Antiallodynic Activity of Ceftriaxone and Clavulanic Acid in Acute Administration is Associated with Serum TNF-α Modulation and Activation of Dopaminergic and Opioidergic Systems.

Preclinical Research The aim of this study was to determine the antiallodynic effect of acute administration of the ß-lactam antimicrobials, ceftriaxone (CFX) and clavulanic acid (CLAV), for the control of established pain on a model of neuropathic pain (NP). We also investigated the involvement of dopaminergic and opioidergic pathways as well as alterations in serum concentrations of TNF-α in the antiallodynic actions of these drugs. CFX, CLAV, or gabapentin (GAP), a reference drug, were administered i.p. twelve days after constriction of the sciatic nerve in rats. Mechanic and cold allodynia were evaluated for 3 h and alterations in serum concentration of TNF-α determined. Both CFX and CLAV had antiallodynic effects in response to mechanical and cold stimulation, similar to GAP. The antiallodynic effects of CFX and CLAV were blocked by haloperidol (HAL), a D2 receptor antagonist, and by naloxone (NLX), an opioid receptor antagonist. Additionally, serum TNF-α levels were attenuated following CFX and CLAV administration. These results suggest that acute administration of CFX and CLAV may represent a promising approach for treating the acute allodynia of NP, and that the mechanisms involved in these effects involve activation of dopaminergic and opioidergic pathways as well as modulation of TNF-α production. Drug Dev Res 78 : 105-115, 2017. © 2017 Wiley Periodicals, Inc.

In vivo estrogen bioactivities and in vitro estrogen receptor binding and transcriptional activities of anticoagulant synthetic 17beta-aminoestrogens.

Estrogenic activities of the two 17beta-aminoestrogen (AE) derivatives, prolame and butolame, were studied upon coagulation, serum luteinizing hormone (LH) and uterine weight, including endometrial morphology in castrated female rats. We have also investigated the ability of these two compounds, as well as another AE pentolame, to activate transcription through the estrogen receptor alpha (ERalpha) and the estrogen receptor beta (ERbeta). Administration of prolame and butolame to castrated animals increased significantly (P < 0.01) the mean clotting time when compared with that obtained in the group of control animals. Butolame was a more potent anticoagulant than prolame (P < 0.01), as judged by their corresponding IC(50) (5.4 +/- 0.65 and 66.6 +/- 2.57 micro;g/animal, respectively). In contrast, estradiol significantly shortened blood clotting times (P < 0.005). Both prolame and butolame caused a significant inhibition of serum LH levels (EC(50) 8.10 +/- 0.79 and 17 +/- 64 microg/animal, respectively), and restored castration-induced reduction in uterine weight of ovariectomized rats (EC(50) 4.14 +/- 1.57 and 17.0 +/- 1.78 microg/animal, respectively). In terms of the effects of prolame, butolame and pentolame in transient transfection assays, all the three AE activated ER dependent reporter gene expression, however, only at high concentrations. Prolame had the highest activity followed by butolame and pentolame. Induction of transcription by these compounds was preferentially mediated through the ERalpha, especially in the case of pentolame where little, if any, activation occurred through the ERbeta. None of the compounds showed antagonistic activities through either ER subtype. The overall data suggest that modifications in the structure and length of the amino-alcohol side-chain at C-17 might have an impact on the affinity and estrogenic intrinsic properties of AE at the level of diverse target tissues.

Estrogenic effects of the synthetic aminoestrogen 17 beta-(5-hydroxy-1-pentylamino)-1,3,5(10)-estratrien-3-ol (pentolame).

In this study, we investigated the effects of pentolame, a 17 beta-aminoestrogen derivative, upon coagulation, serum LH, pituitary progestin receptors, uterine weight, and endometrium morphological changes in the castrated female rat. Groups of animals were subcutaneously (s.c.) injected with either estradiol (E2) (0.1 up to 1000 micrograms/animal), pentolame (1 up to 1000 micrograms/animal), or the vehicle alone daily for 5 consecutive days starting 2 weeks following ovariectomy. Administration of pentolame (10 to 1000 micrograms/animal) increased significantly (p < 0.05) the blood clotting time when compared with that obtained in the group of control animals (EC50 582 micrograms). Pentolame (500 and 1000 micrograms/rat for 5 days) caused a significant inhibition (p < 0.01) of serum LH levels (IC50 860 micrograms), which remained suppressed until Day 5 post last injection. In addition, treatment with pentolame was able to restore in the castrated female rat the presence of specific estrogen-dependent progestin binding sites at the anterior pituitary level. The affinity constants and the number of binding sites of pentolame-induced progestin receptors were similar to those obtained with estradiol at equipotent doses (860 micrograms vs. 1 microgram/animal, respectively). Administration of the 17 beta-aminoestrogen derivative resulted in a significant increase in uterine weight (EC50 420 micrograms) and endometrial characteristics were indistinguishable from those observed in the group of rats treated with E2.

Morphometric analysis of mice uteri treated with the preservatives methyl, ethyl, propyl, and butylparaben.

The alkyl esters of p-hydroxybenzoic acid (PHBA) known as parabens (Pbens) are widely used as preservatives in food, pharmaceuticals, and cosmetics. Several in vivo and in vitro studies have shown these compounds to be estrogenic. Here, for the first time, we present evidence of their estrogenicity using a morphometric analysis of uteri from mice treated with the preservatives methylparaben (MePben), ethylparaben (EtPben), propylparaben (PrPben), and butylparaben (BuPben) compared with estradiol (E2). Different groups of adult ovariectomized (Ovx) CD1 mice were subcutaneously (sc) treated daily for three days with two different equimolar doses (362 and 1086 micromol/kg) of the Pbens: MePben (55 and 165 mg/kg), EtPben (60 and 180 mg/kg), PrPben (65 and 195 mg/kg), BuPben (70 and 210 mg/kg), E2 (10 microg/kg; 0.036 micromol/kg), and vehicle (propyleneglycol; V, 10 mL/kg). On the fourth day, uteri were dissected, blotted, weighed, and placed in a fixative solution for 24 h. The paraffin embeded uteri were cut to obtain 7 microm thick transversal sections. Luminal epithelium heights (LEH), glandular epithelium heights (GEH), and myometrium widths (MW) were measured. The highest Pbens dose was able to produce uterotrophic effects (38 to 76%) compared to E2 efects (100%). The relative uterotrophic potency to E2 (100) was from 0.02 to 0.009. Significant increases (P < 0.05) in LEH, GEH, and MW as compared with V were obtained: LEH from 87 to 113% (E2 153%), GEH from 10 to 40% (E2 60%), and MW from 35 to 43% (E2 88%). These results confirm that Pbens at the doses assayed here induce estrogenic histological changes in the uteri of Ovx mice.