Multifunctional thioxanthone derivatives with acetylcholinesterase, monoamine oxidases and ß-amyloid aggregation inhibitory activities as potential agents against Alzheimer's disease.

A series of 1-hydroxyl-3-aminoalkoxy-thioxanthone derivatives were designed, synthesized and evaluated as potential multifunctional agents against Alzheimer's disease (AD). The results indicated that most of these compounds exhibited good AChE and MAOs inhibitory activities, significant inhibition of self- and Cu2+-induced Aß1-42 aggregation, and moderate to good antioxidant activities. Specifically, compound 9e displayed high inhibitory potency toward AChE (IC50=0.59±0.02µM), MAO-A and MAO-B (IC50=1.01±0.02µM and 0.90±0.01µM respectively), excellent efficiency to block both self- and Cu2+-induced Aß1-42 aggregation (74.8±1.2% and 87.7±1.9% at 25µM, respectively), good metal-chelating property and a low toxicity in SH-SY5Y cells. Furthermore, kinetic and molecular modeling studies revealed that compound 9e binds simultaneously to the catalytic active site and peripheral anionic site of AChE, and could penetrate the BBB. Collectively, these results suggested that 9e might be a potential multifunctional agent for further development in the treatment of AD.

Inhibition of spleen tyrosine kinase as treatment of postoperative ileus.

OBJECTIVE: Intestinal inflammation resulting from manipulation-induced mast cell activation is a crucial mechanism in the pathophysiology of postoperative ileus (POI). Recently it has been shown that spleen tyrosine kinase (Syk) is involved in mast cell degranulation. Therefore, we have evaluated the effect of the Syk-inhibitor GSK compound 143 (GSK143) as potential treatment to shorten POI. DESIGN: In vivo: in a mouse model of POI, the effect of the Syk inhibitor (GSK143) was evaluated on gastrointestinal transit, muscular inflammation and cytokine production. In vitro: the effect of GSK143 and doxantrazole were evaluated on cultured peritoneal mast cells (PMCs) and bone marrow derived macrophages. RESULTS: In vivo: intestinal manipulation resulted in a delay in gastrointestinal transit at t=24 h (Geometric Center (GC): 4.4 ± 0.3). Doxantrazole and GSK143 significantly increased gastrointestinal transit (GC doxantrazole (10 mg/kg): 7.2 ± 0.7; GSK143 (1 mg/kg): 7.6 ± 0.6), reduced inflammation and prevented recruitment of immune cells in the intestinal muscularis. In vitro: in PMCs, substance P (0-90 µM) and trinitrophenyl (0-4 µg/ml) induced a concentration-dependent release of ß-hexosaminidase. Pretreatment with doxantrazole and GSK143 (0.03-10 µM) concentration dependently blocked substance P and trinitrophenyl induced ß-hexosaminidase release. In addition, GSK143 was able to reduce cytokine expression in endotoxin-treated bone marrow derived macrophages in a concentration-dependent manner. CONCLUSIONS: The Syk inhibitor GSK143 reduces macrophage activation and mast cell degranulation in vitro. In addition, it inhibits manipulation-induced intestinal muscular inflammation and restores intestinal transit in mice. These findings suggest that Syk inhibition may be a new tool to shorten POI.

Phase I dose-escalation study of a novel antitumor agent, SR271425, administered intravenously in split doses (d1-d2-d3) in patients with refractory solid tumors.

BACKGROUND: SR271425 is a novel DNA-binding cytotoxic agent with a broad spectrum of antitumor activity in preclinical models,across a variety of the schedule of administration. In toxicological studies, it has been reported to prolong QTc proportionally to C (max). In order to circumvent this C (max)-related QTc prolongation, 5 phase I studies were initiated to investigate 1-h, 24-h, weekly, and split iv infusions. This phase I study assessed a split-dose regimen (a 1-h infusion on each of Days 1 to 3, repeated every 3 weeks) to establish the dose limiting toxicities (DLT), to recommended a phase II dose, and to characterize PK/PD. METHODS: Patient with advanced solid tumors, adequate bone marrow, hepatic, renal function and on specific cardiac criteria were eligible and "3 + 3" design was used for dose escalation. That dose escalation was guided by PK data, toxicities observed and information from other ongoing phase I studies with SR271425. SR271425 plasma levels (PK samples) were measured using a validated LC-MS/MS method. Careful monitoring of ECGs was done, and ECGs were read centrally. RESULTS: Three centers enrolled 19 heavily pretreated patients to six dose levels, from 75 to 450 mg/m(2)/day (i.e., 225-1,350 mg/m(2)/cycle): 12 males and 7 females. Median age 56. Median ECOG, PS = 1. Main tumor types were brain, breast, gynecological, and urological. Patients received a median of 2 cycles (range: 1-6). NCI-CTC Grade 1-2 toxicities included nausea, vomiting, asthenia, rash, and yellow skin discoloration. No DLTs were reported, and there were no dose-limiting prolongations of QTc. Both C (end) and AUC increased in a dose-related manner, with no evidence of accumulation between Day 1 and Day 3, consistent with the mean (+/-SD) terminal elimination half-life of 5.11 +/- 1.21 h. Stable disease was observed in five cases. CONCLUSION: Split doses allow high cumulative exposure to SR271425 without significant toxicity, especially without QTc prolongation. MTD was not reached due to the early termination of the SR271425 program by the sponsor.

Acute psychotic stress is associated with decreased adiponectin serum levels.

OBJECTIVE: To determine the effect of acute psychotic stress on adipokine secretion in non-diabetic subjects. RESEARCH DESIGN AND METHODS: Adiponectin, leptin, and cortisol serum levels were determined in 39 non-diabetic patients with acute psychotic stress reaction admitted to a psychiatric ward. The clinical global impression (CGI) score was used to evaluate the level of psychotic stress. Insulin sensitivity (IS) was determined by the homeostasis model assessment (HOMA). Patients were re-assessed 2 weeks after admission. During hospitalization patients were treated for variable times with either phenothiazines or thioxanthenes. RESULTS: The mean CGI score decreased significantly with time: 5.3+/-0.8 and 2.6+/-0.8 on admission and after 2 weeks respectively (p<0.001). On admission, the mean adiponectin level was significantly lower in patients compared to normal controls: 15.3+/-8.2 mug/ml and 26+/-12.8 mug/ml, respectively (p=0.02). It increased significantly after 2 weeks to 18.2+/-10 mug/ml (p=0.003). By contrast, the leptin and cortisol levels did not change significantly. No correlation was found between the changes in individual CGI scores and adiponectin levels. However, female patients with the highest stress on admission demonstrated the lowest adiponectin levels and insulin sensitivity: p=0.002 and 0.03 respectively. CONCLUSIONS: These data suggest a link between acute psychotic stress reaction and decreased serum adiponectin levels. Further studies are recommended to determine the strength of this association.

Outpatient treatment of 'crack' cocaine smoking with flupenthixol decanoate. A preliminary report.

"Crack" cocaine abuse often produces severe cocaine dependence that is refractory to available pharmacological and outpatient psychotherapeutic treatments. We conducted two preliminary investigations evaluating the efficacy of flupenthixol decanoate, a depot xanthene requiring infrequent intramuscular administration, in the treatment of cocaine withdrawal. Ten outpatient crack cocaine smokers with poor prognoses were administered flupenthixol decanoate in an open-label, open-ended trial. Flupenthixol decanoate was well tolerated and appeared to decrease cocaine craving and use markedly and rapidly, producing a 260% increase in the average time retained in treatment among these subjects. These promising but preliminary data, combined with the magnitude of problems presented by crack, warrant rapid, expanded double-blind assessment of flupenthixol decanoate in cocaine-abuse treatment.

Phase I pharmacokinetic study of the novel antitumor agent SR233377.

SR233377 is a novel thioxanthenone analogue that demonstrated solid tumor selectivity in vitro with activity confirmed in vivo against several murine tumors including those of colon, pancreas, and mammary origin. Its primary preclinical dose-limiting toxicities included myelosuppression and neurological toxicity. The neurological toxicity was acute and could be ameliorated in mice when the drug was administered as a 1-h infusion instead of rapid i.v. injection. As a result of its preclinical efficacy profile, SR233377 entered Phase I clinical investigation. The compound was administered i.v. over 2 h on day 1 repeated every 28 days. The starting dose was 33 mg/m2 (one-tenth the mouse LD10). Escalations continued to 445 mg/m2 (six escalations), where dose-limiting toxicity was observed. At this dose, acute ventricular arrhythmias, including one patient with torsades de pointes and transient cardiac arrest, occurred. Because this toxicity might have been related to the plasma peak, the protocol was amended to a 24-h infusion beginning at 225 mg/m2. With this dose, prolongation of the corrected QT interval (QTc) over the pretreatment levels resulted. Because prolonged QTc is a known forerunner to acute ventricular arrhythmias, clinical development of SR233377 was stopped. However, preclinical antitumor and toxicity studies with analogues are underway with hopes of identifying a new clinical candidate with similar antitumor effects that is devoid of cardiac toxic effects.

Pharmacokinetic studies in mice of two new thioxanthenones (183577 and 232759) that showed preferential solid tumor activity.

Two new thioxanthenones, 183577 and 232759, have rekindled interest in the development of representatives from this class of structures as useful anticancer agents. Although the mechanism of action is unknown, both compounds demonstrated a similar spectrum of solid tumor selectivity. 232759 was selected for clinical development because it showed no hepatotoxicity in preliminary studies, whereas 183577 showed hepatotoxicity but only at the maximum tolerated dose (MTD). The limiting toxicity for the clinical candidate was myelosuppression in preliminary studies. Plasma and tissue drug levels, as well as protein binding, were studied in mice using optimal administration times at the MTD for each drug (for 183577, this was a 4-h infusion at 1350 mg/m2 and for 232759, it was a 5-min injection at 240 mg/m2), as well as at one-half the MTD for the clinical candidate. The drugs were 96-100% bound by plasma proteins. The peak drug concentrations, half-life, and area under the concentration-time curve in plasma for 183577 were 3483 ng/ml, 465 min, and 2018 microgram/ml. min, respectively. The peak drug concentration, half-life, and area under the concentration-time curve in plasma for 232759 were 5257 ng/ml, 44 min, and 276 microgram/ml. min, respectively, at the MTD and 2810 ng/ml, 40 min, and 110 microgram/ml. min at one-half the MTD. In all instances of simultaneous measurements, drug concentrations were equal or higher in tissues than they were in plasma. Unlike the plasma and kidney concentrations of 183577, the liver concentrations did not show a declining trend over the 8-h observation period. Declines in plasma, liver, kidney, and tumor levels of 232759 were detected over the 8-h observation period. The sustained high 183577 concentration in liver is believed to be responsible for its prolonged half-life and hepatotoxicity. Evidence for metabolism of the parent drugs was based on the finding of additional peaks on the high-pressure liquid chromatography tracings. Future studies will focus on identification and antitumor studies of these presumed metabolites in hopes of a better understanding of the solid tumor activity profiles and toxic effects of these compounds.

Cold urticaria: inhibition of cold-induced histamine release by doxantrazole.

Thirteen patients with cold urticaria were studied to assess the effect of the systemic drug doxantrazole, which has actions resembling disodium cromoglycate, on cold evoked histamine release. The patients, all of whom developed an immediate local whealing response after cooling of the forearm, demonstrated release of histamine into venous blood draining that forearm. Following doxantrazole treatment, significant suppression of histamine release occurred. In some but not all patients this was accompanied by diminution of urtication in response to cooling. A double-blind study was carried out in 3 subjects, all of whom showed diminished cold-stimulated histamine release after doxantrazole. Two of these showed clinical improvement. Doxantrazole had no effect on erythema due to intradermal histamine, but did suppress the erythematous reaction to intradermal injection of compound 48/80. Our results suggest that doxantrazole or related anti-allergic agents might be useful in the treatment of cold urticaria.

Analogues of hycanthone and lucanthone as antitumor agents.

Hycanthone analogues (5 and 6) containing 7-substituted hydroxyl groups were prepared and evaluated as antitumor agents. These compounds were significantly more active than the corresponding unsubstituted derivatives. The 7-hydroxylated 4-(hydroxymethyl)-9H-xanthen-9-ones, 11 and 12, were also active antitumor agents. However, the 7-hydroxy-9H-xanthen-9-one counterparts of the 7-hydroxylucanthones were totally devoid of antitumor activity. Results obtained thus far are consistent with the hypothesis that 4-hydroxymethyl substituents in the 9H-xanthen-9-one and 9H-thioxanthen-9-one series are required for antitumor activity.

Preparation and antischistosomal and antitumor activity of hycanthone and some of its congeners. Evidence for the mode of action of hycanthone.

The synthesis of a series of esters of hycanthone (HC) and 7-hydroxyhycanthone, their antitumor activity, and their antischistosomal effects on HC-sensitive and HC-resistant schistosomes are reported. Binding studies using tritium-labeled HC and hycanthone N-methylcarbamate (HNMC) with calf thymus DNA provided evidence that HNMC but not HC alkylated the DNA. Tritiated HNMC also bound to the DNA of intact HeLa cells exposed to the drug while very little tritiated HC bound to DNA under the same conditions. The mechanism proposed previously to account for the antischistosomal action of HC, namely, drug esterification followed by alkylation of DNA, applies also to the antitumor action of the drug as shown in Scheme I.

Effect of trans(E)-clopenthixol on Plasmodium berghei in vivo.

Previous in vitro studies have shown suppression of the growth of Plasmodium falciparum by the neuroleptic agents chlorpromazine and zuclopenthixol (formerly known as cis(Z)-clopenthixol) as well as by the neuroleptic inactive steroisomer trans(E)-clopenthixol. These compounds are chemically related to riboflavin and may act as inhibitors of riboflavin metabolism. As trans(E)-clopenthixol has been found active against chloroquine-resistant strains of P. falciparum in vitro and has been approved for human use, though inactive as a neuroleptic, this drug was selected for the present in vivo study. The dosage of trans(E)-clopenthixol was optimized through a pharmacokinetic study, and the suppression of the growth of Plasmodium berghei in vivo was tested in mice, with chloroquine acting as the positive and saline as the negative control. Trans(E)-clopenthixol did not inhibit the growth of P. berghei, whereas chloroquine almost eradicated the infection. The use of in vitro screening for anti-malarial activity in drugs approved for human use for other indications is discussed in the light of the results. It is concluded that the selection of drugs for further studies in vivo cannot solely be based on positive results in vitro.

3-Methoxy-4-hydroxyphenylglycol excretion in acutely schizophrenic patients during a controlled clinical trial of the isomers of flupenthixol.

Urinary MHPG excretion in patients with acute schizophrenia was studied before and during a trial of the isomers of flupenthixol and placebo. Pretrial MHPG excretion was not related to severity of illness before the trial or to other pretrial clinical variables. In male subjects higher pretrial MHPG excretion was associated with a better outcome 1 year post-trial. However in females no relationship between MHPG excretion and outcome was established. During the trial there was a reduction in MHPG excretion in patients treated with beta-flupenthixol but no decrease in the group treated with alpha-flupenthixol or chlorpromazine. In patients on placebo there was a reduction in MHPG excretion in those who did well clinically, but not in those who did poorly. Thus low MHPG excretion may be a predictor of poor outcome in schizophrenia, but MHPG excretion also changes both as a function of clinical state and of neuroleptic drug administration.

Serum levels and clinical response in long-term pharmacotherapy with zuclopenthixol decanoate.

Twenty-six patients diagnosed as chronic schizophrenics were given injections of zuclopenthixol decanoate (cis(Z)-clopenthixol decanoate) 200 mg every 3 weeks for at least 6 months. Before treatment and on each day of injection the patients' mental state was assessed by Brief Psychiatric Rating Scale (BPRS), 18 items. A registration of side effects and basal laboratory data was also performed. Blood samples were drawn on each day of injection before injection and 3-7 days after injection (time of maximum concentration). Neuroleptic activity, which was considered equivalent to the concentration of zuclopenthixol, was determined in serum by radio-receptor assay (RRA). Based on amelioration scores greater than or equal to 50% on the BPRS, 15 patients were characterized as responders and 11 as non-responders. The responder group showed a statistically significant reduction in BPRS score, whereas this was not the case for the non-responders. Apart from a few patients, the serum concentrations showed a low intra-individual variation, but a relatively high inter-individual variation. The responder group had a significantly higher mean pre-injection concentration than the non-responder group, whereas no significant difference was found in day 3-7 concentrations. The fluctuation of the serum concentration expressed as the ratio between maximum (days 3-7) and minimum (pre-inj.) was found to be significantly lower for responders than for non-responders. Thus although the present study did not demonstrate a clear relationship between serum level and clinical effect, it indicates that the best antipsychotic effect is obtained with a serum concentration which fluctuates only slightly (the ratio max/min concentration not exceeding 2.1).

Zuclopenthixol decanoate in schizophrenia: serum levels and clinical state.

Serum concentrations of zuclopenthixol were determined in a group of 20 patients treated with a depot preparation, zuclopenthixol decanoate in Viscoleo. Clinical assessments according to a Clinical Global Impression (CGI) scale, Comprehensive Psychological Rating Scale (CPRS), 16-item subscale for schizophrenia, and the UKU side effect scale were performed on 3 consecutive days of injection. The serum concentrations showed a limited individual variation and a high and significant correlation between dose and serum concentration. One patient had a particularly high serum concentration of zuclopenthixol. This patient also had an elevated concentration of the N-dealkyl metabolite, but a low concentration of the sulphoxide. For serum concentrations versus clinical state and side effects some significant correlations were found. All correlations were positive, which means that the higher the serum concentration the poorer the clinical state of the patient. We think that this probably reflects a common clinical pattern of increasing the dose, when the antipsychotic response is unsatisfactory. The study also showed that for moderately ill patients, who were given the optimum dose of drug, the subgroup of patients not experiencing side effects had significantly lower serum concentrations than the subgroup with side effects.

Serum concentrations and clinical effect of zuclopenthixol in acutely disturbed, psychotic patients treated with zuclopenthixol acetate in Viscoleo.

Zuclopenthixol acetate, 5%, in Viscoleo was administered IM to 19 acutely disturbed, psychotic patients in doses of 50-150 mg. Fifteen patients received one injection, whereas four of the patients had two or three injections, usually with intervals of 3 days. The zuclopenthixol concentrations in serum were measured in series of samples taken from each patient during a 3-day period following the injection. In patients given identical doses serum concentrations of about the same order were obtained. Significant and good correlations were found between dose and maximal serum concentration and between dose and area under the serum concentration curve. The average serum concentration curve obtained when adjusting the data to a 100 mg dose has a maximum of 41 ng/ml after about 36 h, decreasing to 15 ng/ml after 72 h. A dose of 50-150 mg zuclopenthixol acetate in Viscoleo appeared to be sufficient for controlling the symptoms for most acutely disturbed, psychotic patients. The frequency of side effects, including extrapyramidal reactions, was low and the adverse reactions mostly mild, indicating that the risks for severe complications generally might be minimal. With a rapid onset of action, few and mild side effects, good tolerability at the injection site, and a duration of effect of 2-3 days, zuclopenthixol acetate in Viscoleo appears to offer advantages compared to conventional neuroleptic treatment in patients in whom an acute, calming effect is desired.

Comparative effects of hycanthone in Schistosoma mansoni and Schistosoma japonicum.

After in vitro hycanthone treatment followed by a 20-hour incubation in drug-free medium, Schistosoma mansoni were still resistant to labeling by a fluorescent analog of acetylcholine. S. japonicum, in contrast with the hycanthone sensitive species, showed prompt reversal of the blocking effects of hycanthone on fluorescent labeling. This finding suggests that differences in the reversibility of hycanthone may correlate with the usefulness of the drug in the therapy of schistosome infections by different species of parasites. Scanning electron microscopy has been used to demonstrate that hycanthone treatment causes degeneration of the integument of S. mansoni, but not S. japonicum, over a period of few days after in vivo exposure to hycanthone. The mechanism by which hycanthone causes this effect is not known.

Curative chemotherapy and resistance to reinfection in murine schistosomiasis.

Complete parasitological cure was obtained by specific chemotherapy in mice with a 10-week-old infection induced by inoculating 30 cercariae of Schistosoma mansoni. By challenging the cured animals with 100 cercariae it was found that cutaneous and pulmonary reactivity to invading schistosomula, the ability to modulate periovular granulomas in the liver, and the resistance to reinfection, as measured by survival rates and recovery of worms from the portal vein system, persisted for 1 and 2 months following treatment and disappeared after 6 months. Thus, a residual immunity and reactivity to reinfection seems to persist in the host for some time after curative chemotherapy of schistosomiasis.

Effect of chemotherapy on experimental pulmonary schistosomiasis.

Mice with portal hypertension caused by portal vein ligation reproduced the model of severe pulmonary schistosomiasis when infected for 10 weeks with 30 cercariae of Schistosoma mansoni. Curative treatment promoted reversion, without fibrosis, of the periovular granulomatous lesions formed in the alveolar tissue. However, the arterial and arteriolar lesions were defectively repaired, with segmental vascular fibrosis, narrowing, and angiomatoid changes remaining for up to 120 days after treatment. There was also evidence that eggs are destroyed more rapidly and more completely in the lungs than in the liver.

Control of Schistosoma mansoni transmission by chemotherapy in St. Lucia. I. Results in man.

Control of Schistosoma mansoni transmission solely by treatment of all infected persons was attempted in Marquis Valley (population about 3,100), St. Lucia. Two-year results are reported. Excluding 26 pregnant patients, 709 to 729 persons who were found to be infected received treatment the first year. Most of these, 677, were given a single injection of hycanthone (2.5 mg/kg of body weight), and the same treatment was administered to 159 patients the second year. Side effects were not severe; the major side effect, vomiting, occurred in about 22% on both occasions. In villages with initially high transmission rates, the incidence of new infections in children 0 to 14 years fell from 20.8% before chemotherapy to 7.4% after 1 year and to 3.7% after 2 years. This pattern was significantly different from that in the comparison area where no control scheme exists. Chemotherapy alone appears to be a rapid, effective, and comparatively inexpensive method of controlling S. mansoni transmission in St. Lucia.

A study of the mode of action of hycanthone against Schistosoma mansoni in vivo and in vitro.

Schistosomes obtained by perfusion from host animals as early as 2 hours after in vivo treatment with hycanthone and transferred into untreated recipient hamsters died in the recipient host. In contrast, unexposed schistosomes transferred into recipient hamsters treated from 7 days to 36 hours previously showed a normal survival. In vitro treatment of schistosomes with hycanthone concentrations comparable to those used in in vivo studies, followed by transfer of the parasites into normal hamsters, resulted in death of the worms. The time of lethal hycanthone exposure in vitro could be as short as 15 minutes. Hycanthone-resistant schistosomes or immature worms were not affected under similar in vitro conditions. Our data suggest that the schistosomicidal effect of hycanthone is not caused by a host-derived metabolite.