Orlistat Research Articles

COMPARISON OF THE EFFECTS OF DIFFERENT FATTY ACID SYNTHASE INHIBITORS ON THE CELL CYCLE, APOPTOSIS, AND MORPHOLOGY OF SQUAMOUS CELL CARCINOMA 9 CELLS

The aim of this study was to compare the effect of pharmacologic inhibition of 3 different catalytic domains of fatty acid synthase (FASN) on the cell cycle and apoptosis and associate with the morphologic alterations in squamous cell carcinoma 9 (SCC-9) cells. SCC-9 cells were treated with C75, triclosan (TCS), and orlistat (ORL) (inhibitors of KS, ER, and TE domains of FASN) for 24 to 48 hours and analyzed by flow cytometry and phase contrast microscopy. FASN inhibition with C75, ORL means Orlistat; TCS means Triclosan induced different effects on the morphology of SCC-9 cells. Cells treated with ORL showed a fusiform pattern. Instead, TCS induced the formation of cytoplasmic granules and C75 promoted a decrease of cell area. Also, the treatments reduced the number of cells in the S phase and increased the number of cells in the G0/G1 phase. Also, we observed an increase of apoptotic cells and a decrease of viable cells, which was observed in 3 different concentrations of all the drugs. However, TCS showed higher effectiveness in the apoptosis of SCC-9 cells. The morphologic changes of each inhibitor were linked not only to the specific inhibition of FASN activity but also could be due to adverse effects caused by the drugs. FAPESP.

The influence of orlistat, metformin and diet on serum levels of insulin-like growth factor-1 in obeses women with and without insulin resistance.

A range of studies showed confusing data about the relationship between obesity, weight reduction and circulating total insulin-like growth factor -1 (IGF-1). The aim of the study was to compare the influence of orlistat (IO), metformin (IM), or calorie-restricted diet (LC) on IGF-1, with special respect to insulin-resistance status. One hundred and fourteen obese women aged from 18 to 40 years were divided into insulin sensitive (IS) and insulin resistant (IR) groups and received a low calorie diet (LC), or an isocaloric diet and 500 mg metformin twice daily (IM), or isocaloric diet with 120 mg orlistat three times daily (IO). Before and after the intervention anthropometric parameters, serum lipid profile, serum concentrations of alanine aminotransferase, aspartate aminotransferase, insulin, glucose, IGF-1, HOMA-IR (homeostatic model assessment), and visceral adiposity index (VAI), and their changes were registered. Although the reductions in weight and body fat were comparable in IS and IR groups, only women with IR showed a significant increase in IGF-1 concentration as a result of all interventions. We found significant positive correlations of ΔIGF-1 with initial and Δ values of: HOMA-IR, triglyceride/high-density cholesterol ratio, VAI. IR premenopausal women show significant increase in IGF-1 serum concentrations regardless the method of intervention. The increase in IGF-1 was parallel to the improvement of insulin resistance parameters.

Pancreatic lipase inhibitory activity of selected pharmaceutical agents.

Twenty-five structurally diverse compounds have been tested in vitro for their pancreatic lipase (PL) inhibitory activity. Despite the diversity of tested compounds, the relationship comprising structural attributes of the compounds could be established to correlate with the observed inhibitory activity. Compounds that exerted inhibitory action through surface activity were of different profile from the rest of compounds. When co-incubated with orlistat (OsT), important synergistic effects for some compounds (orphenadrine, gliclazide, cefuroxime and sulfacetamide) were revealed, while antagonistic effects were demonstrated for others (camphor sulfonic acid and dinitro salicylic acid). Docking studies for the most active molecules were performed and molecular interaction forces with the PL active site were identified. The results suggested co-binding of OsT along with the other inhibitor in the binding site in cases of synergistic effect but not in the case of antagonistic effect. These results were additionally supported by affinity capillary electrophoresis. In conclusion, synergistic lipase inhibitory activity between OsT and some other pharmaceutical compounds was demonstrated for the first time, which might help improve the pharmacological effect of OsT.

Abstract 77: Caloric restriction mimetics prevent tumor progression by tumor microenvironment remodeling

Abstract The only non-pharmacological intervention known to date to alleviate the age-related deleterious conditions is caloric restriction (CR). We have previously reported that CR induces metabolic and signaling changes that affect the tumor microenvironment preventing mammary tumors growth and metastases. Despite the beneficial effects of CR, it is not feasible to maintain long-term dietary restriction in humans. Based on this, investigators have been focused on the discovery of CR mimetics that evoke some of the benefits of CR without an actual reduction in the calorie intake. Metformin (MET) is an anti-diabetic and a well-known CR mimetic; while Orlistat (OR) is an anti-obesity drug which has also antitumor properties. In this study we used 4T1, a highly metastatic breast cancer, and the B16F10 melanoma mouse models. At first, we evaluated the effects of CR and MET alone. Then, we investigated whether the combination of MET+OR will enhance the CR mimetic properties of MET alone. Our overall hypothesis is that CR mimetics decrease tumor progression by affecting extracellular matrix, epithelial-to-mesenchymal transition (EMT) and inflammation. Briefly, 8-weeks old female mice were fed with normal diet (ND) or 40% CR and received vehicle, MET (in drinking water, 3mg/ml), OR i.p. injection (240mg/kg/d) or MET+OR. After 5 weeks on diets, 4T1 or B16F10 cells were injected into BALB/c or C57BL6 mice respectively; diets and treatments continued for the remainder of the experiment. CR and Mimetics treated-mice had a reduction in body weight (p<0.01) and adiposity (p<0.05) without any signs of toxicity. CR and mimetics treatments reduced tumor growth (p<0.01), microvessel density, total vessel length (p<0.01) and decreased the number and size of spontaneous lung metastases (p<0.01). Also, CR and mimetics tumor bearing mice had significantly lower levels of intra-tumor uPA, MMP-9 and TGF-β. Moreover, CR and mimetics-treated mice had lower levels of circulating insulin, leptin and increased levels of adiponectin and fibroblast growth factor 21 (FGF21) (p<0.01). In a cell invasion assay, we also showed that MET+OR resulted in a significantly reduction on invasion (p<0.01). It is known that the loss of E-Cadherin promotes metastasis. We observed that CR and treated-mice had greater expression of E-Cadherin compared to the controls; in particular MET+OR had higher expression compared to either agent alone. NFĸB activation, the linker between inflammation and cancer, induces the expression of genes that promote a mesenchymal phenotype. We found that the MET+OR decreased phosphorylated P65S536 in 4T1 tumors, which corresponded with a decreased expression in COX-2 and Bcl-2; and an increased expression of P53 and cleaved caspase-3. Our results suggest that CR and MET+OR reduce tumor growth and metastases may in part be due to NFĸB inhibition and by remodeling the ECM, preventing the loss of E-Cadherin and the local invasion. Citation Format: Anirudh Goyal, Shakir M. Saud, Jessica D. Bedele, Mariana S. De Lorenzo. Caloric restriction mimetics prevent tumor progression by tumor microenvironment remodeling [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 77.

Cardioprotective effect of lipstatin derivative orlistat on normotensive rats submitted to cardiac ischemia and reperfusion

To evaluate in vivo animal model of cardiac ischemia/reperfusion the cardioprotective activity of pancreatic lipase inhibitor of the orlistat. Adult male Wistar rats were anesthetized, placed on mechanical ventilation and underwent surgery to induce cardiac I/R by obstructing left descending coronary artery followed by reperfusion to evaluation of ventricular arrhythmias (VA), atrioventricular block (AVB) and lethality (LET) with pancreatic lipase inhibitor orlistat (ORL). At the end of reperfusion, blood samples were collected for determination of triglycerides (TG), very low-density lipoprotein (VLDL), low-density lipoprotein (LDL), high-density lipoprotein (HDL), lactate dehydrogenase (LDH), creatine kinase (CK), and creatine kinase-MB (CK-MB). Treatment with ORL has been able to decrease the incidence of VA, AVB and LET. Besides that, treatment with ORL reduced serum concentrations of CK and LDL, but did not alter the levels of serum concentration of TG, VLDL and HDL. The reduction of ventricular arrhythmias, atrioventricular block, and lethality and serum levels of creatine kinase produced by treatment with orlistat in animal model of cardiac isquemia/reperfusion injury suggest that ORL could be used as an efficient cardioprotective therapeutic strategy to attenuate myocardial damage related to acute myocardial infarction.

Characterization of Tetrahydrolipstatin and Stereoderivatives on the Inhibition of Essential Mycobacterium tuberculosis Lipid Esterases.

Tetrahydrolipstatin (THL) is a covalent inhibitor of many serine esterases. In mycobacteria, THL has been found to covalently react with 261 lipid esterases upon treatment of Mycobacterium bovis cell lysate. However, the covalent adduct is considered unstable in some cases because of the hydrolysis of the enzyme-linked THL adduct resulting in catalytic turnover. In this study, a library of THL stereoderivatives was tested against three essential Mycobacterium tuberculosis lipid esterases of interest for drug development to assess how the stereochemistry of THL affects respective enzyme inhibition and allows for cross enzyme inhibition. The mycolyltransferase Antigen 85C (Ag85C) was found to be stereospecific with regard to THL; covalent inhibition occurs within minutes and was previously shown to be irreversible. Conversely, the Rv3802 phospholipase A/thioesterase was more accepting of a variety of THL configurations and uses these compounds as alternative substrates. The reaction of the THL stereoderivatives with the thioesterase domain of polyketide synthase 13 (Pks13-TE) also leads to hydrolytic turnover and is nonstereospecific but occurs on a slower, multihour time scale. Our findings suggest the stereochemistry of the β-lactone ring of THL is important for cross enzyme reactivity, while the two stereocenters of the peptidyl arm can affect enzyme specificity and the catalytic hydrolysis of the β-lactone ring. The observed kinetic data for all three target enzymes are supported by recently published X-ray crystal structures of Ag85C, Rv3802, and Pks13-TE. Insights from this study provide a molecular basis for the kinetic modulation of three essential M. tuberculosis lipid esterases by THL and can be applied to increase potency and enzyme residence times and enhance the specificity of the THL scaffold.

Mycolyltransferase from Mycobacterium tuberculosis in covalent complex with tetrahydrolipstatin provides insights into antigen 85 catalysis

Mycobacterium tuberculosis antigen 85 (Ag85) enzymes catalyze the transfer of mycolic acid (MA) from trehalose monomycolate to produce the mycolyl arabinogalactan (mAG) or trehalose dimycolate (TDM). These lipids define the protective mycomembrane of mycobacteria. The current model of substrate binding within the active sites of Ag85s for the production of TDM is not sterically and geometrically feasible; additionally, this model does not account for the production of mAG. Furthermore, this model does not address how Ag85s limit the hydrolysis of the acyl-enzyme intermediate while catalyzing acyl transfer. To inform an updated model, we obtained an Ag85 acyl-enzyme intermediate structure that resembles the mycolated form. Here, we present a 1.45-Å X-ray crystal structure of M. tuberculosis Ag85C covalently modified by tetrahydrolipstatin (THL), an esterase inhibitor that suppresses M. tuberculosis growth and mimics structural attributes of MAs. The mode of covalent inhibition differs from that observed in the reversible inhibition of the human fatty-acid synthase by THL. Similarities between the Ag85-THL structure and previously determined Ag85C structures suggest that the enzyme undergoes structural changes upon acylation, and positioning of the peptidyl arm of THL limits hydrolysis of the acyl-enzyme adduct. Molecular dynamics simulations of the modeled mycolated-enzyme form corroborate the structural analysis. From these findings, we propose an alternative arrangement of substrates that rectifies issues with the previous model and suggest a direct role for the β-hydroxy of MA in the second half-reaction of Ag85 catalysis. This information affords the visualization of a complete mycolyltransferase catalytic cycle.

Stereochemical Structure Activity Relationship Studies (S-SAR) of Tetrahydrolipstatin.

Tetrahydrolipstatin (THL), its enantiomer, and an additional six diastereomers were evaluated as inhibitors of the hydrolysis of p-nitrophenyl butyrate by porcine pancreatic lipase. IC50s were found for all eight stereoisomers ranging from a low of 4.0 nM for THL to a high of 930 nM for the diastereomer with the inverted stereocenters at the 2,3,2'-positions. While the enantiomer of THL was also significantly less active (77 nM) the remaining five stereoisomers retained significant inhibitory activities (IC50s = 8.0 to 20 nM). All eight compounds were also evaluated against three human cancer cell lines (human breast cancers MCF-7 and MDA-MB-231, human large-cell lung carcinoma H460). No appreciable cytotoxicity was observed for THL and its seven diastereomers, as their IC50s in a MTT cytotoxicity assay were all greater than 3 orders of magnitude of camptothecin.

Inhibition of endoplasmic reticulum stress in high-fat-diet-induced obese C57BL/6 mice: Efficacy of a novel extract from mulberry (Morus alba) leaves fermented with Cordyceps militaris

A few clues about correlation between endoplasmic reticulum (ER) stress and mulberry (Morus alba) leaves were investigated in only the experimental autoimmune myocarditis and streptozotocin-induced diabetes. To investigate whether a novel extract of mulberry leaves fermented with Cordyceps militaris (EMfC) could suppress ER in fatty liver, alterations in the key parameters for ER stress response were measured in high fat diet (HFD)-induced obese C57L/6 mice treated with EMfC for 12 weeks. The area of adipocytes in the liver section were significantly decreased in the HFD+EMfC treated group as compared to the HFD+Vehicle treated group, while their level was higher in HFD+Vehicle treated group than No treated group. The level of the eukaryotic initiation factor 2 alpha (eIF2α) and inositol-requiring enzyme 1 beta (IRE1α) phosphorylation and CCAAT-enhancer-binding protein homologous protein (CHOP) expression were remarkably enhanced in the HFD+Vehicle treated group. However, their levels were restored in the HFD+EMfC treated group, although some differences were detected in the decrease rate. Similar recovery was observed on the ER stress-induced apoptosis. The level of Caspase-3, Bcl-2 and Bax were decreased in the HFD+EMfC and HFD+orlistat (OT) treated group compared to the HFD+Vehicle treated group. The results of the present study therefore provide first evidence that EMfC with the antiobesity effects can be suppressed ER stress and ER stress-induced apoptosis in the hepatic steatosis of HFD-induced obesity model.

Characterization of ML0314c of Mycobacterium leprae and deciphering its role in the immune response in leprosy patients

Mycobacterium leprae has a reduced genome size due to the reductive evolution over a long period of time. Lipid metabolism plays an important role in the life cycle and pathogenesis of this bacterium. In comparison to 26 lip genes (Lip A-Z) of M. tuberculosis, M. leprae retained only three orthologs indicating their importance in its life cycle. ML0314c (LipU) is one of them. It is conserved throughout the mycobacterium species. Bioinformatics analysis showed the presence of an α/β hydrolase fold and ‘GXSXG’ characteristic of the esterases/lipases. The gene was expressed in E. coli and purified to homogeneity. It showed preference towards short chain esters with pNP-acetate as the preferred substrate. The enzyme showed optimal activity at 45°C and pH8.0. ML0314c protein was stable between temperatures ranging from 20 to 60°C and pH5.0–8.0, i.e., relatively acidic and neutral conditions. The active site residues predicted bioinformatically were confirmed to be Ser168, Glu267, and His297 by site directed mutagenesis. E-serine, DEPC and Tetrahydrolipstatin (THL) completely inhibited the activity of ML0314c. The protein was localized in cell wall and extracellular medium. Several antigenic epitopes were predicted in ML0314c. Protein elicited strong humoral immune response in leprosy patients, whereas, a reduced immune response was observed in the relapsed cases. No humoral response was observed in treatment completed patients. Overexpression of ml0314c in the surrogate host M. smegmatis showed marked difference in the colony morphology and growth rate. In conclusion, ML0314c is a secretary carboxyl esterase that could modulate the immune response in leprosy patients.

Evaluation of anti-obesity activity of Garuga pinnata Roxb. in high fat diet induced rats

Objective : The objective of the present study was to evaluate the Anti-obesity activity of Garuga pinnata Roxb in high fat diet induced rats. Materials and Methods: Gall part of leaves of Garuga pinnata were collected, dried, powdered and extracted with ethanol (70%) to get Ethanolic extract of Garuga pinnata (EGP). Rats were divided into 5 groups in high fat diet induced model. Normal control animals were fed with the rat chow diet and all other grouped rats were fed with high fat diet, Standard group was treated with Orlistat (10 mg/kg, p.o.) and rats of test groups were treated with the EGP (100 and 200 mg/kg, p.o.) for 4 weeks. Anthropometric parameters were measured once in a week and lipid profile and antioxidant parameters were measured on the 29 th day. Histopathology of kidney and liver was studied. Results: Body weight and BMI was significantly reduced in the test groups (100 and 200 mg/kg, p.o.). TG, TC, LDL-C, VLDL-C, LPO levels were reduced and HDL-C and anti-oxidants were elevated in both test groups as compare to disease control animals. Histopathology of liver showed protection against fat accumulation in Ethanolic extract of Garuga pinnata (100 and 200 mg/kg, p.o.). Conclusion: In the light of finding and discussion, it was concluded that Ethanolic extract of Garuga pinnata (100 and 200 mg/kg) may have anti-obesity in high fat diet induced rats and showed preventive effect against fat accumulation in liver.

Activity-Based Lipid Esterase Profiling of M. bovis BCG at Different Metabolic States Using Tetrahydrolipstatin (THL) as Bait.

This chapter provides a step-by-step protocol using activity-based protein profiling (ABPP) as a chemical-proteomic tool to survey the antibiotic properties of a small molecule. Here, we investigate the molecular mechanism behind the bactericidal activity of tetrahydrolipstatin (THL). ABPP relies on small molecule probes that target the active site of specific enzymes in complex proteomes. These probes in turn are equipped with a reporter tag that allows capturing, visualization, enrichment, identification, and quantification of its targets either in vitro or in situ. THL possesses bactericidal activities, but its precise spectrum of molecular targets is poorly characterized. Here, we used THL analogs functionalized to enable Huisgen-base cycloaddition, commonly known as "click chemistry," to identify target proteins after enrichment from mycobacterial cell lysates obtained from different physiological conditions.

Effects of Lipid-Lowering Drugs on Vancomycin Susceptibility of Mycobacteria.

Tuberculosis is still a cause of major concern, partly due to the emergence of multidrug-resistant strains. New drugs are therefore needed. Vancomycin can target mycobacteria with cell envelope deficiency. In this study, we used a vancomycin susceptibility assay to detect drugs hampering lipid synthesis in Mycobacterium bovis BCG and in Mycobacterium tuberculosis We tested three drugs already used to treat human obesity: tetrahydrolipstatin (THL), simvastatin, and fenofibrate. Only vancomycin and THL were able to synergize on M. bovis BCG and on M. tuberculosis, although mycobacteria could also be inhibited by simvastatin alone. Lipid analysis allowed us to identify several lipid modifications in M. tuberculosis H37Rv treated with those drugs. THL treatment mainly reduced the phthiocerol dimycocerosate (PDIM) content in the mycobacterial cell wall, providing an explanation for the synergy, since PDIM deficiency has been related to vancomycin susceptibility. Proteomic analysis suggested that bacteria treated with THL, in contrast to bacteria treated with simvastatin, tried to recover, inducing, among other reactions, lipid synthesis. The combination of THL and vancomycin should be considered a promising solution in developing new strategies to treat multidrug-resistant tuberculosis.

Adverse Events Associated with Five Anti-Obesity Medications

Five medications are approved for treating obese and overweight patients: orlistat (Xenical; Alli), lorcaserin (Belviq), naltrexone-bupropion (Contrave), phentermine-topiramate (Qsymia), and liraglutide (Saxenda). For this meta-analysis, researchers identified 28 randomized trials that involved 29,018 patients (median age, 46; median baseline body-mass index, 36.1 kg/m2); in all trials, one or more of the five …

Weight loss as a treatment for nonalcoholic fatty liver disease.

Nonalcoholic fatty liver disease (NAFLD) is a chronic liver disease that can progress to cirrhosis and hepatocellular carcinoma. NAFLD has been associated with obesity and other features of the metabolic syndrome, including insulin resistance, impaired glucose tolerance, and dyslipidemia. As a result, and with a lack of other effective treatments, weight loss achieved through lifestyle modifications (diet and exercise) has been promoted as the standard treatment. However, there is very little empiric evidence to support the effectiveness of weight loss for NAFLD. This article reviews the current literature on the effects of weight loss achieved through lifestyle modification or medications on NAFLD. To date, there have been no randomized controlled trials of weight loss interventions on hepatic pathology. Only three published trials (N = 89 subjects), which include a comparison group, have been published. These studies suggest improvement in liver enzymes and/or hepatic pathology; however, direct between group comparisons are lacking. Four small, nonrandomized studies (N = 59 subjects) have evaluated the effect of weight loss achieved with medications (4 of orlistat, 1 of sibutramine) on NAFLD. These suggest some improvement in liver enzymes and histopathology. Finally, a brief review of observational studies on the association between NAFLD pathology or liver enzymes and diet composition suggests a possible role for the manipulation of macronutrients and/or micronutrients in NAFLD treatment. In summary, there is little empiric evidence to support the role of weight loss achieved through lifestyle modification or medication in the treatment of NAFLD. Rigorously conducted, randomized controlled trials are needed in this area.

Estrogen Receptor Beta and 2-arachidonoylglycerol Mediate the Suppressive Effects of Estradiol on Frequency of Postsynaptic Currents in Gonadotropin-Releasing Hormone Neurons of Metestrous Mice: An Acute Slice Electrophysiological Study.

Gonadotropin-releasing hormone (GnRH) neurons are controlled by 17β-estradiol (E2) contributing to the steroid feedback regulation of the reproductive axis. In rodents, E2 exerts a negative feedback effect upon GnRH neurons throughout the estrus-diestrus phase of the ovarian cycle. The present study was undertaken to reveal the role of estrogen receptor subtypes in the mediation of the E2 signal and elucidate the downstream molecular machinery of suppression. The effect of E2 administration at low physiological concentration (10 pM) on GnRH neurons in acute brain slices obtained from metestrous GnRH-green fluorescent protein (GFP) mice was studied under paradigms of blocking or activating estrogen receptor subtypes and interfering with retrograde 2-arachidonoylglycerol (2-AG) signaling. Whole-cell patch clamp recordings revealed that E2 significantly diminished the frequency of spontaneous postsynaptic currents (sPSCs) in GnRH neurons (49.62 ± 7.6%) which effect was abolished by application of the estrogen receptor (ER) α/β blocker Faslodex (1 μM). Pretreatment of the brain slices with cannabinoid receptor type 1 (CB1) inverse agonist AM251 (1 μM) and intracellularly applied endocannabinoid synthesis blocker THL (10 μM) significantly attenuated the effect of E2 on the sPSCs. E2 remained effective in the presence of tetrodotoxin (TTX) indicating a direct action of E2 on GnRH cells. The ERβ specific agonist DPN (10 pM) also significantly decreased the frequency of miniature postsynaptic currents (mPSCs) in GnRH neurons. In addition, the suppressive effect of E2 was completely blocked by the selective ERβ antagonist PHTPP (1 μM) indicating that ERβ is required for the observed rapid effect of the E2. In contrast, the ERα agonist PPT (10 pM) or the membrane-associated G protein-coupled estrogen receptor (GPR30) agonist G1 (10 pM) had no significant effect on the frequency of mPSCs in these neurons. AM251 and tetrahydrolipstatin (THL) significantly abolished the effect of E2 whereas AM251 eliminated the action of DPN on the mPSCs. These data suggest the involvement of the retrograde endocannabinoid mechanism in the rapid direct effect of E2. These results collectively indicate that estrogen receptor beta and 2-AG/CB1 signaling mechanisms are coupled and play an important role in the mediation of the negative estradiol feedback on GnRH neurons in acute slice preparation obtained from intact, metestrous mice.

Development of a Self-Assembled Nanoparticle Formulation of Orlistat, Nano-ORL, with Increased Cytotoxicity against Human Tumor Cell Lines.

Fatty acid synthase (FASN), the enzyme that catalyzes de novo synthesis of fatty acids, is expressed in many cancer types. Its potential as a therapeutic target is well recognized, but inhibitors of FASN have not yet been approved for cancer therapy. Orlistat (ORL), an FDA-approved lipase inhibitor, is also an effective inhibitor of FASN. However, ORL is extremely hydrophobic and has low systemic uptake after oral administration. Thus, new strategies are required to formulate ORL for cancer treatment as a FASN inhibitor. Here, we report the development of a nanoparticle (NP) formulation of ORL using amphiphilic bioconjugates that are derived from hyaluronic acid (HA), termed Nano-ORL. The NPs were loaded with up to 20 wt % weight of ORL at greater than 95% efficiency. The direct inhibition of the human recombinant thioesterase domain of FASN by ORL extracted from Nano-ORL was similar to that of stock ORL. Nano-ORL demonstrated a similar ability to inhibit cellular FASN activity when compared to free ORL, as demonstrated by analysis of (14)C-acetate incorporation into lipids. Nano-ORL treatment also disrupted mitochondrial function similarly to ORL by reducing adenosine triphosphate turnover in MDA-MB-231 and LNCaP cells. Nano-ORL demonstrated increased potency compared to ORL toward prostate and breast cancer cells. Nano-ORL decreased viability of human prostate and breast cancer cell lines to 55 and 57%, respectively, while free ORL decreased viability to 71 and 79% in the same cell lines. Moreover, Nano-ORL retained cytotoxic activity after a 24 h preincubation in aqueous conditions. Preincubation of ORL dramatically reduced the efficacy of ORL as indicated by high cell viability (>85%) in both breast and prostate cell lines. These data demonstrate that NP formulation of ORL using HA-derived polymers retains similar levels of FASN, lipid synthesis, and ATP turnover inhibition while significantly improving the cytotoxic activity against cancer cell lines.

Electroacupuncture Improves Insulin Resistance by Reducing Neuroprotein Y/Agouti-Related Protein Levels and Inhibiting Expression of Protein Tyrosine Phosphatase 1B in Diet-induced Obese Rats

Electroacupuncture (EA) has been shown to exert beneficial effects on obesity, but the mechanism is unclear. This study investigated the effects of EA on diet-induced obese (DIO) rats. Fifty male Sprague–Dawley rats were randomly divided into low-fat diet (LFD, 10 rats) and high-fat diet (HFD, 40 rats) groups. After the DIO models had been established, successful model rats were randomly divided into HFD, EA, and orlistat (OLST) groups. The EA group received EA at Zusanli (ST36) and Quchi (LI11) for 20 minutes once per day for 28 days. The OLST group was treated with orlistat by gavage. The body weight, homeostasis model assessment-insulin resistance index, adipocyte diameters, and neuroprotein Y/agouti-related protein and protein tyrosine phosphatase 1B levels were significantly lower in the EA group than in the HFD group. The rats of the OLST group showed watery stools and yellow hairs whereas those of the EA group had regular stools and sleek coats. The effect of EA on weight loss may be related to improved insulin resistance caused by changes in the adipocyte size and by reductions in the expressions of neuroprotein Y/agouti-related protein and protein tyrosine phosphatase 1B. This study indicates that EA may be a better method of alternative therapy for treating obesity and other metabolic diseases.

ChemInform Abstract: The Asymmetric Synthesis of Tetrahydrolipstatin

AbstractReview: [73 refs.

The Asymmetric Synthesis of Tetrahydrolipstatin

AbstractThe various syntheses of the over‐the‐counter anti‐obesity drug tetrahydrolipstatin (also known as Orlistat) are reviewed. The 31 various syntheses cover the development of enantioselective natural products synthesis since the first synthesis of tetrahydrolipstatin (THL) by Schneider in 1987. After Schneider's landmark synthetic effort there have been numerous total and formal syntheses of THL, which have involved a diverse range of approaches. These various syntheses can be classified by the methods that were used to install the stereochemistry, for instance, chiral auxiliary, asymmetric aldol, asymmetric allylation/crotylation, asymmetric reductions, asymmetric resolutions, asymmetric oxidations, and chiron approach. These routes also feature the elegant use of a chiral phosphate template, a tandem [2+2]‐Mukaiyama aldol‐lactonization, an anti‐aldol segment via a non‐aldol route, a Prins cyclization, and an epoxide carbonylation.