Anti-inflammatory activity of sesquiterpene lactones and related compounds

Some sesquiterpene lactones and related compounds were tested for anti-inflammatory activity in rodents. In the edema-induced carrageenan inflammation screen, the alpha-methylene-gamma-lactone moiety of the sesquiterpene lactones was required for inhibitory activity. The 6-hydroxy group of helenalin also was required for potency. In the tenulin series, the 2,3-epoxy derivatives were marginally active. The same structure was required for inhibition of the writhing reflex. In the chronic adjuvant arthritic screen, compounds containing the alpha-methylene-gamma-lactone moiety, the beta-unsubstituted cyclopentenone ring, and the alpha-epoxy cyclopentenone system afforded significant inhibition at 2.5 mg/kg/day. The sesquiterpene lactones were marginally effective against induced pleurisy. The delayed hypersensitivity was suppressed by these agents whereas immunoglobulin synthesis was slightly stimulated. No delerious side effects were observed with these agents from the limited tests performed.

Stimulation by epinephrine of in vivo phosphorylation and inactivation of acetyl coenzyme A carboxylase of rat epididymal adipose tissue

Intraperitoneal injection of inorganic 32P into rats results in the incorporation of 32P into acetyl-CoA carboxylase without inactivation of the enzyme. Administration of epinephrine stimulates 32P incorporation and results in enzyme inactivation. Incubation of epididymal fat tissues with inorganic 32P also results in incorporation of 32P into carboxylase. This 32P incorporation reaches a maximum level in 3 h and it has no effect on carboxylase activity. Administration of epinephrine at the time of maximum phosphorylation (3 h) results in further phosphorylation and inactivation of carboxylase. Propranolol, a beta-adrenergic blocking agent which inhibits epinephrine action, blocks both the epinephrine-stimulated phosphorylation and the inactivation of the carboxylase. However, propranolol has no effect on that component of the phosphorylation which is unrelated to enzyme inactivation. These results establish that phosphorylation of carboxylase occurs in vivo at two different sites, only one of which results in enzyme inactivation. The phosphorylation site associated with enzyme inactivation is hormonally controlled.

Effect of epinephrine on acetyl-CoA carboxylase in rat epididymal fat tissue

If acetyl-CoA carboxylase in epididymal fat tissue is subject to control by convalent modification as in the case of the liver enzyme, catalytically different forms of carboxylase should exist, independent of polymerization. By treating epididymal fat tissue in culture with epinephrine, we have demonstrated catalytically less active forms of acetyl-CoA carboxylase. The catalytically less active forms of the enzyme reacted to antibody with the same efficiency as the active form of carboxylase. However, the less active enzyme formed by epinephrine treatment of tissues has a sedimentation constant of 30 to 35 S, whereas that of the enzyme from control tissue is 45 S. Incubation of the less active forms of the carboxylase with 10 mM citrate and up to 10 mg/ml of bovine serum albumin activated the enzyme without any change in the sedimentation constant. Therefore, the less active forms of the carboxylase formed as a result of epinephrine treatment are not due to the depolymerization of polymeric forms (45 S) to the protomeric forms (17 to 20 S), but to the formation of intermediate species of carboxylase which cannot form polymeric enzyme (45 S) in the presence of high concentrations of citrate.

Regulation of rat liver acetyl-CoA carboxylase. Stimulation of phosphorylation and subsequent inactivation of liver acetyl-CoA carboxylase by cyclic 3':5'-monophosphate and effect on the structure of the enzyme

The effects of citrate and cyclic AMP on the rate and degree of phosphorylation and inactivation of rat liver acetyl-CoA carboxylase were examined. High citrate concentrations (10 to 20 mM), which are generally used to stabilize and activate the enzyme, inhibit phosphorylation and inactivation of carboxylase. At lower concentrations of citrate, the rate and degree of phosphorylation are increased. Furthermore, phosphorylation and enzyme inactivation are affected by cyclic AMP under these conditions. At high citrate concentrations, cyclic AMP has little or no effect on inactivation and phosphorylation of acetyl-CoA carboxylase. Phosphorlation and inactivation of carboxylase is accompanied by depolymerization of the polymeric form of the enzyme into intermediate and protomeric forms. Depolymerization of carboxylase requires the transfer of the gamma-phosphate group from ATP to carboxylase. Inactivation occurs in the absence of CO2, which indicates that phosphorylation of the enzyme is the cause of inactivation and depolymerization, i.e. carboxylation of the enzyme is not responsible for inactivation of the enzyme.

Antitumor agents XXX: Evaluation of alpha-methylene-gamma-lactone-containing agents for inhibition of tumor growth, respiration, and nucleic acid synthesis

Evidence is presented that a number of sesquiterpene lactones isolated from plants and synthesized pyrimidines containing the alpha-methylene-gamma-lactone moiety are potent inhibitors of Walker 256 carcinosarcoma and Ehrlich ascites tumor growth and marginal inhibitors of P-388 lymphocytic leukemia and Lewis lung tumor growth. In vitro aerobic basal respiration and oxidative phosphorylation processes of Ehrlich ascites cells were inhibited by these agents as well as deoxyribonucleic acid polymerase and thymidylate synthetase enzymatic activities. These studies indicate that the alpha-methylene-gamma-lactone moiety, the beta-unsubstituted cyclopentenone ring, and the alpha-epoxycyclopentanone system are the essential moieties for inhibition of these biochemical parameters.

Antitumor agents 32. Synthesis and antitumor activity of cyclopentenone derivatives related to helenalin

Several new cyclopentenones related to helenalin have been synthesized as potential alkylating antitumor agents. The procedure involved the transformation of 2-methyl-2-carbethoxycyclopentanone (2) to an ethylene ketal 3, bromination of 3 followed by dehydrobromination to yield a ketal olefin 5, reduction of 5 to the alcohol 6, conversion of 6 to the corresponding hydroxycyclopentenone 7, and estrification of 7 to afford the cyclopentenone esters 8--11. Biological assays indicated that only cyclopentenones possessing a conjugated ester side chain, such as 9 and 10, demonstrated significant in vitro cytotoxicity against the growth of tissue culture cells originating from human epidermoid carcinoma of the larynx (H.Ep.-2) as well as in vivo antitumor activity in Walker 256 carcinosarcoma in rats and P-388 lymphocytic leukemia in mice.

Antitumor agents XXVII: Effects of helenalin on anaerobic and aerobic metabolism of Ehrlich ascites cells

Evidence is presented that the antitumor agent helenalin, a sesquiterpene lactone, suppresses anaerobic glycolytic enzymes of tumor cells at a number of sites and not exclusively at glycogen synthetase and phosphofructokinase, previously proposed sites for inhibition by alpha-methylene-gamma-lactones. Of the enzymes tested, the sulfhydryl-containing enzyme hexokinase was inhibited the maximum, i.e., 83%, by helenalin treatment, whereas phosphofructokinase and glycogen synthetase were suppressed approximately 45%. Another sulfhydryl-bearing enzyme, aldolase, was decreased approximately 43%. Phosphorylase a was inhibited 65%, glucose-6-phosphatase was inhibited 46%, and succinic dehydrogenase was inhibited 59% by helenalin treatment. Mitochondrial oxidative phosphorylation processes were also significantly depressed in the presence of helenalin in vitro with either succinate or alpha-ketoglutarate as substrates. Thus, a number of enzymes of anaerobic and aerobic carbohydrate metabolism of Ehrlich ascites cells appear to be inhibited by helenalin, which supposedly can alkylate functional groups, e.g., sulfhydryl groups of these enzymes, by a rapid Michael-type addition.

Macroamylasemia and other chronic nonspecific hyperamylasemias: chemical oddities or clinical entities?

Seventeen patients with chronic hyperamylasemia were studied using standard clinical and laboratory parameters, amylase/creatinine clearance ratios, and polyacrylamide gel electrophoresis of serum amylases. These patients, none of whom had evidence of pancreatic disease or other specific source for the elevated serum amylase, fell into three groups: (1) Normal serum isoamylase profile and normal amylase clearance (6 patients). We postulate that the generalized hyperamylasemia may be due to reduced extrarenal catabolism of amylase, a previously undescribed phenomenon. (2) Macroamylasemia and very low amylase clearance (9 patients). Seven of the nine patients had recurrent epigastric pain. Evidence for an autoimmune basis is discussed. (3) Salivary-type hyperamylasemia and low amylase clearance (2 patients). This entity may really be macroamylasemia in which the macroamylase complex dissociated during analysis. Chronic hyperamylasemia is often not of pancreatic origin. The assumption that the pancreas is at fault, especially if there is abdominal pain, may cause morbidity due to gross overtreatment.

Effects of neuroleptics on morphine-induced tail erection in mice

Morphine elicits dose-dependent tail erection in mice. Pretreatment of mice with atropine, phenoxybenzamine, propranolol, diphenhydramine, cyproheptadine or parachlorophenylalanine did not interfere with tail erection induced by morphone. Several neuroleptic drugs which are dopamine receptor blocking agents showed a clear antagonistic effect on morphine-induced tail erection (MITE). Haloperidol and penfluridol blocked MITE at doses which only produced a slight behavioral depression. Pimozide and chlorpromazine were less antagonistic than haloperidol and penfluridol and inhibited MITE only at doses which produced a marked behavioral depression. Results indicated that dopamine might be involved in tail erection induced by morphine. MITE in mice might be a useful model for the evaluation of neuroleptic drugs.

Antitumor agents XXIII: Helenalin, and antitumor principle from Anaphalis morrisonicola HAY

A chloroform extract of the whole plant of Anaphalis morrisonicola HAY, showed significant antitumor activity against Ehrlich ascites carcinoma, Walker 256 carcinosarcoma, and P-388 lymphocytic leukemia. Systematic fractionation of the extract led to isolation and characterization of helenalin, a pseudoguaianolide, as the major active principle.

Antitumor agents. 25. Synthesis and antitumor activity of uracil and thymine alpha-methylene-gamma-lactones and related derivatives

Uracil and thymine alpha-methylene-gamma-lactones and related derivatives have been synthesized as novel potential alkylating antitumor agents. The synthesis of these compounds involved the convenient Reformatsky-type reaction between ethyl-alpha-(bromomethyl)acrylate and the proper pyrimidinyl ketones. Preliminary in vivo tumor assay indicated that these compounds were active against the Walker 256 carcinosarcoma in rats and the P-388 lymphocytic leukemia as well as the B-16 melanotic melanoma in mice at 2.5-25 mg/kg.

On the cause of raised serum-amylase in diabetic ketoacidosis

7 of 13 patients with diabetic ketoacidosis had raised serum-amylase concentrations. Isoenzymes analysis by polyacrylamide-gel electrophoresis showed that salivary-type amylases and not pancreatic-type amylases were responsible for the rise in 6 or the 7 cases. This demonstrates that the pancreas is usually not the origin of the increase in serum-amylase. Since salivary-type amylases are widely distributed in glandular epithelium, it is suggested that hyperamylasaemia in diabetic ketoacidosis is most often caused by systemic derangement of carbohydrate metabolism.

Sesquiterpene antitumor agents: inhibitors of cellular metabolism

Helenalin and tenulin injected into CF1 male mice bearing Ehrlich ascites tumors inhibit DNA synthesis and DNA polymerase enzymatic activity in the tumor cells. Helenalin inhibited protein synthesis. Both drugs increased the concentration of adenosine 3',5'-monophosphate, and interfered with glycolytic and mitochondrial energy processes. Cholesterol synthesis was also inhibited, resulting in lower serum cholesterol levels in tumor-bearing animals. Data obtained in vitro indicate that the cyclopentenone-bearing sesquiterpene lactone and related compounds do not alkylate puring bases of nucleic acids but rather undergo a Michael-type addition reaction with the sulfhydryl groups of reduced glutathione and l-cysteine. Thus, the inhibition of cellular enzyme activities and metabolism that has been observed with these drugs might be explained by the occurrence of a Michael-type teaction.

Antitumor agents. 21. A proposed mechanism for inhibition of cancer growth by tenulin and helenalin and related cyclopentenones

Evidence is presented that sesquiterpene lactones or ketones containing the O=CC=CH2 moiety, e.g., tenulin and helenalin, alkylate the thiol group of reduced glutathione and L-cysteine in vitro. A proposal is offered that this mechanism of action is responsible for the observed potent in vivo antitumor activity of these agents in the Ehrlich ascites and Walker 256 carcinosarcoma and to a lesser extent in the P388 leukemic screen. Inhibition of tumor growth is thought to occur due to the O=CC=CH2 system alkylating by rapid Michael addition the SH biological nucleophiles of key regulatory enzymes of nucleic acid and chromatin metabolism. This proposition is in accord with the ability of these agents to inhibit DNA synthesis and gene activity of Ehrlich ascites cells.