Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 111
Filter
1.
Am J Kidney Dis ; 83(1): 58-70, 2024 Jan.
Article in English | MEDLINE | ID: mdl-37690631

ABSTRACT

RATIONALE & OBJECTIVE: Optimal approaches to treat secondary hyperparathyroidism (SHPT) in patients on maintenance hemodialysis (HD) have yet to be established in randomized controlled trials (RCTs). STUDY DESIGN: Two observational clinical trial emulations. SETTING & PARTICIPANTS: Both emulations included adults receiving in-center HD from a national dialysis organization. The patients who had SHPT in the period between 2009 and 2014, were insured for≥180 days by Medicare as primary payer, and did not have contraindications or poor health status limiting theoretical trial participation. EXPOSURE: The parathyroid hormone (PTH) Target Trial emulation included patients with new-onset SHPT (first PTH 300-600pg/mL), with 2 arms defined as up-titration of either vitamin D sterols or cinacalcet within 30 days (lower target) or no up-titration (higher target). The Agent Trial emulation included patients with a PTH≥300 pg/mL while on≥6µg weekly of vitamin D sterol (paricalcitol equivalent dose) and no prior history of cinacalcet. The 2 arms were defined by the first dose or agent change within 30 days (vitamin D-favoring [vitamin-D was up-titrated] vs cinacalcet-favoring [cinacalcet was added] vs nondefined [neither applies]). Multiple trials per patient were allowed in trial 2. OUTCOME: The primary outcome was all-cause death over 24 months; secondary outcomes included cardiovascular (CV) hospitalization or the composite of CV hospitalization or death. ANALYTICAL APPROACH: Pooled logistic regression. RESULTS: There were 1,152 patients in the PTH Target Trial (635 lower target and 517 higher target). There were 2,726 unique patients with 6,727 patient trials in the Agent Trial (6,268 vitamin D-favoring trials and 459 cinacalcet-favoring trials). The lower PTH target approach was associated with reduced adjusted hazard of death (HR, 0.71 [95% CI, 0.52-0.93]), CV hospitalization (HR, 0.78 [95% CI, 0.63-0.98]), and their composite (HR, 0.74 [95% CI, 0.61-0.89]). The cinacalcet-favoring approach demonstrated lower adjusted hazard of death compared to the vitamin D-favoring approach (HR, 0.79 [95% CI, 0.62-0.99]), but not of CV hospitalization or the composite outcome. LIMITATIONS: Potential for residual confounding; low use of cinacalcet with low power. CONCLUSIONS: SHPT management that is focused on lower PTH targets may lower mortality and CV disease in patients receiving HD. These findings should be confirmed in a pragmatic randomized trial. PLAIN-LANGUAGE SUMMARY: Optimal approaches to treat secondary hyperparathyroidism (SHPT) have not been established in randomized controlled trials. Data from a national dialysis organization was used to identify patients with SHPT in whom escalated treatment may be indicated. The approach to treatment was defined based on observed upward titration of SHPT-controlling medications: earlier titration (lower target) versus delayed titration (higher target); and the choice of medication (cinacalcet vs vitamin D sterols). In the first trial emulation, we estimated a 29% lower rate of death and 26% lower rate of cardiovascular disease or death for patients managed with a lower versus higher target approach. Cinacalcet versus vitamin D-favoring approaches were not consistently associated with outcomes in the second trial emulation. This observational study suggests the need for additional clinical trials of SHPT treatment intensity.


Subject(s)
Cardiovascular Diseases , Hyperparathyroidism, Secondary , Adult , Humans , Cinacalcet/therapeutic use , Naphthalenes/therapeutic use , Treatment Outcome , Hyperparathyroidism, Secondary/drug therapy , Hyperparathyroidism, Secondary/etiology , Vitamin D/therapeutic use , Renal Dialysis/adverse effects , Vitamins/therapeutic use , Parathyroid Hormone , Sterols/therapeutic use , Cardiovascular Diseases/etiology
2.
Cell Chem Biol ; 30(5): 553-568.e7, 2023 05 18.
Article in English | MEDLINE | ID: mdl-37160123

ABSTRACT

Filamentation is an important virulence factor of the pathogenic fungus Candida albicans. The abolition of Candida albicans hyphal formation by disrupting sterol synthesis is an important concept for the development of antifungal drugs with high safety. Here, we conduct a high-throughput screen using a C. albicans strain expressing green fluorescent protein-labeled Dpp3 to identify anti-hypha agents by interfering with ergosterol synthesis. The antipyrine derivative H55 is characterized to have minimal cytotoxicity and potent inhibition of C. albicans hyphal formation in multiple cultural conditions. H55 monotherapy exhibits therapeutic efficacy in mouse models of azole-resistant candidiasis. H55 treatment increases the accumulation of zymosterol, the substrate of C-24 sterol methyltransferase (Erg6). The results of enzyme assays, photoaffinity labeling, molecular simulation, mutagenesis, and cellular thermal shift assays support H55 as an allosteric inhibitor of Erg6. Collectively, H55, an inhibitor of the fungal-specific enzyme Erg6, holds potential to treat C. albicans infections.


Subject(s)
Candida albicans , Candidiasis , Animals , Mice , Sterols/therapeutic use , Methyltransferases , Candidiasis/drug therapy , Antifungal Agents/pharmacology , Antifungal Agents/therapeutic use
3.
OMICS ; 26(12): 671-682, 2022 12.
Article in English | MEDLINE | ID: mdl-36508280

ABSTRACT

Genome-scale metabolic modeling (GEM) is one of the key approaches to unpack cancer metabolism and for discovery of new drug targets. In this study, we report the Transcriptional Regulated Flux Balance Analysis-CORE (TRFBA-), an algorithm for GEM using key growth-correlated reactions using hepatocellular carcinoma (HCC), an important global health burden, as a case study. We generated a HepG2 cell-specific GEM by integrating this cell line transcriptomic data with a generic human metabolic model to forecast potential drug targets for HCC. A total of 108 essential genes for growth were predicted by the TRFBA-CORE. These genes were enriched for metabolic pathways involved in cholesterol, sterol, and steroid biosynthesis. Furthermore, we silenced a predicted essential gene, 11-beta dehydrogenase hydroxysteroid type 2 (HSD11B2), in HepG2 cells resulting in a reduction in cell viability. To further identify novel potential drug targets in HCC, we examined the effect of nine drugs targeting the essential genes, and observed that most drugs inhibited the growth of HepG2 cells. Some of these drugs in this model performed better than Sorafenib, the first-line therapeutic against HCC. A HepG2 cell-specific GEM highlights sterol metabolism to be essential for cell growth. HSD11B2 downregulation results in lower cell growth. Most of the compounds, selected by drug repurposing approach, show a significant inhibitory effect on cell growth in a wide range of concentrations. These findings offer new molecular leads for drug discovery for hepatic cancer while also illustrating the importance of GEM and drug repurposing in cancer therapeutics innovation.


Subject(s)
Carcinoma, Hepatocellular , Liver Neoplasms , Humans , Carcinoma, Hepatocellular/drug therapy , Carcinoma, Hepatocellular/genetics , Carcinoma, Hepatocellular/metabolism , Liver Neoplasms/drug therapy , Liver Neoplasms/genetics , Liver Neoplasms/metabolism , Sorafenib/pharmacology , Sorafenib/therapeutic use , Hep G2 Cells , Cell Proliferation/genetics , Cell Line, Tumor , Sterols/pharmacology , Sterols/therapeutic use
4.
BMC Res Notes ; 15(1): 315, 2022 Oct 03.
Article in English | MEDLINE | ID: mdl-36192786

ABSTRACT

OBJECTIVE: Non-alcoholic steatohepatitis (NASH) has become a global medical problem. Currently, there is no approved pharmacologic treatment for this condition. Previous studies have suggested that in the pathogenesis of this disease, regulatory pathways associated with de novo lipogenesis and ß-oxidation pathways genes are misregulated. Capparis spinosa (CS) belongs to the family of Capparidaceae and is a traditional plant used to treat various diseases, particularly dyslipidemia. The compounds and extracts of this plant in In vivo and in vitro studies resulted in a reduction in lipid profiles and glucose. However, the mechanism of these effects remains unknown. This study aimed to evaluate the effects of (CS) fruit extract on NASH compared to fenofibrate and explored the related molecular mechanism. RESULTS: In the rats (n = 40) model of NASH, biochemical and histopathological examinations showed that liver steatosis, inflammation, and hepatic fibrosis were markedly attenuated in response to CS and fenofibrate interventions. At the molecular level, CS treatment down-regulated sterol regulatory element-binding protein-1c (SREBP-1c) (p < 0.001), acetyl-CoA carboxylase (ACC) (p < 0.001), and up-regulated Carnitine palmitoyltransferase I (CPT1) expression (p < 0.001). In conclusion, CS has favorable therapeutic effects for NASH, which was associated with ameliorating steatosis and fibrosis via regulation of the DNL and ß-oxidation pathway genes.


Subject(s)
Capparis , Fenofibrate , Non-alcoholic Fatty Liver Disease , Acetyl-CoA Carboxylase/metabolism , Acetyl-CoA Carboxylase/pharmacology , Animals , Capparis/metabolism , Carnitine O-Palmitoyltransferase/genetics , Carnitine O-Palmitoyltransferase/metabolism , Carnitine O-Palmitoyltransferase/pharmacology , Diet, High-Fat/adverse effects , Fenofibrate/metabolism , Fenofibrate/pharmacology , Fenofibrate/therapeutic use , Glucose/metabolism , Lipids/pharmacology , Liver/metabolism , Non-alcoholic Fatty Liver Disease/drug therapy , PPAR alpha/genetics , PPAR alpha/metabolism , PPAR alpha/pharmacology , Rats , Sterol Regulatory Element Binding Protein 1/genetics , Sterol Regulatory Element Binding Protein 1/metabolism , Sterol Regulatory Element Binding Protein 1/pharmacology , Sterols/metabolism , Sterols/pharmacology , Sterols/therapeutic use
5.
Antiviral Res ; 207: 105401, 2022 11.
Article in English | MEDLINE | ID: mdl-36049554

ABSTRACT

Crimean-Congo hemorrhagic fever (CCHF) is a medically relevant tick-borne viral disease caused by the Bunyavirus, Crimean-Congo hemorrhagic fever virus (CCHFV). CCHFV is endemic to Asia, the Middle East, South-eastern Europe, and Africa and is transmitted in enzootic cycles among ticks, mammals, and birds. Human infections are mostly subclinical or limited to mild febrile illness. Severe disease may develop, resulting in multi-organ failure, hemorrhagic manifestations, and case-fatality rates up to 30%. Despite the widespread distribution and life-threatening potential, no treatments have been approved for CCHF. Antiviral inhibitory peptides, which antagonize viral entry, are licensed for clinical use in certain viral infections and have been experimentally designed against human pathogenic bunyaviruses, with in vitro and in vivo efficacies. We designed inhibitory peptides against CCHFV with and without conjugation to various polyethylene glycol and sterol groups. These additions have been shown to enhance both cellular uptake and antiviral activity. Peptides were evaluated against pseudotyped and wild-type CCHFV via neutralization tests, Nairovirus fusion assays, and cytotoxicity profiling. Four peptides neutralized CCHFV with two of these peptides shown to inhibit viral fusion. This work represents the development of experimental countermeasures for CCHF, describes a nairovirus immunofluorescence fusion assay, and illustrates the utility of pseudotyped CCHFV for the screening of entry antagonists at low containment settings for CCHF.


Subject(s)
Hemorrhagic Fever Virus, Crimean-Congo , Hemorrhagic Fever, Crimean , Orthobunyavirus , Animals , Antiviral Agents/pharmacology , Antiviral Agents/therapeutic use , Hemorrhagic Fever, Crimean/epidemiology , Humans , Mammals , Peptides/pharmacology , Peptides/therapeutic use , Polyethylene Glycols/therapeutic use , Sterols/therapeutic use
6.
Eur J Prev Cardiol ; 29(13): 1731-1739, 2022 10 18.
Article in English | MEDLINE | ID: mdl-35512252

ABSTRACT

AIMS: Statin treatment did not reduce the risk of cardiovascular events in haemodialysis patients in the 4D and AURORA trials. Post hoc analyses in the 4D study suggested that high cholesterol absorption was associated with increased cardiovascular risk and that atorvastatin would reduce cardiovascular risk in haemodialysis patients with low cholesterol absorption but not in those with high cholesterol absorption. METHODS AND RESULTS: AURORA is a randomized, double-blind, placebo-controlled, multi-centre trial in haemodialysis patients. The participants were randomly assigned to receive either rosuvastatin, 10 mg daily, or a matching placebo. There was a follow-up for cardiovascular death with a median duration of 3.9 years. The cholestanol and lathosterol to cholesterol ratios were used to estimate cholesterol absorption and synthesis, respectively. Measurement of non-cholesterol sterols was available in 2332 participants of the 2733 patients included in the primary analysis of the AURORA study. A total of 598 participants died from cardiovascular diseases. The 3rd vs. the 1st tertile of the cholestanol-to-cholesterol ratio was significantly associated with increased risk of cardiovascular death [hazard ratio, HR (95% confidence interval, CI) = 1.36 (1.11-1.65)] in univariate (P = 0.002) and multivariate models (P = 0.034). In contrast, the 3rd vs. the 1st tertile of the lathosterol-to-cholesterol ratio was significantly associated with decreased risk of cardiovascular death [HR (95% CI) = 0.81 (0.67-0.99)] in univariate (P = 0.041) and multivariate (P = 0.019) models. There was no significant interaction between the cholestanol and lathosterol to cholesterol tertiles and treatment group in predicting cardiovascular death. CONCLUSION: The present data from the AURORA study confirm that high cholesterol absorption is associated with increased cardiovascular risk in haemodialysis patients. Assessment of the individual cholesterol absorption rate to guide initiation of statin treatment is not supported by the findings in the AURORA study.


Subject(s)
Cardiovascular Diseases , Hydroxymethylglutaryl-CoA Reductase Inhibitors , Hypercholesterolemia , Hyperlipidemias , Humans , Hydroxymethylglutaryl-CoA Reductase Inhibitors/therapeutic use , Cardiovascular Diseases/diagnosis , Cardiovascular Diseases/epidemiology , Cardiovascular Diseases/prevention & control , Atorvastatin/therapeutic use , Rosuvastatin Calcium/adverse effects , Risk Factors , Hypercholesterolemia/drug therapy , Cholestanol , Renal Dialysis/adverse effects , Hyperlipidemias/drug therapy , Sterols/therapeutic use , Heart Disease Risk Factors
7.
Clin Nephrol ; 98(1): 17-25, 2022 Jul.
Article in English | MEDLINE | ID: mdl-35200136

ABSTRACT

BACKGROUND: Abnormalities related to mineral and bone metabolism are a common finding in chronic kidney disease (CKD). Vitamin D compounds are often prescribed to CKD patients with the purpose to control secondary hyperparathyroidism and reduce the risk of high-turnover bone disease. However, data on the effect of vitamin D sterols on bone histology in non-dialysis CKD is limited. MATERIALS AND METHODS: A prospective controlled study was conducted on a cohort of 56 patients with CKD stages 3 and 4. 19 patients on calcitriol and 12 patients on cholecalciferol were compared to a group of 25 age- and sex-matched controls. Participants underwent a tetracycline double-labelled transiliac bone biopsy before starting therapy and again 12 months later. Changes from baseline in circulating biomarkers and bone histomorphometric parameters were analyzed. RESULTS: Low-turnover bone disease was the most common pattern of renal osteodystrophy on the initial biopsy. There was no difference in biochemical or histomorphometric values between the three study groups at baseline. Serum intact parathormone (iPTH) and bone formation rate decreased significantly in calcitriol-treated patients, with prevalence of low-turnover bone disease doubling from baseline. In contrast, no significant changes were noted in cholecalciferol-treated and control subjects. CONCLUSION: Calcitriol was effective in preventing secondary hyperparathyroidism and high-turnover bone disease. However, it was associated with an increased risk of developing or aggravating low-turnover bone disease. In the absence of a bone biopsy, calcitriol use in pre-dialysis CKD should be reserved for patients with a progressive rise in iPTH levels, in whom high-turnover bone disease is suspected.


Subject(s)
Chronic Kidney Disease-Mineral and Bone Disorder , Hyperparathyroidism, Secondary , Renal Insufficiency, Chronic , Vitamin D , Calcitriol , Cholecalciferol , Chronic Kidney Disease-Mineral and Bone Disorder/drug therapy , Chronic Kidney Disease-Mineral and Bone Disorder/etiology , Dialysis/adverse effects , Humans , Hyperparathyroidism, Secondary/drug therapy , Hyperparathyroidism, Secondary/etiology , Hyperparathyroidism, Secondary/prevention & control , Parathyroid Hormone , Prospective Studies , Renal Dialysis/adverse effects , Renal Insufficiency, Chronic/complications , Renal Insufficiency, Chronic/therapy , Sterols/therapeutic use , Vitamin D/therapeutic use , Vitamins
8.
Hum Exp Toxicol ; 41: 9603271211069034, 2022.
Article in English | MEDLINE | ID: mdl-35128947

ABSTRACT

Background: Taraxasterol (TX), a pentacyclic triterpene, is one of the main active constituents isolated from Taraxacum officinale. A growing number of studies have reported that TX exhibits a wide range of biological activities such as anti-oxidative, anti-inflammatory, and neuro-protective effects. Recently, TX has been demonstrated to be a potential drug candidate for treatment of some types of cancers. However, the specific role of TX in melanoma remains unclear.Purpose: In this study, we aimed at exploration of the effect of TX on melanoma cell viability, apoptosis, migration, invasion, and epithelial-mesenchymal transition (EMT) as well as the underlying mechanisms.Research design: A375 and SK-MEL-28 cells were treated with various concentrations of TX for different times. Cell viability was measured using CCK-8 assay. Cell apoptosis was determined by flow cytometry. Transwell assays were performed to measure cell migration and invasion. The expression of E-cadherin, α-catenin, N-cadherin, vimentin, p-PI3K, PI3K, p-Akt and Akt was detected using western blot.Results: The study showed that TX induced A375 and SK-MEL-28 cell apoptosis. Furthermore, exposure to TX inhibited A375 and SK-MEL-28 cell migration and invasion. Besides, the EMT process was reversed in A375 and SK-MEL-28 cells after TX treatment. We also observed that TX reduced the protein expression of p-PI3K and p-Akt; thus, inhibiting activity of the PI3K/Akt pathway in A375 and SK-MEL-28 cells. In addition, TX treatment increased the levels of reactive oxygen species (ROS) in A375 and SK-MEL-28 cells, and treatment with the ROS scavenger NAC significantly rescued TX-induced down-regulation of p-PI3K and p-Akt in A375 and SK-MEL-28 cells.Conclusions: In conclusion, our study demonstrated that TX induced ROS accumulation followed by inactivation of the PI3K/Akt pathway and subsequently attenuated melanoma progression, suggesting that TX may be a potential candidate for treatment of melanoma.


Subject(s)
Antineoplastic Agents/therapeutic use , Cell Proliferation/drug effects , Melanoma/drug therapy , Reactive Oxygen Species/metabolism , Signal Transduction/drug effects , Sterols/therapeutic use , Triterpenes/therapeutic use , Cell Line, Tumor/drug effects , Gene Expression Regulation, Neoplastic , Humans , Phosphatidylinositol 3-Kinases/drug effects , Proto-Oncogene Proteins c-akt/drug effects
9.
Int Immunopharmacol ; 102: 108380, 2022 Jan.
Article in English | MEDLINE | ID: mdl-34848154

ABSTRACT

Discovery of anti-inflammatory drugs that can suppress T lymphocyte activation and proliferation by inhibiting TCR/CD3 and IL-2/IL-2R signaling is still needed in clinic, though rapamycin and other related reagents have made great success. Taraxasterol (TAS) is an active ingredient of dandelion, an anti-inflammatory medicinal herb with low in vivo toxicity that has long been used in China. Yet the action mechanism of TAS on lymphocytes remains elusive. The anti-inflammatory effects of TAS were evaluated in C57BL/6 mouse primary lymphocytes stimulated with concanavalin A (Con A) in vitro and in mouse model of Con A-induced acute hepatitis in vivo. Our results showed that TAS significantly suppressed Con A-induced acute hepatitis in a mouse model, reducing the hepatic necrosis areas, the release of aminotransferases, and the production of IL-2 and other inflammatory cytokines. Supporting this, in vitro study also showed that TAS reduced the production of IL-2 and the expression of IL-2 receptor subunit α (CD25) upon the stimulation of Con A, which was likely mediated by suppressing NF-κB activation. The downstream pathways of IL-2/IL-2R signaling, including the activation of PI3K/PDK1/mTOR, STAT3 and STAT5, were also suppressed by TAS. Consistently, Con A-induced T cell proliferation was also inhibited by TAS in vitro. Our data indicate that TAS can suppress both T lymphocyte activation and cell proliferation by down-regulating IL-2 expression and its signaling pathway thereby ameliorating Con A-induced acute hepatitis, highlighting TAS as a potential drug candidate for treating inflammatory diseases including autoimmune hepatitis.


Subject(s)
Anti-Inflammatory Agents/therapeutic use , Chemical and Drug Induced Liver Injury/drug therapy , Interleukin-2/immunology , Sterols/therapeutic use , T-Lymphocytes/drug effects , Triterpenes/therapeutic use , Animals , Anti-Inflammatory Agents/pharmacology , Cell Proliferation/drug effects , Chemical and Drug Induced Liver Injury/blood , Chemical and Drug Induced Liver Injury/immunology , Chemical and Drug Induced Liver Injury/pathology , Concanavalin A , Cytokines/blood , Female , Liver/drug effects , Liver/immunology , Liver/pathology , Mice, Inbred C57BL , Signal Transduction/drug effects , Sterols/pharmacology , T-Lymphocytes/immunology , Triterpenes/pharmacology
10.
Front Immunol ; 12: 632606, 2021.
Article in English | MEDLINE | ID: mdl-33679781

ABSTRACT

Taraxasterol (TAS) is an active ingredient of Dandelion (Taraxacum mongolicum Hand. -Mazz.), a medicinal plant that has long been used in China for treatment of inflammatory disorders. But the underlying mechanism for its therapeutic effects on inflammatory disorders is not completely clear. Inflammasome activation is a critical step of innate immune response to infection and aseptic inflammation. Among the various types of inflammasome sensors that has been reported, NLR family pyrin domain containing 3 (NLRP3) is implicated in various inflammatory diseases and therefore has been most extensively studied. In this study, we aimed to explore whether TAS could influence NLPR3 inflammasome activation in macrophages. The results showed that TAS dose-dependently suppressed the activation of caspase-1 in lipopolysaccharide (LPS)-primed murine primary macrophages upon nigericin treatment, resulting in reduced mature interleukin-1ß (IL-1ß) release and gasdermin D (GSDMD) cleavage. TAS greatly reduced ASC speck formation upon the stimulation of nigericin or extracellular ATP. Consistent with reduced cleavage of GSDMD, nigericin-induced pyroptosis was alleviated by TAS. Interestingly, TAS time-dependently suppressed the mechanistic target of rapamycin (mTOR) complex 1 (mTORC1) and mTORC2 signaling induced by LPS priming. Like TAS, both INK-128 (inhibiting both mTORC1 and mTORC2) and rapamycin (inhibiting mTORC1 only) also inhibited NLRP3 inflammasome activation, though their effects on mTOR signaling were different. Moreover, TAS treatment alleviated mitochondrial damage by nigericin and improved mouse survival from bacterial infection, accompanied by reduced IL-1ß levels in vivo. Collectively, by inhibiting the NLRP3 inflammasome activation, TAS displayed anti-inflammatory effects likely through regulation of the mTOR signaling in macrophages, highlighting a potential action mechanism for the anti-inflammatory activity of Dandelion in treating inflammation-related disorders, which warrants further clinical investigation.


Subject(s)
Inflammasomes/drug effects , Macrophages/drug effects , NLR Family, Pyrin Domain-Containing 3 Protein/metabolism , Pyroptosis/drug effects , Signal Transduction/drug effects , Sterols/pharmacology , TOR Serine-Threonine Kinases/metabolism , Triterpenes/pharmacology , Animals , Anti-Inflammatory Agents/pharmacology , Bacterial Infections/drug therapy , CARD Signaling Adaptor Proteins/metabolism , Inflammasomes/metabolism , Lipopolysaccharides/pharmacology , Macrophages/metabolism , Macrophages/pathology , Mice , Mitochondria/drug effects , Mitochondria/pathology , Nigericin/pharmacology , Sterols/therapeutic use , Survival Analysis , Triterpenes/therapeutic use
11.
Int J Biol Macromol ; 171: 398-413, 2021 Feb 28.
Article in English | MEDLINE | ID: mdl-33422516

ABSTRACT

Diatoms are ubiquitous, biologically widespread, and have global significance due to their unique silica cell wall composition and noteworthy applied aspects. Diatoms are being extensively exploited for environmental monitoring, reconstruction, and stratigraphic correlation. However, considering all the rich elements of diatoms biology, the current literature lacks sufficient information on the therapeutic attributes and applied aspects of biological macromolecules from diatoms, hampering added advances in all aspects of diatom biology. Diatoms offer numerous high-value compounds, such as fatty acids, polysaccharides, polypeptides, pigments, and polyphenols. Diatoms with a high content of PUFA's are targets of transformation into high-value products through microalgal technologies due to their wide application and growing market as nutraceuticals and food supplements. Diatoms are renewable biomaterial, which can be used to develop drug delivery systems due to biocompatibility, surface area, cost-effective ratio, and ease in surface modifications. Innovative approaches are needed to envisage cost-effective ways for the isolation of bioactive compounds, enhance productivity, and elucidate the detailed mechanism of action. This review spotlights the notable applications of diatoms and their biologically active constituents, such as fucoxanthin and omega 3 fatty acids, among others with unique structural and functional entities.


Subject(s)
Diatoms/chemistry , Macromolecular Substances/therapeutic use , Dietary Supplements , Drug Delivery Systems , Fatty Acids/isolation & purification , Fatty Acids/therapeutic use , Humans , Macromolecular Substances/economics , Macromolecular Substances/isolation & purification , Peptides/isolation & purification , Peptides/therapeutic use , Polyphenols/isolation & purification , Polyphenols/therapeutic use , Polysaccharides/isolation & purification , Polysaccharides/therapeutic use , Protective Agents/therapeutic use , Sterols/isolation & purification , Sterols/therapeutic use , Xanthophylls/isolation & purification , Xanthophylls/therapeutic use
12.
Int Immunopharmacol ; 88: 106990, 2020 Nov.
Article in English | MEDLINE | ID: mdl-33182051

ABSTRACT

Acute lung injury (ALI)/acute respiratory distress syndrome (ARDS) is a serious respiratory disease, the mechanism is unclear. This paper revealed the mechanism of ganoderic acid B (BB) on lipopolysaccharide-induced pneumonia in mice. Pneumonia model was induced by LPS in mice and A549 cells. Lung dry/wet weight (W/D) and myeloperoxidase (MPO) activity in lung were examined. Lung histopathological changes was observed by HE staining. Superoxide dismutase (SOD), malondialdehyde (MDA) and proinflammatory cytokines, including tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß) and interleukin-6 (IL-6) in mice and A549 cells were detected. Rho/NF-κB pathway in mice and A549 cells were examined by Western Blot. BB significantly reduced W/D and MPO activity, restored lung histopathological changes. BB also increased SOD, decreased MDA, TNF-α, IL-1ß and IL-6 in mice and A549 cells. In addition, BB inhibited Rho/NF-κB pathway in mice and A549 cells. BB has protective effect on LPS-induced pneumonia in mice, and its mechanism is related to the regulation of Rho/NF-κB signaling pathway.


Subject(s)
Acute Lung Injury/chemically induced , Acute Lung Injury/drug therapy , Lipopolysaccharides/toxicity , Polysaccharides/therapeutic use , Sterols/therapeutic use , A549 Cells , Animals , Cell Survival/drug effects , Cytokines/genetics , Cytokines/metabolism , Gene Expression Regulation/drug effects , Humans , Lung/pathology , Male , Malondialdehyde/metabolism , Mice , Mice, Inbred BALB C , Peroxidase/genetics , Peroxidase/metabolism , Superoxide Dismutase/genetics , Superoxide Dismutase/metabolism
13.
Clin J Am Soc Nephrol ; 15(11): 1603-1613, 2020 11 06.
Article in English | MEDLINE | ID: mdl-33046525

ABSTRACT

BACKGROUND AND OBJECTIVES: With multiple medications indicated for mineral metabolism, dialysis providers can apply various strategies to achieve target phosphate and parathyroid hormone (PTH) levels. We describe common prescribing patterns and practice variation in mineral metabolism treatment strategies over the last decade. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: In a cohort of adults initiating hemodialysis at Dialysis Clinic, Inc. facilities, we assessed prescriptions of vitamin D sterols, phosphate binders, and cinacalcet longitudinally. To identify the influence of secular trends in clinical practice, we stratified the cohort by dialysis initiation year (2006-2008, 2009-2011, and 2012-2015). To measure practice variation, we estimated the median odds ratio for prescribing different mineral metabolism treatment strategies at 12 months post-dialysis initiation across facilities using mixed effects multinomial logistic regression. Sensitivity analyses evaluated strategies used after detection of first elevated PTH. RESULTS: Among 23,549 incident patients on hemodialysis, there was a decline in vitamin D sterol-based strategies and a corresponding increase in strategies without PTH-modifying agents (i.e., phosphate binders alone or no mineral metabolism medications) and cinacalcet-containing treatment strategies between 2006 and 2015. The proportion with active vitamin D sterol-based strategies at dialysis initiation decreased across cohorts: 15% (2006-2008) to 5% (2012-2015). The proportion with active vitamin D sterol-based strategies after 18 months of dialysis decreased across cohorts: 52% (2006-2008) to 34% (2012-2015). The odds of using individual strategies compared with reference (active vitamin D sterol with phosphate binder) varied from 1.5- to two-fold across facilities in 2006-2008 and 2009-2011 cohorts, and increased to two- to three-fold in the 2012-2015 cohort. Findings were similar in sensitivity analyses starting from first elevated PTH measurement. CONCLUSIONS: Over time, mineral metabolism management involved less use of vitamin D sterol-based strategies, greater use of both more conservative and cinacalcet-containing strategies, and increased practice variation, suggesting growing equipoise.


Subject(s)
Calcium-Regulating Hormones and Agents/therapeutic use , Cinacalcet/therapeutic use , Drug Prescriptions/statistics & numerical data , Practice Patterns, Physicians' , Renal Dialysis , Renal Insufficiency/therapy , Vitamin D/therapeutic use , Aged , Calcimimetic Agents/therapeutic use , Drug Therapy, Combination , Female , Humans , Male , Middle Aged , Minerals/metabolism , Parathyroid Hormone/blood , Phosphates/blood , Sterols/therapeutic use , United States , Vitamin D/analogs & derivatives
14.
Pharmacol Res ; 160: 105191, 2020 10.
Article in English | MEDLINE | ID: mdl-32911073

ABSTRACT

Sea cucumbers are widely consumed in traditional medicine and food. Sea cucumbers-derived sulfated sterol exhibits a sulfate group at C-3 position, which is different from phytosterol with a hydroxyl group. However, the effect of sterol sulfate on metabolic syndrome remains unknown. The purpose of the present study is to investigate the alleviation of sterol sulfate on high-fat-high-fructose diet (HFFD)-induced insulin resistance and inflammation. After 2 weeks feeding with HFFD, male C57BL/6J mice were continuously fed with HFFD plus 0.4 % (w/w) sterol sulfate or phytosterol for 6 weeks. The OGTT was carried out at 7 weeks. At the end of the experimental period, the changes of glycogen, circulating glucose, insulin, pro-inflammatory cytokine and adiponectin were measured. H&E staining was used to observe the morphological changes in adipose tissue. Furthermore, the underlying molecular mechanisms were investigated. Dietary sterol sulfate was superior to phytosterol in reducing body weight gain, adipocyte hypertrophy, and levels of circulating glucose and insulin, as well as increasing the glycogen content of tissues. Furthermore, sterol sulfate ameliorated insulin resistance mainly due to the inhibition of gluconeogenesis, the promotion of glycogen synthesis and GLUT4 translocation by activating PI3K/Akt signaling pathway. Additionally, sterol sulfate effectively attenuated inflammation by increasing serum adiponectin and reducing pro-inflammatory cytokine release. Sterol sulfate exhibited a more significant effect than phytosterol in alleviating HFFD -induced insulin resistance and inflammation, which might be closely related to the sulfate group. The results might provide insights into the prevention and alleviation of metabolic syndrome.


Subject(s)
Anti-Inflammatory Agents/therapeutic use , Diet, High-Fat/adverse effects , Fructose/adverse effects , Inflammation/drug therapy , Insulin Resistance , Obesity/drug therapy , Sea Cucumbers/chemistry , Sterols/therapeutic use , Adiponectin/metabolism , Adipose Tissue/drug effects , Adipose Tissue/metabolism , Animals , Blood Glucose/metabolism , Cytokines/metabolism , Glucose Tolerance Test , Glycogen/metabolism , Male , Mice , Mice, Inbred C57BL , Obesity/complications , Signal Transduction/drug effects
15.
Int Immunopharmacol ; 71: 259-266, 2019 Jun.
Article in English | MEDLINE | ID: mdl-30927736

ABSTRACT

BACKGROUND AND AIM: Taraxasterol, a pentacyclic-triterpene, has been reported to exert potent anti-inflammatory activity. However, the molecular mechanisms by which taraxasterol attenuates acute experimental colitis (AEC) remain undocumented. METHODS: A network pharmacology approach was used to identify the candidate and collective targets of taraxasterol and acute colitis, and an AEC model was established by oral administration of dextran sulfate sodium (DSS) in mice. Body weight and colon lengths were then examined, the pathological scoring was assessed by using hematoxylin and eosin staining, and the expression levels of target genes were further confirmed by qRT-PCR and immunohistochemistry (IHC) analysis in taraxasterol treated AEC models. RESULTS: 14 collective targets of taraxasterol and acute colitis were identified by a network pharmacology analysis, including PPARG, JAK2, MMP3, NR1I2 and PTPN11. Further investigations in an AEC model showed that, taraxasterol alleviated the unfavorable clinical symptoms and attenuated the intestinal inflammation response by reducing the cytokines TNF-α, IL-1ß and IL-6 levels. qRT-PCR and IHC analysis evidenced that, taraxasterol decreased MMP3 expression levels, but increased PPARG expression levels in AEC models as compared with the DSS group. CONCLUSIONS: Our findings demonstrated that taraxasterol improved DSS-induced AEC through regulating MMP3 and PPARG expression, providing a new insight into the potential therapeutic strategies for acute colitis.


Subject(s)
Anti-Inflammatory Agents/pharmacology , Colitis/drug therapy , Colon/pathology , Sterols/pharmacology , Triterpenes/pharmacology , Animals , Anti-Inflammatory Agents/therapeutic use , Cytokines/metabolism , Dextran Sulfate , Disease Models, Animal , Gene Expression Regulation , Humans , Inflammation Mediators/metabolism , Male , Matrix Metalloproteinase 3/genetics , Matrix Metalloproteinase 3/metabolism , Mice , Mice, Inbred C57BL , PPAR gamma/genetics , PPAR gamma/metabolism , Protein Interaction Maps , Sterols/therapeutic use , Taraxacum/immunology , Triterpenes/therapeutic use
16.
Int Immunopharmacol ; 70: 274-283, 2019 May.
Article in English | MEDLINE | ID: mdl-30851708

ABSTRACT

Previous study has indicated that taraxasterol (TAR), one of bioactive pentacyclic triterpenes mainly isolated from Chinese medicine herb Taraxacum officinale, displays considerable anti-inflammatory effects in various kinds of models. However, its effects on rheumatoid arthritis (RA) have still not been elucidated. In this study, we aim to investigate its anti-inflammatory effects and underlying mechanisms of TAR against RA using both interleukin (IL)-1ß-stimulated human fibroblast-like synoviocytes rheumatoid arthritis (HFLS-RA) in vitro and collagen-induced arthritis (CIA) mice in vivo. Firstly, our results demonstrated that TRA significantly suppressed the IL-1ß-induced expressions of pro-inflammatory cytokines, including tumor necrosis factor-α (TNF-α), IL-6, and IL-8 and productions of matrix metalloproteinases (MMPs), like MMP-1 and MMP-3 in HFLS-RA in vitro. Moreover, TRA alleviated arthritis progressions and prevented inflammatory processes in the joint tissues of CIA mice in vivo. Further mechanism studies indicated that TRA blocked nuclear factor kappa B (NF-κB) activation via modulating inhibitor of kappa B (IκB), IκB kinase (IKK) and transforming growth factor-ß-activated kinase 1 (TAK1). Results also demonstrated that TRA suppressed the NOD-like receptor protein 3 (NLRP3) inflammasomes through blocking expressions of NLRP3, apoptosis-associated speck-like protein containing (ASC), and caspase-1 in both IL-1ß-induced HFLS-RA and CIA mice. In conclusions, current findings suggested that TRA might one of considerable therapeutic compounds for relieving rheumatoid arthritis progress via suppressing inflammations through modulating NF-κB and NLRP3 inflammasomes pathways.


Subject(s)
Anti-Inflammatory Agents/therapeutic use , Arthritis, Experimental/drug therapy , Arthritis, Rheumatoid/drug therapy , Drugs, Chinese Herbal/therapeutic use , Fibroblasts/pathology , Sterols/therapeutic use , Synoviocytes/drug effects , Triterpenes/therapeutic use , Animals , Apoptosis , Arthritis, Rheumatoid/chemically induced , Cells, Cultured , Disease Models, Animal , Disease Progression , Humans , Interleukin-1beta/metabolism , Male , Mice , Mice, Inbred DBA , NF-kappa B/metabolism , NLR Family, Pyrin Domain-Containing 3 Protein/metabolism , Signal Transduction , Synoviocytes/pathology
17.
Curr Mol Med ; 19(1): 12-19, 2019.
Article in English | MEDLINE | ID: mdl-30806316

ABSTRACT

Diabetes is a metabolic hyperglycemic condition that progressively develops, effect small and large sensory fibers in the affected population. It has various complications as hypertension, coronary artery disease, stroke, blindness, kidney disease as well as peripheral neuropathy. Sulfonylureas, thiazolidinediones, metformin, biguanidine, acarbose and insulin are commonly used drugs for diabetic patients, but these all have certain side effects. Even metformin, that is known as the miracle drug for diabetes has been found to be associated with side effects, as during treatment it involves complications with eyes, kidneys, peripheral nerves, heart and vasculature. In the present article, we hypothesize recent discoveries with respect to active ingredients from Indian medicinal plants i.e., polypeptide-p (protein analogue act as artificial insulin), charantin (a steroidal saponin), momordicin (an alkaloid) and osmotin (ubiquitous plant protein and animal analogue of human adeponectin) possessing anti-hyperglycemic potential for diabetes type II. Therefore, plants as herbal therapy have preventive care of hyperglycemia accompanied with healthy lifestyle which can provide significant decline in the incidences of diabetes in future.


Subject(s)
Diabetes Mellitus, Type 2/drug therapy , Hyperglycemia/drug therapy , Hypoglycemic Agents/therapeutic use , Phytotherapy , Animals , Diabetes Mellitus, Type 2/epidemiology , Humans , Hyperglycemia/epidemiology , Hypoglycemic Agents/chemistry , Metformin/adverse effects , Metformin/therapeutic use , Peptides/therapeutic use , Plant Proteins/therapeutic use , Saponins/therapeutic use , Sterols/therapeutic use , Thiazolidinediones/therapeutic use
18.
Molecules ; 23(8)2018 Aug 05.
Article in English | MEDLINE | ID: mdl-30081608

ABSTRACT

The sterols ß-sitostenone (1), stigmast-4,6,8(14),22-tetraen-3-one (2), ß-sitosterol (3) and stigmasterol (4), the aromatic derivatives antiarol (5) and gentisic acid (6), the phenylpropanes coniferyl alcohol (7), epoxyconiferyl alcohol (8) and ferulic acid (9), the apocarotenoid vomifoliol (10), the flavonoids naringenin (11), 7,4'-dimethoxytaxifolin (7,4'-dimethoxydihydroquercetin, 12), aromadendrin (13), kaempferol (14), taxifolin (dihydroquercetin, 15), prunin (naringenin-7-O-ß-d-glucoside, 16), populnin (kaempferol-7-O-ß-d-glucoside, 17) and senecin (aromadendrin-7-O-ß-d-glucoside, 18) and the lignans kobusin (19) and pinoresinol (20), were isolated from the dried bark of Cochlospermum vitifolium Spreng (Cochlospermaceae), a Mexican medicinal plant used to treat jaundice, liver ailments and hepatitis C. Fourteen of these compounds were isolated for the first time from this plant and from the Cochlospermum genus. Compounds 3⁻4, 6⁻7, 9⁻11, 13⁻17 and 20 have previously exhibited diverse beneficial liver activities. The presence of these compounds in C. vitifolium correlates with the use of this Mexican medicinal plant.


Subject(s)
Bixaceae/chemistry , Flavonoids/chemistry , Flavonoids/pharmacology , Lignans/chemistry , Liver/drug effects , Liver/metabolism , Plant Extracts/chemistry , Plant Extracts/pharmacology , Plants, Medicinal/chemistry , Sterols/chemistry , Sterols/pharmacology , Animals , Flavonoids/therapeutic use , Humans , Lignans/pharmacology , Lignans/therapeutic use , Plant Bark/chemistry , Plant Extracts/therapeutic use , Sterols/therapeutic use
19.
Mar Drugs ; 16(7)2018 Jul 14.
Article in English | MEDLINE | ID: mdl-30011911

ABSTRACT

Hypertension and obesity are two significant factors that contribute to the onset and exacerbation of a cascade of mechanisms including activation of the sympathetic and renin-angiotensin systems, oxidative stress, release of inflammatory mediators, increase of adipogenesis and thus promotion of systemic dysfunction that leads to clinical manifestations of cardiovascular diseases. Seaweeds, in addition to their use as food, are now unanimously acknowledged as an invaluable source of new natural products that may hold noteworthy leads for future drug discovery and development, including in the prevention and/or treatment of the cardiovascular risk factors. Several compounds including peptides, phlorotannins, polysaccharides, carotenoids, and sterols, isolated from brown, red and green macroalgae exhibit significant anti-hypertensive and anti-obesity properties. This review will provide a comprehensive overview of the recent advances on bioactive pure compounds isolated from different seaweed sources focusing on their potential use as drugs to treat or prevent hypertension and obesity. On the other hand, although it is obvious that macroalgae represent promising sources of antihypertensive and anti-obesity compounds, it is also clear that further efforts are required to fully understand their cellular mechanisms of action, to establish structure-inhibition relationships and mainly to evaluate them in pre-clinical and clinical trials.


Subject(s)
Anti-Obesity Agents/pharmacology , Antihypertensive Agents/pharmacology , Hypertension/drug therapy , Obesity/drug therapy , Seaweed/metabolism , Adipogenesis/drug effects , Anti-Obesity Agents/chemistry , Anti-Obesity Agents/isolation & purification , Anti-Obesity Agents/therapeutic use , Antihypertensive Agents/chemistry , Antihypertensive Agents/isolation & purification , Antihypertensive Agents/therapeutic use , Carotenoids/chemistry , Carotenoids/isolation & purification , Carotenoids/pharmacology , Carotenoids/therapeutic use , Drug Discovery , Humans , Oxidative Stress/drug effects , Peptides/chemistry , Peptides/isolation & purification , Peptides/pharmacology , Peptides/therapeutic use , Polysaccharides/chemistry , Polysaccharides/isolation & purification , Polysaccharides/pharmacology , Polysaccharides/therapeutic use , Renin-Angiotensin System/drug effects , Sterols/chemistry , Sterols/isolation & purification , Sterols/pharmacology , Sterols/therapeutic use , Structure-Activity Relationship
20.
Inflammation ; 41(5): 1755-1761, 2018 Oct.
Article in English | MEDLINE | ID: mdl-29951871

ABSTRACT

In the present study, we used the human umbilical vein endothelial cells (HUVECs) to investigate the anti-inflammatory effects and mechanism of taraxasterol on vascular inflammation. HUVECs were pre-treated with taraxasterol 1 h before lipopolysaccharide (LPS) treatment. The concentrations of TNF-α, IL-8, PGE2, and NO were measured. The expression of VCAM-1, ICAM-1, iNOS, COX-2, NF-κB, and LXRα was detected by western blot analysis. The results showed that taraxasterol not only reduced the production of TNF-α, IL-8, PGE2, and NO induced by LPS, but also reduced the expression of iNOS and COX-2. Taraxasterol also suppressed LPS-induced NF-κB activation and VCAM-1 and ICAM-1 expression. Furthermore, taraxasterol concentration-dependently increased the expression of LXRα. The inhibition of taraxasterol on TNF-α, IL-8, PGE2, and NO production can be reversed by geranylgeranyl diphosphate (GGPP, the LXRα inhibitor). Here, we found that taraxasterol inhibited vascular inflammation through activating LXRα.


Subject(s)
Anti-Inflammatory Agents/pharmacology , Human Umbilical Vein Endothelial Cells/drug effects , Sterols/pharmacology , Triterpenes/pharmacology , Anti-Inflammatory Agents/therapeutic use , Cells, Cultured , Cytokines/drug effects , Humans , Inflammation/drug therapy , Lipopolysaccharides , Liver X Receptors , NF-kappa B/metabolism , Sterols/therapeutic use , Triterpenes/therapeutic use
SELECTION OF CITATIONS
SEARCH DETAIL
...