TDZD-8 suppresses rheumatoid arthritis induced by collagen type II in rats: potential role of apoptosis and inflammation / TDZD-8 suprime la artritis reumatoide inducida por colágeno tipo II en ratas: papel potencial de la apoptosis y la inflamación

SUMMARY: Rheumatoid arthritis (RA) is considered an autoimmune disease distinguished by chronic synovial membrane inflammation, degraded cartilage, as well as bone destruction, which lead to joints pain and stiffness. The pathogenesis of RA involved at least two mechanisms: Cellular proliferation and activation of glycogen synthase kinase-3β (GSK3β) enzyme. Thus, we tested the hypothesis that the GSK3binhibitor, TDZD-8, can treat the synovial tissue toward collagen type II (COII)-mediated RA linked to apoptosis induction and biomarker suppression of inflammation. Wistar rats were immunized with COII (the model group) for 21 days. Matched immunized rats were daily injected with TDZD-8 (1 mg/kg; i.p) for three additional weeks (COII+TDZD- 8).After 42 days of post-immunization, blood and tissues were collected. Histology (H&E) and immunohistochemistry (CD45; leukocyte common antigen) images showed that COII induced RA was demonstrated by profound damage to the synovial tissue and infiltration of the inflammatory cells, which were substantially ameliorated with TDZD-8. In addition, COII immunization caused the induction of rheumatoid factor (RF), tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and interleukin 1 beta (IL-1β) that were substantially (p<0.05) suppressed by TDZD-8. Whereas, TDZD-8 augmented the apoptotic biomarker, Bcl-2-associated X protein (Bax), which was significantly (p<0.05) ameliorated by RA. We also showed a substantial relationship (p<0.001) between the blood levels of RF and the synovial tissue levels of TNF-α (r = 0.759), IL-1b (r = 0.969), IL-6 (r = 0.749), and Bax (r = - 0.914). These results indicate effective treatment of the injured synovial tissue by TDZD-8 against COII-induced RA in rats, which also decreases inflammatory biomarkers and augmentation of apoptosis.

RESUMEN: La artritis reumatoide (AR) es una enfermedad autoinmune que se distingue por la inflamación crónica de la membrana sinovial, el cartílago degradado y la destrucción de los huesos, lo que provoca dolor y rigidez en las articulaciones. La patogenia de la AR involucra al menos dos mecanismos: la proliferación celular y la activación de la enzima glucógeno sintasa quinasa-3b (GSK3β) Por lo tanto, probamos la hipótesis de que el inhibidor de GSK3β, TDZD-8, puede tratar el tejido sinovial hacia el colágeno tipo II (COII) - AR mediada por inducción de apoptosis y supresión de biomarcadores de inflamación. Se inmunizaron ratas Wistar con COII (el grupo modelo) durante 21 días. Se inyectaron diariamente ratas emparejadas inmunizadas con TDZD-8 (1 mg / kg; i.p) durante tres semanas adicionales (COII + TDZD-8). Después de 42 días de post-inmunización, se recolectó sangre y tejidos. Las imágenes de histología (H&E) e inmunohistoquímica (CD45; antígeno común de leucocitos) mostraron que la AR inducida por COII presentaba un daño profundo en el tejido sinovial e infiltración de las células inflamatorias, las que mejoraron con TDZD-8. Además, la inmunización con COII provocó la inducción de factor reumatoide (FR), factor de necrosis tumoral alfa (TNF-α), interleucina-6 (IL-6) e interleucina 1 beta (IL-1β) que fueron suprimidos por TDZD-8 de manera significativa (p < 0.05). Considerando que TDZD-8 aumentó el biomarcador apoptótico, la proteína X asociada a Bcl-2 (Bax), que fue mejorado (p <0,05) por RA. También se observó una relación sustancial (p <0,001) entre los niveles sanguíneos de RF y los niveles de tejido sinovial de TNF-α (r = 0,759), IL-1β (r = 0,969), IL-6 (r = 0,749), y Bax (r = -0,914). Estos resultados indicaron un tratamiento eficaz del tejido sinovial lesionado por TDZD-8 contra la AR inducida por COII en ratas, que también disminuye los biomarcadores inflamatorios y el aumento de la apoptosis.

De novo in vitro shoot morphogenesis from shoot tip-induced callus cultures of Gymnema sylvestre (Retz.) R. Br. ex Sm

BACKGROUND: Gymnema sylvestre is a medicinal woody perennial vine known for its sweetening properties and antidiabetic therapeutic uses in the modern and traditional medicines. Its over-exploitation for the therapeutic uses and to meet the demand of pharmaceutical industry in raw materials supply for the production of anti-diabetic drugs has led to considerable decline in its natural population. RESULTS: An efficient system of shoot bud sprouting from nodal segment explants and indirect plant regeneration from apical meristem-induced callus cultures of G. sylvestre have been developed on Murashige and Skoog (MS) medium amended with concentrations of cytokinins. Of the three growth regulators tested, N6-benzylaminopurine (BAP) was the most efficient and 2.0 mg L-1 gave the best shoot formation efficiency. This was followed by thidiazuron (TDZ) and kinetin (Kin) but, most of the TDZ-induced micro shoots showed stunted growth. Multiple shoot formation was observed on medium amended with BAP or TDZ at higher concentrations. The produced micro shoots were rooted on half strength MS medium amended with auxins and rooted plantlets acclimatized with 87% survival of the regenerates. CONCLUSIONS: The developed regeneration system can be exploited for genetic transformation studies, particularly when aimed at producing its high yielding cell lines for the anti-diabetic phytochemicals. It also offers opportunities for exploring the expression of totipotency in the anti-diabetic perennial vine.

Thidiazuron (TDZ) increases fruit set and yield of 'Hosui' and 'Packham's Triumph' pear trees

ABSTRACT The low fruit set is one of the main factors leading to poor yield of pear orchards in Brazil. The exogenous application of thidiazuron (TDZ) and aminoethoxyvinilglycine (AVG) has shown promising results in some pear cultivars and other temperate fruit trees. The objective of this study was to evaluate the effect of TDZ and AVG on fruit set, yield, and fruit quality of 'Hosui' and 'Packham's Triumph' pears. The study was performed in a commercial orchard located in São Joaquim, SC. Plant material consisted of 'Hosui' and 'Packham's Triumph' pear trees grafted on Pyrus calleryana. Treatments consisted on different rates of TDZ (0 mg L-1, 20 mg L-1, 40 mg L-1 and 60 mg L-1) sprayed at full bloom for both cultivars. An additional treatment of AVG 60 mg L-1 was sprayed one week after full bloom in 'Hosui'. The fruit set, number of fruit per tree, yield, fruit weight, seed number, and fruit quality attributes were assessed. Fruit set and yield of both cultivars are consistently increased by TDZ, within the rates of 20 to 60 mg L-1. Besides, its application increased fruit size of 'Hosui' and did not negatively affect fruit quality attributes of both cultivars.

Mannitol-induced drought stress on calli of Trigonella foenum-graecum L. Var. RMt-303.

Different explants of fenugreek, T. foenum-graecum L. (Var. RMt-303), were compared for their callus induction and subsequent shoot regeneration capabilities on Murashige and Skoog media supplemented with different phytohormones in varying concentration. The highest percentage of callus induction frequency was observed in 1ppm benzylaminopurine (BAP). Maximum shoots were induced on media supplemented with 0.5ppm BAP using leaf and stem tissues as explants. However, root tissues showed only callusing with no subsequent shooting. Cotyledonary node responded better than hypocotyls in terms of shoot induction on media supplemented with thidiazuron (0.1ppm). The callus was subjected to drought stress as simulated by reduced water potential of growth media due to addition of mannitol. Calli could withstand -2 MPa water potential till 30 days indicating that the drought stress tolerance mechanisms are functional in this variety. Chlorophyll a and b and total chlorophyll, proline and total phenolic contents, total peroxidase and catalase activities increased under stress conditions suggesting the tolerance of callus to drought stress. However, ascorbate peroxidase, guaiacol peroxidase activities were found to decrease slightly. Malondialdehyde and H2O2 contents were found to decrease while only a slight disturbance was found in membrane stability index. These results underline the mechanisms that are crucial for drought stress tolerance in fenugreek.

Megazol and its bioisostere 4H-1,2,4-triazole: comparing the trypanocidal, cytotoxic and genotoxic activities and their in vitro and in silico interactions with the Trypanosoma brucei nitroreductase enzyme

Megazol (7) is a 5-nitroimidazole that is highly active against Trypanosoma cruzi and Trypanosoma brucei, as well as drug-resistant forms of trypanosomiasis. Compound 7 is not used clinically due to its mutagenic and genotoxic properties, but has been largely used as a lead compound. Here, we compared the activity of 7 with its 4H-1,2,4-triazole bioisostere (8) in bloodstream forms of T. brucei and T. cruzi and evaluated their activation by T. brucei type I nitroreductase (TbNTR) enzyme. We also analysed the cytotoxic and genotoxic effects of these compounds in whole human blood using Comet and fluorescein diacetate/ethidium bromide assays. Although the only difference between 7 and 8 is the substitution of sulphur (in the thiadiazole in 7) for nitrogen (in the triazole in 8), the results indicated that 8 had poorer antiparasitic activity than 7 and was not genotoxic, whereas 7 presented this effect. The determination of Vmax indicated that although 8 was metabolised more rapidly than 7, it bounds to the TbNTR with better affinity, resulting in equivalent kcat/KM values. Docking assays of 7 and 8 performed within the active site of a homology model of the TbNTR indicating that 8 had greater affinity than 7.

Biochemical markers assisted screening of Fusarium wilt resistant Musa paradisiaca (L.) cv. Puttabale micropropagated clones.

An efficient protocol was standardized for screening of panama wilt resistant Musa paradisiaca cv. Puttabale clones, an endemic cultivar of Karnataka, India. The synergistic effect of 6-benzyleaminopurine (2 to 6 mg/L) and thidiazuron (0.1 to 0.5 mg/L) on MS medium provoked multiple shoot induction from the excised meristem. An average of 30.10 ± 5.95 shoots was produced per propagule at 4 mg/L 6-benzyleaminopurine and 0.3 mg/L thidiazuron concentrations. Elongation of shoots observed on 5 mg/L BAP augmented medium with a mean length of 8.38 ± 0.30 shoots per propagule. For screening of disease resistant clones, multiple shoot buds were mutated with 0.4% ethyl-methane-sulfonate and cultured on MS medium supplemented with Fusarium oxysporum f. sp. cubense (FOC) culture filtrate (5–15%). Two month old co-cultivated secondary hardened plants were used for screening of disease resistance against FOC by the determination of biochemical markers such as total phenol, phenylalanine ammonia lyase, oxidative enzymes like peroxidase, polyphenol oxidase, catalase and PR-proteins like chitinase, β-1-3 glucanase activities. The mutated clones of M. paradisiaca cv. Puttabale cultured on FOC culture filtrate showed significant increase in the levels of biochemical markers as an indicative of acquiring disease resistant characteristics to FOC wilt.

Cytokinin preconditioning enhances multiple shoot regeneration in Pongamia pinnata (L) Pierre - a potential, non-edible tree seed oil source for biodiesel

An efficient, highly reproducible protocol for multiple shoot induction and plant regeneration of Pongamia pinnata has been successfully developed using cotyledonary node explants. This study also demonstrates that preconditioning of explant stimulates production of multiple shoots from cotyledonary nodes of P. pinnata. The highest direct shoot regeneration (90 percent) with an average of 18.4 +/- 3.1 shoots/explant were obtained when cotyledonary node explants were excised from seedlings germinated on Murashige and Skoog (MS) media supplemented with benzyladenine (BA) 1 mg l-1, and subsequently cultured on MS media with 1 mgl-1 thidiazuron (TDZ). Scanning electron microscope observations of cotyledonary node (CN) explants excised from pre-conditioned and normal seedlings, revealed larger buds with rapid development in BA-preconditioned CN explants. The addition of adenine sulphate significantly increased the average number of shoots per explant. The highest direct shoot regeneration (93 percent) with an average of 32.2 +/- 0.93 shoots/explant was obtained from BA-preconditioned CN when cultured on MS media supplemented with 1 mg l-1 TDZ and 200 mg l-1 adenine sulphate (ADS). Repeated shoot proliferation was observed from BA preconditioned CN explants up to 3 cycles with an average of 15 shoots/explant/cycle when cultured on MS media supplemented with 1 mg l-1 TDZ and 150 mg l-1 L-glutamine, thus producing 45 shoots/CN explant. Shoots were elongated on hormone free MS media and rooted on 1/2 MS media supplemented with 1 mg l-1 of IBA. Rooted shoots were successfully acclimatized and established in soil with 80 percent success. The highly regenerative system developed in this investigation for this important tree could be a useful tool for genetic transformation.

Homology modeling and QSAR analysis of 1,3,4-thiadiazole and 1,3,4-triazole derivatives as carbonic anhydrase inhibitors.

Carbonic anhydrase (CA) inhibitors are very interesting target for designing anticancer (hypoxic) and antiglaucoma drugs. In the present study, a 3D homology modeling of human carbonic anhydrase-IX (hCA-IX) isozyme, based upon the crystal structure of murine CA-XIVA (PDB CODE 1RJ5) was performed, as no experimental 3D structures are available. A homology model of hCA-IX was developed and validated. To explore the responsible physicochemical properties of 1,3,4-thiadiazole and 1,3,4-triazole derivatives for carbonic anhydrase inhibition, a quantitative structure activity relationship (QSAR) study was performed having hCA-II and hCA-IX inhibitory activity respectively. In hCA-II and hCA-IX inhibitory activities, four significant models with good correlations ( 0.945 & 0.926) were obtained; two models (models 1 and 3) were selected based on statistical criterion. The QSAR study revealed that in case of hCA-II, overall increase in size and volume of molecule, introduction of electropositive surfaces might increase the inhibitory activity, whereas in case of hCA-IX, decreasing the hydrophobicity and introduction of electron releasing substituents might increase the hCA-IX inhibitory activity.

Efeitos do ácido silícico e do acibenzolar-S-methyl sobre Schizaphis graminum (Rondani) (Hemiptera: Aphididae) em plantas de trigo / Effects of silicon acid and of acibenzolar-S-methyl on Schizaphis graminum (Rondani) (Hemiptera: Aphididae) in wheat plants

Neste trabalho, o objetivo foi avaliar os efeitos do ácido silícico e do acibenzolar-S-methyl (ASM) sobre a biologia e o comportamento do pulgão-verde em plantas de trigo. O experimento constituiu-se em um fatorial 4 (sem silício, silício via foliar, silício via solo e silício via solo + foliar) x 2 (com e sem acibenzolar-S-methyl), em delineamento inteiramente ao acaso. Um teste de preferência com chance de escolha foi montado em delineamento em blocos casualizados, com dez repetições. A concentração de ácido silícico foi 1 por cento e de ASM, 0,5 por cento. Para a avaliação dos tratamentos foram realizados testes de preferência com chance de escolha (contagem de pulgões adultos em secções foliares de plantas de trigo), avaliação da biologia (duração dos períodos pré-reprodutivo, reprodutivo e pós-reprodutivo, mortalidade no período pré-reprodutivo, número de ninfas produzidas, longevidade e taxa de crescimento populacional) e colonização dos pulgões (número de pulgões adultos e ninfas). No teste de preferência com chance de escolha, as plantas tratadas com ASM não foram preferidas pelos pulgões. A aplicação de silício ou ASM reduziu o número de ninfas produzidas, a taxa de crescimento populacional, o período pós-reprodutivo e a longevidade do pulgão-verde. Na colonização o número de pulgões foi reduzido pela aplicação de ASM ou silício. A aplicação de ácido silícico, principalmente via solo, ou de ASM, é promissora para uso no manejo integrado do pulgão-verde em trigo.

The objective of this work was to evaluate the effects of silicon acid and acibenzolar-S-methyl (ASM) on biology and behavior of the aphid (greenbug) in wheat plants. The experiment involved a 4 factorial (no silicon, silicon on leaf, silicon in the soil and silicon in the soil + on leaf), x 2 (with and without acibenzolar-S-methyl), in a completely randomized design. A preference test with chance of choice was set in blocks randomized, with 10 replications. Silicon acid was used at 1 percent and ASM at 0.5 percent. The treatments were evaluated by means of preference tests with chance of choice (adult aphids in leaf sections of wheat plants were counted), biological studies (length of pre-reproductive, reproductive and post-reproductive periods, mortality rate during the pre-productive period, number of nymphs, longevity and population growth rate were determined) and colonization of aphids (number of adult aphids and nymphs were determined). In the preference test, plants that received ASM were not chosen by the aphids. The application of the silicon or ASM reduced significantly the number of nymphs, the population growth rate, the post-reproductive period and the longevity of the greenbug. A significant reduction of the number of aphids was observed during aphids colonization when ASM or silicon were applied. The addition of silicon acid, mostly in the soil, or of ASM is promising as a control method in the integrated management of aphid in wheat.

The influence of growth regulators on shoot proliferation and rooting of in vitro propagated caper.

The objectives of this study were to examine the effect of TDZ and BAP on shoot proliferation and to develop a satisfactory rooting procedure for in vitro propagation of caper (Capparis spinosa L). TDZ was found to be more effective than BAP in shoot production. The highest shoot number per explant (45.7) was achieved on the media that contained 4.54 microM TDZ in the absence of IAA. TDZ at 4.54 microM alone or in combination with 0.57 microM IAA did not inhibit shoot elongation, although they produced the most shoots. Dipping the caper shoots in the solution of IBA at 24.6 microM for 10 minutes before planting on MS media, improved the rooting percentage up to 80.5% under a 16 hr photoperiod.

Local anesthetic and antiarrhythmic activity of certain new 1,3,4-thiadiazole derivatives

A series of 2-[1-oxo-2-[substitutedamino] ethylamino and 2- or 3-[substitutedamino] propylamino] 5 trifluoromethy1-1,3,4-thiadiazoles [5a-f, 6a-f and 7a-f] was synthesized and evaluated for their local anesthetic and antiarrhythmic activity. Some of the tested compounds showed promising activity. The detailed synthesis, spectroscopic and biological data are reported

Synthesis and antischistosomal activity of some new thiazolidinones and 1,3,4-thiadiazoline

In this study, new series of thiazolidinones 3a-e was synthesized by the cyclocondensation of the Schiff bases 2a-e with mercaptoacetic acid. The thiadiazole 5 was obtained by refluxing 4 with carbondisulfide. The antischistosomal activity was determined for the new representative compounds

Inhibition of albumin denaturation and anti-inflammatory activity of acetamido [(phenyl-4'-yl)-oxymethyl)]2-(p-substituted phenylamino)-1,2,4-triazoles and -1,3,4-thiadiazoles.

Acetamido [(phenyl-4'-yl)-oxymethyl)]-2-(p-substituted-phenylamino)-1,2,4-tr iazoles (4a-4d) and 1,3,4-thiadiazoles (5a-5d) inhibited the thermal denaturation of bovine serum albumin. As protein denaturation is implicated in inflammation, some compounds which showed good inhibition of denaturation were tested in vivo for anti-inflammatory activity by carrageenan induced edema in the rat paw. Although there was no complete correlation, compounds which showed good inhibition of denaturation also showed significant anti-inflammatory activity.

Mechanism of action of a nitroimidazole-thiadiazole derivate upon Trypanosoma cruzi tissue culture amastigotes

Megazol (CL 64,855) a very effective drug in experimental infections by Trypanosoma cruzi, and also in in vitro assays with vertebrate forms of the parasite, had its parasite, had its activity upon macromolecule biosynthesis tested using tissue culture-derived amastigote forms. Megazol presented a drastic inhibition of [3H]-uridine incorporation, suggesting a selective activity upon protein synthesis. Comparing the three drugs, megazol was more potent than nifurtimox and benznidazole in inhibiting protein an DNA synthesis. Megazol showed a 91% of inhibition of [3H]-leucine incorporation whereas nifurtimox and benznidazole, 0% and 2%, respectively. These latter two drugs inhibited the incorporation of all the precursors tested at similar levels, but the concentration of benznidazole was always three times higher, suggesting different mechanisms of action or, more probably, a greater efficiency of the 5-nitrofuran derivate in relation to the 2-nitroimidazole. So, wes conclude that the mode of action of megazol is different from the ones of nifurtimox and benznidazole and that its primary effect is associated with an impairment of protein synthesis