Synthesis and antihyperlipidemic activity of some novel 4-(substitutedamino)-5-substituted-3-mercapto- (4H)-1,2,4-triazoles

Hyperlipidemia is considered one of the key factors for cardiovascular diseases. Based on earlier work on a series of 5-alkyl-4-aryl-3-mercapto-(4H)-1,2,4-triazoles, for further lead modification, a series of 4-(substituted)amino-5-substituted-3-mercapto-(4H)-1,2,4-triazoles was designed. Target compounds were synthesized by the well known Hoggarth synthesis of substituted 1,2,4-triazoles. Synthesized compounds were screened for lipid lowering activity using the "Poloxamer 407 induced hyperlipidemia in rats" model at a dose of 100 mg/kg p.o. Compounds were found to alter serum lipid levels significantly. Most of the compounds significantly reduced serum cholesterol and triglyceride levels. Some of the compounds were found to reduce triglycerides and elevate high density lipoprotein (HDL) levels more than the standard drug atorvastatin (CAS 134523-03-8). Compounds with chloro substitution on aryl rings were found more active in reducing serum lipid levels than other substitutions.     

Synthesis and pharmacological activity of 1-(4-substituted phenyl)-1-alkyl(aryl)-3-piperidinopropanol hydrochlorides

Aminomethylation of substituted acetophenones with paraformaldehyde and piperidine hydrochloride yielded 4-substituted β-piperidinopropiophenones. Interaction of compounds I with the Grignard reagents in ether yielded 1-(4-substituted phenyl)-1-alkyl(aryl)-3-piperidinopropanols. The anti-inflammatory, analgesic, antipyretic, central m-cholinoblocking, and peripheral n-cholinoblocking actions of 1-(4-substituted phenyl)-1-alkyl(aryl)-3-piperidinopropanol hydrochlorides were studied. The study compounds were found to have marked central m-cholinoblocking and peripheral n-cholinoblocking activities. Only 1-(4-methoxyphenyl)-1-cyclohexyl-3-piperidinopropanol hydrochloride had anti-inflammatory activity.     

Further evaluation of a series of anti-inflammatory N-pyrrolylcarboxylic acids: effects on the nociception in rats

The analgesic activity of nine substituted N-pyrrolylcarboxylic acids, previously reported as anti-inflammatory agents, has been evaluated. The effects on nociception were examined in male Wistar rats by the Randall-Selitto paw-pressure test. The compounds were administrated in doses 10, 20, and 40 mg/kg both i.p. and p.o. As a whole, the activities of 3-(N-pyrrolyl)propanoic acids 3e-3h and 2-[3-(ethoxycarbonyl)-2-methyl-5-phenyl-1H-1-pyrrolyl]-3-methylpentanoic acid 3i were comparable with or superior to that of metamizole used as a reference (200 mg/kg, i.p.), whereas only 3a from among the N-pyrrolyl-acetic acids 3a-3d showed analgesic activity on the inflamed paw. The compounds found most promising to increase the pain threshold significantly were the same ones with the higher anti-inflammatory activity registered in our previous study: 3-[3-(ethoxycarbonyl)-2-methyl-5-(3-nitrophenyl)-1H-1-pyrrolyl]propanoic acid 3e, together with its 5-(4-nitrophenyl)- 3f, 5-phenyl- 3g, and 5-(4-methylphenyl)- 3h analogs. Certain parallels between the analgesic activities and some physicochemical properties were observed.     

Anti-inflammatory activity of substituted 1,3,4-oxadiazoles

Various 2-(4-biphenoxymethyl)-5-arylamino-1,3,4-oxadiazoles were synthesized by cyclization of the corresponding 1-(4-biphenoxyacetyl)-4-substituted thiosemicarbazides. These compounds were characterized by their elemental analyses and infrared, mass, and nuclear magnetic resonance spectral data. All substituted thiosemicarbazides (100 mg/kg, ip) and cyclized substituted oxadiazoles (100 mg/kg, ip) possessed anti-inflammatory activity, as reflected by their ability to provide protection against carrageenin-induced edema in the rat paw which ranged from 28 to 68% and 36 to 76%, respectively. Cyclization of the substituted thiosemicarbazides, in general, resulted in an increase in the anti-inflammatory activity of their corresponding substituted oxadiazoles, with the exception of those containing 2,4-dimethyl and 3,4-dimethyl substituents in their molecular structure. Hydrocortisone (10 mg/kg, ip) and oxyphenbutazone (40 mg/kg, ip) were used as the standard reference drugs and these provided 45 and 53% protection, respectively. All compounds (1 mM) possessed antiproteolytic activity and the in vitro inhibition of trypsin-induced hydrolysis of bovine serum albumin ranged from 13 to 75% for substituted thiosemicarbazides and 39 to 70% for substituted oxadiazoles. There was no relationship between the anti-inflammatory activity of substituted thiosemicarbazides and substituted oxadiazoles and their antiproteolytic effectiveness. The low toxicity of these compounds was reflected by their high approximate LD50 values, ranging from 500 to 1000 mg/kg.     

Synthesis and evaluation of the analgesic and anti-inflammatory activity of new 3(2H)-pyridazinone derivatives

A series of 6-substituted-3(2H)-pyridazinone derivatives were synthesized and evaluated for analgesic and anti-inflammatory activities. The structures of these new pyridazinone derivatives were confirmed by their IR, 1H-NMR spectra and elementary analysis. Analgesic and anti-inflammatory activities of the title compounds have been evaluated. Four of the ten tested compounds possessed significant analgesic effects in the phenylbenzoquinone-induced writhing test (PBQ test). The most active derivatives 8a, 8b, 8d, 8e were void of gastric ulcerogenic effect or acute toxicity at the maximal dose (200 mg/kg p.o.). In the carrageenan-induced paw edema model, compound 8d (6- [4- (2-fluorophenyl) piperazin-1-yl]-3(2H)-pyridazinone) showed anti-inflammatory activity similar to that of the standard drug indometacin (CAS 53-86-1). A significant dependence of the anti-inflammatory effect on the substituents was observed; The pharmacological study of these compounds confirms that modification of the chemical group at position 6 of the 3(2H)-pyridazinone ring influences analgesic and anti-inflammatory activities.     

Newer indolyl imidazolones as anti-inflammatory agents

Sixteen new 1,2-disubstituted-4-(indol-3'-yl)methylene imidazol-5-ones were synthesized by the condensation of oxazolone with different aryl amines and evaluated as to their anti-inflammatory and antiproteolytic activities. These derivatives showed 2-38% protection against carrageenin-induced paw oedema in albino rats at a dose of 100 mg/kg p.o. All compounds showed antiproteolytic activity. The degree of inhibition against trypsin-induced hydrolysis of casein ranged from 10 to 75% at a concentration of 4 X 10(-4) mol/l. Furthermore, active compounds of the series were also screened for their analgesic activity against aconitine-induced writhing in albino mice. The toxicity of the compounds was reflected by their approximate LD50 values.     

Anti-inflammatory activity of two cucurbitacins isolated from Cayaponia tayuya roots

Fractionation of an anti-inflammatory extract from Cayaponia tayuya roots yielded two active compounds, identified as 23,24-dihydrocucurbitacin B (1) and cucurbitacin R (2). Both were evaluated for their anti-inflammatory activity on several experimental models of pain and inflammation. In addition, their cytotoxicity and effects on leukotriene B4 (LTB4) formation were evaluated in rat polymorphonuclear leukocytes. Both compounds showed activity in the following models: carrageenan-induced mouse paw oedema (1, 4 mg/kg p.o., 46% inhibition at 3 h), phospholipase A2-induced mouse paw oedema (2, 3 mg/kg i.p., 61% inhibition at 60 min), serotonin-induced mouse paw oedema (1 and 2, 0.5 mg/kg s.c., 73% and 79% inhibition, respectively), 12- O-tetradecanoylphorbol 13-acetate (TPA)-induced acute ear oedema (2, 36% inhibition at 4 mg/kg p.o., and 87% inhibition at 0.1 mg/ear topically). The compounds were also active against the inflammation induced by repeated application of TPA on mouse ears, affecting both the oedema itself (1 and 2 at 0.1 mg/ear, 44% and 56% inhibition, respectively) as well as cell infiltration (68% and 69%, respectively). The activity of both compounds against oedema induced by serotonin was not modified by the glucocorticoid receptor antagonist mifepristone; however, the protein synthesis inhibitor cycloheximide abolished the anti-inflammatory response in both cases. Neither compound modified the production of LTB4 in rat polymorphonuclear leukocytes, nor did they exhibit analgesic properties at the dose assayed.     

Syntheses and Anti-inflammatory Activities of Substituted Arylamino-(N′-benzylidene)acetohydrazides and Derivatives

The substituted arylamino-(N′-benzylidene)acetohydrazides 1–6 , substituted acetic acid arylamino-(N′-benzyl)acetohydrazides 7–12 and N-(3-chloro-2-oxo-4-phenylazetan-1-yl) (phenylamino)acetamides 13–16 , containing a β-lactam ring were synthesized and studied for their anti-inflammatory activities against carrageenin induced paw oedema in albino rats. Compound 7 was most active (30.6% at 50mg/kg p. o.) with minimum acute toxicity. All compounds showed a marked but variable (44–80%) inhibition of antiproteolytic activity.     

Synthesis of 2-(aryl)-5-(arylidene)-4-thiazolidinone derivatives with potential analgesic and anti-inflammatory activity

A series of novel N-[5-(arylidene)-2-(aryl)-4-oxo-thiazolidin-3-yl]-4-biphenylcarboxamide derivatives was synthesized and evaluated for analgesic and anti-inflammatory activity. In this study, biphenyl-4-carboxylic acid hydrazide was converted to the corresponding aryl hydrazones using aryl aldehydes in the presence of catalytic amount of glacial acetic acid. The aryl hydrazones on reaction with thioglycolic acid in the presence of anhydrous zinc chloride yielded N-[2-(aryl)-4-oxo-thiazolidin-3-yl]-4-biphenylcarboxamide which further on reaction with aromatic aldehydes in the presence of anhydrous sodium acetate and glacial acetic acid furnished the title compounds. All compound exhibited anti-inflammatory activity at the dose 10?mg/kg. The structures of all these newly synthesized compounds were confirmed by their elemental analyses (C, H, N) and spectral data (IR and ¹H NMR).     

Synthesis and pharmacological evaluation of (indol-3-yl)alkylamides as potent analgesic agents.

A series of (indol-3-yl)alkylamides was synthesized and evaluated for analgesic activity. Two N-(pyridin-4-yl)acetamides, compounds 24 and 25, bearing benzyl or 4-fluorobenzyl moieties in 1-position of indole ring exhibited promising analgesic properties (ED50 = 8.1 and 11 mg/kg p.o., respectively), being as potent as the reference drugs flupirtine (CAS 56995-20-1), ibuprofen (CAS 15687-27-1) and diclofenac (CAS 15307-86-5). The two test compounds were tested for their anti-inflammatory activity by carrageenin-induced edema in rat paw test. 4-Fluorobenzyl derivative 25 whose ID50 was 0.085 +/- 0.021 mmol/kg was selected as a lead compound for further pharmacomodulation.     

Pharmacological studies on 3-[gamma-(p-fluorobenzoyl)propyl]-2,3,4,4a,5,6-hexahydro-1-(H)-pyrazino(1,2-a)quinoline hydrochloride (compound 69/183). Part IV: other CNS effects and acute toxicity

3-[gamma-(p-Fluorobenzoyl)propyl]-2,3,4,4a,5,6-hexahydro-1-(H)-pyrazino(1,2-a)quinoline hydrochloride (centpyraquin), a potent antihypertensive and tranquillising agent, was tested for anticonvulsant, analgesic and anti-inflammatory activities in mice and for anti-emetic activity in dogs. It did not modify supramaximal electroshock seizures and failed to protect the animals against pentylenetetrazole and strychnine induced convulsions. It, however, produced some elevation in the threshold dose of strychnine. Tremorine induced tremors and salivation were not antagonised. The compound had weak analgesic activity as detected by antagonism to phenylquinone writhing and the hot plate test. It had no anti-inflammatory activity. Centpyraquin had strong anti-emetic activity against apomorphine as well as morphine. At high doses it produced fall out in the rota-rod test. The LD50 of centpyraquin in mice was 296 mg/kg i.p. and more than 1000 mg/kg p.o. and in rats it was 161 mg/kg i.p. and more than 800 mg/kg p.o. The observed CNS effects resemble those of other neuroleptics.     

Synthesis of new Mannich bases of arylpyridazinones as analgesic and anti-inflammatory agents

A series of 2-[[4-(substituted-phenyl/ benzyl)-1-piperazinyllmethyl]-6-(4-methoxyphenyl)-3(2H)pyridazinone derivatives was prepared and examined for analgesic and anti-inflammatory activities. The structures of these new pyridazinone derivatives were confirmed by their IR and 1H-NMR spectra and elementary analysis. Among the compounds prepared, 2-[[4-(4-fluorophenyl)-1-piperazinyl]methyl]-6-(4-methoxyphenyl)-3(2H)pyridazinone IVe was found to be a most promising analgesic and anti-inflammatory agent. Compound IVe showed more potent analgesic activity than acetylsalicyclic acid in the phenylbenzoquinone-induced writhing test. Also IVe showed anti-inflammatory activity comparable to that of the standard compound indometacin against the carrageenan-induced paw edema. Side effects of the compounds were examined on gastric mucosa. None of the compounds showed a gastric ulcerogenic effect compared with reference nonsteroidal anti-inflammatory drugs. On the basis of the available data, the structure-activity relationship of the series of 2-[[4-(substituted-phenyl/benzyl)-1-piperazinyl]methyl]-6-(4-methoxyphenyl)-3(2H) pyridazinones is also discussed.     

The analgesic effect profile of FR122047, a selective cyclooxygenase-1 inhibitor, in chemical nociceptive models

The pharmacological profile of the analgesic agent, 1-[(4, 5-bis(4-methoxyphenyl)-2-thiazoyl)carbonyl]-4-methylpiperazine hydrochloride (FR122047), was investigated. In recombinant human cyclooxygenase enzyme assays, the inhibition of prostaglandin E(2) formation by FR122047 was 2300 times more selective for cyclooxygenase-1 than cyclooxygenase-2. Oral administration of FR122047 (3.2-100 mg/kg) dose dependently reduced the phase 2 response (10-60 min) of the formalin test in rats. This effect was 3 times less potent than that of indomethacin. FR122047 (1-32 mg/kg; p. o.) showed a dose-dependent analgesic effect against the acetic acid-induced writhing response in mice. Furthermore, FR122047 (0. 01-10 mg/kg, p.o.) inhibited the increase in 6-keto prostaglandin F(1alpha) level in acetic acid-injected mouse peritoneal cavity. However, a selective cyclooxygenase-2 inhibitor, NS-398, had no effect in these cyclooxygenase-1 sensitive pain models. These results suggest that FR122047, a selective cyclooxygenase-1 inhibitor, shows an analgesic effect in chemical nociceptive models and may be a useful analgesic agent.     

Effects of alminoprofen on sodium urate crystal-induced inflammation]

Effects of alminoprofen (AP), a non-steroidal anti-inflammatory agent, were investigated using several experimental gouty models. AP (3-30 mg/kg, p.o.) dose-dependently inhibited urate crystal-induced rat paw edema. AP (3-30 mg/kg, p.o.) inhibited the accumulation of exudate and decreased the total counts of leukocytes and the amount of PGE2 in a dose-dependent manner in sodium urate crystal-induced pleuritic rats. AP (0.3-10 mg/kg, p.o.) showed a dose-related analgesic activity on the pain response in sodium urate crystal-induced arthritic rats. AP (10(-5)-10(-3)M) inhibited the sodium urate crystal-induced beta-glucuronidase release from guinea pig neutrophils at more than 10(-4) M. AP (10(-5)-10(-3)M) did not inhibit the sodium urate crystal-induced production of O2- from guinea-pig neutrophils. AP (10(-6)-10(-4) M) inhibited dose-dependently the chemotaxis of leukocytes induced by chemotactic factors from guinea pig neutrophils stimulated with sodium urate crystals. AP (10(-6)-10(-4) M) inhibited the sodium urate crystal-induced production of PGE2 from rat peritoneal leukocytes in a dose-related manner. These results suggest that AP has a potent anti-inflammatory and analgesic activity in sodium urate crystal-induced inflammations, and these effects are exerted through its combined inhibitions of PGE2 synthesis, leukocyte chemotaxis and lysosomal enzyme release.     

Synthesis and pharmacological evaluation of 2-hydroxymethylbenzamides as anti-inflammatory and analgesic agents

The ring opening of some phthalimide derivatives with sodium borohydride in methanol/water (6:1) afforded the corresponding 2-hydroxymethylbenzamides irrespective of the substituents. The most active members of the series evaluated for anti-inflammatory and analgesic activities were 2-hydroxymethyl-N-[4-(2-methoxyphenyl)-piperazin-1-yl]-ethylbenzamide (3d) and 2-hydroxymethyl-N-[4-(2-methoxyphenyl)-piperazin-1-yl]-propylbenzamide (3e), respectively.     

Suppressive effects of propolis in rat adjuvant arthritis

The effects of ethanolic extract (EEP) of propolis on chronic inflammation were evaluated using rat adjuvant arthritis. In the chronic inflammatory animal model, the arthritis index was suppressed by EEP treatments (50 mg/kg/day and 100 mg/kg/day, p.o.). Moreover, physical weakness, induced by the chronic disease state, was dose-dependently improved in the EEP-treated groups. Its analgesic effect, assessed using the tail-flick test, was comparable to prednisolone (2.5 mg/kg/day, p.o.) and acetyl salicylic acid (100 mg/kg/day, p.o.). In carrageenan rat hind paw edema, which was conducted to test the effects of subfractions of EEP, the petroleum ether sub-fraction (100 mg/kg, p.o.) showed an inhibitory effect on the paw edema whereas EEP (200 mg/kg, p.o.) showed a significant anti-inflammatory effect at 3 and 4 hrs after carrageenan injection. From these results, we conclude that the ethanolic extract of propolis had a profound anti-inflammatory effects on both chronic and acute inflammations.     

Synthesis and analgesic, anti-inflammatory activities of 3-(3-methoxyphenyl)-2-substituted amino-quinazolin-4(3H)-ones

A variety of novel 3-(3-methoxyphenyl)-2-substituted amino-quinazolin-4(3H)-ones were synthesized by reacting the amino group of 2-hydrazino-3-(3-methoxyphenyl)-quinazolin-4(3H)-one with a variety of aldehydes and ketones. The starting material 2-hydrazino-3-(3-methoxyphenyl)-quinazolin-4(3H)-one was synthesized from 3-methoxy aniline. The title compounds were investigated for analgesic, anti-inflammatory, and ulcerogenic behavior. Among these the compound 2-(1-methyl butylidene-hydrazino)-3-(3-methoxyphenyl)-3H-quinazolin-4-one (AS3) emerged as the most active compound for the analgesic activity, while the compound 2-(1-ethyl propylidene-hydrazino)-3-(3-methyoxyphenyl)-3H-quinazolin-4-one (AS2) showed most potent anti-inflammatory activity of the series and these compounds are moderately more potent when compared to the reference standard diclofenac sodium. Interestingly the test compounds showed only mild ulcerogenic potential when compared to acetylsalicylic acid.     

The analgesic,anti-inflammatory and calcium antagonist potential of<Emphasis Type="Italic">Tanacetum artemisioides</Emphasis>

Several species of the genus Tanacetum are traditionally used in a variety of health conditions including pain, inflammation, respiratory and gastrointestinal disorders. In the current investigation, we evaluated the plant extract of T. artemisioides and some of its pure compounds (flavonoids) for analgesic, anti-inflammatory and calcium antagonist effects in various in-vivo and in vitro studies. Using the actetic acid induced writhing test, intraperitoneal (i.p) administration of the plant extract (25-50 mg/kg) and its flavonoid compounds TA-1 and TA-2 (1-5 mg/kg ) exhibited significant analgesic actvity. The maximum analgesic effect observed with the crude extract of the plant was 71% at 50 mg/kg, while that of compounds TA-1 and TA-2 (5 mg/kg i.p) was 75 and 47%, respectively. The plant extract and its pure compounds caused inhbition of formalin induced paw licking in mice predominatly in the second phase of the test. Diclofenac sodium, a standard reference compound, showed a simlar effect in these chemical induced pain models. In the carrgeenan induced rat paw edema assay, the plant extract (50-200 mg/kg i.p) demonstrated significant (P< 0.01) anti-inflammatory activity which was comparable to that obtained with diclofenac sodium and indomethacin. In isolated rabbit jejunum preprations the plant extract showed an atropine sensitive dose-dependent (0.10-1.0 mg/mL) spasmogenic activity followed by a spasmolytic effect at the next higher doses (3-5 mg/mL). The crude extract of the plant also inhibited the high K+-induced contractions, indicating a calcium channel blocking (CCB) activity, which was further confirmed when the plant extract caused a rightward shift in the Ca++ concentration response curves in the isolated rabbit jejunum preparations, similar to that seen with verapamil. The flavonoid compounds isolated from the plant were devoid of any activity in the isolated tissue preparations. These results indicate that the plant extract of T. artemisioides possesses analgesic, anti-inflammatory and CCB activities. The flavonoid compounds of the plant may have a role in its observed analgesic and antiinflammatory activities, while the CCB activity of the plant may be attributed to some other chemical constituents present. Moreover the findings support the traditional reputation of the genus Tanacetum for its therapeutic benefits in pain and inflammatory conditions.     

Pharmacological properties of MDL 19,301: A novel,nonsteroidal, anti-inflammatory agent

Oral administration of MDL 19,301 (N-(1,3-dithiolan-2-ylidene)-4-hexyl-benzenamine) inhibited rat paw edema induced by carrageenan (ED30 4.8 mg/kg) or an Arthus reaction (ED30 8.2 mg/kg p.o.). The oral dose which induced gastric ulceration in 50% of fasted rats (UD50) was greater than 1,000 mg/kg, demonstrating a more favorable therapeutic ratio than conventional nonsteroidal anti-inflammatory agents. Its major metabolite ((MDL16,861, 4[1,3-dithiolan-2-yliden)amino]-benzeneacetic acid) was also a potent inhibitor of carrageenan paw edema (ED50 5.5 mg/kg p.o.), although it was more ulcerogenic (UD50 52 mg/kg p.o.). The anti-inflammatory activity of MDL 19,301, but not that of MDL 16,861, was attenuated by co-administration of an inhibitor of drug metabolism (SK&F525A 30 mg/kg i.p.). This suggests that MDL 19,301 is a prodrug of MDL 16,861 and this phenomenon would explain its lack of ulcerogenicity. Additional anti-inflammatory properties of MDL 19,301 included inhibition of carrageenan pleurisy, adjuvant arthritis, and acetic-acid-induced writhing. Other pharmacological data indicate that MDL 19,301 administration results in inhibition of prostaglandin synthesis; inhibition of arachidonic-acid-induced, but not prostaglandin-E₂-induced, diarrhea in mice; and inhibition of ex vivo arachidonic-acid-induced, but not adenosine-diphosphate-induced, rat platelet aggregation. MDL 19,301 and MDL 16,861 were unexpectedly weak antipyretic agents in rats. In summary, MDL 19,301 is an anti-inflammatory, analgesic prodrug which, unlike conventional agents, is devoid of ulcerogenic activity at therapeutic doses.