Effects of inhibitors of eicosanoid synthesis in the uterus of ovariectomized rats and rats in natural oestrus: relation with calcium

Synthesis, characterization and in vitro antimicrobial studies of Co(II), Ni(II) and Cu(II) complexes derived from macrocyclic compartmental ligand

New Co(II), Ni(II) and Cu(II) complexes derived from tetradentate macrocyclic nitrogen ligand, (1E,4E,8E,12E)-5,8,13,16-tetramethyl-1,4,9,12-tetrazacyclohexadeca-4,8,12,16-tetraene (EDHDH) have been synthesized. The complexes have been characterized by elemental analysis, spectral (IR, UV-Vis, (1)H NMR and ESR (for Cu(II) complex)) mass, and magnetic as well as thermal analysis measurements. The complexes afforded the formulae: [Cu(EDHDH)Cl2]·2EtOH and [M(EDHDH)X2]·nH2O where M=Co(II) and Ni(II), X=Cl(-) or OH(-), n=1,0, respectively. The data revealed an octahedral arrangement with N4 tetradentate donor sites in addition to two Cl atoms occupying the other two sites. ESR spectrum of Cu(2+) complex confirmed the suggested geometry with values of a α(2)and β(2) indicating that the in-plane σ-bonding and in-plane π-bonding are appreciably covalent, and are consistent with very strong σ-in-plane bonding in the complexes. The molecular modeling is drawn and showed the bond length, bond angle, chemical reactivity, energy components (kcal/mol) and binding energy (kcal/mol) for all the title compounds using DFT method. Also, the thermal behavior and the kinetic parameters of degradation were determined using Coats-Redfern and Horowitz-Metzger methods. Moreover, the in vitro antibacterial studies of all compounds screened against pathogenic bacteria (two Gram +ve and two Gram -ve) to assess their inhibiting potential. The assay indicated that the inhibition potential is metal ion dependent. The ligand, EDHDH, Co(II) and Cu(II) complexes exhibited a remarkable antibacterial activity against Streptococcus Pyogenes as Gram +ve and Proteus vulgaris as Gram -ve bacterial strains. On the other hand, Ni(II) complex revealed a moderate antibacterial activity against both Gram +ve organisms and no activity against Gram -ve bacterial strain.

Synthesis and characterization of divalent metal complexes of the macrocyclic ligand derived from isatin and 1,2- diaminobenzene

A novel series of complexes of the type [M(C28H18N6)X2], where M=Co(II), Ni(II), Cu(II) or Zn(II) and X=Cl-, NO3- or CH3COO-, were synthesized by template condensation of isatin and 1,2-diaminobenzene in methanolic medium. The complexes were characterized with the help of various physico-chemical techniques, such as elemental analyses, molar conductance measurements, magnetic measurements, and NMR, infrared and far infrared spectral studies. The low value of molar conductance indicates them to be non-electrolytes. Based on various studies, a distorted octahedral geometry may be proposed for all the complexes. All the synthesized macrocyclic complexes were also tested for their in vitro antibacterial activity against some pathogenic bacterial strains. The MIC values shown by the complexes against these bacterial strains were compared with those of the standard antibiotics linezolid and cefaclor. Some of the complexes showed good antibacterial activities.

Contribution of cAMP to the inhibitory effect of non-steroidal anti-inflammatory drugs in rat uterine smooth muscle

1. The effect of the non-steroidal anti-inflammatory drugs naproxen, mefenamic acid, phenylbutazone, piroxicam and tolmetin on the vanadate (0.3 mM)-induced tonic contraction, as well as the modifications of these effects by the G-protein inhibitor pertussis toxin, and the inhibitors of protein kinase A, Rp-cAMPS (Rp-Adenosine 3',5'-cyclic monophosphothioate triethylamine salt) and protein kinase C, H-7 [1(5-isoquinolynilsulfonyl)-2-methyl-piperazine], have been assayed to study the possible nature of intracellular mediators contributing to the inhibitory effects of NSAIDs in rat uterine smooth muscle incubated in medium lacking calcium plus EDTA. The effect of phorbol 12,13-dibutyrate on vanadate contraction and its modification with H-7 has also been examined. 2. Naproxen (6-600 microM), mefenamic acid (6-300 microM), phenylbutazone (6-300 microM), piroxicam (6-600 microM) and tolmetin (6-600 microM) produced concentration-dependent relaxation of vanadate-induced tonic contraction. The potency order, in accordance with their respective IC50 values was: phenylbutazone > or = mefenamic acid > or = naproxen > tolmetin > or = piroxicam. 3. The relaxant effects of naproxen, phenylbutazone, piroxicam and tolmetin were significantly antagonized with pertussis toxin (50 ng ml-1), Rp-cAMPS (100 microM) and H-7 (1 microM). However, the effect of mefenamic acid was unmodified by the three drugs. This suggests that the effect of mefenamic acid and other NSAIDs occur by different mechanisms. 4. Phorbol 12,13-dibutyrate relaxed the vanadate contraction but the maximal relaxation achieved (54.8 +/- 8.3%, n = 4) was lower than those induced with the NSAIDs. On the other hand, H-7 (1 microM) did not modify the relaxant effect of phorbol 12,13-dibutyrate. This suggests that H-7 behaves as a PKA, but not a PKC inhibitor, under the present experimental conditions. 5. The relaxation by naproxen, phenylbutazone, piroxicam and tolmetin is presumably produced by increasing cAMP because the effects of these are antagonized with Rp-cAMPS and H-7, and by pertussis-toxin-sensitive mechanisms.

Influence of hormonal status in relaxant effect of diethylstilbestrol and nifedipine on isolated rat uterus contraction

1. The effects of diethylstilbestrol (DES, 10(-7)-10(-5) M) and nifedipine (10(-10)-10(-7) M) on KCl (60 mM)-induced tonic contraction in the uterus of ovariectomized and 17 beta-estradiol (0.1 mg/kg/day, s.c.)-, 17 alpha-estradiol (0.1 mg/kg/day, s.c.)-, or progesterone (2 mg/kg/day, s.c.)-treated rats have been assayed. 2. The dose-dependent relaxation produced by nifedipine in ovariectomized rats (EC50 = 5.59 +/- 1.25 x 10(-9) M) is potentiated in uterus of rats treated with 17 beta-estradiol and progesterone (EC50 = 0.59 +/- 0.1 and 0.49 +/- 0.1 x 10(-9) M, respectively) but not in the 17 alpha-estradiol-treated rats (3.01 +/- 0.6 x 10(-9) M). 3. The relaxation produced by DES on ovariectomized rats (EC50 = 0.84 +/- 0.14 x 10(-6) M) is reduced when the rats are treated with 17 beta-estradiol (EC50 = 2.22 +/- 0.2 x 10(-6)M) or progesterone (EC50 = 1.24 +/- 0.08 x 10(-6) M), but unmodified by 17 alpha-estradiol (EC50 = 0.58 +/- 0.01 x 10(-6) M). 4. The nifedipine-induced relaxation is reversed with Bay K 8644 (10(-10)-10(-6) M) in all experimental conditions. However, Bay K 8644 counteracted the relaxation of DES at 45.7% on ovariectomized rats but this was lower than 30% in the other groups. 5. Our results suggest that in ovariectomized rats the effects of both nifedipine and DES are similar, but 17 beta-estradiol and progesterone produce a contrary effect on the relaxation induced by nifedipine and DES (by increasing the nifedipine and decreasing the DES effects).(ABSTRACT TRUNCATED AT 250 WORDS)

Spasmolytic and calmodulin inhibitory effect of non-steroidal anti-inflammatory drugs in vitro

The effect of several anti-inflammatory drugs (NSAIDs), the calmodulin inhibitor W-7 and cortisol on vanadate-induced tonic contraction and on calmodulin dependent cAMP-phosphodiesterase activity have been assayed. Indomethacin, diclofenac, phenylbutazone, mefenamic acid, naproxen, tolmetin, piroxicam, aspirin and W-7, but not metimazol, produce dose-dependent relaxation of vanadate-induced tonic contraction on isolated rat uterus. Cortisol relaxes the vanadate contraction up to 45%. None of the drugs assayed inhibit the basal activity of phosphodiesterase with concentrations lower than 1 mM. However, indomethacin, diclofenac, phenylbutazone, mefenamic acid, naproxen, piroxicam, aspirin and W-7 inhibit, in a concentration-dependent way, the calmodulin-stimulated activity of phosphodiesterase. The maximum inhibition achieved with tolmetin (1 mM) and cortisol (1 mM) was 38% and 24%, respectively. Metamizol has no effect on basal or/and stimulated phosphodiesterase. This, as far as we know, is the first description of relationship between NSAIDs and calmodulin-dependent processes and our results suggest that the inhibition of calmodulin with NSAIDs may be directly related to their pKa and liposolubility.

Mechanisms involved in the effects of phenidone, diclofenac and ethacrynic acid in rat uterus in vitro

1. The effects of phenidone (P, 10(-4)-10(-3) M), sodium diclofenac (D, 10(-5)-10(-4) M) and ethacrynic acid (E, 10(-5)-10(-4) M), proposed as inhibitors of eicosanoid synthesis, on the contractions of rat uterus induced by several agonists have been studied. 2. P, D and E inhibit the motility induced by oxytocin (4 mU/ml) (IC50: 4.62 x 10(-4), 2.55 x 10(-4) and 2.98 x 10(-5) M, respectively). 3. P (10(-3) M), D (10(-4) M) and E (10(-4) M) also inhibit the contraction induced by methacholine (10(-5) M), prostaglandin F2a (10(-6) M) and CaCl2 (6 mM), and relaxed, in a dose-dependent way, the tonic component of contraction to KCl (60 mM) (IC50: 5.81 x 10(-4), 6.67 x 10(-5) and 7.55 x 10(-5) M, respectively). 4. The CaCl2 (0.1-10 mM) reverted the relaxation of KCl contraction produced by P, but not by D or E. None of the inhibitions on CaCl2 (6 mM) are reverted by Bay K 8644. 5. D and E also relaxed the tonic contraction to vanadate (10(-4) M) in uterus incubated in calcium free solution P, enhances the vanadate-induced contractions.