PEG-crosslinked-chitosan hydrogel films for in situ delivery of Opuntia ficus-indica extract

In the present study, chitosan-based wound dressings loaded with the extract of Opuntia ficus-indica (OPU) were prepared. OPU is known for its capability to accelerate skin injury repair. Chitosan (Ch) was crosslinked with a low molecular weight diepoxy-poly(ethylene glycol) (diePEG), and hydrogel films with different Ch/PEG composition and OPU content were prepared by casting. The occurrence of crosslinking reaction was confirmed by FTIR spectroscopy. FTIR and DSC analysis suggested that ionic interactions occur between chitosan and OPU. Tensile tests evidenced that the crosslinking caused a decrease of Young's modulus, which approaches the value of the human skin modulus. Swelling characteristics, water vapor transmission rate, and release kinetics demonstrated that these films are adequate for the proposed application. Finally, a scratch test on a keratinocytes monolayer showed that the rate of cell migration in the presence of OPU-loaded samples is about 3-fold higher compared to unloaded films, confirming the repairing activity of OPU.

Involvement of inducible nitric oxide synthase and cyclooxygenase-2 in the anti-inflammatory effects of a red orange extract in human chondrocytes

In the present study, a complex of compounds (red orange complex, ROC), obtained from three red orange varieties (Citrus sinensis varieties: Moro, Tarocco and Sanguinello), containing cyanidin glycosides, hydroxycinnamic acids, flavanone glycosides and ascorbic acid, was screened to discover new lead compounds in the suppression of the production of key molecules released during inflammatory events in interleukin-1beta (IL-beta) stimulated human primary chondrocytes. The expression of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX)-2 and intercellular adhesion molecule-1 (ICAM-1), and the release of nitric oxide, prostaglandin (PG)E(2) and interleukin-8 (IL-8) were determined. Indomethacin was used as an anti-inflammatory drug reference. ROC acts as a potent inhibitor of iNOS and COX-2 gene expression while also suppressing the production of PGE(2) and nitrite in human chondrocytes. In addition, ROC induces a significant decrease in ICAM expression and IL-8 release. These findings suggest that ROC exerts anti-inflammatory effects probably through the suppression of COX-2 and iNOS expression.

Effect of hyaluronic acid and polysaccharides from Opuntia ficus indica (L.) cladodes on the metabolism of human chondrocyte cultures

Conventional medications in articular disease are often effective for symptom relief, but they can also cause significant side effects and do not slow the progression of the disease. Several natural substances have been shown to be effective as non-steroidal anti-inflammatory drugs at relieving the symptoms of osteoarthritis (OA), and preliminary evidence suggests that some of these compounds may exert a favourable influence on the course of the disease. In this study, we assay the anti-inflammatory/chondroprotective effect of some lyophilised extracts obtained from Opuntia ficus indica (L.) cladodes and of hyaluronic acid (HA) on the production of key molecules released during chronic inflammatory events such as nitric oxide (NO), glycosaminoglycans (GAGs), prostaglandins (PGE(2)) and reactive oxygen species (ROS) in human chondrocyte culture, stimulated with proinflammatory cytokine interleukin-1 beta (IL-1 beta). Further the antioxidant effect of these extracts was evaluated in vitro employing the bleaching of the stable 1,1-diphenyl-2-picrylhydrazyl radical (DPPH test). All the extracts tested in this study showed an interesting profile in active compounds. Particularly some of these extracts were characterized by polyphenolic and polysaccharidic species. In vitro results pointed out that the extracts of Opuntia ficus indica cladodes were able to contrast the harmful effects of IL-1 beta. Our data showed the protective effect of the extracts of Opuntia ficus indica cladodes in cartilage alteration, which appears greater than that elicited by hyaluronic acid (HA) commonly employed as visco-supplementation in the treatment of joint diseases.

In vitro protective effect of a Jacquez grapes wine extract on UVB-induced skin damage

Several studies have shown that UV radiation on the skin results in the formation of reactive oxygen species (ROS) that interact with proteins, lipids and DNA, thus altering cellular functions. The epidermis is composed mainly of keratinocytes, rich in ROS detoxifying enzymes and in low-molecular-mass antioxidant molecules. However, the increased generation of ROS can overwhelm the natural defences against oxidative stress. Therefore treatment of the skin with products containing plant-derived antioxidant ingredients may be a useful strategy for the prevention of UV-mediated cutaneous damage. In the present study we have investigated the in vitro capability of a Jacquez grapes wine extract (containing a significant level of proanthocyanidins, together with lower amounts of anthocyanins and hydroxycinnamic acids; JW-E), to protect skin against UVB-induced oxidative damage by using a three-dimensional tissue culture model of human epidermis. The endpoints of our experiments were cell viability, release of interleukin-1alpha and prostaglandin E(2) (well-known mediators of cutaneous inflammatory processes), accumulation in the epidermis of malondialdehyde/4-hydroxynonenal and protein carbonyl groups (derived by the oxidative damage respectively of lipids and proteins) and tissue redox balance (expressed by the levels of reduced glutathione, oxidized glutathione, glutathione peroxidase and glutathione reductase). Taken together, our findings demonstrate that the JW-E is an efficient botanical mixture able to prevent skin oxidative damage induced by UV-B exposure and may thus be a potential promising candidate as a skin photoprotective agent.

The in vitro effect of a lyophilized extract of wine obtained from Jacquez grapes on human chondrocytes

The present work was aimed at evaluating the in vitro effects of a lyophilized extract of wine (JW-E) obtained from Jacquez grapes (Vitis aestivalis-cinereaxVitis vinifera grapes) on the production of key molecules released in inflammatory disease utilising interleukin-1beta (IL-1beta) activated chondrocytes. The extract contains large amounts of phenolic components, in particular some flavonoids (flavan-3-ols, also known as catechins) and proanthocyanidins, as hydroxycinnamic acids and anthocyanins, that possess several biological features such as antiinflammatory and antioxidant effects and a "radical scavenger" activity too. In this study, we assayed the effect of JW-E on the production of key molecules released during chronic inflammatory events as nitric oxide (NO), prostaglandins E(2) (PGE(2)) and reactive oxygen species (ROS) in human chondrocytes culture, stimulated with proinflammatory cytokine interleukin-1beta. The JW-E proved to possess good ability against the harmfull effects of IL-1beta. Our data showed the protective effects of JW-E in cartilage alteration, that appears greater than that elicited by indomethacin, a not steroidal antiinflammatory drug (NSAID), commonly employed in joint diseases.

Protective effect of Capparis spinosa on chondrocytes

The aim of the present study was to evaluate the in vitro chondroprotective effects of the lyophilised methanolic extract from flowering buds of Capparis Spinosa L (LECS). This plant, common to the Mediterranean basin, has been used by the traditional medicine for its diuretic and antihypertensive effects and also in certain pathological conditions related to uncontrolled lipid peroxidation. The extract contains many constituents, in particular some flavonoids (kaempferol and quercetin derivatives) and hydrocinammic acids with several known biological effects such as the anti-inflammatory and the antioxidant ones. In this study, we assayed the effect of LECS on human chondrocytes cultures stimulated by proinflammatory cytokine interleukin-1beta (IL-1beta) and we determined the production of key molecules released during chronic inflammatory events (nitric oxide, glycosaminoglycans, prostaglandins and reactive oxygen species). We observed that LECS was able to counteract the harmful effects induced by IL-1beta. This protection appeared to be greater than that elicited by indomethacin, which is usually employed in joint diseases. Since LECS possess a chondroprotective effect, it might be used in the management of cartilage damage during the inflammatory processes.

Vehicle effects on in vitro skin permeation of thiocolchicoside

Thiocolchicoside, a semi-synthetic derivative of colchicoside, is used in topical formulations for its anti-inflammatory and muscle-relaxant properties. The objective of this study was to evaluate the effect of a (propylene glycol diperlagonate) DPPG and (propylene glycol) PG mixture present in an innovative foam formulation (Miotens) on the flux of thiocolchicoside through excised human skin. Furthermore, the in vitro permeation behaviour of this new formulation (Miotens foam) was compared to another commercial product (Muscoril ointment) and to a control gel formulation (thiogel), both enhancer free. The best permeation profile was obtained from the foam formulation (Miotens) which was able to increase the thiocolchicoside flux about three fold compared to control formulation (thiogel) and about two fold compared to the commercial formulation Muscoril ointment.

In vitro antioxidant and in vivo photoprotective effects of a lyophilized extract of Capparis spinosa L buds

The aim of the present study was to evaluate the in vitro antioxidant and in vivo photoprotective activities of a lyophilized extract of Capparis spinosa L. (LECS) obtained by methanolic extraction from the flowering buds of this plant. For the in vitro experiments, LECS was tested employing three different models: (a). bleaching of the stable 1,1-diphenyl-2-picrylhydrazyl radical (DPPH test); (b). peroxidation, induced by the water-soluble radical initiator 2,2'-azobis(2-amidinopropane) hydrochloride, of mixed dipalmitoylphosphatidylcholine/linoleic acid unilamellar vesicles (LUVs) (LP-LUV test); and (c). UV-induced peroxidation of phosphatidylcholine multilamellar vesicles (UV-IP test). The in vivo antioxidant/radical scavenger activity was assessed by determining the ability of topically applied LECS to reduce UVB-induced skin erythema in healthy human volunteers. From the results obtained in in vitro and in vivo tests, LECS showed a significant antioxidant effect. Furthermore, by chromatographic fractionation and spectroscopic methods, we identified the major constituents of LECS, and particularly some flavonols (kaempferol and quercetin derivatives) and hydroxycinnamic acids (caffeic acid, ferulic acid, p-cumaric acid, and cinnamic acid).

Oligoethylene ester derivatives of ketoprofen, naproxen and diclofenac as oral prodrugs: a pharmacological evaluation

Polyoxyethylene esters of ketoprofen (1a-e), naproxen (2a-e) and diclofenac (3a-e) were tested in vitro to determine their stability in pH 7.4 phosphate buffer and in simulated gastric fluid (pH 2.0 buffer) and their susceptibility in undergoing enzymatic cleavage in human plasma. Furthermore their in vivo antiinflammatory and analgesic activity and GI toxicity were evaluated in rodents. All the prodrugs showed a good stability both in pH 7.4 phosphate buffer and in pH 2.0 buffer. They were readily hydrolyzed by human plasma and, for each group of prodrugs, no significant difference in hydrolysis rate was observed as the length of the oligoethylene chain increased. Esters 1a-e, 2a-e and 3a-e showed an anti-inflammatory activity (expressed as inhibition percent of carrageenan-induced edema in the rat) similar to that of their respective parent drug although at higher doses. The results obtained in the writhing test in mice demonstrated that all the prodrugs tested exhibited, following acute administration, a good analgesic effect. Furthermore these esters were significantly less irritating to the gastric mucosa, although administered at doses higher than the respective parent drug.

Evaluation of in vitro percutaneous absorption of lorazepam and clonazepam from hydro-alcoholic gel formulations

Clonazepam and lorazepam are two anxiolytics, antidepressant agents, having suitable features for transdermal delivery. The objectives of this study were to evaluate the in vitro percutaneous absorption of these drugs through excised human skin (stratum corneum and epidermis, SCE) and to determine their in vitro permeation behavior from a series of hydro-alcoholic gel formulations containing various enhancing agents. The best permeation profile was obtained for both drugs applying them together with Azone in combination with propylene glycol (PG): these enhancers were able to increase the clonazepam and lorazepam percutaneous fluxes at steady-state about threefold, compared to the free enhancer formulations (Control). To explain the mechanism of the used promoters, the benzodiazepine diffusion and partitioning coefficients from the gel containing the enhancers were calculated. The results indicated that the Azone in combination with PG could act by increasing the benzodiazepine diffusion coefficients, Transcutol increased only the SC/vehicle partition coefficients, limonene in combination with PG appeared to increase both partition and diffusion coefficients moderately, while PG did not increase both the parameters. Furthermore, to evaluate the potential application of tested benzodiazepine formulations containing Azone in combination with PG using the flux values from the in vitro experiments, the corresponding steady-state plasma concentrations (C(SS)) were calculated. The obtained calculated C(SS) values are within the lorazepam therapeutic range and suggest that transdermal delivery of this drug could be regarded as feasible.

In-vitro antioxidant and in-vivo photoprotective effect of three lyophilized extracts of Sedum telephium L. leaves

Sedum telephium L. is a medicinal plant used in antiquity to cure many types of inflammatory skin diseases. The leaves (without the external cuticle), are used to promote healing and reduce skin inflammation and pain, and contain various components. We found two major components: flavonol glycosides and polysaccharides, with molecular weight between 13,000 and 13,500 Da. We evaluated the in-vitro antioxidant and in-vivo skin photoprotective effects of three lyophilized extracts obtained from the juice of S. telephium L. leaves: a total lyophilized juice, a lyophilized flavonolic fraction, and a lyophilized polysaccharidic fraction. Two in-vitro models were used: the bleaching of the stable 2,2-diphenyl-1-picrylhydrazyl (DPPH*) radical, and the protective effect against UV-induced peroxidation on phosphatidylcholine multilamellar vesicles, as model membranes. The antioxidant/radical scavenging activity of each lyophilized extract was also assessed in-vivo by determining their ability to reduce UVB-induced skin erythema (monitored by reflectance spectrophotometry) in healthy human volunteers. The findings of the in-vitro experiments clearly demonstrated that, unlike the lyophilized polysaccharidic fraction, the lyophilized flavonolic fraction and total lyophilized juice possess strong antioxidant/free radical scavenging properties, which are likely due to phenolic compounds. Consistent with these findings, gel formulations of both the total lyophilized juice and, to a greater degree, the lyophilized flavonolic fraction appeared to possess a strong protective effect against UV-induced skin erythema in-vivo, whereas the lyophilized polysaccharidic fraction was completely ineffective. The in-vitro and in-vivo results suggest that, both the total lyophilized juice and, in particular, the lyophilized flavonolic fraction, but not the lyophilized polysaccharidic fraction of S. telephium L. leaves, have photoprotective effects against UVB-induced skin damage.

In vitro and in vivo evaluation of caffeic and ferulic acids as topical photoprotective agents

Topically-applied antioxidant drugs represent a successful strategy for protecting the skin against UV-mediated oxidative damage. However, they can afford to the skin a satisfactory photoprotection only if able to permeate through the stratum corneum and thus to reach deeper cutaneous layers. Caffeic and ferulic acids, dissolved in saturated aqueous solutions at pH 3 or 7.2, have been tested for their capability to permeate through excised human skin mounted in Franz cells. At both pH values, ferulic and, at a lower degree, caffeic acids appeared able to permeate through the stratum corneum. The known higher lipophilicity of ferulic acid may explain the fact that it permeates through the stratum corneum better than caffeic acid. However, vehicle pH values proved to have no influence on biophenol skin permeation profile; this observed lack of pH effect may reflect the drug higher concentration attainable in saturated solutions at high pH. On the basis of the findings obtained in these in vitro experiments, we designed the schedule of a series of in vivo experiments, carried out to evaluate the ability of caffeic and ferulic acids to reduce, in healthy human volunteers, UVB-induced skin erythema, monitored by means of reflectance spectrophotometry. Caffeic and ferulic acids, dissolved in saturated aqueous solution pH 7.2, proved to afford a significant protection to the skin against UVB-induced erythema. To conclude, we have confirmed, by means of in vitro and in vivo experiments, that caffeic and ferulic acids may be successfully employed as topical protective agents against UV radiation-induced skin damage; however their skin absorption is not influenced by the pH of the formulation.

Systemically administered D-glucose conjugates of 7-chlorokynurenic acid are centrally available and exert anticonvulsant activity in rodents

We have synthesized D-glucose or D-galactose esters of 7-chlorokynurenic acid (7ClKynA) as prodrugs to facilitate the transport of 7ClKynA across the blood-brain barrier. Intraperitoneal (i.p.) administration of either 7ClKynA-D-glucopyranos-6'-ylester (7ClKynA/Glu6) or 7ClKynA-D-glucopyranos-3'-yl ester (7ClKynA/Glu3) was protective against seizures induced by N-methyl-D-aspartate (NMDA) in mice, with the former drug showing the highest anticonvulsive activity. Systemic injection of equal amounts of 7ClKynA-D-galactopyranos-6'-yl ester (7ClKynA/Gal6) or free 7ClKynA did not protect against NMDA seizures. Microdialysis in freely moving rats showed the presence of significant amounts of 7ClKynA/Glu6, as well as of 7ClKynA or KynA, in cortical perfusates after i.p. injections of 7ClKynA/Glu6. In contrast, only small amounts of 7ClKynA or KynA were detected after i.p. injection of unconjugated 7ClKynA. Prodrug metabolism has also been examined in mouse cortical cultures containing both neurons and astrocytes. 7ClKynA/Glu6 and 7ClKynA/Gal6 were rapidly metabolized into 7ClKynA and KynA, whereas 7ClKynA/Glu3 was metabolized with a slower kinetics. As a result of its conversion into 7ClKynA and KynA, 7ClKynA/Glu6 protected cortical neurons against NMDA toxicity. We conclude that sugar conjugates of 7ClKynA (and perhaps of other excitatory amino acid receptor antagonists) are prodrugs of potential interest in the experimental therapy of epilepsy and acute or chronic neurodegenerative disorders.

Antioxidant effectiveness as influenced by phenolic content of fresh orange juices

Several fresh orange juices, obtained from five different Citrus sinensis (L.) Osbeck varieties (three pigmented varieties, Moro, Sanguinello, and Tarocco, and two blond varieties, Valencia late and Washington navel), were subjected to antioxidant profile determination (including total polyphenols, flavanones, anthocyanins, hydroxycinnamic acids, and ascorbic acid). The antioxidant activity of these juices was then assessed by means of different "in vitro" tests (bleaching of the stable 1,1-diphenyl-2-picrylhydrazyl radical; peroxidation, induced by the water-soluble radical initiator 2,2'-azobis(2-amidinopropane) hydrochloride, on mixed dipalmitoylphosphatidylcholine/linoleic acid unilamellar vesicles; scavenging activity against nitric oxide; total antioxidant status). All orange juices tested showed an evident antioxidant effect. Our findings indicate the following: (1) the antioxidant efficiency of orange juices may be attributed, in a significant part at least, to their content of total phenols, (2) while ascorbic acid seems to play a minor role; (3) the antioxidant activity of orange juices is related not only to structural features of phytochemicals contained in them, but also to their capability to interact with biomembranes; (4) finally, as to pigmented juices, their antioxidant efficiency appears to be widely influenced by the anthocyanin level. One could speculate that the supply of natural antioxidant phenols through daily consumption of orange juice might provide additional protection against in vivo oxidation of cellular biomolecules.

Dipalmitoylphosphatidylcholine/linoleic acid mixed unilamellar vesicles as model membranes for studies on novel free-radical scavengers

Large unilamellar vesicles (LUVs) are generally accepted to be a suitable model for peroxidation studies. In the present report, dipalmitoylphosphatidylcholine (DPPC)/linoleic acid-mixed LUVs were employed as model membranes to verify the inhibitory effect of tocopherol (an efficient representative antioxidant) against 2,2'-azobis(2-amidinopropane)hydrochloride-induced peroxidation (evaluated by monitoring conjugated diene accumulation). In this model, the appropriate experimental conditions (particularly, liposome composition and peroxidation temperature) were selected following characterization of bilayer physical state, and not only by evaluation of peroxidation rate. Thus, the experiments described provide a routine screening procedure that would be appropriate for assessing the activity profile of novel free-radical scavengers.

Transport of alpha-tocopherol and its derivatives through erythrocyte membranes

PURPOSE

To investigate the transport of alpha-tocopherol (T), tocopherol succinate (TS) and tocopherol succinate-3-glucose (a newly synthetized, less hydrophobic T ester; TSG) through bovine erythrocyte membranes.

METHODS

Our experiments were carried out on erythrocytes (obtained from heparinized fresh bovine blood), because they represent a suitable model for investigations of membrane transport.

RESULTS

T was shown to reside almost completely in the suspension medium, while the greater part of TS disappeared from the suspension medium and was mainly incorporated into erythrocyte membranes. In comparison with T, a larger amount of TSG was incorporated into erythrocyte membranes and taken up by cells; however the TSG intracellular accumulation was significantly lower than that observed with TS. Furthermore, the transport of TS and TSG was partially inhibited by p-chloromercuribenzenesulfonate (which inhibits monocarboxylate uptake; PCMBS) and by maltose (a competitive inhibitor of glucose transport) respectively, with a concomitant increase in drug membrane incorporation. No significant change in drug transport was observed in the presence of 4,4'-diisothiocyanostilbene-2,2'-disulfonate, a selective and irreversible blocker of band 3 protein (DIDS).

CONCLUSIONS

Our results show 1) the existence of large differences in membrane incorporation of T, TS and TSG (very likely caused by differing abilities to fill spaces in the lipid bilayer) and 2) a specific contribution of the monocarboxylate transport protein and of the glucose transport protein in the cellular uptake of TS and TSG, respectively. A tempting suggestion is that the unique cytoprotective properties of TS may be related to the differences in the transmembrane mobility observed between T and its succinate ester. Furthermore, T conjugation to a monocarboxylate or glycoside moiety could provide suitable substrates for active membrane transport, thus appearing as a promising pharmaceutical strategy for the improved delivery of tocopherol derivatives.

Flavonoids as antioxidant agents: importance of their interaction with biomembranes

Flavonoids, a group of phenolic compounds widely occurring in the plant kingdom, have been reported to possess strong antioxidant activity. In the present study, four flavonoids (quercetin, hesperetin, naringenin, rutin), chosen according to their structural characteristics, were tested in two different in vitro experimental models: (1) Fe(2+)-induced linoleate peroxidation (Fe(2+)-ILP), by detection of conjugated dienes; and (2) autooxidation of rat cerebral membranes (ARCM), by using thiobarbituric acid for assay of free malondialdehyde production. The results obtained were also interpreted in the light of flavonoid interactions, studied by differential scanning calorimetry, with dipalmitoylphosphatidylcholine (DPPC) vesicles as a biological membrane model. The antilipoperoxidant activity of the flavonoids tested can be classified as follows: rutin > hesperetin > quercetin > naringenin in the Fe(2+)-ILP test: quercetin > rutin > hesperetin > naringenin in the ARCM test. Quercetin, hesperetin, and naringenin interacted with DPPC liposomes causing different shifts, toward lower values, of the main transition peak temperature (Tm) typical for DPPC liposomes; however, no change in Tm of DPPC dispersion was observed in the presence of rutin. The hypothesis will be discussed that flavonoid capacity to modify membrane-dependent processes, such as free-radical-induced membrane lipoperoxidation, is related not only to their structural characteristics but also to their ability to interact with and penetrate the lipid bilayers.

Determination of vitamin A, vitamin E, and their esters in tablet preparations using supercritical fluid extraction and HPLC

A rapid and precise method for the isolation of vitamins A and E and their acetate or palmitate esters from table matrices was developed using supercritical fluid extraction (SFE). The vitamins were analyzed by nonaqueous reversed-phase high-performance liquid chromatography after a 15-min extraction of the dosage form with supercritical carbon dioxide at 40 degrees C and at a pressure of 250 atm. A quantitative comparison of SFE with an established liquid extraction procedure was performed on commercial tablet formulations. Vitamin recoveries of over 95.6% compared with conventional liquid extraction were achieved by the SFE technique with a much shorter sample preparation time (15 min vs 2h). Moreover, the automated SFE process minimized the number of sample handling operations, drastically reduced the consumption of harmful solvents, and provided mild extraction conditions for the analysis of the labile vitamins. The described SFE method is suitable for quality control analyses of pharmaceutical tablets.

Assay of vitamin A palmitate and vitamin E acetate in cosmetic creams and lotions by supercritical fluid extraction and HPLC

The use of supercritical fluid extraction (SFE) as an alternative to liquid extraction was examined for the isolation of vitamin A palmitate and vitamin E acetate from cream and lotion preparations. Investigation of the factors controlling the extraction efficiency in SFE indicated that vitamin recoveries were affected mainly by the extraction pressure and by the degree of sample dispersion. The vitamins were analysed by high-performance liquid chromatography after a 30-min extraction of the cosmetic product with supercritical carbon dioxide at 40 degrees C and at a pressure of 250 atm. Compared with conventional liquid extraction SFE produced slightly lower recoveries (> 91.6%) but afforded a more effective purification of the cosmetic matrices. Moreover, SFE minimized sample handling and the use of harmful solvents and provided mild extraction conditions for the analysis of the labile vitamins. Vitamin E acetate and vitamin A palmitate were assayed in commercial cream and lotion formulations using the proposed SFE technique.

Synthesis and pharmacological evaluation of oligoethylene ester derivatives as indomethacin oral prodrugs

Five indomethacin oligoethylene ester derivatives (3-7) were synthesized and evaluated for their anti-inflammatory, analgesic, and ulcerogenic activity after oral administration. The molecular weight of the oligoethylene glycols used for synthesizing esters 3-7 ranged from 106 to 282. The chemical and enzymatic stabilities of esters 3-7 were evaluated in pH 7.4 and 2.0 buffers and in human plasma, respectively. All the prodrugs showed a good stability both in pH 7.4 phosphate buffer and in pH 2.0 buffer, and they were readily hydrolyzed by human plasma. Esters 3-7 showed an anti-inflammatory activity, determined as the percent inhibition of carrageenan-induced edema, similar to that of indomethacin, although at higher doses. From writhing test results, we observed that all the prodrugs exhibited better or similar analgesic activity compared to indomethacin. Esters 3-7 were significantly less irritating to the gastric mucosa than indomethacin, after oral administration, and esters 3-5 did not show any ulcerogenic activity, although they were administered at higher doses than indomethacin.

Carboxymethyl- and carboxy-derivatives of 7H- and 5H-1,2,4-triazolo [3,4-b][1,3,4] thiadiazine: synthesis and biological evaluation

Some carboxymethyl- and carboxy-derivatives of 7H- and 5H-1,2,4-triazolo [3,4-b][1,3,4] thiadiazine were prepared. Their structure are discussed on the basis of IR, NMR and mass spectra. The synthesized compounds were subjected to a preliminary pharmacological screening for antiinflammatory-analgesic activity and to microbiological test on various species of mycetes and bacteria.

Synthesis and analgesic antiinflammatory activities of 2-aryl-ethenyl-4-aryl-thiazole-5-acetic acids

A series of fifty-five 2-aryl-ethenyl-4-aryl-thiazole-5-acetic acids (IV-LVIII) were synthesized and evaluated for analgesic and antiinflammatory activities. Most of the synthesized compounds showed a good analgesic activity whereas some exhibited significant antiinflammatory activity.

[Reactivity of 3-aryl-4-amino-5-mercapto-4H-1,2,4-triazoles: synthesis and biological evaluation of 3,6-diaryl derivatives of 7H-1,2,4-thiazole[3,4-b][1,3,4]thiadiazines, of 3-aryl-4-amino-5-carboxymethylthio-4H-1,2,4-triazoles]

Starting from 3-aryl-4-amino-5-mercapto-4H-1,2,4-triazoles (II), two series of 3,6-disubstituted 7H-1,2,4-triazol [3,4-b] [1,3,4] thiadiazines (III) and their 5-carboxymethylthio derivatives (IV) were prepared. From the mercapto-amino-triazoles (II) because of their reactivity in some oxidising media, were obtained the triazole derivatives (V), (VI) and (VII). The synthesis of the alpha-thioketones (VIII) of 3-aryl-5-mercapto-1,3,4-oxadiazoles (I), used in alternative synthesis of triazole-thiadiazines (III), is also reported. All the substances described were subjected to biological screening. In the tests, the carboxymethylthiotriazole (IV) showed weak antiinflammatory activity (carrageenin edema) and more consistent scavanger activity, in vitro, on superoxide anions. The triazole-thiadiazines (III) and triazoles (II), (V) and (VI) showed moderate antimycotic activity.

[Synthesis and pharmacologic activity of 2-arylethenylthiazol-4-acetic and 4-carboxylic acids]

Two new series of 2-aryletenylthiazolo-4-acetic (IV-XII) and 4-carboxylic (XIII-XXI) acids substituted with alkoxy groups in the benzene ring were synthesized. The compounds were subjected to comparative tests of antiinflammatory, analgesic and antipyretic activity.

[Synthesis and preliminary biological investigation of 2,6-diaryl substituted imidazo(1,2-b)-1,3-4-thiadiazoles]

The synthesis of imidazo [2,1-b]-1,3,4-thiadiazole derivatives and preliminary pharmacological screening are reported. The compounds studied showed mainly antiphlogistic, antipyretic and analgesic activity. From the results it appears that analgesic activity is peripheral.

[2,5-diaryl-substituted 1,3,4-oxadiazoles: synthesis and preliminary pharmacological investigation]

Seven 2,5-diarylalkyloxysubstituted 1,3,4-oxadiazoles were synthesized. They showed pronounced antiphlogistic action together with central activity (sedative, analgesic) that principally seems to be connected with the presence in the molecule of the 3,4-dioxymethylenephenyl radical.

Synthesis and biological evaluation of some 5-aryl-2-amino-1,3,4-oxa(thia)diazoles

Three series of 5-aryl-2-amino or 2-amino substituted 1,3,4-oxadiazoles (IV-XVIII) were prepared together with the corresponding series of the analogous 5-aryl-2-amino-1,3,4-thiadiazoles (XIX-XXXIII). The purpose of this work is two-fold: to study their pharmacological action in relation to the substituents bound to the positions -2 and -5, and to observe whether the isosteric substitution of the oxygen of he oxadiazolic nucleus with the sulfur leading to a thiadiazolic nucleus causes any activity variation. The AA. report and discuss the results obtained studying the antifungal as well as the antiinflammatory and antipyretic activity of the synthetized compounds.

[3-Methylthio-, 3-(amino-substituted)ethylthio-, 3-carboxymethylthio-, 3,3'-(dithiobis)-5-aryl-4H(R)-1,2,4-triazoles and 2-aminomethyl-N-substituted derivatives of 5-aryl-4H(R)-1,2,4-triazolin-3-thione: synthesis and biological activity]

Following previous research which showed the antibacterial and antimycotic activity of triazolin-3-thiones (II), a series of compounds has been prepared and tested to correlate and clarify the structure-activity relationships. The compounds were of the type represented in (II) where (R = H, CH3 or C6H5) and were in detail: 3-methylthiotriazoles (III-VIII), 3-(amino-substituted)ethylthiotriazolines (IX-XXVI), 3-carboxymethylthiotriazolines (XXVII-XXX), 3,3'dithiobistriazolines (XXXI-XXXVI) and 2-amino-methyl-N-substituted triazolin-3-thiones (XLVIII-LXVI). The 2-aminooxadiazoles (XXXVII-XLII), obtained in place of the expected 1-aroyl-S-methylisothiosemicarbazides (II a) from the reaction between thiosemicarbazides (I) (R = H; CH3, C6H5) and methyl iodide, are also described.

[Synthesis of 1-aroyl-4H(R)-thiosemicarbazides, the corresponding 5-aryl 4H(R)-1,2,4-triazolin-3-thiones and some derivatives of pharmaceutical interest]

A series of 1-aroyl-4H(R)-thiosemicarbazides (IV-XVIII) and the corresponding 5-phenyl-4H(R)-1,2,4-triazolin-3-thiones (XIX-XXXIII) were synthesized: biological assay demonstrated their in vitro antibacterial and antimycotic activities. The preparation of same hydrazinoaroylthiazoles (XXXIV-XXXVI) was reported also, obtained by condensation of 1-aroyl-4H-thiosemicarbazides with phenacyl bromide and the synthesis of thiazole[3,2-b]-s-triazol-3(2H)-ones (XLIX-LI) prepared by cyclodehydration of carboxymethylthiotriazoles (XLVI-XLVIII). The results of pharmacological testing for both series of derivatives (XLIX-LI) and (XLVI-XLVIII) showed good antiinflammatory and antipyretic activities.

[Aminoethyl derivatives of various 5-aryl-1,3,4-oxadiazol-2-ones: synthesis and pharmacological activity]

In continuation of previous work, the Authors describe the synthesis of 3-aminoethyl derivatives of some 5-aryl-1,3,4-oxadiazol-2-ones whose structure has been confirmed by I.R., N.M.R. and mass spectral methods. The results of pharmacological testing are also reported and these further clarify some aspects of the biological activity of the oxadiazole structure.

[Synthesis and antimycotic activity of 3-methylamino derivatives of various 2-mercapto-5-aryl-1,3,4-oxadiazoles]

In continuation of previous work designed to obtain derivatives of 2-mercapto-1,3,4-oxadiazole of possible biological interest, the Mannich bases (III - XXX) were prepared. The compounds prepared bear at position 5, with respect to the oxadiazole nucleus, 3,4,5-trimethoxy and 3,4-dihydroxymethylenephenyl radicals which have proved of interest in other series of derivatives. The antimycotic activity of the compounds is reported.

[Some aroylhydrazones of halobenzaldehydes and halogen-substituted 2,5-diaryl-1,3,4-oxadiazoles]

The preparation of a series of aroylhydrazones of halogenobenzaldehydes (I) - (XI) is described together with that of the corresponding reduction products (XII) - (XXV) and of 2,5-diaryl-1,3,4-oxadiazoles with halogen substitution (XXVI) - (XLIII). The results of pharmacological and microbiological examination of the compounds is reported.

[Effects of lymphocyte stimulation in vitro of alkaline salts of some aroyl-hydrazino-carbodithioic acids and 1,3,4-oxadiazole derivatives: preliminary research]

The behaviour of alkaline salts of some aroyl-hydrazine-carbodithioic acids [comp. Ia,b,c,] and derivatives of 1,3,4-oxadiazole [comp. IIa,b,c, e IIIa,b,c] , has been studied, on the capability of lymphoblasts in vitro, in consequence of stimulation by some mitogen agents (PHA, PWM). It has been pointed out that the considered compounds inhibit the cellular mitosis in variable percentage in relation to their structure and to the used mitogen agent, frequently causing some mitogen-like morphological modification, also revealable under a optical microscope. The higher inhibition has been obtained by the Ic, IIc, and IIIc compounds, in which Ar is the 3,4-dihydroxymethylenephenyl radical, proving selective, in some cases, for the T lymphocytes.

[Reactions of potassium salts and methyl esters of some aroylhydrazino-carbodithioic acids]

In continuation of previous research designed to obtain compounds of pharmacological interest, the following substances were prepared, from the potassium salts (I-III) and from the methyl esters (IV-VI) of some aroylhydrazinocarbodithioic acids, derivatives of 1,3,4-oxadiazole (VII-XV), of 3-aminorhodanine (XVI-XVIII), of 1,2,4-triazole (XIX-XXI), of 7H-(1,2,4)-triazol[3,4-b] [1,3,4] thiadiazine (XXII-XXIV) and of 1,3,4-thiadiazole (XXV-XXX). The compounds have present in the molecule a nucleus and radical which have produced marked biological activity in other series of compounds. To date some of the above compounds have shown antibacterial, antimycotic and antimitotic activity.

[Synthesis and pharmacological study of various 2-(alkylaminoalkyl)mercapto-5-aryl-1,3,4-oxadiazoles]

Work was continued on the pharmacological study of the 1,3,4-oxadiazole nucleus using aroylhydrazines already used for the synthesis of anti-MAO compounds. S-alkylaminoalkyl derivatives of some 2-mercapto-5-aryl-1,3,4-oxadiazoles were prepared bearing in the 5-position a 3,4,5-trimethoxyphenyl, a 3,5-dimethoxy-4-ethoxyphenyl or a 3,4-dihydroxymethylenephenyl radical. When subjected to pharmacological investigation the compounds showed clear hypotensive activity partially antagonized by atropine and antispastic activity on smooth muscle.