Squalamine Restores the Function of the Enteric Nervous System in Mouse Models of Parkinson's Disease.

BACKGROUND: Parkinson's disease (PD) is a progressive neurodegenerative disorder thought to be caused by accumulation of α-synuclein (α-syn) within the brain, autonomic nerves, and the enteric nervous system (ENS). Involvement of the ENS in PD often precedes the onset of the classic motor signs of PD by many years at a time when severe constipation represents a major morbidity. Studies conducted in vitro and in vivo, have shown that squalamine, a zwitterionic amphipathic aminosterol, originally isolated from the liver of the dogfish shark, effectively displaces membrane-bound α-syn. OBJECTIVE: Here we explore the electrophysiological effect of squalamine on the gastrointestinal (GI) tract of mouse models of PD engineered to express the highly aggregating A53T human α-syn mutant. METHODS: GI motility and in vivo response to oral squalamine in PD model mice and controls were assessed using an in vitro tissue motility protocol and via fecal pellet output. Vagal afferent response to squalamine was measured using extracellular mesenteric nerve recordings from the jejunum. Whole cell patch clamp was performed to measure response to squalamine in the myenteric plexus. RESULTS: Squalamine effectively restores disordered colonic motility in vivo and within minutes of local application to the bowel. We show that topical squalamine exposure to intrinsic primary afferent neurons (IPANs) of the ENS rapidly restores excitability. CONCLUSION: These observations may help to explain how squalamine may promote gut propulsive activity through local effects on IPANs in the ENS, and further support its possible utility in the treatment of constipation in patients with PD.

Squalamine blocks tumor-associated angiogenesis and growth of human breast cancer cells with or without HER-2/neu overexpression.

Angiogenesis is critical for breast cancer progression. Overexpression of HER-2/neu receptors occur in 25-30% of breast cancers, and treatment with trastuzumab inhibits HER-2-overexpressing tumor growth. Notably, HER-2-mediated signaling enhances vascular endothelial growth factor (VEGF) secretion to increase tumor-associated angiogenesis. Squalamine (aminosterol compound) suppresses VEGF-induced activation of kinases in vascular endothelial cells and inhibits tumor-associated angiogenesis. We assessed antitumor effects of squalamine either alone or with trastuzumab in nude mice bearing breast tumor xenografts without (MCF-7) or with HER2-overexpression (MCF-7/HER-2). Squalamine alone inhibited progression of MCF-7 tumors lacking HER2 overexpression, and squalamine combined with trastuzumab elicited marked inhibition of MCF-7/HER2 growth exceeding that of trastuzumab alone. MCF-7/HER-2 cells secrete higher levels of VEGF than MCF-7 cells, but squalamine elicited no growth inhibition of either MCF-7/HER-2 or MCF-7 cells in vitro. However, squalamine did stop growth of human umbilical vein endothelial cells (HUVECs) and reduced VEGF-induced endothelial tube-like formations in vitro. These effects correlated with blockade of focal adhesion kinase phosphorylation and stress fiber assembly in HUVECs. Thus, squalamine effectively inhibits growth of breast cancers with or without HER-2-overexpression, an effect due in part to blockade of tumor-associated angiogenesis.

Cholestane-3ß, 5α, 6ß-triol suppresses neuronal hyperexcitability via binding to voltage-gated sodium channels.

Neuronal hyperexcitability is identified as a critical pathological basis of epileptic seizures. Cholestane-3ß, 5α, 6ß-triol (Triol) is a major metabolic oxysterol of cholesterol. Although its neuroprotective effect on ischemia-induced neuronal injury and negative modulation of voltage-gated sodium (Nav) channels were well established, the physical binding site of triol to sodium channels and its effects on neuronal hyperexcitability have not yet been explored. In this study, we utilized molecular docking and molecular dynamics simulation to investigate the interaction between triol and Nav Channels. Our results demonstrated that triol binds to the indole ring of Trp122 of the Nav Channel in silico with a high biological affinity. We further found that triol negatively modulates the action potentials bursts of hippocampal neurons by cell-attached patch recording. Moreover, triol significantly inhibits low Mg2+-induced hyperexcitability in vitro. In addition, triol attenuates pentylenetetrazole (PTZ)-induced convulsive-form behavioral deficits in vivo. Together, our results suggest that triol suppresses neuronal hyperexcitability via binding to Nav channel, indicating that triol might be an attractive lead compound for the treatment of neuronal hyperexcitability-related neurological disorders, especially epileptic seizures.

[Eye Drops Instead of Intravitreal Injections? The Dream of Treating Macular Diseases by Topically Administered Drugs]. / Tropfen statt spritzen? Der Traum von einer Therapie von Makulaerkrankungen mit Augentropfen.

Background The introduction of VEGF inhibitors revolutionized treatment for age-related macular degeneration. However, it requires regular intravitreal (IVT) injections. Hence, replacement of IVT injections by topical, non-invasive eye drop treatment is subject to intensive research. Material and Methods Literature and database research on topical therapies for neovascular AMD. Results Several clinical projects with topical inhibitors of the VEGF pathway were initiated recently. Several candidate molecules were investigated and should have an efficacy potential in neovascular AMD given their ability to block the VEGF pathway. Preclinical experiments were quite promising. Still, translation into the clinical application has not been successful thus far. Differences in preclinical and clinical pharmacokinetics are assumed to be the major barrier to successful translation. In addition, specific algorithms for monitoring of disease activity are required for successful clinical implementation; otherwise, a topical therapy may reduce the IVT injection number, but patients would not gain independence through fewer office visits. Discussion It is required to refine the scientific basis including preclinical models and screening cascades. This will enable targeted selection of future candidates for clinical development.

The Bile Acid Receptor GPBAR1 Regulates the M1/M2 Phenotype of Intestinal Macrophages and Activation of GPBAR1 Rescues Mice from Murine Colitis.

GPBAR1 (TGR5 or M-BAR) is a G protein-coupled receptor for secondary bile acids that is highly expressed in monocytes/macrophages. In this study, we aimed to determine the role of GPBAR1 in mediating leukocyte trafficking in chemically induced models of colitis and investigate the therapeutic potential of BAR501, a small molecule agonist for GPBAR1. These studies demonstrated that GPBAR1 gene ablation enhanced the recruitment of classically activated macrophages in the colonic lamina propria and worsened the severity of inflammation. In contrast, GPBAR1 activation by BAR501 reversed intestinal inflammation in the trinitrobenzenesulfonic acid and oxazolone models by reducing the trafficking of Ly6C+ monocytes from blood to intestinal mucosa. Exposure to BAR501 shifted intestinal macrophages from a classically activated (CD11b+, CCR7+, F4/80-) to an alternatively activated (CD11b+, CCR7-, F4/80+) phenotype, reduced the expression of inflammatory genes (TNF-α, IFN-γ, IL-1ß, IL-6, and CCL2 mRNAs), and attenuated the wasting syndrome and severity of colitis (≈70% reduction in the Colitis Disease Activity Index). The protective effect was lost in Gpbar1-/- mice. Exposure to BAR501 increased the colonic expression of IL-10 and TGF-ß mRNAs and the percentage of CD4+/Foxp3+ cells. The beneficial effects of BAR501 were lost in Il-10-/- mice. In a macrophage cell line, regulation of IL-10 by BAR501 was GPBAR1 dependent and was mediated by the recruitment of CREB to its responsive element in the IL-10 promoter. In conclusion, GPBAR1 is expressed in circulating monocytes and colonic macrophages, and its activation promotes a IL-10-dependent shift toward an alternatively activated phenotype. The targeting of GPBAR1 may offer therapeutic options in inflammatory bowel diseases.

Topical Squalamine 0.2% and Intravitreal Ranibizumab 0.5 mg as Combination Therapy for Macular Edema Due to Branch and Central Retinal Vein Occlusion: An Open-Label, Randomized Study.

BACKGROUND AND OBJECTIVE: To evaluate the effects of squalamine (OHR-102; Ohr Pharmaceuticals, New York, NY) and ranibizumab (Lucentis; Genentech, South San Francisco, CA) on macular edema (ME) secondary to retinal vein occlusion (RVO). PATIENTS AND METHODS: Twenty consecutive, treatment-naïve patients with RVO-related ME received topical squalamine and intravitreal ranibizumab 0.5 mg for 10 weeks, followed by randomization to continue or discontinue squalamine. Groups received as-needed ranibizumab from weeks 2 through 34. The primary endpoint was the proportion of eyes gaining 15 or more Early Treatment Diabetic Retinopathy Study (ETDRS) letters at week 38. Safety and tolerability were assessed. Data from 13 treatment-naïve control eyes previously enrolled in three similar trials evaluating monthly ranibizumab 0.5 mg for RVO-related ME were included for comparison. RESULTS: At baseline, mean best-corrected visual acuity (BCVA) measures were 55.6 ETDRS letters and 55.0 ETDRS letters in the squalamine and control groups, respectively. At week 38, BCVA improved 25.6 letters in the squalamine group; at month 9, BCVA improved 16.3 letters in the control group. This corresponds to a between-treatment-group difference of 9.2 letters. Squalamine and ranibizumab combination therapy was well-tolerated. CONCLUSIONS: In patients with RVO-related ME, topical squalamine combined with early, as-needed ranibizumab appears to enhance visual recovery versus ranibizumab alone. Combination therapy appears safe and was well-tolerated. [Ophthalmic Surg Lasers Imaging Retina. 2016;47:914-923.].

Small molecules preventing GAPDH aggregation are therapeutically applicable in cell and rat models of oxidative stress.

Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) is one of the most abundant targets of the oxidative stress. Oxidation of the enzyme causes its inactivation and the formation of intermolecular disulfide bonds, and leads to the accumulation of GAPDH aggregates and ultimately to cell death. The aim of this work was to reveal the ability of chemicals to break the described above pathologic linkage by inhibiting GAPDH aggregation. Using the model of oxidative stress based on SK-N-SH human neuroblastoma cells treated with hydrogen peroxide, we found that lentivirus-mediated down- or up-regulation of GAPDH content caused inhibition or enhancement of the protein aggregation and respectively reduced or increased the level of cell death. To reveal substances that are able to inhibit GAPDH aggregation, we developed a special assay based on dot ultrafiltration using the collection of small molecules of plant origin. In the first round of screening, five compounds were found to possess anti-aggregation activity as established by ultrafiltration and dynamic light scattering; some of the substances efficiently inhibited GAPDH aggregation in nanomolar concentrations. The ability of the compounds to bind GAPDH molecules was proved by the drug affinity responsive target stability assay, molecular docking and differential scanning calorimetry. Results of experiments with SK-N-SH human neuroblastoma treated with hydrogen peroxide show that two substances, RX409 and RX426, lowered the degree of GAPDH aggregation and reduced cell death by 30%. Oxidative injury was emulated in vivo by injecting of malonic acid into the rat brain, and we showed that the treatment with RX409 or RX426 inhibited GAPDH-mediated aggregation in the brain, reduced areas of the injury as proved by magnetic resonance imaging, and augmented the behavioral status of the rats as established by the "beam walking" test. In conclusion, the data show that two GAPDH binders could be therapeutically relevant in the treatment of injuries stemming from hard oxidative stress.

A double-blind randomized placebo-controlled clinical trial of squalamine ointment for tinea capitis treatment.

BACKGROUND: Novel treatments against for tinea capitis are needed, and the natural aminosterol squalamine is a potential topical antidermatophyte drug candidate. OBJECTIVES: This phase II randomized double-blind placebo-controlled clinical trial aimed at testing the efficacy and safety of a three-week squalamine ointment regimen for the treatment of tinea capitis. PATIENTS: Males aged 6-15 years presenting with tinea capitis were treated with either topical squalamine ointment or placebo for 3 weeks. The primary endpoint was complete clinical cure. The secondary endpoints were the occurrence of local and/or systemic adverse events, mycological cure, and partial clinical response. Prospective follow-up of clinical adverse events was performed daily. RESULTS: Five patients were treated with 1% squalamine ointment and 15 with placebo. No complete cure was observed. No clinical or biological adverse event was recorded. A significantly (p = 0.03) better hair-growth score, indicating a partial clinical improvement of the tinea capitis lesion, was observed in the patients treated with squalamine compared to those treated with placebo. CONCLUSION: This three-week squalamine ointment regimen was well tolerated and showed an encouraging partial clinical activity for the treatment of tinea capitis. Further studies are needed to evaluate the efficacy of topical squalamine alone against tinea corporis or in combination with a systemic antidermatophyte drug against tinea capitis.

Biological activities of new monohydroxylated brassinosteroid analogues with a carboxylic group in the side chain.

Thirteen monohydroxylated brassinosteroids analogues were synthesized and tested for their biological activity in plant and animal systems. The cytotoxic activity of the products was studied using human normal and cancer cell lines with 28-homocastasterone as positive control, their brassinolide type activity was established using the bean second-internode test with 24-epibrassinolide as standard.

Development of high drug-loading nanomicelles targeting steroids to the brain.

The objective of this research was to develop and evaluate high drug-loading ligand-modified nanomicelles to deliver a steroidal compound to the brain. YC1 (5α-cholestane-24-methylene-3ß, 5α, 6ß, 19-tetraol), with poor solubility and limited access to the brain, for the first time, has been proved to be an effective neuroprotective steroid by our previous studies. Based on the principle of 'like dissolves like', cholesterol, which shares the same steroidal parent nucleus with YC1, was selected to react with sodium alginate, producing amphiphilic sodium alginate- cholesterol derivatives (SACDs). To increase the grafting ratio and drug loading, cholesterol was converted to cholesteryl chloroformate, for the first time, before reacting with sodium alginate. Further, lactoferrin was conjugated on SACDs to provide lactoferrin-SACDs (Lf-SACD), which was established by immune electron microscopy (IEM) and self-assembled into brain-targeting nanomicelles. These nanomicelles were negatively charged and spherical in nature, with an average size of <200 nm. The YC1 drug loading was increased due to the cholesteryl inner cores of the nanomicelles, and the higher the grafting ratio was, the lower the critical micelle concentration (CMC) value of SACD, and the higher drug loading. The in vitro drug release, studied by bulk-equilibrium dialysis in 20 mL of 6% hydroxypropyl-ß-cyclodextrin solution at 37°C, indicated a prolonged release profile. The YC1 concentration in mouse brain delivered by lactoferrin-modified nanomicelles was higher than in those delivered by non-modified nanomicelles and YC1 solution. The unique brain-targeting nanomicelle system may provide a promising carrier to deliver hydrophobic drugs across the blood-brain barrier for the treatment of brain diseases.

Antibacterial efficacy of inhaled squalamine in a rat model of chronic Pseudomonas aeruginosa pneumonia.

OBJECTIVES: Squalamine is a steroid extracted from sharks with proven in vitro antibacterial activity. We assessed its efficacy in reducing the lung bacterial load and histological lesions when given via inhalation in a rat model of chronic Pseudomonas aeruginosa pneumonia. METHODS: Sprague-Dawley rats were inoculated by tracheal intubation with 150 µL of a solution containing 10(8) cfu/mL of agar bead-embedded P. aeruginosa strain PAO1. MICs of squalamine and colistin for this strain were 2-8 and 0.5-1 mg/L, respectively. Starting the day after infection, the animals were treated twice daily with aerosolized squalamine (3 mg), colistin (160 mg) or 0.9% saline for 6 days. The bacterial load and lung histological lesions were evaluated on the seventh day. RESULTS: Aerosols of squalamine and colistin resulted in a significant reduction in median (IQR) pulmonary bacterial count compared with saline [10(3) (6 × 10(2)-2 × 10(3)), 10(3) (9 × 10(2)-6 × 10(3)) and 10(5) (9 × 10(4)-2 × 10(5)) cfu/lung, respectively; P < 0.001 for both treated groups versus saline]. The lung weight and the lung histological severity score were significantly lower in both treated groups. CONCLUSIONS: In a model of chronic P. aeruginosa pneumonia, treatment twice daily with a squalamine aerosol for 6 days leads to a significant reduction in the pulmonary bacterial count and pneumonia lesions with an efficacy comparable to that of colistin.

Squalamine ointment for Staphylococcus aureus skin decolonization in a mouse model.

OBJECTIVES: Staphylococcus aureus colonization of the skin and the nostrils remains a major cause of surgical-site infections despite preoperative and preventive procedures. To date, many compounds have been used for S. aureus decolonization, including mupirocin ointments and antiseptics, with variable results. The emergence of mupirocin-resistant S. aureus strains has led to the search for new antimicrobial agents specifically for S. aureus decolonization. In this work we evaluated squalamine and related parent-derived ointments (1%) as potential new compounds for S. aureus decolonization in a new mouse model. METHODS: We report the development and application of squalamine and related parent-derived ointments in a new mouse skin model. After skin shaving, mice were colonized with an S. aureus suspension that was calibrated to 104-106 cfu/mL. The remaining bacterial load was monitored for 2 days after a single application of squalamine by spreading. RESULTS: We found that S. aureus colonization of the skin was stable for at least 2 days before it was naturally eliminated. Using this model we found that squalamine ointment (1%) could reduce S. aureus viable cells by up to 4 log with a single, 1 h application of ointment, whereas mupirocin application reduced viable cell numbers by only 1.3 log during that same time (P < 0.05). CONCLUSIONS: Our results suggest that such compounds may be useful for S. aureus nasal and skin decolonization and may constitute a potent alternative for skin and nasal antisepsis before surgery.

Evaluation of ambrein and epicoprostanol for their antioxidant properties: protection against adriamycin-induced free radical toxicity.

Ambrein and epicoprostanol were evaluated for their antioxidant potential in vitro by chemiluminescence (CL), as well as in vivo using lipid peroxides and glutathione levels as indicators in liver tissue of rats treated with adriamycin (doxorubicin) a well known free radicals producing drug. In the in vitro test, the inhibition in CL by ambrein was dose dependent. Both the high concentrations of ambrein (20-40 microg/ml) inhibited CL response significantly (P<0.05 and P<0.01, respectively) when compared to control. Similarly two low concentrations (5-20 microg/ml) of epicoprostanol inhibited CL significantly (P<0.001 and P<0.01, respectively) in comparison of DMSO control. The high concentration (40 microg/ml) of epicoprostanol behaved exceptionally and caused an increase in CL response that was more than control and significantly (P<0.001) higher than both the low concentrations. In the in vivo studies adriamycin treatment significantly (P<0.05) increased malondialdehyde (MDA) and decreased non-protein sulfhydryl (NP-SH) contents in the liver tissue of mice after 5 days treatment. Ambrein (25 and 50 mg/kg) treatment as a solo therapy at both the dose levels significantly (P<0.001) decreased MDA contents in the liver tissue. On the other hand, in the combined treatment the high dose effectively prevented any rise in MDA contents and it remained around the levels of ambrein alone. In the same experiment, adriamycin declined NP-SH contents significantly (P<0.001). Ambrein alone at both the dose levels caused a decline (P<0.01) in NP-SH contents when compared to adriamycin group. But in the combined treatment this decline in NP-SH was significantly (P<0.05) different from adriamycin alone. In the experiments dealing with epicoprostanol, adriamycin treatment increased MDA contents significantly (P<0.05) that declined significantly (P<0.001) with epicoprostanol (10- or 20mg/kg) treatment. In the same experiment co-treatment with adriamycin prevented any rise in MDA contents significantly (P<0.001) as it was observed in adriamycin alone group. Although, this treatment failed to prevent any decline in NP-SH contents either alone or in combination with adriamycin. Epicoprostanol itself had the comparative declining effect on the contents of NP-SH as seen in adriamycin group. From the results of our experiments it seems that ambrein at all concentrations behaves like antioxidant in in vitro studies but the same time it decreased NP-SH contents in vivo accompanied by a decline in MDA contents. Whereas, epicoprostanol at two low concentrations had a decline in CL indicating a possible antioxidant potential but the high concentration increased CL showing a tendency towards oxidant prospective. However, in animal studies it has shown a clear protection against adriamycin induced free radical damage.

Danshen inhibits oxysterol-induced endothelial cell apoptosis in vivo.

Oxysterols induce apoptosis in vascular endothelial cells in vitro, but it is not clear whether they do so in vivo. We intravenously injected an oxysterol, cholestan-3beta, 5alpha, 6beta-triol, into rats and quantitatively analyzed endothelial cell apoptosis in the aorta. Oxysterol significantly promoted apoptosis in a time- and dose-dependent fashion. The apoptosis had increased 4.5-fold 6 hrs after injection, and returned to the background level at 48 hrs. An extract of the Chinese herb Danshen as well as probucol abolished triol-induced endothelial cell apoptosis in vitro and in vivo. Since apoptotic cells are quickly cleared, oxysterol-induced apoptosis could significantly affect endothelial integrity over a long period of time. Radical scavengers may be useful for the prevention of endothelial damage.

Lack of biliary lipid excretion in the little skate, Raja erinacea, indicates the absence of functional Mdr2, Abcg5, and Abcg8 transporters.

The ABC transporters bile salt export pump (BSEP; encoded by the ABCB11 gene), MDR3 P-glycoprotein (ABCB4), and sterolin 1 and 2 (ABCG5 and ABCG8) are crucial for the excretion of bile salt, phospholipid, and cholesterol, respectively, into the bile of mammals. The current paradigm is that phospholipid excretion mainly serves to protect membranes of the biliary tree against bile salt micelles. Bile salt composition and cytotoxicity, however, differ greatly between species. We investigated whether biliary phospholipid and cholesterol excretion occurs in a primitive species, the little skate, which almost exclusively excretes the sulphated bile alcohol scymnolsulphate. We observed no phospholipid and very little cholesterol excretion into bile of these animals. Conversely, when scymnolsulphate was added to the perfusate of isolated mouse liver perfusions, it was very well capable of driving biliary phospholipid and cholesterol excretion. Furthermore, in an erythrocyte cytolysis assay, scymnolsulphate was found to be at least as cytotoxic as taurocholate. These results demonstrate that the little skate does not have a system for the excretion of phospholipid and cholesterol and that both the MDR3 and the two half-transporter genes, ABCG5 and ABCG8, have evolved relatively late in evolution to mediate biliary lipid excretion. Little skate plasma membranes may be protected against bile salt micelles mainly by their high sphingomyelin content.

A phase I/IIA trial of continuous five-day infusion of squalamine lactate (MSI-1256F) plus carboplatin and paclitaxel in patients with advanced non-small cell lung cancer.

PURPOSE: Squalamine is an antitumor agent that has been shown to have antiangiogenic activity in animal models. This Phase I/IIA study was designed to assess the safety, clinical response, and pharmacokinetics of squalamine when administered as a 5-day continuous infusion in conjunction with standard chemotherapy every 3 weeks in patients with stage IIIB (pleural effusion) or stage IV non-small cell lung cancer. EXPERIMENTAL DESIGN: Patients with chemotherapy-naive non-small cell lung cancer were treated with escalating doses of squalamine in combination with standard doses of paclitaxel and carboplatin. Paclitaxel and carboplatin were administered on day 1, followed by squalamine as a continuous infusion on days 1-5, every 21 days. RESULTS: A total of 45 patients were enrolled (18 patients in the Phase I dose escalation arm and 27 in the Phase IIA arm). The starting dose of squalamine was 100 mg/m(2)/day and escalated to 400 mg/m(2)/day; two of three patients at 400 mg/m(2)/day had dose-limiting toxicity that included grade 3/4 arthralgia, myalgia, and neutropenia. On the basis of safety and toxicity, 300 mg/m(2)/day was selected as the Phase II dose of squalamine in this combination regimen. An additional 27 patients (a total of 33) were enrolled according to the protocol treatment schema at 300 mg/m(2)/day. There was no pharmacokinetic evidence of drug interactions for the combination of squalamine, carboplatin, and paclitaxel. Forty-three patients were evaluable for response. Partial tumor responses were observed in 12 (28%) of these patients; an additional 8 evaluable patients (19%) were reported to have stable disease. For all of the patients treated, the median survival was 10.0 months; and 1-year survival was 40%. CONCLUSIONS: The combination of squalamine given continuously daily for 5 days, with paclitaxel and carboplatin given on day 1, is well tolerated. Patient survival data and the safety profile of this drug combination suggests that the use of squalamine given at its maximum tolerated dose with cytotoxic chemotherapy should be explored further as a potentially effective therapeutic strategy for patients with stage IIIB or IV non-small cell lung cancer.

Effect of squalamine on iris neovascularization in monkeys.

PURPOSE: To investigate the effect of squalamine, an antiangiogenic aminosterol, in an experimental model of iris neovascularization. METHODS: Iris neovascularization was created in cynomolgus monkeys by occluding retinal veins with an argon laser and inducing persistent hypotony with a central corneal suture. Twenty-four eyes were treated in three groups. In Group 1, four eyes were injected intravitreally with 3 microg/0.1 mL squalamine and four eyes with balanced saline solution (controls) immediately after vein occlusion (day 1); injections were repeated every 3 days for 3 weeks. In Group 2, 1 mg/kg squalamine was administered with intravenous infusion in dextrose 5% in four animals; four control animals received only dextrose. Infusions began on day 1 and were repeated every 3 days for 3 weeks. In Group 3, after development of iris neovascularization on day 7, 1 mg/kg squalamine was injected systemically in four animals; four control animals received dextrose 5%. Monkeys were examined by slit-lamp biomicroscopy and underwent color photography and fluorescein angiography. RESULTS: Group 1: All eyes, treated and control, developed intense and persistent rubeosis iridis. Group 2: Two of the four treated eyes in this group developed minimal iris neovascularization; the other two had no iris neovascularization. All four control eyes developed intense, persistent iris neovascularization. Group 3: All eyes developed extensive rubeosis iridis; iris neovascularization regressed in all four treated eyes after squalamine injections. Two of four treated eyes retained minimal iris neovascularization; two showed complete regression of rubeosis iridis. Rubeosis iridis completely regressed in two of the four control eyes; the remaining two control eyes had intense, persistent iris neovascularization. CONCLUSIONS: Intravitreally injected squalamine did not affect the development of iris neovascularization; however, systemic squalamine injection inhibited the development of iris neovascularization and caused partial regression of new vessels in a primate model.

Appetite suppression and weight reduction by a centrally active aminosterol.

The rise in obesity and its complications has generated enormous interest in the regulation of feeding and body weight. We show that a spermine metabolite of cholesterol (MSI-1436) decreases body weight, specifically fat, by suppressing feeding and preventing the reduction in energy expenditure, hormonal changes, and patterns of neuropeptide expression normally associated with weight loss. MSI-1436 enters the brain after peripheral injection and is more potent when injected into the cerebral ventricle (intracerebroventricular [ICV]). Systemic or ICV MSI-1436 administration induced similar patterns of Fos immunoreactivity in the brain, especially the paraventricular hypothalamic nucleus (PVN). This brain region integrates neural signals from hypothalamic and brain stem nuclei and regulates feeding behavior, autonomic function, and neuroendocrine function. Microinjection of MSI-1436 into the PVN potently suppressed feeding and reduced body weight for several days. Unlike caloric restriction, MSI-1436 decreased mRNA levels of agouti-related peptide and neuropeptide Y in the hypothalamus. These findings indicate that MSI-1436 acts in the brain to regulate food intake and energy expenditure, likely through suppression of orexigenic hypothalamic pathways.

Identification of cyprinol and cyprinol sulfate from grass carp bile and their toxic effects in rats.

To elucidate the responsible toxic components of grass carp bile, the bile salt 5 alpha-cyprinol sulfate and its desalted form 5 alpha-cyprinol from grass carp bile were purified and identified by analyses of infrared spectrum, (1)H-, (13)C-nuclear magnetic resonance spectra and mass spectrum. The toxicity of grass carp bile powder, butanol extract of grass carp bile powder, 5 alpha-cyprinol and 5 alpha-cyprinol sulfate in rats were further determined. The kidney and liver functions were significantly affected by grass carp bile powder, butanol extract and 5 alpha-cyprinol sulfate. However, 5 alpha-cyprinol also significantly affected the kidney function, but the toxic effect was less.

Squalamine improves retinal neovascularization.

PURPOSE: Modalities for inhibiting neovascularization may be one avenue to the development of effective therapies for retinopathy. The effect of squalamine, an antiangiogenic amino sterol, on oxygen-induced retinopathy (OIR) was assessed in a mouse model. METHODS: OIR was induced in C57BL6 mice by a 5-day exposure to 75% oxygen from postnatal day (P)7 through P12. Squalamine (25 mg/kg, subcutaneous)treated animals received either daily doses for five days from P12 to P16 or one dose just after removal from oxygen on P12. Each set of animals was killed at P17 to P21. Retinopathy was assessed with a retinopathy scoring system evaluation of retinal wholemounts and by quantification of neovascular nuclei on retinal sections. RESULTS: Animals receiving 5 days of squalamine after a 5-day exposure to oxygen had total retinopathy scores (expressed as median score with 25th and 75th quartiles in parentheses) of 4(3, 5) versus oxygen-only-reared animals with scores of 8(7, 9; P < 0.001). Animals reared in room air and animals exposed to squalamine only had similar retinopathy scores: 1(1, 2) and 1(0, 2). Oxygen-reared animals receiving single-dose squalamine also showed improvement, with a median retinopathy score of 4(4, 6.75) versus oxygen-only-reared animals with median retinopathy score of 9(7, 10; P < 0.001). There was a decreased number of neovascular nuclei extending beyond the inner limiting membrane on retinal sections in animals treated with 5 days (P < 0.01) and 1 day (P < 0.001) of squalamine. CONCLUSIONS: Squalamine significantly improved retinopathy and may be a novel agent for effective treatment of ocular neovascularization.