Orthotopic tumorgrafts in nude mice as a model to evaluate calcitriol effects in breast cancer / Modelo de enxerto tumoral ortotópico em camundongos para avaliar os efeitos do calcitriol em câncer de mama

Abstract Calcitriol antiproliferative effects were observed in xenografts of breast cancer cell lines, however they were not yet investigated in tumorgrafts, consisting of freshly collected breast cancer samples xenografted into animals. Objectives To establish a tumorgraft model, from freshly collected breast cancer samples, which were directly implanted in nude mice, to study calcitriol effects. Methods Breast cancer samples collected from 12 patients were orthotopically implanted into nude mice. Animals were treated with weekly intratumoral injections of calcitriol 3 μg/Kg, which was previously shown to induce peak serum calcitriol levels in the predicted therapeutic range. Results Success engraftment rate was 25%. Tumorgrafts were established from aggressive (HER2 positive or histological grade 3) highly proliferative samples and original tumor characteristics were preserved. Calcitriol highly induced its target gene, CYP24A1, indicating that the genomic vitamin D pathway is active in tumorgrafts. However, no differences in the expression of proliferation and apoptosis markers (BrdU incorporation, Ki67, CDKN1A, CDKN1B, BCL2 expression) were observed in these highly proliferative tumor samples. Conclusions Tumorgrafts seem a promising model to explore other calcitriol doses and regimens, considering the heterogeneity of the disease and microenvironment interactions.

Resumo Os efeitos antiproliferativos de calcitriol foram observados em xenotransplantes de linhagens celulares de câncer de mama, entretanto, não foram ainda investigados em enxertos tumorais, consistindo de implantes em animais de amostras de câncer de mama recém-coletadas. Objetivos Estabelecer modelo de enxerto tumoral, a partir de amostra de câncer de mama recém-coletada e diretamente implantada em camundongos nude, para estudar o efeito do calcitriol. Métodos Amostras de câncer de mama de 12 pacientes foram implantadas ortotopicamente em camundongos nude. Os animais foram tratados com injeção intratumoral semanal de calcitriol 3 μg/Kg, a qual foi previamente associada com indução de pico sérico de calcitriol dentro do intervalo de nível terapêutico. Resultados A taxa de sucesso de pega do enxerto foi de 25%. Os enxertos tumorais foram estabelecidos de tumores agressivos com alta taxa de proliferação (HER2 positivo ou grau histológico 3) e as características do tumor original foram preservadas. O calcitriol induziu fortemente a expressão do gene alvo, CYP24A1, indicando que a via genômica da vitamina D está ativa nos enxertos tumorais, entretanto, não se observou diferenças na expressão de marcadores de proliferação e apoptose (incorporação de BrdU, expressão de Ki67, CDKN1A, CDKN1B e BCL2) nestas amostras altamente proliferativas. Conclusões Os enxertos tumorais parecem ser um modelo promissor para explorar outros esquemas e doses de calcitriol, considerando a heterogeneidade da doença e interações com o microambiente.

Orthotopic tumorgrafts in nude mice as a model to evaluate calcitriol effects in breast cancer.

OBJECTIVES: Calcitriol antiproliferative effects were observed in xenografts of breast cancer cell lines, however they were not yet investigated in tumorgrafts, consisting of freshly collected breast cancer samples xenografted into animals. To establish a tumorgraft model, from freshly collected breast cancer samples, which were directly implanted in nude mice, to study calcitriol effects. METHODS: Breast cancer samples collected from 12 patients were orthotopically implanted into nude mice. Animals were treated with weekly intratumoral injections of calcitriol 3 µg/Kg, which was previously shown to induce peak serum calcitriol levels in the predicted therapeutic range. RESULTS: Success engraftment rate was 25%. Tumorgrafts were established from aggressive (HER2 positive or histological grade 3) highly proliferative samples and original tumor characteristics were preserved. Calcitriol highly induced its target gene, CYP24A1, indicating that the genomic vitamin D pathway is active in tumorgrafts. However, no differences in the expression of proliferation and apoptosis markers (BrdU incorporation, Ki67, CDKN1A, CDKN1B, BCL2 expression) were observed in these highly proliferative tumor samples. CONCLUSIONS: Tumorgrafts seem a promising model to explore other calcitriol doses and regimens, considering the heterogeneity of the disease and microenvironment interactions.

Orthotopic tumorgrafts in nude mice as a model to evaluate calcitriol effects in breast cancer / Modelo de enxerto tumoral ortotópico em camundongos para avaliar os efeitos do calcitriol em câncer de mama

Calcitriol antiproliferative effects were observed in xenografts of breast cancer cell lines, however they were not yet investigated in tumorgrafts, consisting of freshly collected breast cancer samples xenografted into animals. Objectives To establish a tumorgraft model, from freshly collected breast cancer samples, which were directly implanted in nude mice, to study calcitriol effects. Methods Breast cancer samples collected from 12 patients were orthotopically implanted into nude mice. Animals were treated with weekly intratumoral injections of calcitriol 3 µg/Kg, which was previously shown to induce peak serum calcitriol levels in the predicted therapeutic range. Results Success engraftment rate was 25%. Tumorgrafts were established from aggressive (HER2 positive or histological grade 3) highly proliferative samples and original tumor characteristics were preserved. Calcitriol highly induced its target gene, CYP24A1, indicating that the genomic vitamin D pathway is active in tumorgrafts. However, no differences in the expression of proliferation and apoptosis markers (BrdU incorporation, Ki67, CDKN1A, CDKN1B, BCL2 expression) were observed in these highly proliferative tumor samples. Conclusions Tumorgrafts seem a promising model to explore other calcitriol doses and regimens, considering the heterogeneity of the disease and microenvironment interactions.

Os efeitos antiproliferativos de calcitriol foram observados em xenotransplantes de linhagens celulares de câncer de mama, entretanto, não foram ainda investigados em enxertos tumorais, consistindo de implantes em animais de amostras de câncer de mama recém-coletadas. Objetivos Estabelecer modelo de enxerto tumoral, a partir de amostra de câncer de mama recém-coletada e diretamente implantada em camundongos nude, para estudar o efeito do calcitriol. Métodos Amostras de câncer de mama de 12 pacientes foram implantadas ortotopicamente em camundongos nude. Os animais foram tratados com injeção intratumoral semanal de calcitriol 3 µg/Kg, a qual foi previamente associada com indução de pico sérico de calcitriol dentro do intervalo de nível terapêutico. Resultados A taxa de sucesso de pega do enxerto foi de 25%. Os enxertos tumorais foram estabelecidos de tumores agressivos com alta taxa de proliferação (HER2 positivo ou grau histológico 3) e as características do tumor original foram preservadas. O calcitriol induziu fortemente a expressão do gene alvo, CYP24A1, indicando que a via genômica da vitamina D está ativa nos enxertos tumorais, entretanto, não se observou diferenças na expressão de marcadores de proliferação e apoptose (incorporação de BrdU, expressão de Ki67, CDKN1A, CDKN1B e BCL2) nestas amostras altamente proliferativas. Conclusões Os enxertos tumorais parecem ser um modelo promissor para explorar outros esquemas e doses de calcitriol, considerando a heterogeneidade da doença e interações com o microambiente.

Estudo comparativo entre os sistemas de umidificação aquoso aquecido e trocador de calor e de umidade na via aérea artificial de pacientes em ventilação mecânica invasiva / Comparative study between heated water humidifiers and hygroscopic heat and moisture exchangers in artificial airways for patients undergoing invasive mechanical ventilation

CONTEXTO: Nos pacientes recebendo suporte ventilatório invasivo através de tubos endotraqueais é essencial o uso de umidificadores. OBJETIVO: avaliar os níveis de temperatura (TºC) e de umidade relativa (UR) do gás administrado ao paciente em ventilação mecânica através da umidificação aquosa aquecida (UAA) e do filtro trocador de calor e de umidade (FTCU). MÉTODO: Este foi um estudo prospectivo, randomizado, onde foram estudados 20 pacientes divididos em dois grupos: um grupo usou a UAA (n=10) e o outro grupo (n=10) usou FTCU Hygrobac "S", marca Mallinckrodt®. As variáveis analisadas foram: níveis de temperatura (T) e umidade relativa (UR) do gás, volume minuto (VM), volume corrente (VC) e volume de condensação. RESULTADOS: Verificou-se que o sistema de umidificação aquosa aquecida atingiu temperaturas mais baixas que o filtro trocador (29,01 ± 1,33 ºC, versus 30,14 ± 1,24 ºC; p<0,001). A umidade relativa foi maior na UAA do que no FTCU (97,45 ± 5,22 por cento, versus 89,87 ± 11.04 por cento, p < 0,021). O volume de condensação do circuito do grupo usando UAA foi maior que o do grupo usando o FTCU (p < 0,05). CONCLUSÃO: Os resultados demonstram que ambos os sistemas, UAA e o FTCU forneceram umidades absolutas abaixo do valor recomendado, sendo que o sistema de UAA ofereceu uma umidade relativa maior, enquanto que o aquecimento do gás com o FTCU obteve um melhor desempenho.

BACKGROUND: In patients receiving invasive mechanical ventilation through endotracheal tubes, the use of humidifiers is essential. OBJECTIVE: To evaluate temperature and relative humidity levels in the gas administered to patients undergoing mechanical ventilation by means of heated water humidifiers (HWH) and hygroscopic heat and moisture exchangers (HHME). METHOD: This was a prospective randomized study on 20 patients divided into two groups: one group using HWH (n=10) and the other using the Hygrobac "S" model of HHME, made by Mallinckrodt® (n=10). The variables analyzed were: temperature and relative humidity levels of the gas, minute volume (MV), tidal volume (V T) and condensation volume. RESULTS: It was found that HWH attained lower temperatures than did HHME (29.01 ± 1.33 ºC versus 30.14 ± 1.24 ºC; p<0.001). The relative humidity was higher in HWH than in HHME (97.45 ± 5.22 percent versus 89.87 ± 11.04 percent; p<0.021). The condensation volume in the ventilator circuit for the group using HWH was greater than for the HHME group (p<0.05). CONCLUSION: The results demonstrate that both systems (HWH and HHME) supplied absolute humidity that was below recommended values, while the HWH offered higher relative humidity. On the other hand, HHME produced better performance regarding gas heating.

Avaliação da qualidade de vida pos-cirurgia cardiaca na fase I da reabilitação atraves do questionario MOS SF-36 / Quality of life assessment following heart surgery, during phase I reabilitation, Through MOS SF-36 questionnarie

O questionario de qualidade de vida Medical Outcome Study Short From -36 (MOS SF-36) permite monitorar condicao de saude antes e apos o tratamento instituido, sendo sencivel a melhora clinica. O objetivo desse estudo foi avaliar a qualidade de vida de pacientes submetidos a cirurgia de revascularizacao do mocardio e que participaram de um programa de reabilitacao cardiaca, atraves da aplicacao do questionario MOS SF-36. Metodologia: foram incluidos nesse estudo 24 individuos de ambos os sexos (15 homens e 9 mulheres) na faixa etaria entre 23 e 77 anos (idade media 58+-6 anos) submetidos a cirurgia de revascularizacao do miocardio, com quadro clinico estavel e que participem de uma programa de reabilitacao cardiaca fase I. O questionario foi aplicado em tres momentos antes, no 5º dia do pos-operatorio e 2 meses apos a cirurgia. Para analise estatistica foi utilizado o teste de wilcoxon para amostras pareadas. Resultados Observou-se queda dos seguintes parametros Funcionamento do Organismo (p=0,000), Limitacao por Disturbios fisicos (p=0,002), vitalidade (p=0,003) e dor (p=0,000) apos a cirurgia, havenso recuperacao significativa 2 meses apos (p=0,008, p=0,000,p=0,000 e p=0,000 respectivamente).Este estudo sugere que o questionario MOS SF-36 permite avaliar os beneficios da reabilitacao cardiaca fase I a qual propocionou autoconfianca e retorno as atividades diarias

Inspiratory muscular activation during threshold therapy in elderly healthy and patients with COPD.

UNLABELLED: Inspiratory muscles training in COPD is controversial not only in relation to the load level required to produce muscular conditioning effects but also in relation to the group of patients benefiting from the training. Consequently, inspiratory muscular response assessment during Threshold therapy may help optimizing training strategy. The objective of this study was to evaluate the participation of the diaphragm and the sternocleidomastoid (SMM) muscle to overcome with a 30% Threshold load using surface electromyography (sEMG) and to analyze the correlation between SMM activation, maximum strength level of inspiratory muscles (MIP) and obstruction degree in COPD patients (FEV1). We studied seven healthy elderly subjects, mean age of 68+/-4 years and seven COPD patients, FEV1 45+/-17% of the predicted value, with mean age 66+/-8 years. sEMG analysis of SMM muscles and diaphragm were obtained through RMS (root-mean-square) during three stages: pre-loading, loading and post-loading. RESULTS: In the COPD group, the RMS of the SMM increased 28% during load (p<0.05) while the RMS of the diaphragm remained constant. In the elderly there was a trend of a 11% increase in diaphragm activity and of 7% in SMM activity but, without reaching significance levels. SMM activity demonstrated good correlation with the obstruction level (r=-0.537). CONCLUSION: To overcome the load required by Threshold therapy, COPD patients demonstrated an increase of accessory muscles activity, represented by SMM. For the same relative load this increase seems to be proportional to the degree of pulmonary obstruction.

A sesquiterpene drimane with antinociceptive activity from Drimys winteri bark.

Along with three known drimanes, polygodial. 1-beta-(p-methoxycinnamoyl) polygodial and mukaadial, the sesquiterpene drimane named drimanial was isolated from the bark of Drimys winteri (Winteraceae). Its structure was elucidated based on spectroscopic evidence. Drimanial exhibited antinociceptive action against acetic acid induced pain, being about 3-fold less active than polygodial.

A comparative chemical study of Maytenus ilicifolia mart. reiss and Maytenus robusta reiss (Celastraceae).

This work describes a comparative qualitative and quantitative chemical analysis of Maytenus ilicifolia and Maytenus robusta (Celastraceae), extracts by high-resolution gas chromatography (HRGC), using external standards as the method of determination and thin layer chromatographic (TLC). The results show that both plants have a similar chromatographic profile. However, M. robusta exhibited about three times higher concentration of triterpene friedelin than M. ilicifolia.

Antinociceptive properties of extracts of new species of plants of the genus Phyllanthus (Euphorbiaceae).

The hydroalcoholic extract (HE) of the four new species of Phyllanthus, given intraperitoneally, produced significant inhibition of acetic acid-induced abdominal constrictions, with mean ID(50) values of 0.3, 1.8, 7.4 and 26.5 mg/kg for Phyllanthus amarus, Phyllanthus orbiculatus, Phyllanthus fraternus and Phyllanthus stipulatus, respectively. In the formalin test, the four species of Phyllanthus, also produced graded inhibition against both phases of formalin-induced licking, being more active in relation of the late phase. The HE of the Phyllanthus species elicited significant inhibition of the capsaicin-induced neurogenic pain, with mean ID(50) values of 8.9, 6.7, >30 and approximately 30 mg/kg for P. amarus, P. fraternus, P. stipulatus and P. orbiculatus, respectively. Given orally all HE of the Phyllanthus species were less potent and efficacious than when given by intraperitoneally. Results of the present study extend previous data and indicate that all extracts of Phyllanthus plants so far studied exhibit pronounced antinociception when assessed in chemical models of nociception, namely acetic acid-induced writhing, and formalin and capsaicin-induced licking.

Naturally occurring antinociceptive substances from plants.

Despite the progress that has occurred in recent years in the development of therapy, there is still a need for effective and potent analgesics, especially for the treatment of chronic pain. One of the most important analgesic drugs employed in clinical practice today continues to be the alkaloid morphine. In this review, emphasis will be given to the important contribution and the history of Papaver somniferum, Salix species, Capsicum species and Cannabis sativa in the development of new analgesics and their importance in the understanding of the complex pathways related to electrophysiological and molecular mechanisms associated with pain transmission. Recently discovered antinociceptive substances include alkaloids, terpenoids and flavonoid. Plant-derived substances have, and will certainly continue to have, a relevant place in the process of drug discovery, particularly in the development of new analgesic drugs.

Analgesic activity of cyclic imides: 1,8-naphthalimide and 1,4,5,8-naphthalenediimide derivatives.

In early studies, we have reported the synthesis and biological activities of several cyclic imides. The present study describes the analgesic activity of 1,8-naphthalimide and 1,4,5,8-naphthalenediimide derivatives in a standard murine model of analgesia. The pharmacological results show that all compounds studied, given intraperitoneally, produced significant inhibition of acetic acid-induced abdominal constrictions. At the ID50 (micromol/kg) level, these cyclic imide derivatives were about 40-270-fold more potent in this assay than aspirin and acetaminophen, two well-known and widely used analgesics. These results extend previous studies on the analgesic activity of cyclic imides.

Action of polygodial on agonist-induced contractions of the rat portal vein in vitro.

This study investigated the vasorelaxant action of the sesquiterpene polygodial, isolated from the bark of Drymis winteri, on rat portal vein in vitro, contracted by various agonists. Polygodial (21-342 microM) preincubated 20 min before, produced graded antagonism of the contractile responses caused by bradykinin, endothelin-1, noradrenaline, the stable analogue of thromboxane A2 U46619, substance P, neurokinin B, and senktide (an NK3-selective agonist). Polygodial, at the same concentration, also produced graded inhibition of the contractile response induced by potassium chloride and by phorbol ester. At the median inhibitory concentration (IC50) level, polygodial was approximately 114- to 177-fold more active in inhibiting mediated contractions to senktide and phorbol ester. When assessed in the tonic contraction induced by endothelin-1 (0.5 nM) or by phorbol (3 microM), polygodial (0.1-100 microM) produced concentration-dependent relaxation, with maximal inhibition (E(max)) of 62 +/- 2% and 100%, respectively. Finally, polygodial (0.1-100 microM) inhibited the rhythmic spontaneous contractions of the rat portal vein (E(max) of 75 +/- 2%). Taken together, these results suggest that the vasorelaxant actions caused by polygodial in rat portal vein are, at least in part, associated with inhibition of calcium influx through voltage-sensitive channels and interaction with protein kinase C-dependent mechanisms. In addition, these data confirm and extend our previous suggestion that polygodial preferentially antagonizes tachykinin-mediated contraction, especially the NK3-mediated responses.

Antinociceptive properties of the methanolic extract and two triterpenes isolated from Epidendrum Mosenii stems (Orchidaceae).

The antinociceptive effect of the methanolic extract (ME) and two triterpenes isolated from E. mosenii (Orchidaceae) has been investigated in chemical and thermal models of nociception in mice. The ME of E. mosenii (0.3-30 mg kg(-1), i.p. or 50-400 mg kg(-1), p.o.) produced dose-related, significant and long-lasting (4 to 6 h) inhibition of acetic acid-induced abdominal constriction, with ID50 values of 3.9 and 137.0 mg kg(-1), respectively. Pholidotin and 24-methylenecycloartenol isolated from E. mosenii (0.1-3.0 mg kg(-1), i.p.) also produced marked and dose-related inhibition of acetic acid-induced pain, with ID50 values of 0.9 and 1.1 mg kg(-1). However, these compounds and the ME were about 3- to 13-fold more potent at the level of ID50 than diclofenac when assessed in acetic acid-induced abdominal constriction. The ME of E. mosenii in the same range of doses produced dose-related inhibition of both phases of formalin-induced licking, with mean ID50 values for the first and the second phases of 0.9, 122.0 mg kg(-1) and 0.7, 258.0 mg kg(-1), respectively by i.p. or p.o. routes. In addition, the ME (0.3-30 mg kg(-1), i.p., or 50-400 mg kg(-1), p.o.) also caused dose-related inhibition of capsaicin-induced neurogenic pain with mean ID50 values of 5.2 and 130.0 mg kg(-1), respectively. Treatment of animals with naloxone (5 mg kg(-1), i.p.) completely reversed the antinociceptive effect caused by morphine (5 mg kg(-1), s.c.) and that caused by ME of E. mosenii (1 mg kg(-1), i.p.) when assessed against either phase of the formalin-induced pain. Furthermore, when assessed in the hot-plate test, ME (100 mg kg(-1), i.p.) and morphine (10 mg kg(-1), s.c.) caused significant increase in response latency. However, ME given daily for to 7 consecutive days did not develop tolerance to itself nor did it induce cross-tolerance to morphine. Taken together these data demonstrate that the ME of E. mosenii elicited pronounced antinociception, when assessed by i.p. or p.o. routes, against several models of pain. Its actions involve, at least in part, an interaction with opioid system, seeming no to be related with a non-specific peripheral or central depressant actions. Finally, the active principle(s) responsible for the antinociceptive action of E. mosenii is likely related to the presence of the triterpenes.

Assessment of mechanisms involved in antinociception caused by sesquiterpene polygodial.

Polygodial, a sesquiterpene isolated from the bark of Drymis winteri given systemically, intraplantarly, or by spinal or supraspinal sites, produced antinociception when assessed in both phases of the formalin test and against capsaicin-induced pain. Polygodial, even at high doses, had no antinociceptive or antihyperalgesic effect when assessed in hot-plate assay or in glutamate-induced hyperalgesia, nor did it significantly interfere with the motor coordination of animals when tested in the rota-rod test. The polygodial antinociception assessed in the formalin test was not affected by i.p. treatment of animals with cyprodime, yohimbine, phaclofen, bicuculine, or nitric oxide precursor or by intrathecal administration of potassium channel blockers such as apamin, charybdotoxin, glibenclamide, or tetraethylammonium. In contrast, polygodial antinociception was significantly attenuated by i.p. treatment of animals with naloxone, naltrindole, 2-(3, 4-dichlorophenyl)-n-methyl-n-[(1S)-1-(3-isothiocynatophenyl)-2-(1- pry rolidinyl)ethyl]acetamide, p-chlorophenylalanine, prazosin, or by i. c.v. treatment with pertussis toxin. In addition, polygodial antinociception was not cross-tolerant to morphine, nor was its effect affected by the adrenalectomy of animals. Together, these results show that polygodial produces pronounced systemic, spinal, and supraspinal antinociception in mice, mainly preventing the neurogenic pain produced by formalin and capsaicin. The mechanism by which polygodial produces antinociception seems likely to involve an interaction with the opioid system, mainly kappa and delta subtypes, depend on the activation of G(i/o) protein sensitive to pertussis toxin, alpha(1)-adrenoceptors, and the serotoninergic system. Collectively, these results suggest that polygodial itself or its derivatives may have potential therapeutic value for the development of new analgesic drugs.

The mechanisms underlying the relaxant effect of methyl and ethyl gallates in the guinea pig trachea in vitro: contribution of potassium channels.

The relaxant response and the possible contribution of K+ channels to the relaxation caused by both methyl and ethyl gallates, two compounds isolated from the Brazilian medicinal plant Phyllanthus urinaria, were investigated in the guinea pig trachea in vitro. Both methyl and ethyl gallate (0.01-30 microM) caused graded and complete relaxation of the guinea pig trachea without epithelium, pre-contracted by histamine, with mean EC50 values of 1.8 (1.2-2.2) microM and 0.7 (0.6-0.8) microM, respectively, and Emax of both 100+/-0%. Response to ethyl, but not methyl gallate, was significantly shifted to the right, with no change in the maximum effect when the epithelium was removed. The increase in K+ concentration in the medium to 80 mM completely abolished the relaxant response caused by both methyl and ethyl gallate. In addition, tetraethylammonium (10 mM) reduced by 50+/-6% and 43+/-4% the relaxation caused by methyl and ethyl gallates. In contrast, glibenclamide (3 microM) shifted (by about two- and fourfold) the concentration-response curves for both methyl and ethyl gallates, with no changes in the maximum effect. Charybdotoxin (100 nM), but not apamin (100 nM), significantly blocked by 54+/-5% and 59+/-4% the relaxation of both methyl and ethyl gallates. In contrast, SQ 22536 (10 microM; a selective adenylyl cyclase inhibitor), methylene blue (10 microM) or ODQ (1 microM; a guanylyl cyclase inhibitor) did not significantly affect the relaxant response caused by either of the compounds. These results provide evidence that the relaxation caused by both methyl and ethyl gallates in the guinea pig trachea in vitro may involve the activation of large-conductance Ca2+-activated K+ channels, and, to a lesser extent, ATP-sensitive K+ channels. Such results extend our previous observations and are consistent with the notion that methyl and ethyl gallates are mainly responsible for the relaxant action previously demonstrated in the extract of this plant.

Chemical and pharmacological examination of antinociceptive constituents of Wedelia paludosa.

The present work describes the antinociceptive effects of some fractions and two pure compounds obtained from the Wedelia paludosa, a Brazilian medicinal plant employed in folk medicine against a variety of diseases, including dolorous pathologies. It was found that such fractions as well as kaurenoic acid and luteolin exhibit marked antinociceptive action in mice using acetic acid-induced writhing. They were more active than some well-known analgesic drugs, such as acetyl salicylic acid, acetaminophen, dipyrone and indomethacin. The results confirm our previous studies conducted with this plant, suggesting that different chemical constituents are responsible for the antinociceptive activity shown by the extracts and fractions prepared from W. paludosa.

Anti-allergic effects and oedema inhibition caused by the extract of Drymis winteri.

OBJECTIVE: To study the acute anti-inflammatory and anti-allergic properties of an extract of D. winteri. MATERIAL AND METHODS: Paw oedema induced in rats with various stimuli and anaphylactic shock in mice. RESULTS: The hydroalcoholic extract (HE) of D. winteri (Winteraceae) (30 to 100 mg/kg, p.o., 1 h prior) inhibited carrageenan (300 micrograms/paw) and dextran (100 micrograms/paw)-induced paw oedema formation in a dose-dependent manner, with mean ID50 values of 49 and < 30 mg/kg, respectively. The HE of D. winteri (30 to 100 mg/kg) also inhibited paw oedema induced by bradykinin (BK) (3 nmol), substance P (SP) (10 nmol) and PAF-acether (PAF) (10 nmol), in a dose-dependent manner, with mean ID50 values of 56, 63, and 58 mg/kg, respectively. However, the HE inhibited the rat paw oedema induced by prostaglandin E2 (PGE2) (10 nmol) (29 +/- 7 and 33 +/- 2% at 60 and 240 min) to a smaller extent, and had no effect on oedema elicited by histamine (100 nmol). In adrenalectomized animals, the inhibition by the HE of D. winteri (100 mg/kg, p.o., 1 h prior) of BK-elicited oedema (3 nmol/paw) was significantly smaller when compared with that observed in control animals. When assessed in rats actively sensitised to ovalbumin (OVO), the oedema caused by OVO (6 micrograms/paw) was significantly inhibited by HE of D. winteri (30 to 100 mg/kg, p.o.), with a mean ID50 of about 65 mg/kg. The HE of D. winteri (100 and 200 mg/kg, p.o.) significantly increased survival rate when assessed in anaphylactic shock in mice actively sensitised to the antigen. The protective effect was long-lasting, being observed for up to 15 h. Dexamethasone, used as positive control (0.5, 1 and 2 mg/kg) produced a long-lasting (up to 24 h) increase in the survival rate of the animals. CONCLUSIONS: These results confirm and extend our previous studies, and demonstrate the clear oral anti-inflammatory and anti-allergic properties of the active principle(s) present in the barks of D. winteri, thus confirming its reported medicinal use in folk medicine for the management of airway diseases.

Antinociceptive action of 2-(4-bromobenzoyl)-3-methyl-4,6-dimethoxy benzofuran, a novel xanthoxyline derivative on chemical and thermal models of nociception in mice.

The antinociceptive effect of the novel xanthoxyline derivative 2-(4-bromobenzoyl)-3-methyl-4-6-dimethoxy benzofuran) (BMDB), given i.p., p.o., s.c., subplantarly, intrathecally or by i.c.v. routes was assessed in five models of chemical and thermal nociception in mice, namely acetic acid-induced abdominal constriction, formalin and capsaicin-induced licking, hot-plate and tail-flick tests. BMDB given by i.p., s.c., subplantarly or by i.c.v. routes elicited dose-related and long-lasting (4 hr) antinociception, but had no significant effect by p.o. route. At the ID50 level, this compound was about 15- to 100-fold more potent than aspirin and acetaminophen, but it was about 2- to 50-fold less potent than morphine. Its analgesic action was not influenced by naloxone, L-arginine, antagonist of alpha-1 adrenoceptor, prazosin, tau -aminobutyric acid (B) antagonist, phaclofen, after adrenalectomy, but was reversed in part by p-chlorophenylalanine methyl ester. Its analgesic action was not secondary to an anti-inflammatory effect, or was it associated with nonspecific effect such as muscle relaxant or sedative actions of animals. We conclude that BMDB produces dose-dependent spinal and supraspinal antinociception as evaluated in several algesic models in mice, including the neurogenic nociception responses induced by formalin and capsaicin. Its antinociceptive effect was insensitive to naloxone, suggesting the lack of involvement of endogenous opioid, was not modulated by adrenal glands and does not involve interaction with the L-arginine-nitric oxide pathway, activation of alpha-1 adrenoceptors or tau-aminobutyric acidB receptors, but requires, at least in part, the serotoninergic pathway.

Analysis of the mechanisms underlying the antinociceptive effect of the extracts of plants from the genus Phyllanthus.

1. We examine some of the mechanisms underlying the analgesic effects of the hydroalcoholic extracts (HE) of Phyllanthus urinaria and P. niruri against formalin-induced nociception in mice. In addition, we also investigate the action of both HEs against capsaicin-mediated pain. 2. Both prazosin and yohimbine (0.15 mg/kg, i.p.) induced a marked inhibition of the analgesic effect caused by phenylephrine (10 mg/kg, i.p.) and clonidine (0.1 mg/kg, i.p.), respectively, but had no effect on the antinociceptive action caused by HE of P. urinaria (10 mg/kg, i.p.) or P. niruri (30 mg/kg, i.p.). 3. NG-nitro-L-arginine (L-NOARG, 75 mg/kg, i.p.) caused marked analgesic effect against the second phase of formalin-induced pain. Treatment of animals with L-arginine (600 mg/kg) completely antagonized the antinociceptive effect of L-NOARG but had no significant effect against the HE of P. urinaria (10 mg/kg, i.p.) or P. niruri (30 mg/kg. i.p.) analgesic properties. 4. The antinociceptive effects caused by the HEs of P. urinaria (10 mg/kg, i.p.) and P. niruri (30 mg/kg, i.p.) were unaffected by methysergide (5 mg/kg, i.p.), p-chloro-phenylalanine-methyl-ester (100 mg/kg, i.p., once a day for 4 consecutive days) or after previous adrenalectomy of animals. 5. The HE of P. urinaria and P. niruri given either intraperitoneally (1-30 mg/kg) or orally (25-200 mg/kg) caused marked and dose-related inhibition of capsaicin-induced pain with ID50 of 2.1 and 6.1 mg/kg given intraperitoneally and 39 and 35 mg/kg given orally, respectively.