18.7% (95% CI 15.1-22.9) among those who did not. Compared to patients who did not receive prophylactic anticoagulation, those who did had a 27% decreased risk for 30-day mortality (HR 0.73, 95% CI 0.66-0.81). Similar associations were found for inpatient mortality and initiating therapeutic anticoagulation. Quantitative bias analysis demonstrated that results were robust to unmeasured confounding (e-value lower 95% CI 1.77). Results persisted in a number of sensitivity analyses. CONCLUSIONS AND RELEVANCE: Early initiation of prophylactic anticoagulation among patients hospitalized with COVID-19 was associated with a decreased risk of mortality. These findings provide strong real-world evidence to support guidelines recommending the use of prophylactic anticoagulation as initial therapy for COVID-19 patients upon hospital admission.

Functional Imaging of Neurotransmitters in Hymenolepis diminuta Treated with Senna Plant Through Light and Confocal Microscopy.

Previous studies have shown the anthelmintic efficacy of Senna alata, Senna alexandrina and Senna occidentalis on the zoonotic parasite Hymenolepis diminuta through microscopic studies on morphological structure. The present study is based on the light and confocal microscopic studies to understand if Senna extracts affect neurotransmitter activity of the parasites. A standard concentration (40 mg/mL) of the three leaf extracts and one set of 0.005 mg/mL concentration of the reference drug praziquantel were tested against the parasites, keeping another set of parasites in phosphate buffer saline as a control. Histochemical studies were carried out using acetylthiocholine iodide as the substrate and acetylcholinesterase as the marker enzyme for studying the expression of the neurotransmitter of the parasite and the staining intensity was observed under a light microscope. Immunohistochemical studies were carried out using anti serotonin primary antibody and fluorescence tagged secondary antibody and observed using confocal microscopy. Intensity of the stain decreases in treated parasites compared with the control which implies loss of activity of the neurotransmitters. These observations indicated that Senna have a strong anthelmintic effect on the parasite model and thus pose as a potential anthelmintic therapy.

Anthelmintic efficacy of Clerodendrum viscosum on fowl tapeworm Raillietina tetragona.

CONTEXT: Clerodendrum viscosum Vent. (Verbenaceae) is a shrub, widely used amongst the natives of India against various diseases. OBJECTIVE: Crude extract of the plant was tested in vitro on a tapeworm Raillietina tetragona Molin (Davaineidae) to evaluate its potential anthelmintic efficacy and ultrastructural changes in the parasite. MATERIALS AND METHODS: Parasites were exposed to different concentrations of ethanolic leaf extract (10-80 mg/mL) and praziquantel (0.0005-0.005 mg/mL) and incubated in phosphate-buffered saline (PBS). The pH was 7.4 at 37 °C, while one set of worms was incubated only with PBS as a control. Permanent immobilization of worms was determined visually when no motility occurred on physically disturbing them. The parasites exposed to high concentrations of leaf extract and praziquantel treatments were processed for histological and electron microscopic studies, as these concentrations took the least time for paralysis and death to occur. RESULT: With an increase in the concentration of the leaf extract from 10 to 80 mg/mL and praziquantel from 0.0005 to 0.005 mg/mL, the time for the onset of paralysis and death was shortened. The treated parasites lost their spontaneous movement rapidly followed by death. Electron microscopic observations revealed disruptions in the tegument and parenchymal layer, accompanied by deformities in cell organelles. DISCUSSION AND CONCLUSION: Extensive structural alterations in the tegument indicate that the plant-derived components cause permeability changes in the parasite leading to paralysis and subsequent death. These observations suggest that phytochemicals present in C. viscosum have vermifugal or vermicidal activity, and thus may be exploited as alternative chemotherapeutic agents.

Senna leaf extracts induced Ca(+2) homeostasis in a zoonotic tapeworm Hymenolepis diminuta.

Context Plants and plant products have been used in traditional medicine as anthelmintic agents in human and veterinary medicine. Three species of Senna plant, S. alata (L), S. alexandrina (M) and S. occidentalis (L.) Link (Fabaceae) have been shown to have a vermicidal/vermifugal effect on a zoonotic tapeworm Hymenolepis diminuta (Rudolphi) (Cyclophyllidean). Objective The present study validates the mode of action of these Senna plants on the parasite. The alcoholic leaf extract was determined to obtain information on the intracellular free calcium concentration level. Materials and methods Hymenolepis diminuta was maintained in Sprague-Dawley rat model for 2 months. Live parasites collected from infected rat intestine were exposed to 40 mg/mL concentration of each plant extracts prepared in phosphate buffer saline at 37 °C, till parasite gets paralyzed. The rate of efflux of calcium from the parasite tissue to the medium and the level of intracellular Ca(2+ )concentration were determined by an atomic absorption spectroscopy. Results This study revealed that exposure of the worms to the plant extract leads to disruption in intracellular calcium homeostasis. A significant increase (44.6% and 25%) of efflux in Ca(2+ )from the tissue to the incubated medium was observed. Senna alata showed high rate of efflux (5.32 mg/g) followed by S. alexandria and S. occidentalis (both 4.6 mg/g) compared with control (3.68 mg/g). Discussion and conclusion These results suggest that leaf extracts caused membrane permeability to Ca(2+ )after vacuolization of the tegument under stress and the extracts may contain compound that can be used as a chemotherapeutic agent.

Purification and biophysical characterization of an 11S globulin from Wrightia tinctoria exhibiting hemagglutinating activity.

Wrightia tinctoria globulin (WTG), one of the major seed storage proteins, was isolated for the first time from seeds of the medicinal plant. WTG was extracted and purified to homogeneity in two steps using anion-exchange and size-exclusion chromatographies. On an SDS-PAGE gel under non-reducing conditions, a major band of ~56 kDa was observed; under reducing conditions, however, two major polypeptides, one with molecular weight ~32-34 kDa and the other with molecular weight ~22-26 kDa were observed. Intact mass determination by MALDI-TOF supported this observation. The N-terminal amino acid sequence of WTG matched in NCBI database with an expressed sequence tag obtained from the c-DNA of developing embryo m-RNA of Wrightia tinctoria. The EST sequence was further substantiated by partial de novo internal sequencing using MALDI-TOF/TOF. The high sequence homology with seed storage protein 11S globulin confirmed that WTG is a type of 11S globulin. Circular dichroism analysis showed that the secondary structure of WTG consists predominantly of ß-sheets (44.2%) and moderate content of α-helices (10.3%). WTG showed hemagglutinating property indicating that the protein may possess lectin-like activity. WTG was crystallized at 20 Å°C by the vapour diffusion method using PEG 400 as precipitant. The crystals belonged to the orthorhombic space group P212121 with cell dimensions of a=109.9Å, b=113.2Å and c=202.2Å with six molecules per asymmetric unit. Diffraction data were collected to a resolution of 2.2Å under cryocondition. Preliminary structure solution of WTG indicated the possibility of a hexameric assembly in its asymmetric unit.

Metabolic products of soluble epoxide hydrolase are essential for monocyte chemotaxis to MCP-1 in vitro and in vivo.

Monocyte chemoattractant protein-1 (MCP-1)-induced monocyte chemotaxis is a major event in inflammatory disease. Our prior studies have demonstrated that MCP-1-dependent chemotaxis requires release of arachidonic acid (AA) by activated cytosolic phospholipase A(2) (cPLA(2)). Here we investigated the involvement of AA metabolites in chemotaxis. Neither cyclooxygenase nor lipoxygenase pathways were required, whereas pharmacologic inhibitors of both the cytochrome-P450 (CYP) and the soluble epoxide hydrolase (sEH) pathways blocked monocyte chemotaxis to MCP-1. To verify specificity, we demonstrated that the CYP and sEH products epoxyeiscosatrienoic acids (EETs) and dihydroxyeicosatrienoic acids (DHETs), respectively, restored chemotaxis in the presence of the inhibitors, indicating that sEH-derived products are essential for MCP-1-driven chemotaxis. Importantly, DHETs also rescued chemotaxis in cPLA(2)-deficient monocytes and monocytes with blocked Erk1/2 activity, because Erk controls cPLA(2) activation. The in vitro findings regarding the involvement of CYP/sEH pathways were further validated in vivo using two complementary approaches measuring MCP-1-dependent chemotaxis in mice. These observations reveal the importance of sEH in MCP-1-regulated monocyte chemotaxis and may explain the observed therapeutic value of sEH inhibitors in treatment of inflammatory diseases, cardiovascular diseases, pain, and even carcinogenesis. Their effectiveness, often attributed to increasing EET levels, is probably influenced by the impairment of DHET formation and inhibition of chemotaxis.

Cassia alata L: potential role as anthelmintic agent against Hymenolepis diminuta.

The efficacy of Cassia alata against cestode Hymenolepis diminuta was evaluated in our study. Worms were maintained between rat model and beetle. Air-dried leaves of C. alata were subjected to ethanol extraction. Different concentrations (10-80 mg/ml) of the extract were prepared in phosphate buffer saline and tested on the parasite in vitro. Parasites treated with C. alata showed a decrease in motility with an increase in concentrations and complete immobilization took lesser time compared to control. The paralyzed parasites were further processed for electron microscopic studies. Ultrastructural micrographs revealed swelling of the tegument and blebbing on the tegumental surface throughout the body accompanied with destruction of microtriches and changes such as shrinkage in the scolex region. Depletion of parenchyma cells and destruction in the connective tissues along with sparsely cytoplasmic cytons were also observed, and these observations are similar with worms treated with a known drug praziquantel. These results may suggest that the plant leaves could be considered for controlling helminth infection and can represent a step forward in the search for alternative anthelmintic drug.

Regional fractionation and dominant frequency in persistent atrial fibrillation: effects of left atrial ablation and evidence of spatial relationship.

AIMS: The aim was to study regional fractionation and dominant frequency (DF) to determine if any relationship exists between the two parameters and also to assess the impact of limited left atrial ablation. METHODS AND RESULTS: Patients undergoing catheter ablation of persistent AF using three-dimensional navigation were studied. Regional left atrial electrograms were analysed in the frequency domain by assessing DF and organization index (OI), and for degree of fractionation [using complex fractionated electrograms (CFE)-mean] before and after circumferential pulmonary vein and left atrial roof ablation. Twenty-three patients with persistent AF were studied. After ablation, global CFE-mean increased [100 ± 5 to 147 ± 11 ms (P= 0.0003)], DF decreased [6.1 ± 0.2 to 5.3 ± 0.2 Hz (P= 0.0003)], and OI was unchanged [0.27 ± 0.01 to 0.26 ± 0.02, (P= 0.70)]. Comparing sites close to and distant from ablation lines, percentage change in CFE-mean was 94 ± 10 vs. 37 ± 6% (P< 0.0001), DF change was -13 ± 3 vs.-12 ± 2% (P= 0.98), and OI change was 3 ± 6 vs. 10 ± 5% (P= 0.75), respectively. There was modest correlation between CFE-mean and DF points prior to ablation (r = -0.33, P< 0.0001) which was reduced following left atrial ablation (r = -0.24, P= 0.005). CONCLUSIONS: Left atrial ablation reduces global left atrial DF and decreases the degree of fractionation. Complex fractionated electrograms-mean and DF appear to share only modest spatial correlation and are affected to different extents by ablation, suggesting that they are either separate entities or reflect different components of the same substrate.

Increase in organization index predicts atrial fibrillation termination with flecainide post-ablation: spectral analysis of intracardiac electrograms.

AIMS: The mechanism of the action of flecainide in the termination of human atrial fibrillation (AF) is not fully understood. We studied the acute effects of flecainide on AF electrograms in the time and frequency domain to identify factors associated with AF termination. METHODS AND RESULTS: Patients who were still in AF at the end of catheter ablation for AF were given intravenous flecainide. Dominant frequency (DF) and organization index (OI) were obtained by fast Fourier transform of electrograms from the coronary sinus catheter over 10 s in AF, before and after flecainide infusion. Mean AF cycle length (CL) was also calculated. Twenty-six patients were studied (16 paroxysmal AF and 10 persistent AF). Seven converted to sinus rhythm (SR) with flecainide. In all patients, mean CL increased from 211 +/- 44 to 321 +/- 85 ms (P < 0.001). Mean DF decreased from 5.2 +/- 1.03 to 3.6 +/- 1.04 Hz (P < 0.001). Mean OI was 0.33 +/- 0.13 before and 0.32 +/- 0.11 after flecainide (P = 0.90). Comparing patients who converted to SR with those who did not, OI post-flecainide was 0.41 +/- 0.12 vs. 0.29 +/- 0.10 (P = 0.013), and the relative change in OI was 29 +/- 33 vs. -3.9 +/- 27% (P = 0.016), respectively. No significant difference was noted in the change in CL and DF in the two groups. CONCLUSION: Increase in OI, independent of changes to CL and DF, appears critical to AF termination with flecainide. Increase in OI holds promise as a sensitive predictor of AF termination.

Proposed amino acid sequence and the 1.63 A X-ray crystal structure of a plant cysteine protease, ervatamin B: some insights into the structural basis of its stability and substrate specificity.

The crystal structure of a cysteine protease ervatamin B, isolated from the medicinal plant Ervatamia coronaria, has been determined at 1.63 A. The unknown primary structure of the enzyme could also be traced from the high-quality electron density map. The final refined model, consisting of 215 amino acid residues, 208 water molecules, and a thiosulfate ligand molecule, has a crystallographic R-factor of 15.9% and a free R-factor of 18.2% for F > 2sigma(F). The protein belongs to the papain superfamily of cysteine proteases and has some unique properties compared to other members of the family. Though the overall fold of the structure, comprising two domains, is similar to the others, a few natural substitutions of conserved amino acid residues at the interdomain cleft of ervatamin B are expected to increase the stability of the protein. The substitution of a lysine residue by an arginine (residue 177) in this region of the protein may be important, because Lys --> Arg substitution is reported to increase the stability of proteins. Another substitution in this cleft region that helps to hold the domains together through hydrogen bonds is Ser36, replacing a conserved glycine residue in the others. There are also some substitutions in and around the active site cleft. Residues Tyr67, Pro68, Val157, and Ser205 in papain are replaced by Trp67, Met68, Gln156, and Leu208, respectively, in ervatamin B, which reduces the volume of the S2 subsite to almost one-fourth that of papain, and this in turn alters the substrate specificity of the enzyme.