Hypericum polyanthemum cyclohexane extract potentiates behavioral effects and neurodegeneration induced by nigral infusions of 6-hydroxydopamine in rats.

INTRODUCTION: Parkinson's Disease (PD) is a progressive neurodegenerative disorder, hallmark of which is loss of nigral dopaminergic neurons. Since a Hypericum polyanthemum extract inhibits monoamine reuptake and some of its constituents present cytotoxic properties, the aim of this study was to evaluate the effect of this extract in an animal PD model. METHODS: Adult Wistar rats (110 days old) received 6-hydroxydopamine (6-OHDA) infusions into the right medial forebrain bundle. A cyclohexane extract from aerial parts of H. polyanthemum (POL; 90 mg/kg/administration; gavage) was administered in three different regimens. In Regimens 1 and 2, rats received 3 administrations of POL starting 4 or 24 h after 6-OHDA infusion, respectively. In Regimen 3, these administrations were carried out 1 day before any evaluation of ipsilateral rotational activity induced by methylphenidate (MP, 20 mg/kg, i.p.). MP was administered 10, 45, and 85 days after 6-OHDA infusion in all groups. Nigral tyrosine hydroxylase (TH) immunocontent was evaluated 120 days after 6-OHDA infusion in animals submitted to Regimen 2 only. The effect of POL on apomorphine-induced climbing behavior in non-lesioned adult CF1 mice (60 days old) treated with POL was also evaluated. RESULTS: Regimen 2 increased MP-induced rotational activity and decreased nigral TH levels in 6-OHDA-lesioned rats. Rotational activity was not altered in regimens 1 and 3. In addition, no change in climbing behavior was observed in non-lesioned mice. CONCLUSION: Together, these results indicate that, in 6-OHDA-lesioned rats, a cyclohexane H. polyanthemum extract potentiates neurotoxicity and MP-induced motor asymmetry depending on the time of administration. In the short term, it seems to not act directly on mice dopaminergic receptors.

Denudatin A, a Dimeric Acylphloroglucinol from Hypericum denudatum Presents an Antinociceptive Effect in Mice.

A new dimeric acylphloroglucinol, denudatin A (1), was isolated from the flowering aerials parts of Hypericum denudatum, along with the known phloroglucinols selancin A (2), hyperbrasilol A (3), uliginosin B (4), and isouliginosin B (5). The structure of 1 was elucidated using 1D, 2D NMR, and MS experiments, and by comparison with previously reported data for Hypericum dimeric acylphloroglucinols. Denudatin A (1) and selancin A (2) were administered orally to mice displaying antinociceptive activity in the hot plate test. The compounds did not induce motor impairment in the rotarod apparatus.

Uliginosin B, a Possible New Analgesic Drug, Acts by Modulating the Adenosinergic System.

Uliginosin B (ULI) is a natural acylphloroglucinol that has been proposed as a new molecular scaffold for developing analgesic and antidepressant drugs. Its effects seem to be due to its ability to increase monoamines in the synaptic cleft by inhibiting their neuronal uptake without binding to their respective transporters, but its exact mode of action is still unknown. Considering the importance of the purinergic system to pain transmission and its modulation by monoamines availability, the aim of this study was to investigate the involvement of adenosinergic signaling in antinociceptive effect of uliginosin B. The selective adenosine A1 receptor antagonist DPCPX and the selective A2A antagonist ZM 241385 prevented the effect of ULI in the hot-plate test in mice. Pretreatment with inhibitors of adenosine reuptake (dipyridamole) or adenosine deaminase (EHNA) did not affect the ULI effect. On the other hand, its effect was completely prevented by an inhibitor of ecto-5'-nucleotidase (AMPCP). This finding was confirmed ex vivo, whereby ULI treatment increased AMP and ATP hydrolysis in spinal cord and cerebral cortex synaptosomes, respectively. Altogether, these data indicate that activation of A1 and A2A receptors and the modulation of ecto-5'-nucleotidase activity contribute to the antinociceptive effect of ULI.

Repeated forced swimming impairs prepulse inhibition and alters brain-derived neurotrophic factor and astroglial parameters in rats.

Glutamate perturbations and altered neurotrophin levels have been strongly associated with the neurobiology of neuropsychiatric disorders. Environmental stress is a risk factor for mood disorders, disrupting glutamatergic activity in astrocytes in addition to cognitive behaviours. Despite the negative impact of stress-induced neuropsychiatric disorders on public health, the molecular mechanisms underlying the response of the brain to stress has yet to be fully elucidated. Exposure to repeated swimming has proven useful for evaluating the loss of cognitive function after pharmacological and behavioural interventions, but its effect on glutamate function has yet to be fully explored. In the present study, rats previously exposed to repeated forced swimming were evaluated using the novel object recognition test, object location test and prepulse inhibition (PPI) test. In addition, quantification of brain-derived neurotrophic factor (BDNF) mRNA expression and protein levels, glutamate uptake, glutathione, S100B, GluN1 subunit of N-methyl-D-aspartate receptor and calmodulin were evaluated in the frontal cortex and hippocampus after various swimming time points. We found that swimming stress selectively impaired PPI but did not affect memory recognition. Swimming stress altered the frontal cortical and hippocampal BDNF expression and the activity of hippocampal astrocytes by reducing hippocampal glutamate uptake and enhancing glutathione content in a time-dependent manner. In conclusion, these data support the assumption that astrocytes may regulate the activity of brain structures related to cognition in a manner that alters complex behaviours. Moreover, they provide new insight regarding the dynamics immediately after an aversive experience, such as after behavioural despair induction, and suggest that forced swimming can be employed to study altered glutamatergic activity and PPI disruption in rodents.

Phloroglucinol derivatives present an antidepressant-like effect in the mice tail suspension test (TST).

The antidepressant-like effects of phloroglucinol and seven synthetic related derivatives were investigated using the tail suspension test (TST) in mice. Compounds 2-methyl-1-[2,4,6-trihydroxy-3-(2-methylpropanoyl)phenyl] propan-l-one (5), 1-(2,4,6-trihydroxyphenyl)ethan-l-one (6), 1-(3-acetyl-2,4,6-trihydroxyphenyl)ethan-l-one (7), 2-methyl-1 -[2,4,6-trihydroxy-3-(2-methylpropanoyl)-5-{ [2,4,6-trihydroxy-3,5-bis(2-methylpropanoyl)phenyl]methyl phenyl] propan-1-one (9) and 1-{3-acetyl-5-[(3,5-diacetyl-2,4,6-trihydroxyphenyl)methyl]-2,4,6-trihydroxyphenyl}ethan-1-one (10), containing acyl groups, decreased the immobile behavior of mice treated orally with equimolar doses of imipramine 20 mg/kg, with no alterations in locomotor activity as assessed by the open-field test. These results suggest that these phloroglucinol derivatives could represent a new molecular model in the search for antidepressant drugs.

Acute and repeated-doses (28 days) toxicity study of Hypericum polyanthemum Klotzsch ex Reichardt (Guttiferare) in mice.

Hypericum polyanthemum, a South Brazilian species showed antidepressant-like and antinociceptive effects in rodents. Since limited information is available on the toxicity and safety profile of the Hypericum genus, we therefore investigated whether H. polyanthemum cyclo-hexane extract (POL) treatment could be associated with toxicity in preclinical setting using mice as an experimental model. These toxicity studies were based on the guidelines of the Organization for Economic Cooperation and Development (OECD-guidelines 423 and 407). Animals received POL single dose (2000 mg/kg, p.o.) or daily for 28-days (90, 450 and 900 mg/kg, p.o.). Acute toxicity study did not detect any clinical signs, changes in behavior or mortality. In repeated dose toxicity study, POL affected the body weight gain and induced biochemical, hematological and liver histological changes at 450 and 900 mg/kg. Mice treated with POL 90 mg/kg did not show any toxicity signs. In conclusion H. polyanthemum can be classified as safe (category 5) according to OECD acute toxicity parameters. However, the alterations observed after repeated treatment with high doses suggest that the liver could be the target organ on potential H. polyanthemum toxicity and point to the need of further toxicity studies.

Effect of storage time and conditions on the diene valepotriates content of the extract of Valeriana glechomifolia obtained by supercritical carbon dioxide.

INTRODUCTION: Valepotriates (epoxy iridoid esters) represent an important group of constituents that contribute to pharmacological effects for the genus Valeriana. Storage and extraction of valepotriates is a demanding task, as these compounds are thermolabile and unstable: even when decomposition products are not formed, isovaleric acid liberation from the iridoid nucleus originate compounds with less complex substituents. OBJECTIVE: To study the influence of time and storage conditions on the diene valepotriates (valtrate, isovaltrate, acevaltrate, 1-ß-acevaltrate, 1-ß-aceacevaltrate) content of the Valeriana glechomifolia (native to southern Brazil), extract was obtained by supercritical fluid extraction using CO2 as the fluid (SF-CO2). METHODOLOGY: Above-ground and below-ground material of V. glechomifolia was extracted by SF-CO2 (40 °C, 90 bar). The extract was stored under nitrogen atmosphere or solubilised in methanol. Valepotriates stability was accessed during storage at -20 °C over 8 months through reverse-phase HPLC (mobile phase acetonitrile:water 50:50 (v/v); 254 nm). RESULTS: A gradual increase in valtrate levels and decrease in acevaltrate, 1-ß-acevaltrate and 1-ß-aceacevaltrate, concentration were observed from the first month of storage for the dry extract. However, for the methanol solubilised extract these changes occurred only after the third month and were accompanied by reduction in isovaltrate levels and formation of decomposition products. CONCLUSION: SF-CO2 showed high selectivity for valepotriates extraction. This is the first report on valepotriates molecular conversion, which was less accelerated when the extract was stored in methanol, but under this condition degradation products are also present, probably baldrinals, that are not observed in the dry extract.

The anti-immobility effect of hyperoside on the forced swimming test in rats is mediated by the D2-like receptors activation.

The crude extracts of HYPERICUM species native to South Brazil showed analgesic and antidepressant-like effects in rodents. The chemical characterization of these species revealed that they are rich in flavonoids and phloroglucinol derivatives. In the present study a detailed investigation was performed on the activities of hyperoside (HYP), a common flavonoid in the genus HYPERICUM. Hyperoside was obtained from the aerial parts of H. CAPRIFOLIATUM by chromatographic procedures. Mice treated with single doses (10, 20 and 40 mg/kg i.p.) did not present signs of toxicity or weight loss. At 20 and 40 mg/kg i.p. the mice exploratory behavior in the open field test was reduced. At 20 mg/kg i. p. the pentobarbital sleeping time increased, but not the sleeping latency. No activity was found on the hot-plate (10 and 20 mg/kg i.p.) or in the acetic acid-induced writhing test (20 and 40 mg/kg p.o.). Nevertheless, an antidepressant-like effect in the forced swimming test in mice and rats was observed (HYP 10 and 20 mg/kg i.p. in mice; HYP 1.8 mg/kg/day p.o. in rats). The antidepressant-like effect in rats was prevented by the administration of sulpiride (50 mg/kg i.p.) a D2 antagonist. In conclusion, hyperoside was found to present a depressor effect on the central nervous system as well as an antidepressant-like effect in rodents which is, at least in part, mediated by the dopaminergic system.

The antinociceptive effect of a benzopyran (HP1) isolated from Hypericum polyanthemum in mice hot-plate test is blocked by naloxone.

Several species of the genus Hypericum (Guttiferae) have been used for analgesic purposes all over the world and some of them have demonstrated to possess this effect in rodents. This study describes the antinociceptive effect of the cyclohexane extract from aerial parts of H. polyanthemum (POL) as well as of benzopyrans, 6-isobutyryl-5,7-dimethoxy-2,2-dimethyl-benzopyran (HP1), 7-hydroxy-6-isobutyryl-5-methoxy-2,2-dimethyl-benzopyran (HP2), and 5-hydroxy-6-isobutyryl-7-methoxy-2,2-dimethyl-benzopyran (HP3), which are the main components of POL. The antinociceptive effect was evaluated through hot-plate and writhing tests in mice, and the opioid system involvement was assessed by using naloxone (2.5 mg/kg, s.c.) antagonism. In the hot-plate test, POL (45, 90, 180 mg/kg, p.o) showed a dose-dependent effect, and out of the benzopyrans only HP1 (30, 60, 90 mg/kg, i.p.) was active. Its effect was also dose-dependent, with the maximum reached at 60 mg/kg. HP1 60 mg/kg (p.o.) also inhibited acetic acid-induced writhing in 58%. The pretreatment with naloxone abolished the antinociceptive effect of HP1 60 mg/kg (i.p) in the hot plate. Furthermore, the H. polyanthemum cyclohexane extract and HP1 did not affect the mice performance in the rota-rod apparatus suggesting that at antinociceptive doses they do not present gross neurotoxicity nor induce motor impairment. From these data it is reasonable to assume that the benzopyran HP1 accounts for the H. polyanthemum cyclohexane extract antinociceptive effect, and this effect is, at least in part, mediated by an opioid-like mechanism.

Plants popularly used for loosing weight purposes in Porto Alegre, South Brazil.

In this study, 14 herbalists (herb sellers) were interviewed about popular use of plants with weight loss purpose in Porto Alegre, a South Brazil city. For all identified species, scientific data were reviewed aiming to establish a correlation between popular use and biological properties. Seventy-eight samples were reported as having weigh loss properties. These samples come from 23 species and Asteraceae encompasses the greatest number of representatives. The greatest number of herbalist's citations was Baccharis articulata. The majority of plants have traditional use in Brazil but none is explicitly cited for loosing weight purposes. The pharmacological data are mainly from animal and in vitro studies and do not straight related to obesity. Only Ilex paraguariensis presents clinical data of efficacy in the treatment of obesity. Seven species present pre-clinical data that indicate a potential role in the control of certain conditions which are associated with obesity, such as hyperlipidemia (Campomanesia xanthocarpa, Cuphea carthagenensis, Cynara scolymus, Hibiscus sabdariffa, Ilex paraguariensis) and high levels of blood glucose (Achyrocline satureioides, Baccharis trimera, Campomanesia xanthocarpa). In conclusion, scientific data found are insufficient to guarantee the efficacy and safety of these plants for treating obesity. However, some of them present activities which could be useful to treat certain obesity comorbidities and deserve further studies.

Plantas utilizadas na medicina popular brasileira com potencial atividade antifúngica / Plants with potencial antifungal activity employed in Brazilian folk medicine

Neste trabalho foi realizado um levantamento bibliográfico etnobotânico sobre plantas utilizadas pela população brasileira no tratamento de sinais e sintomas relacionados às infecções fúngicas. Foram citadas 409 espécies, distribuídas em 98 famílias, com maior concentração em Fabaceae e Asteraceae. Para as dez espécies mais citadas, foi realizada uma busca relativa a estudos de atividade antifúngica na base de dados MEDLINE-PubMed. Somente foram encontrados estudos para Phytolacca americana L., Rosmarinus officinalis L., Mirabilis jalapa L., Schinus molle L. Entre as dez espécies mais utilizadas, seis correspondem a espécies nativas: Anacardium occidentale L., Cecropia peltata L., Schinus molle L., Schinus terebinthinfolius Raddi, Stryphnodendron adstringens (Mart.) Coville e Tabebuia heptaphylla (Vell.) Toledo.

The aim of this work was to draw up a list of plants used by Brazilian population for the treatment of signs and symptoms related to fungal infections and to verify the existence of scientific data related to the antifungal activity in the databasis MEDLINE-PubMed. Four hundread and nine species were listed, which are distributed in ninety eight families, mainly Fabaceae and Asteraceae. Among the more frequently mentioned species (10), only four were evaluated regarding to the antifungal activity: Phytolacca americana L., Rosmarinus officinalis L., Mirabilis jalapa L. and Schinus molle L. From those ten species, six are native (Anacardium occidentale L., Cecropia peltata L., Schinus molle L., Schinus terebinthifolius Raddi, Stryphnodendron adstringens (Mart.) Coville e Tabebuia heptaphylla (Vell.) Toledo.

Botanical (morphological, micrographic), chemical and pharmacological characteristics of Pfaffia species (Amaranthaceae) native to South Brazil

Some parameters for the quality control of P. glomerata and P. paniculata roots using their botanical and chemical characteristics are presented. it was also carried out an in vitro pharmacological screening to evaluate some biological properties of P. glomerata that could be related to its popular use as "tonic". Relating to biological assays, ethanolic extract from P. glomerata roots did not presented antiviral, antiproliferative, antifungal or MAO inhibitory activities. The cytotoxicity evaluation of P. glomerata determined that `IC IND. 50ï is >2,000 µg/mL. The main morphological and micrographic characteristics of P. glomerata and P. paniculata roots are described in this paper in order to aid in their unequivocal identification

Avaliaçäo da qualidade de produtos fitoterápicos comercializados em Porto Alegre - RS / Qualitative evaluation of herbal medicines comercialized in Porto Alegre - RS (Brazil)

Este trabalho é uma avaliaçäo qualitativa de produtos fitoterápicos e insumos vegetais comercializados em Porto Alegre no período de julho a outubro de 1997, com o objetivo de verificar as mudanças geradas na qualidade destes produtos após a vigência da Portaria n§ 6 da SVS-MS (DOU de 31/01/95). Foram analisados 42 produtos, adquiridos mediante compra em ervaterios, farmácias de manipulaçäo e drogarias de Porto Alegre. As técnicas utilizadas foram baseadas na Farmacopéia Brasileira 4ª ed. e em literatura especializada ou desenvolvidas na disciplina de Farmacognosia da Faculdade de Farmácia - UFRGS. Foram considerados como indicadores de qualidade: identidade, ausência de matérias orgânicas estranhas, estado de conservaçäo e presença dos principais constituintes químicos das amostras em análise. Os resultados obtidos demonstraram que a vigência da Portaria n§6 da SVS-MS (DOU 31/01/95) ainda näo induziu uma alteraçäo no quadro de qualidade dos produtos fitoterápicos comercializados em Porto Alegre, visto que das 42 amostras analisadas, 71,4(por cento) näo atendem aos quesitos mínimos de qualidade exigidos por esta norma, à semelhança de resultados obtidos em trabalhos anteriores. (AU)

This paper presents a qualitative evaluation of some herbal Medicines commerciali- zed in Porto Alegre - RS (Brazil) from july to october, 1997, in order to verify if the new Brazilian legislation about these products (Portaria 6 - SVS - MS - DOU 01.31.95) induced the improve- ment in their quality. Forty-two samples purchased from herbalists, drugstores and pharmacies Were analysed considering botanical identity, absence of foreign organic materiaIs, conservation state and presence of the main chemical compouds as quality indicators. The methods employed were based in the Farmacopéia Brasileira 4. ed and specialized literature The results showed that the Portaria 6 ­ SVS - MS (DOU 01.31.95) validity has not yet influenced the quality State of herbal products com- mercialized in Porto Alegre, since 71,4 % of the analysed samples do not fit the minimum quality demands required by such legal rule, These results meet the ones observed in previous researchs in rela- tion to the unsatisfactory qualitity 'of the Brazilian herbal medicines. (AU)