Palmitoylated PrRP analog decreases body weight in DIO rats but not in ZDF rats.

Anorexigenic neuropeptides produced and acting in the brain have the potential to decrease food intake and ameliorate obesity, but are ineffective after peripheral application, owing to a limited ability to cross the blood-brain barrier. We have designed lipidized analogs of prolactin-releasing peptide (PrRP), which is involved in energy balance regulation as demonstrated by obesity phenotypes of both Prrp-knockout and Prrp receptor-knockout mice. The aim of this study was to characterize the subchronic effect of a palmitoylated PrRP analog in two rat models of obesity and diabetes: diet-induced obese Sprague-Dawley rats and leptin receptor-deficient Zucker diabetic (ZDF) rats. In the rats with diet-induced obesity (DIO), a two-week intraperitoneal treatment with palmitoylated PrRP lowered food intake by 24% and body weight by 8%. This treatment also improved glucose tolerance and tended to decrease leptin levels and adipose tissue masses in a dose-dependent manner. In contrast, in ZDF rats, the same treatment with palmitoylated PrRP lowered food intake but did not significantly affect body weight or glucose tolerance, probably in consequence of severe leptin resistance due to a nonfunctional leptin receptor. Our data indicate a good efficacy of lipidized PrRP in DIO rats. Thus, the strong anorexigenic, body weight-reducing, and glucose tolerance-improving effects make palmitoylated PrRP an attractive candidate for anti-obesity treatment.

Antileukotrienic phenethylamido derivatives of arylalkanoic acids in the treatment of ulcerative colitis.

A series of arylalkanoic acid derivatives bearing methyl(phenethyl)amino groups were prepared and their inhibition of LTB(4) biosynthesis was evaluated. Regression analysis showed the slightly different parabolic dependences of this activity on lipophilicity of alpha-methyl and alpha-unsubstituted alkanoic acid derivatives. The relationship derived for alpha-unsubstituted alkanoic acids was extended by previously prepared group of similar derivatives of arylacetic acids without any change of regression coefficients and statistical criteria. It was concluded that the most active compounds belong to 2-arylpropanoic acid derivatives with lipophilicity close to logP(opt) (=6.97). But generally, the structural changes in the acidic part of compounds under study did not yield the substantial improvement of LTB(4) biosynthesis inhibition in comparison with the previously prepared series of derivatives IV. The anti-inflammatory effect of the compounds under study was evaluated in three animal models of inflammation and their possible utilization in the treatment of ulcerative colitis (UC) was followed. From 12 evaluated compounds, 4 compounds are more active in UC inhibition than the standard sulfasalazine but it can be stated that the change of connecting chain between aromatic ring and carboxyl did not bring about the important improvement of this activity in comparison with previous derivatives of arylacetic acids. Possible relation between LTB(4) biosynthesis inhibition and ulcerative colitis is seriously broken by the compound 8a with carbonyl as the additional functional group on the connecting chain between carboxyl and aromatic ring.

Antileukotrienic N-arylethyl-2-arylacetamides in the treatment of ulcerative colitis.

A series of arylacetic acid derivatives bearing methyl(arylethyl)amino groups were prepared and their antileukotrienic activities involving LTB(4) were evaluated. Regression analysis has shown a strong dependence of these activities on lipophilicity for both LTB(4) receptor binding and inhibition of LTB(4) biosynthesis; parabolic relationships were derived. The values of slopes of the ascending linear parts of these dependences indicate various types of hydrophobic binding at the site of ligand interaction with relevant biomacromolecules. The anti-inflammatory effect of the compounds under study was also evaluated in three animal models of inflammation and their possible utilization in the treatment of ulcerative colitis (UC) was followed. The importance of antileukotrienic activities for the anti-inflammatory effect, especially in the model of UC was discussed, but further experiments are necessary to confirm the respective relations.

Identification and synthesis of a novel selective partial PPARdelta agonist with full efficacy on lipid metabolism in vitro and in vivo.

The aim was to identify a novel selective PPARdelta agonist with full efficacy on free fatty acid (FFA) oxidation in vitro and plasma lipid correction in vivo. Using the triple PPARalpha,gamma,delta agonist 1 as the structural starting point, we wanted to investigate the possibility of obtaining selective PPARdelta agonists by modifying only the acidic part of 1, while holding the lipophilic half of the molecule constant. The structure-activity relationship was guided by in vitro transactivation data using the human PPAR receptors, FFA oxidation efficacy performed in the rat muscle L6 cell line, and in vivo rat pharmacokinetic properties. Compound 7 ([4-[3,3-bis-(4-bromo-phenyl)-allylthio]-2-chloro-phenoxy]-acetic acid) was identified as a selective, partial agonist with good oral pharmacokinetic properties in rat. Chronic treatment of high fat fed ApoB100/CETP-Tgn mice with 7 corrected the plasma lipid parameters and improved insulin sensitivity. These data suggest that selective PPARdelta agonists have the potential to become a novel treatment of dyslipidemia.

Pharmacological profile of 4-(2',4'-difluorobiphenyl-4-yl)-2-methylbutyric acid (deoxoflobufen).

4-(2',4'- Difluorobiphenyl-4-yl)-2-methylbutyric acid (deoxoflobufen, VUFB 19053, CAS 847475-35-8) has been developed as a new omega-biphenyl-alkanoic acid and studied in comparison with the racemic form of 4-(2',4'-difluorobiphenyl-4-yl)-2-methyl-4-oxobutanoic acid (flobufen, CAS 112344-52-2). The compounds were tested in a series of models including acute inflammation induced by carrageenan, adjuvant arthritis, in vitro inhibition of the leuktotriene B4 (LTB4) production, reaction of the graft versus the host (GVHR), production of specific antibodies against ovalbumin, peritoneal exudate formation induced by thioglycollate and phagocytosis of thioglycollate-stimulated mouse peritoneal macrophages. Deoxoflobufen exhibited strong anti-inflammatory, antiarthritic and immunomodulatory effects in most of the performed tests. Anti-inflammatory and antiarthritic effects are fully comparable with those of flobufen, however, the compound is less toxic and has apparently stronger immunomodulating effects.

Novel tricyclic-alpha-alkyloxyphenylpropionic acids: dual PPARalpha/gamma agonists with hypolipidemic and antidiabetic activity.

Synthesis and structure-activity relationships of tricyclic alpha-ethoxy-phenylpropionic acid derivatives guided by in vitro PPARalpha and PPARgamma transactivation data and computer modeling led to the identification of the novel carbazole analogue, 3q, with dual PPARalpha (EC(50) = 0.36 microM) and PPARgamma (EC(50) = 0.17 microM) activity in vitro. Ten days treatment of db/db mice with 3q improved the insulin sensitivity, as measured by OGTT, better than that seen with both pioglitazone and rosiglitazone treatment, suggesting in vivo PPARgamma activity. Likewise, 3q lowered plasma triglycerides and cholesterol in high cholesterol fed rats after 4 days treatment, indicating in vivo PPARalpha activity. Investigations of the pharmacokinetics of selected compounds suggested that extended drug exposure improved the in vivo activity of in vitro active compounds.