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141 records · Page 8Linked to original sources
PubMed1979

[Inhibition of ovulation with 17-alpha-ethinyl-18-methyl-11-methylene-4-estren-17-ol plus ethinylestradiol].

A combined oral application of 30 micrograms ethinylestradiol with 50 micrograms 17 alpha-ethinyl-18-methyl-11-methylene-4-estren-17-ol (a newly developed progestagen) -- for 21 days resulted in a distinct antigonadotrophic effect, shown by hormone analysis (LH, FSH, estradiol and progesterone) in serum samples of three healthy and fertile women. A final recommendation on the daily dosage, however, depends on the results of clinical experimental investigation still in progress.

Estradiol↗
PubMedDate not supplied

Potential antitumor agent: steroidal bilactam ester of p-N, N-bis (2-chloroethyl) aminophenylacetic acid.

7 alpha-, 17 alpha-Diaza-7, 17-dioxo-B, D-dihomo-5-androsten 3 beta-p-N, N-bis (2- chloroethyl)aminophenylacetate, a modified steroidal alkylating agent, is active in the treatment of P388 and L1210 leukemias in vivo. The compound was also tested in vitro against L1210 and P388 leukemias, on DNA, RNA and protein synthesis and showed high inhibition effect. Also increases the frequency of Sister Chromatid Exchanges and reduces the replication index of human lymphocytes.

Animals↗
PubMedDate not supplied

Conjugated system of homo-aza-steroidal esters in cancer chemotherapy.

The homo-aza-steroidal esters of conjugated carboxylic derivatives of nitrogen mustards are reviewed. Particularly we discuss the antitumor activity of cinnamic acid and benzoic acid mustard isomers, esters of homo-aza-steroids in which the mustard acid is linked to the C-3 or C17 position, while the lactam nucleus is in the D or A ring of the steroid respectively. The current literature indicates that the potential is due to the synergistic activity of both the steroidal lactam and the mustard of the acids. Steroidal lactams, namely 3 beta-hydroxy-13 alpha-amino-13,17-seco-5 alpha-androstan-17-oic-13,17-lactam, the isomer 3 alpha-hydroxy-13 alpha-amino-13,17-seco-5 alpha-androstan-17-oic- 13,17-lactam, 3 beta-hydroxy-13 alpha-amino 13,17-seco-5-androsten-17-oic-13,17-lactam and the 17 beta-hydroxy-3-aza-A-homo- 4 alpha-androsten-4-one, have been used as biological platforms of the cinnamic acid, of the benzoic acid mustard isomers and the 4-methyl-benzoic acid mustard. The twelve esters of cinnamic acid mustard isomers were tested against P388, L1210 leukemias Ehrlich ascites tumor (EAT) and melanoma B16 in vivo. The effect of homo-aza-steroidal esters of N,N-bis(2-chloroethyl) amino cinnamic acid isomers on the incorporation of the radioactive precursors into DNA, RNA and proteins of L1210, P388 leukemias, Ehrlich ascites tumor (EAT) and Baby Hamster Kidney (BHK) cells, was investigated. The effect of the homo-aza-steroidal esters of N,N-bis(2-chloroethyl) aminobenzoic acid isomers on the incorporation of radioactive precursors into DNA, RNA and proteins was studied in L1210, P388 leukemias, Ehrlich ascites tumor and Baby hamster kidney cells.

Animals↗
PubMed1994

Effects of scalaradial, a type II phospholipase A2 inhibitor, on human neutrophil arachidonic acid mobilization and lipid mediator formation.

The role of scalaradial (SLD) (or its 12-epi analog), a marine natural product purified from sponge (Cacospongia mollior) in human neutrophil (polymorphonuclear leukocyte, PMN) arachidonic acid metabolism was studied. SLD potently inhibited human recombinant (rh) type II-14 kDa-phospholipase A2 (PLA2) (IC50 = 0.07 microM) but displayed weak inhibition of U937 cell, 85 kDa-PLA2 (IC50 = 20 microM). Sn-2 acylhydrolytic activity expressed in human PMN acid extract, that was completely neutralized by anti-rh type II-14 kDa-PLA2 monoclonal antibody, was inhibited by SLD in a concentration-dependent manner (IC50 = 35 microM). Exposure of human PMN to SLD resulted in a concentration-dependent inhibition of calcium ionophore (A23187)-induced leukotriene B4 release (IC50 = 0.1-0.6 microM). In contrast to the action of selective 5-lipoxygenase inhibitors (WY 50295 or zileuton), SLD decreased A23187-induced PMN liberation of arachidonic acid mass and platelet-activating factor biosynthesis (IC50 = 1-2 microM). PMN acetyltransferase activity was not significantly affected by SLD suggesting that platelet-activating factor inhibition was due, predominantly, to inactivation of PLA2 activity. In vivo, topical application of SLD on mouse ear treated with phorbol ester, not only inhibited edema formation but also the increase in myeloperoxidase activity (an index of cellular infiltration). SLD had little or no effect on arachidonic acid-induced ear edema or myeloperoxidase which is consistent with an action on PLA2. Take together these data suggest that the predominant mechanism of SLD is via inhibition of 14 kDa-like-PLA2 and suggests that this enzyme may participate in PMN arachidonic acid liberation and lipid mediator formation.

Animals↗
PubMed1993

Regulation of CD11b/CD18 expression in human neutrophils by phospholipase A2.

Recent evidence suggests that phospholipase A2 (PLA2)-derived lipid mediators may regulate a number of neutrophil responses including degranulation and adhesion. In view of the potential role of PLA2 in stimulus-secretion coupling, we examined the relationship between PLA2 activation and the surface expression of CD11b/CD18 (MAC-1) in human polymorphonuclear leukocytes (hPMNL), including the functional consequences of PLA2 inactivation on MAC-1-dependent adhesion. The selective inhibition of PLA2 by the marine natural products manoalide (MLD) and scalaradial (SLD) blocks [3H]arachidonic acid (AA) release in calcium ionophore A23187-stimulated neutrophils, and also inhibits secretion of specific and azurophilic granule constituents. Additional studies demonstrate that MLD, SLD, and other less potent PLA2 inhibitors such as 4-bromophenacylbromide and nordihydroguiaretic acid inhibit the surface expression of MAC-1 (IC50: MLD, 0.33 microM; SLD, 0.23 microM; 4-bromophenacylbromide, 2.8 microM; NDGA, 3.5 microM) at concentrations similar to those at which they inhibit [3H]AA release. Inhibitors of cyclooxygenase, 5-lipoxygenase, protein kinase C, or calcium channel antagonists have no effect on MAC-1 expression. PLA2 inactivation also prevents MAC-1 up-regulation in hPMNL stimulated with FMLP, IL-8, TNF-alpha, PMA, or platelet activating factor. In FMLP-stimulated hPMNL, under conditions in which no secondary granule constituents are secreted, MAC-1 and alkaline phosphatase up-regulation from intracellular granules is inhibited by MLD and SLD. Functional assays also demonstrate that MLD and SLD block MAC-1-dependent adhesion of activated neutrophils to keyhole limpet hemocyanin at concentrations that block the surface expression of MAC-1. [3H]AA release and MAC-1 expression in MLD and SLD-treated hPMNL could be recovered in the presence of 1 mM hydroxylamine in a time-dependent fashion, consistent with reported data that MLD and SLD inactivate PLA2 through Schiff base formation. In summary, these data emphasize the role of PLA2 as a key regulator of MAC-1 expression in models of neutrophil adhesion.

Arachidonic Acid↗
PubMedDate not supplied

Antitumor activity of homo-aza-steroidal esters of p-N, N-bis(2-chloroethyl)aminophenoxyacetic acid.

The homo-aza-steroidal esters of carboxylic derivatives of N, N-bis (2-chloroethyl) aniline are reviewed. In particular, we discuss the antitumor activity of the esters of homo-aza steroids in which the p-N,N-bis(2-chloroethyl)aminophenoxyacetic acid is linked to the C-3 or C-17 position, while the lactam nucleus is linked to the D or A ring of the modified steroid respectively. The current literature indicates clearly that the potential of these esters is due to the synergistic activity of both the lactam and the p-N,N-bis(2-chloroethyl)aminophenoxyacetic acid.

Animals↗
PubMed1998

Selective inhibitors of cytosolic or secretory phospholipase A2 block TNF-induced activation of transcription factor nuclear factor-kappa B and expression of ICAM-1.

TNF signaling mechanisms involved in activation of transcription factor NF-kappaB were studied in the human keratinocyte cell line HaCaT. We show that TNF-induced activation of NF-kappaB was inhibited by the well-known selective inhibitors of cytosolic phospholipase A2 (cPLA2): the trifluoromethyl ketone analogue of arachidonic acid (AACOCF3) and methyl arachidonyl fluorophosphate. The trifluoromethyl ketone analogue of eicosapentaenoic acid (EPACOCF3) also suppressed TNF-induced NF-kappaB activation and inhibited in vitro cPLA2 enzyme activity with a similar potency as AACOCF3. The arachidonyl methyl ketone analogue (AACOCH3) and the eicosapentanoyl analogue (EPACHOHCF3), which both failed to inhibit cPLA2 enzyme activity in vitro, had no effect on TNF-induced NF-kappaB activation. TNF-induced NF-kappaB activation was also strongly reduced in cells stimulated in the presence of the secretory PLA2 (sPLA2) inhibitors 12-epi-scalaradial and LY311727. Addition of excess arachidonic acid suppressed the inhibitory effect of 12-epi-scalaradial and LY311727. Moreover, both methyl arachidonyl fluorophosphate and 12-epi-scalaradial blocked TNF-mediated enhancement of expression of ICAM-1. Activation of NF-kappaB by IL-1beta was markedly less sensitive to both cPLA2 and sPLA2 inhibitors. The results indicate that both cPLA2 and sPLA2 may be involved in the TNF signal transduction pathway leading to nuclear translocation of NF-kappaB and to NF-kappaB-activated gene expression in HaCaT cells.

Animals↗