Cytotoxicity of imides-N-alkyl semicarbazones, thiosemicarbazones, acetylhydrazones and related derivatives.

The semicarbazones, thiosemicarbazones and acetyl-hydrazones of phthalimide, o-benzosulfimide, naphthalimide and diphenimide demonstrated potent cytotoxicity against murine and human leukemia cell growth and cultured cell growth from human solid tumors. The major site of inhibition in L1210 leukemia cells was DNA synthesis after 60 min incubated with the agents at 25, 50 and 100 microM. De novo synthesis of purines at the regulatory enzyme sites of PRPP amidotransferase and IMP dehydrogenase were the major targets of the agent. Thymidylate synthetase, dihydrofolate reductase and ribonucleoside reductase activities were inhibited by the agents in a manner which would contribute to the overall reduction of DNA synthesis and cell death. d(NTP) pools were significantly reduced and the evidence suggests that the agents interacted with DNA affording DNA strand scission which would interfere with both template utilization by the polymerases and also ultimately reduce nucleic acid synthesis.

Investigation of 3,5-isoxazolidinediones as hypolipidemic agents in rodents.

A series of 2-benzoyl-4,4-dialkyl-3,5-isoxazolidinediones proved to have potent hypolipidemic activity, lowering both serum cholesterol and triglyceride levels at 10 or 20 mg/kg/day, IP and orally in rodents. 2-(3,4,5-Trimethoxybenzoyl)-4,4-diethyl-3,5-isoxazolidinedione+ ++ (4) afforded the best hypolipidemic activity lowering normolipidemic CF1 mouse serum cholesterol levels 49% and serum triglyceride levels 34% at 20 mg/kg/day, IP. Compound 4 was selected as a typical derivative of the chemical class for further detailed studies. Serum cholesterol levels in normolipidemic Sprague Dawley male rats were reduced 45% after 8 weeks at 10 and 20 mg/kg/day of compound, orally. Serum triglyceride levels were reduced 38-49% at 10 and 20 mg/kg/day, orally. In vitro liver enzyme activities studies in normolipidemic CF1 mice showed the compound inhibited mitochondrial citrate exchange, acetyl CoA synthetase, HMG CoA reductase, acyl CoA cholesterol acyl transferase, acetyl CoA carboxylase, sn-glycerol-3-phosphate acyl transferase, phosphatidylate phosphohydrolase and heparin-induced lipoprotein lipase activities with increases in the activities of cholesterol ester hydrolase and ATP-dependent citrate lyase. Similar enzyme activities were inhibited in vivo except HMG CoA reductase activity was not inhibited in rat liver or small intestinal mucosa after 8 weeks drug administration. Cholesterol levels were reduced in tissues after 8 weeks administration of compound 4 in normolipidemic rats. Bile cholesterol and triglyceride levels were elevated after two weeks administration to rats at 20 mg/kg/day. Serum lipoprotein levels in normolipidemic and hyperlipidemic rats showed the cholesterol levels in VLDL and LDL fractions after 4, 6 and 8 weeks at 10 and 20 mg/kg/day were reduced whereas HDL-cholesterol levels were significantly elevated. Studies demonstrated that 3H-cholesterol and 14C-palmitic acid incorporation into lipids of the lipoprotein fraction was reduced by the drug but 32P-incorporation was generally elevated. The agent demonstrated no observable toxicity in rats after 8 weeks administration, orally. The acute toxicity study in normolipidemic mice at 20, 40 and 100 mg/kg/day, IP, demonstrated no observable harmful effects of the drug.

Anti-inflammatory activity of amine-carboxyboranes in rodents.

Amine-carboxyboranes are potent anti-inflammatory agents reducing induced edema and pleural effusion at 8 mg/Kg, i.p. They protect against LPS (Salmonella) induced septic shock from 2-8 mg/Kg/day and are effective in blocking pain mediated both locally and centrally. The mode of action of these agents is by blocking release of cytokines from macrophages, thus reducing lysosomal hydrolytic and proteolytic enzyme activities of affected cells. The agents also reduce prostaglandin and leukotriene synthesis by blocking the activities of regulatory enzymes of the respective pathways.

The effects of boron derivatives on lipid absorption from the intestine and on bile lipids and bile acids of sprague dawley rats.

N,N-dimethyl-n-octadecylamine borane 1 at 8 mg/kg/day, tetrakis-u-(trimethylamine boranecarboxylato)-bis(trimethyl-carboxyborane)-dicopper(II) 2 at 2.5 mg/kg/day and trimethylamine-carboxyborane 3 at 8 mg/kg/day were evaluated for their effects on bile lipids, bile acids, small intestinal absorption of cholesterol and cholic acid and liver and small intestinal enzyme activities involved in lipid metabolism. The agent administered orally elevated rat bile excretion of lipids, e.g. cholesterol and phospholipids, and compounds 2 and 3 increased the bile flow rate. These agents altered the composition of the bile acids, but there was no significant increase in lithocholic acid which is most lithogenic agent in rats. The three agents did decrease cholesterol absorption from isolated in situ intestinal duodenum loops in the presence of drug. Hepatic and small intestinal mucosa enzyme activities, e.g. ATP-dependent citrate lyase, acyl CoA cholesterol acyl transferase, cholsterol-7-alpha -hydroxylase, sn glycerol-3-phosphate acyl transferase, phosphatidylate phosphohydrolase, and lipoprotein lipase, were reduced. However, the boron derivatives 1 and 3 decreased hepatic HMG-CoA reductase activity, the regulatory enzyme for cholesterol synthesis, but the compounds had no effects on small intestinal mucosa HMG-CoA reductase activity. There was no evidence of hepatic cell damage afforded by the drugs based on clinical chemistry values which would induce alterations in bile acid concentrations after treatment of the rat.

The cytotoxicity of N-Pyridinyl and N-quinolinyl substituted derivatives of phthalimide and succinimide.

The N-pyridinyl and N-quinolinyl substituted derivatives of phthalimides and succinimides demonstrated cytotoxicity against the growth of a number of cultured cell lines. The substituted succinimides were more effective than the unsubstituted succinimide derivative in reducing cell growth. On the other hand, phthalimide demonstrated more potent cytotoxicity than its N-substituted derivatives. Three representative examples N-[2-pyridinyl-1-oxide) methyl] phthalimide 8, 1-[N-2-phthalimidoethyl]-3,4-dihydroiso-quinoline 12, and 1-[N-(2-(1,2,3,4-tetrahydro-2-quinolinyl)] ethylphthalimide 14 were shown to inhibit L1210 leukemia DNA synthesis whereas RNA synthesis was not inhibited at 25-100 uM. All three agents inhibited the activities of DNA polymerase alpha, PRPP-amido transferase, nucleoside kinases, and dihydrofolate reductase. The cellular pool levels of d[GTP], d[CTP], and d[TTP] were reduced after 60 minutes incubation at 100 uM. The DNA molecule itself was not a target of these agents.

Cytotoxicity and mode of action of substituted indan-1, 3-diones in murine and human tissue cultured cells.

N-Substituted indan-1.3-diones have proven to be potent cytotoxic agents effective against the growth of single cell leukemia tumors and cell lines derived from solid tumors. A number of the derivatives were active against growth of solid tumors e.g. colon, lung bronchogenic and osteosarcoma for which few effective agents are available to inhibit their growth. These agents inhibited DNA and RNA synthesis of L1210 cells. The de novo purine synthetic pathway was inhibited at PRPP amido transferase and IMP dehydrogenase. The pyrimidine synthetic pathway was inhibited at aspartate transcarbamylase. Other sites which demonstrate minor inhibition were DNA polymerase alpha, r- and t-RNA polymerase, ribonucleoside reductase, dihydrofolate reductase, nucleoside kinases and thymidylate synthetase. In addition d(NTP) pool levels were reduced by the drugs. L1210 DNA strand scission was evident after exposure to drugs for 24 hr. at 100 microM.

The cytotoxicity of 3-imino-1-oxoisoindolines in murine and human tissue culture cells.

Certain types of hypolipidemic agents have been observed to also function as cytotoxic agents. Previously reported hypolipidemic agents, 3-imino-1-oxoisoindolines, were evaluated for their anti-neoplastic activity. Selected agents were effective at inhibiting L1210, Tmolt3, HeLa-S3, KB nasopharynx, lung, osteosarcoma and glioma growth. 2-Propyl-3-imino-1-oxoisoindoline, (4), a representative compound of the class of agents, inhibited DNA and RNA syntheses of L1210 cells. The major site of inhibition was the purine pathway at IMP dehydrogenase. Other enzyme sites which were affected by (4) marginally were t-RNA and r-RNA polymerases, dihydrofolate reductase, aspartate transcarboxylase, and nucleoside kinases. d(NTP) pools of L1210 cells were reduced after 60 min. Incubation with (4).

Acute toxic and teratogenic effects of cyclic imides in rodents.

Four structurally different cyclic imides or related derivatives (o-(N-phthalimido)acetophenone (1), 2,3-dihydrophthalazine-1,4-dione (2), N-(4-methylphenyl)diphenamide (3), and 4,6-dihydro-5H-dibenz[c,e]azepine (4) were examined for acute toxicity in mice at multiple doses, for long term toxicity at a single dose in rats, and for deleterious effects on fertility and pup development in rodents. No deleterious effects were observed when mice were administered agents at 20, 50, and 100 mg/kg/day for seven days. All other measured characteristics and values were normal for the four compounds. The principle effect of the compounds was to reduce the percent pregnancies in treated mice compared to the controls. Compound 2 afforded the greatest reduction of pregnancy (54%) at 100 mg/kg/day. Compounds 3 and 4 caused a minor reduction in pregnancy (12-20%). The compounds did not appear to cause measureable teratogenic effects; pups of treated rodents thrived and survived as well as controls. There were no effects on murine male fertility when compounds were administered at 20, 50, and 100 mg/kg/day for six weeks.

Hypolipidemic activity of 4-substituted 1,2-diacyl-1,2,4-triazolidine-3,5-diones in rodents.

A series of 4-substituted 1,2-diacyl-1,2,4-triazolidine-3,5-diones were synthesized and shown to be hypolipidemic in rodents; serum cholesterol and triglyceride levels were significantly reduced following intraperitoneal and oral dosing at 20 mg/kg/day. The hypolipidemic activity of the triazolidine-3,5-diones was improved when R1 was either a phenyl or a butyl group. Tissue lipid levels were reduced in the liver, aorta, and small intestine, while fecal lipids, e.g. cholesterol, were increased after 14 days. Very low density lipid cholesterol levels were reduced but high density lipid cholesterol levels were significantly increased. It appears that the mode of action of the 1,2-diacyl-1,2,4-triazolidine-3,5-diones is by the inhibition of the de novo rate limiting enzyme for lipid synthesis. Enzyme activities suppressed by the agents included ATP-dependent citrate lyase, HMG CoA reductase, acyl CoA cholesterol acyl transferase, acetyl CoA carboxylase, sn-glycerol-3-phosphate aryl transferase, phosphatidylate phosphohydrolase, and cholesterol-7 alpha-hydroxylase.

The cytotoxic activity of cyclic imido alkyl ethers, thioethers, sulfoxides, sulfones and related derivatives.

Cyclic imides such as N-substituted alkyl ethers, thioethers, sulfoxides, sulfones and related derivatives were potent agents against human single cell tumors and selected solid tumor growths, eg adenocarcinoma of the colon and glioma. These agents in the L1210 lymphoid leukemia tumor model preferentially inhibited DNA synthesis. The regulatory enzyme sites in the purine pathway were targets of the agents. Other sites of inhibition were DNA polymerase alpha and thymidylate synthetase activities. d(NTP) pool levels were also reduced by the agents over 60 min.

The hypolipidemic activity of metal complexes of amine carboxyboranes in rodents.

The metal complexes of amine-carboxyborane including copper, chromium, zinc, calcium amd cobalt were effective hypolipidemic agents lowering both serum cholesterol and triglyceride levels significantly in mice at 8 mg/kg/day, I.P. after 16 days. The agents reduced acetyl CoA synthetase, ATP-dependent citrate lyase, acyl CoA cholesterol acyl transferase, sn-glycerol-3-phosphate acyl transferase activities of rat liver and small intestinal mucosa after 14 days treatment. The neutral cholesterol ester hydrolase activity was elevated by the agents in both tissues. The metal complexes altered lipid levels in the bile of rats after treatment as well as the bile acid composition after 14 days administration, orally. The agents blocked enterohepatic absorption of cholesterol from rat isolated intestinal loops.

The cytotoxicity of N-substituted diphenimides and 6,7-dihydro-5H-dibenz[c,e]azepines.

N-substituted diphenimides and 6,7-dihydro-5H-dibenz[c,e]azepines demonstrated significant cytotoxic activity against the growth of murine and human cells. These derivatives were active against leukemias, carcinomas and sarcomas. Different derivatives with N-substitutions showed specific activity against the growth of several tumor types. These agents inhibited L1210 leukemia IMP dehydrogenase and PRPP amido transferase activities; this was reflected in the inhibition of purine and DNA synthesis. Other sites inhibited to a minor degree by these agents included DNA polymerase alpha, r- and tRNA polymerases, ribonucleoside reductase, dihydrofolate reductase, pyrimidine synthesis, and nucleoside kinase. d(NTP) pool levels were reduced after 24 h incubation with these derivatives. L1210 DNA strand scission was evident after drug treatment.

The hypolipidemic effects of 1-acetyl-4-phenyl-1,2,4-triazolidine-3,5-dione in rodents.

1-Acetyl-4-phenyl-1,2,4-triazolidine,5-dione (APTD), a potent hypolipidemic agent, lowered both serum cholesterol and triglyceride levels in normo- and hyperlipidemic rats at 10 or 20 mg/kg/day. The agent effectively lowered VLDL-cholesterol (VLDL-C) and LDL-C content and raised HDL-C content in normal and hyperlipidemic rats treated from 4 to 8 weeks. Similar effects on the incorporation of cholesterol into the lipoprotein fractions were observed after drug treatment. Tissue lipids, e.g. cholesterol, were lowered, whereas fecal cholesterol levels were increased. APTD's primary targets were acyl CoA cholesterol acyl transferase (ACAT) for cholesterol ester synthesis and sn-glycerol-3-phosphate acyl transferase (GPAT) and phosphatidylate phosphohydrolase (PPH) for triglyceride synthesis.

Comparison between 6,7-dihydro-5H-dibenz(c,e)azepine and lovastatin as hypolipidemic agents in rats.

6,7-Dihydro-5H-dibenz(c,e)azepine (azepine) and lovastatin were investigated for their hypolipidemic activity in Sprague-Dawley male rats. Azepine lowered both serum total cholesterol and serum triglyceride levels, whereas lovastatin only lowered serum total cholesterol levels significantly. Lovastatin also elevated lipid levels in tissues, whereas azepine in general did not have a similar effect. High-density lipoprotein cholesterol levels were significantly elevated and low-density lipoprotein cholesterol levels were reduced after treatment with both agents. Concentrations of ApoE and ApoAl of high-density lipoprotein were increased after treatment, a result that should enhance the reverse cholesterol transport process of returning cholesterol to the liver for excretion. Azepine appeared to be safe in its therapeutic range in rodents.

The cytotoxicity of N-substituted indazolones in murine and human tumor cells.

N-Substituted indazolones are effective cytotoxic agents, causing cell death in a number of tissue culture lines, e.g. L1210, Tmolt3, colon adenocarcinoma and HeLa-S3. Selected agents were also active against the growth of KB, bronchogenic lung, osteosarcoma and glioma. The mode of action of the derivatives involves inhibition of de novo purine synthesis of L1210 cells, which reduces DNA and RNA syntheses. Agents lowered d(NTP) pools, further reducing DNA synthesis. DNA strand scission was evident after incubation with N-substituted indazolones for 24 h at 100 microM, lowering DNA synthesis and causing cell death.

Synthesis and hypolipidemic activity of 4-substituted 1-acyl-1,2,4-triazolidine-3,5-diones in rodents.

A series of 4-substituted 1-acyl-1,2,4-triazolidine-3,5-diones demonstrated potent activity in CF1 mice when administered intraperitoneally at 20 mg/kg/day, lowering both serum cholesterol and triglyceride levels significantly. The 4-(4-chlorophenyl)-substituted compounds demonstrated better hypolipidemic activity in rodents than 4-methoxy-, 4-nitro-, and 4-t-butylphenyl substitutions. Aryl and alkyl substitutions rather than benzoyl substitutions at position 4 demonstrated good hypocholesterolemic activity. Selected compounds were examined for the mode of action in rats in which serum cholesterol and triglyceride levels were reduced after administration of 20 mg/kg/day orally; tissue lipids were reduced after 14 days of administration, and bile and fecal lipids were increased by 44-250%. Serum lipoprotein levels were also modulated by the agents, with cholesterol levels in very low density lipoprotein and low density lipoprotein fractions being reduced by 2-57%. Cholesterol levels in the high density lipoprotein fraction were elevated by 94-341%. Activities of mouse hepatic enzymes were suppressed by the agents in a manner that suggested that the compounds interfere with de novo synthesis of lipids.

Hypolipidemic activity of 6-alkoxycarbonyl-3-aryl-1,3,5- triazabicyclo[3.1.0]hexane-2,4-diones and 2-alkoxycarbonyl-5-aryl-1,3,5-triazine-4,6(1H,5H)-diones in rodents.

Significant hypolipidemic activity was demonstrated by 6-ethoxycarbonyl-1-3-phenyl-1,3,5-triazabicyclo[3.1.0]hexane-2,4-dione, 2-ethoxycarbonyl-5-phenyl-1,3,5-triazine-4,6(1H,5H)-dione and 2-ethoxycarbonyl-5-(4-chlorophenyl)-1,3,5-triazine-4,6(1H,5H)-dione in rodents at 20 mg/kg/day. These agents lowered serum cholesterol and triglyceride levels by approximately 40% in mice after 16 d. Tissue lipids in rat liver, small intestinal mucosa, aortic wall and feces were reduced by treatment with the agents. Very low density lipoprotein (VLDL) and low density lipoprotein (LDL) cholesterol levels were reduced in the rat; high density lipoprotein (HDL) cholesterol levels were elevated after 14 d of treatment. The activities of regulatory enzymes, e.g., acetyl-CoA synthetase, acyl-CoA:cholesterol acyltransferase, cholesterol 7 alpha-hydroxylase, sn-glycerol-3-phosphate acyltransferase, phosphatidylate phosphohydrolase and heparin-induced lipoprotein lipase, involved in de novo synthesis of hepatic lipids were affected by the agents. The new compounds may represent another class of potentially useful hypolipidemic agents for the treatment of atherosclerosis since HDL cholesterol levels were increased and VLDL and LDL cholesterol levels were lowered by some of the agents.

The effects of cyclic imides on lipid absorption from the intestine and on bile lipids and bile acids of Sprague Dawley rats.

The cyclic imides, o-(N-phthalimido)acetophenone, 2,3-dihydrophthazine-1,4-dione and N(4-methyl phenyl)diphenimide, were evaluated for their effects on bile lipids, bile acids, small intestinal absorption of cholesterol and cholic acid and liver and small intestinal enzyme activities involved in lipid metabolism. The agent at 20 mg/kg/day orally elevated rat bile excretion of lipids, e.g. cholesterol and phospholipids, and increased the bile flow rate. These agents altered the composition of the bile acids, but there was no significant increase in lithocholic acid which is most lithogenic in rats. The three agents did decrease cholesterol and cholic acid absorption from isolated in situ intestinal duodenum loops in the presence of drug. Hepatic and small intestinal mucosa enzyme activities, e.g. ATP-dependent citrate lyase, acyl CoA cholesterol acyl transferase, cholesterol-7-alpha hydroxylase, sn-glycerol-3-phosphate acyl transferase, phosphatidylate phosphohydrolase, and lipoprotein lipase were reduced. However, the cyclic imides did not accelerate HMG-CoA reductase activity, the regulatory enzyme for cholesterol synthesis, in a manner which would accelerate biliary cholesterol excretion. There was no evidence of hepatic cell damage afforded by the drugs based on clinical chemistry values which would induce alterations in bile acid concentrations after treatment of the rat.

Hypolipidemic activity of 1-acyl- and 1,2-diacyl-3,5-pyrazolidinediones.

A series of substituted 1-acyl- and 1,2-diacyl-3,5-pyrazolidinediones were found to have hypolipidemic properties lowering both serum cholesterol and triglyceride levels in rodents. For optimal activity of the pyrazolidinediones, both nitrogen atoms of the ring needed to be substituted preferentially with MeCO groups. This compound lowered rat VLDL but did not elevate HDL cholesterol content.

The hypolipidemic effects of 2-furoic acid in Sprague-Dawley rats.

2-Furoic acid was shown to be effective in lowering both serum cholesterol and serum triglyceride levels significantly in rats with an elevation of HDL cholesterol level at 20 mg/kg/day orally. LDL receptor activity was reduced in hepatocytes, aorta foam cells, small intestinal epithelium cells and fibroblasts. HDL receptor activity was elevated in the rat hepatocytes and small intestinal cells. These activities were correlated with inhibition of acyl CoA cholesterol acyl transferase activity. Neutral cholesterol ester hydrolase activity was elevated in rat hepatocytes and human fibroblasts. Thus, 2-furoic acid appears to interfere directly with activity of intracellular enzymes rather than affecting high affinity-mediated lipoprotein membrane receptors. In vivo treatment with 2-furoic acid led to reduction in the liver and small intestine ATP dependent citrate lyase, acetyl CoA synthetase, acyl CoA cholesterol acyl transferase, sn-glycerol 3-phosphate acyl transferase, phosphatidylate phosphohydrolase and heparin induced lipoprotein lipase activities. 2-Furoic acid reduced biliary cholesterol levels but the agent increased bile salts which are lithogenic. Acute toxicity studies in mice suggest that the agent has some hepatic toxicity effects. The LD50 was relatively low at 250 mg/kg IP in mice.