Effect of N-acetyl-L-cysteine supplementation in semen extenders on semen quality and reactive oxygen species of chilled canine spermatozoa.

The objective of this study was to evaluate the quality of chilled dog semen processed with extenders containing various concentrations of N-acetyl-L-cysteine (NAC). Ejaculates from five dogs were collected, pooled and evaluated for concentration, motility, rapid steady forward movement (RSF-movement), viability, acrosomal integrity and by the hypo-osmotic swelling test (HOST). In addition, superoxide anion (O(2)(-*)) production, hydroxyl radicals (OH(*)) and total reactive oxygen species (tROS) were determined. The pool was divided into five aliquots, which were diluted to a final concentration of 66.66 x 10(6) spermatozoa/ml with Tris-glucose-egg yolk extender containing one of the following concentrations of NAC (0, 0.5, 1, 2.5 or 5 mm). The semen aliquots were chilled and preserved at 4 degrees C. Semen quality was evaluated after rewarming at 72 h. Sperm motility was significantly higher with the 0.5 mm concentration compared with the control group (p = 0.001). Rapid steady forward movement was higher with the 0.5 and 1 mm concentrations compared with the control and 5 mm group (p < 0.001). Viability and HOST percentages were not significantly altered. Compared with the control, the 5 mm concentration showed significantly reduced percentages of spermatozoa with normal acrosomes (p = 0.049). None of the ROS values at 72 h were significantly affected by the presence of NAC in semen extenders, although all NAC concentrations showed lower O(2)(-*) and OH(*) values compared with the control. Only the concentrations of 1 and 5 mm inhibited the significant increase of tROS values after 72 h, compared with the fresh semen value. In conclusion, NAC supplementation of semen extenders is beneficial to semen motility of canine spermatozoa during chilling with the 0.5 mm concentration being the most effective, although no significant ROS inhibition was observed at 72 h.

Quality and reactive oxygen species of extended canine semen after vitamin C supplementation.

The objective of this study was to evaluate the quality of extended dog semen processed with diluents containing various concentrations of vitamin C. Ejaculates from five dogs were collected, pooled and evaluated for concentration, sperm motility, rapid steady forward movement (RSF-movement), viability, acrosomal integrity and by the hypo-osmotic swelling test. Also, superoxide (O(2)(-)*) production, hydroxyl radicals (OH*) and total reactive oxygen species (tROS) were determined. The pool was divided in five aliquots, which were diluted to a final concentration of 66 x 10(6) spermatozoa/ml with a Tris-glucose-egg yolk extender containing one of the following concentrations of vitamin C (0, 0.1, 0.5, 1 or 2.5 mM). The semen aliquots were chilled and preserved at 4 degrees C. Portions of chilled semen were removed at 24 and 72 h, and semen quality was evaluated after rewarming. This process was repeated 10 times in pooled semen of the same origin and data were analysed by one-way analysis of variance. At both times, none of the semen quality parameters were positively influenced (p>0.05) by vitamin C supplementation. At 24 h, none of the reactive oxygen species (O(2)(-)*, OH*, tROS) were significantly altered. At 72 h, significant reductions of O(2)(-)* production were observed by the concentrations of 0.1, 0.5 and 2.5 mM compared with the 0 mM concentration (p=0.049). Also, at 72 h, the 2.5 mM concentration showed significantly lower OH* values in comparison with the control group (p=0.048). In conclusion, addition of vitamin C to semen extenders does not benefit the quality of canine extended spermatozoa.

Matrix metalloproteinase inhibitors: a review on pharmacophore mapping and (Q)SARs results.

The matrix metalloproteinases (MMPs) are a family of more than 20 enzymes that are intimately involved in tissue remodelling. These zinc-containing endopeptidases consist of several subsets of enzymes, including collagenase, stromelysins and gelatinases and are involved in the degradation of the extracellullar matrix (ECM) that forms the connective material between cells and around tissues. Disease processes associated with the MMPs are generally related to imbalance between the inhibition and activation of MMPs resulting in excessive degradation of the ECM. These indications include osteoarthritis rheumatoid arthritis, tumour metastasis and congestive heart failure. Inhibitors for these enzymes have been developed for the treatment of a starthingly wide array of disease process where matrix remodelling plays a key role. There are three major components to most MMP inhibitors- the zinc binding group ZBG, the peptidic backbone and the pocket occupying side chain. Most MMPs inhibitors are classified according to their ZBG. Inhibitors interactions at active-site zinc plays a critical role in defining the binding mode and relative inhibitor potency. The majority of MMP inhibitors reported in the literature contain an effective zinc binding group (e.g. hydroxamic acid, carboxylic acid, sulfhydryl group) that is either generally substituted with a peptide-like structure that mimics the substrates that they cleave or appended to smaller side chains that may interact with specific subsites (e.g., P1', P2', P3') within the active site. Although carboxylates exhibit weaker zinc binding properties than hydroxamates, they are known to show better oral bioavailability and are less prone to metabolic degradation. The expected loss of binding affinity after replacement of hydroxamates against carboxylates is faced by adequate choice of elongated S1' directed substituents. The need for novel selective MMP inhibitors makes them an attractive target for the QSAR and molecular modelling. 3-D QSAR models were derived using CoMFA, CoMSIA and GRID approaches leading to the identification of binding regions where steric, electronic or hydrophobic effects are important for affinity. Some structural requirements essential for achieving high binding affinity and selectivity are: an acidic unit tightly anchored through four contact points, bidentate chelation of Zn2+, carbonyl groups for hydrogen bonding, more than two extra units for hydrogen bonds, a hydrophobic moiety.

In vivo anticancer, anti-inflammatory, and toxicity studies of mixed-ligand Cu(II) complexes of dien and its Schiff dibases with heterocyclic aldehydes and 2-amino-2-thiazoline. Crystal structure of [Cu(dien)(Br)(2a-2tzn)](Br)(H(2)O).

A new series of complexes of the type [Cu(dien)(2a-2tzn)Y(2)] and [Cu(dienXX)(2a-2tzn)Y(2)], where dien=diethylenetriamine and dienXX=Schiff dibase of diethylenetriamine formed with 2-furaldehyde (dienOO), 2-thiophenecarboxaldehyde (dienSS), or pyrrol-2-carboxaldehyde (dienNN); Y=Cl, Br or NO(3); and 2a-2tzn=2-amino-2-thiazoline, were synthesized and their structure established by C, H, N and Cu analysis; IR and electronic spectra; magnetic susceptibility; and molar conductivity. The isolated complexes are monomers, paramagnetic, and electrolytes of types 1:1 or 1:2. In both types of solid state complexes, [Cu(dien)(2a-2tzn)Y(2)] and [Cu(dienXX)(2a-2tzn)Y(2)], dien and its Schiff dibases are bonded to Cu(II) in a tridentate fashion through 3N atoms. The coordination sphere is completed by the endocyclic nitrogen of the thiazoline moiety and by two Cl, Br, or NO(3) groups with distorted octahedral geometry. The proposed structure of these compounds was supported by X-ray analysis of [Cu(dien)(Br)(2a-2tzn)](Br)(H(2)O). The coordination polyhedron around the copper atom can be described as a distorted square pyramid [Cu(dien)(Br)(2a-2tzn)](+). Its basal plane is occupied by the four nitrogen atoms of the dien and thiazoline ligands with Cu-N distances ranging between 1.996(6) and 2.032(3)A, and the axial position is occupied by one of the two bromine atoms (Br1) with a Cu1-Br1 bond distance of 2.782(1)A. The second bromine atom (Br2) is 4.694(2)A from the copper atom, which exists as a discrete anion and is responsible for the cationic nature of the complex. Results regarding toxicity, antitumor, and anti-inflammatory activities of the investigated compounds are promising and allow the selection of a lead compound for further biological studies.

Non steroidal anti-inflammatory and anti-allergy agents.

Non steroidal anti-inflammatory drugs (NSAIDs) are among the most commonly used for inflammation therapy. The major drawback in using the NSAIDs is in their tendency to cause gastrointestinal toxicity. Since the roles of arachidonic acid (A.A) metabolites, as leukotrienes (Lts), prostaglandins (PGs) and thromboxanes (TXA(2)) as mediators of the inflammatory reaction were clarified, much effort has been made to develop inhibitors of the production of these chemical mediators as anti-inflammatory agents. These mediators also play important roles in some inflammatory or allergic diseases, acting either alone or in combination and inhibitors of 5-lipoxygenase (5-LOX) and/or cyclooxygenase isoforms 1,2 (COX-1,2) may be useful for the treatment of asthma, psoriasis and rheumatoid arthritis. Leukotrienes, the products of 5-LOX metabolism have been associated with immediate hypersensitivity reactions, anaphylaxis and asthma. In addition, active oxygen species (AOS) including superoxide anion (O(2)(-)), hydrogen peroxide, hydroxyl radical and ferric radical, mediate cell damage in a variety of pathophysiological conditions and are responsible for oxidative injury of enzymes, lipid membranes and DNA in living cells and tissues. Prostaglandins and leukotrienes in the arachidonate pathway linked with lipid peroxidation may amplify the oxidative damage. Nitric oxide (NO) plays also a role as an effector in inflammation, since PG and NO thought to be important in maintaining mucosal integrity. Dual or selective inhibitors, specific receptor antagonists, AOS scavengers, and NO donors have been under development for therapeutic application. Several classes of inhibitors have been identified and at least 12 major chemical series are known to affect PGs production directly. In this review, we account on our research work concerning NSAIDs combined with a reference of the recent literature.

QSAR studies of some sulphonamidobenzophenone oximes with antiviral activity.

A study of quantitative structure-activity relationships (QSAR) has been performed for some sulphonamidobenzophenone oximes to investigate the mechanism of their antiviral activity against polio and rhino viruses. It has been shown that viral macromolecule synthesis could be the target of their action and that the antiviral activity of the compounds is predominantly controlled by steric factors.

Effect of antioxidant supplementation in semen extenders on semen quality and reactive oxygen species of chilled canine spermatozoa.

The objective of this study was to evaluate quality of chilled dog semen processed with extenders containing various antioxidants. Single ejaculates from five dogs were always pooled and evaluated for concentration, sperm motility, progressive motility (RSF-movement), viability, acrosomal integrity and by the hypo-osmotic swelling (HOS)-test. Also, superoxide (O(2)(-)) production, hydroxyl radicals (OH) and total reactive oxygen species (tROS) were determined. Pooled semen was divided in seven aliquots (for control and test conditions), which were diluted to a final concentration of 67x10(6)spermatozoa/ml with TRIS-glucose-egg yolk extender with or without the following supplements: control (without antioxidants), vitamin C (0.5mM), N-acetyl-l-cysteine (NAC; 0.5mM), taurine (0.2mM), catalase (100u/ml), vitamin E (0.1mM) and 5-(4-dimethylamino-phenyl)-2-phenyl-penta-2,4-dienoic acid (B16; 0.1mM). The semen aliquots were chilled and preserved at 4 degrees C. Portions of chilled semen were removed at 24 and 72h, and semen quality was evaluated after rewarming. At 24h the mean (+/-S.E.M.) sperm motility was higher (p<0.001) when vitamin E, taurine and B16 were added in the extender, whereas more spermatozoa with RSF-movement were observed (p<0.001) in the vitamin E, catalase, B16 and taurine groups. Sperm viability was higher (p=0.040) in B16 and vitamin E groups and the percentage of swollen spermatozoa was higher (p=0.002) only in the B16 group. Acrosomal integrity and OH were not significantly influenced by any of the antioxidants tested. Superoxide production was significantly lower when vitamin C, B16 and vitamin E were added in semen extenders compared with the control (p=0.017). All antioxidant groups, except vitamin C and NAC, contained less tROS compared to the control group, but only the B16 group value differed significantly (p=0.05). At 72h sperm motility was higher (p<0.001) when vitamin E, catalase, B16, taurine and NAC were added in the extender. More spermatozoa with RSF-movement were observed (p<0.001) in the vitamin E, catalase, B16, taurine and NAC treatment groups. Sperm viability was higher (p=0.001) when vitamin E, B16, taurine and vitamin C were added in semen extenders. HOS-test percentages were higher (p=0.016) in the B16, vitamin E, catalase and NAC groups. Acrosomal integrity was not influenced in any case. Production of O(2)(-) was significantly higher using catalase compared to all the other groups (p=0.006), while OH was not significantly influenced by any of the antioxidants tested. The addition of vitamin E, catalase and B16 in semen extenders resulted in significantly lower tROS values compared with the controls (p<0.0005). The results suggest that vitamin E and B16 had the most pronounced effect in preserving semen quality of chilled dog spermatozoa.

Recent developments in the chemistry and in the biological applications of amidoximes.

Amidoximes are compounds bearing both a hydroxyimino and an amino group at the same carbon atom which makes them versatile building blocks for the synthesis of various heterocycles. Their importance in chemistry along with their rich biology, make amidoximes an attractive target for medicinal chemists, biochemists and biologists. Amidoximes and simple O-substituted derivatives possess very important biological activities functioning as antituberculotic, antibacterial, bacteriostatic, insecticidal, elminthicidal, antiviral, herbicidal, fungicidal, antineoplastic, antiarrythmic, antihypertensive, antihistaminic, anxiolytic-antidepressant, anti-inflammatory/antioxidant, antiaggregatory (NO donors) or plant growth regulatory agents. A number of amidoximes has already been used as drugs, or currently being in clinical trials. Their numerous pharmaceutical applications have been recently enriched, due to the fact that some mechanistic pathways, concerning their conversion to amidines, as well as their ability to release NO were clarified, giving a new insight to their mode of action and allowing the design of new therapeutic agents. The main subject of the present review paper is to highlight aspects concerning chemical and biological questions on this interesting class of compounds. Some new synthetic methodologies as well as improvements of previously reported general reactions involving amidoximes, acylated amidoximes, and amidines are presented. The biological applications of amidoximes over the end of 2006 are also extensively reviewed.

New diaminoether coumarinic derivatives with anti-inflammatory activity.

Four coumarinyl-oxy-diamines were synthesized and tested as anti-inflammatory agents. pKa and log P were theoretically calculated. These compounds were tested for their ability to interact with 1,1-diphenyl-2-picrylhydrazyl stable free radical (DPPH), to inhibit proteolysis and soybean lipoxygenase (LOX) in vitro. They were found to inhibit proteolysis (82-90%) and soybean lipoxygenase activity (52-79%) very significant. On the contrary, their reducing ability was found to be low (8-22%). The effect of the synthesised compounds on inflammation using the carageenan-induced rat paw oedema model was studied. They showed a potent inhibitory effect on inflammation (37-55%). Both anti-inflammatory and antioxidant activities depended on some structural characteristics of the synthesised compounds.

Anti-inflammatory activity of some novel 1-[3-(aroylo)] and one 1-[3-(aryloxy)]-propyl aminothiazole in correlation with structure and lipophilicity.

The effect of some new 1-[3-(aroylo)] and one 1-[3-[aryloxy)]-propyl aminothiazole on inflammation was investigated in the carrageenin-induced mouse paw edema (36-58% edema inhibition). In addition they exhibited significant analgesic activity (55-80.6%) in the writhing test. Their antioxidant activity in vitro using the stable free radical 1.1-diphenyl-2-picrylhydrazyl (DPPH), was determined. Antiproteolytic ability and beta-glucuronidase inhibition have been studied. The tested compounds did not inhibit soybean 12-lipoxygenase. RM values, as an expression of lipophilicity, were determined.

In vitro studies of some 2,4-disubstituted thiazolyl-aminoketones with anti-inflammatory activity. Correlation with lipophilicity and structural characteristics.

A number of ring and chain substituted aminothiazole derivatives with strong anti-inflammatory activity were studied for their antiproteolytic and oxygen radical scavenging properties. Their interactions with the stable free radical 1,1-diphenyl-2-picrylhydrazyl was determined. Their inhibition of the soybean 12-lipoxygenase and beta-glucuronidase enzymes was evaluated. They scavenged superoxide anion and inhibited proteolysis to a non appreciable extent, whereas no activity on beta-glucuronidase and lipoxygenase was found. Their reducing ability was found to be low. Good correlation was obtained between the anti-inflammatory activity and clog P (theoretically calculated lipophilicity) and between anti-inflammatory activity and proteolytic inhibition. RM values were also determined.

Effect of 2,4-disubstituted thiazol-5yl-aminoketones on inflammation. In vitro and in vivo biological studies: a structure-activity approach.

Some modified novel thiazol-5yl-aminoketones were evaluated for their anti-inflammatory, analgesic and antiproteolytic activities. Their inhibitory activity on 12-lipoxygenase (12-LO) and beta-glucuronidase in vitro was estimated. Their interaction with the stable free radical 1,1-diphenyl-2-picrylhydrazyl (DPPH) and their RM values were also determined. For two of them, the effect on zoxazolamine-induced paralysis after a prolonged treatment was determined. The duration of paralysis for the same compounds, (only one administration, one before zoxazolamine injection) was recorded too. The 2-amino substituted derivatives seem to be more potent in comparison with the 2-phenyl. The tested compounds were found to influence proteolysis but not the activities at beta-glucuronidase and 12-LO. Their interaction with DPPH was mild. Compound 2 seems to modify the activity of the hepatic drug metabolizing enzymes. In conclusion, their activity is related to certain structural characteristics.

Synthesis of some new thienyl and 1,3-thiazolyl-aminoketones with anti-inflammatory activity.

Eight thienyl and 1,3-thiazolyl-aminoketones were synthesised and tested as anti-inflammatory agents. pKa and log P were theoretically calculated. The compounds were tested for antioxidant activity, as hydroxyl radical scavengers, as superoxide anion scavengers and for their ability to interact with 1,1-diphenyl-2-picryl hydrazyl stable free radical (DPPH). The effects of the synthesised compounds on inflammation were studied using the carrageenan induced mice paw oedema model. Both anti-inflammatory and antioxidant activities depended on some structural characteristics of the synthesised compounds.

Thiazolyl and benzothiazolyl Schiff bases as novel possible lipoxygenase inhibitors and anti inflammatory agents. Synthesis and biological evaluation.

Several thiazolyl derivatives are reported to act as lipoxygenase inhibitors affecting inflammation and/or psoriasis. Two series of new thiazolyl and benzothiazolyl Schiff bases have been designed, synthesized and identified. RM values were determined as an expression of lipophilicity. The compounds were screened for their reducing activity (with the stable free radical 1,1-diphenyl-2-picrylhydrazyl DPPH), for radical scavenging activity (with the xanthine/xanthine oxidase system for O2.-) and for inhibition of soybean lipoxygenase (LO). Anti inflammatory activity was examined in vivo, using the carrageenin induced mice paw edema (24-71.8% inhibition was observed). The results are discussed in terms of structural and physicochemical characteristics of the compounds. Comparing the results among all tests, the benzothiazolyl derivatives seem to be more potent.

Antioxidant activity of DL omega-phenyl-amino acid octyl esters with anti-inflammatory activity. Correlation of the structure with lipophilicity.

The antioxidant activities (in vitro) and the lipophilicity (as RM values) of 12 DL-omega-phenyl-amino acid octyl esters with anti-inflammatory/analgesic activities were studied. The tested compounds were found to interact with 1,1-diphenyl-2-picrylhydrazyl stable free radical (DPPH), whereas most of them were essentially inactive in other tests. DL-2-Amino-4-(4-aminophenyl)butyric acid octyl ester was found to be the most active. The anti-inflammatory activity does not seem to be connected with O2-. or HO. scavenging activity at least under the experimental conditions applied. However, the interaction with DPPH was found to be correlated with their anti-inflammatory activity. Between the lipophilicity and the anti-inflammatory activity only a poor relationship exists. For a subgroup of the derivatives of the phenyl glycine octyl ester (1-8) a significant correlation was found between the RM values and the calculated clog P lipophilicity.

Synthesis of some new aroyl/aryloxy-2-amino-1,3-thiazole derivatives with anti-inflammatory activity.

The synthesis of some novel aroyl/aryloxy aminothiazoles from the appropriate gamma-chloro-butyrophenones, gamma-chloro-butyrothienones, gamma-chloro-aryloxypropanes with the corresponding substituted 2-amino-1,3-thiazoles is described. The spectroscopical data (UV, IR, 1H-NMR and MS) of the derivatives are presented.