Hypericum perforatum is a herbal medicine that has been used for centuries for the treatment of depression. Many studies have been conducted in the Northern hemisphere on the efficacy of the HP extracts produced there. These studies include clinical trials and pharmacological investigations using a standardised HP extract or a fraction of the HP extract containing certain compounds, such as hypericin, pseudohypericin, hyperforin and several of the flavonoids thought to be responsible for the antidepressant activity. The mechanism of action of HP and its constituents is still not completely clear and it is speculated that the antidepressant activity is the result of several of the compounds acting synergistically. HP is indigenous to and also cultivated in the Western Cape of South Africa. Extracts from these plants are sold in the local health shops and there are no previous studies evaluating the efficacy of these products. The aim of this thesis is to investigate the antidepressant activity of one of these products and two of its constituents, quercetin and caffeic acid, to gain further insight into their mode of antidepressant action and to compare these results with similar studies which used a standardised extract produced in the northern hemisphere. The first study investigated the effect of HP, quercetin and caffeic acid on pineal metabolism. Changes in the synthesis of melatonin produced by the pineal gland have been implicated in depression. The results showed an increase in the level of melatonin produced in the animals treated with quercetin, which suggests that this compound may mediate antidepressant activity through such a mechanism. There are no previous reports on the in vivo effects of HP or any of its constituents on pineal metabolism. The second study investigated the effect of HP, quercetin and caffeic acid on the activity of the liver enzyme, tryptophan-2,3-dioxygenase (TDO). Inhibition of this enzyme has been shown to increase plasma levels of tryptophan, a precursor of serotonin and thereby result in increased serotonin levels in the brain. Low levels of serotonin in the brain have been implicated in depression. This study revealed significant inhibition of TDO by caffeic acid and this suggests that this constituent of HP could be contributing to its antidepressant activity through such a mechanism. There are no previous reports investigating the in vivo effect of HP or any of its constituents on TDO activity. Modulation of the levels of indoleamines, serotonin (5-HT) and dopamine (DA) as well as the metabolites, 3,4 dihydroxyphenyl acetic acid (DOPAC), 5-hydroxyindole acetic acid (5-HIAA) and homovallinic acid (HVA) in the brain have been implicated in the neuropharmacology of depression. Different studies using enzyme-linked immunosorbant assay (ELISA), high performance liquid chromatography with electrochemical detection (HPLC-ECD) and liquid chromatography-mass spectrometry (LC-MS) were used to determine changes in the levels of these indoleamines brought about after treatment with HP caffeic acid and quercetin. The results of the ELISA study showed significant increases in 5-HT levels in the brains of the animals treated with caffeic acid and quercetin. The results of the HPLC-ECD studies also revealed significant increases in 5-HT levels and a decrease in the turnover of 5-HT in the animals treated with quercetin. A significant increase in DA levels in the animals treated with quercetin was shown in both the HPLC-ECD and LC-MS studies. There was also an increase in DA turnover in the animals treated with HP shown in the HPLC-ECD and LC-MS studies. These results suggest that HP and its constituents, quercetin and caffeic acid mediate their antidepressant effects through serotonergic and dopaminergic neurotransmission. Adaptive changes in the density of b-adrenergic (b-AR), 5-HT2 and N-methyl-D-aspartate (NMDA) receptors have been implicated in depression. Several studies, investigating the effect of treatment with HP and quercetin on these different receptor densities, were undertaken using radioactive binding assays. Treatment with HP resulted in significant down regulation of b-AR and NMDA receptor densities and up-regulation of 5HT2 receptors. The effects on the b-AR and 5-HT2 receptors are similar to the results reported using HP in the Northern hemisphere, but the effect on the NMDA receptors is novel providing insight into the mode of action of HP. Apoptosis of neuronal cells has been implicated in neuro-degenerative and depressive disorders. Detection of apoptosis, using fluorescent microscopy observed through the labelling of DNA strand breaks, showed a decrease in the amount of apoptosis in the animals treated with HP and quercetin. This adds further support for the use of HP as an antidepressant and these results are similar to results reported from the Northern hemisphere. The results of all these studies suggest that the quality of the locally produced tincture is similar in efficacy to that of the standardised product of the Northern hemisphere.

Espécies de Hypericum (Guttiferae) são mundialmente reconhecidas por seus efeitos farmacológicos, destacando-se H. perforatum pela atividade antidepressiva. O estudo com espécies brasileiras vem apresentando resultados promissores. Hypericum polyanthemum e H. caprifoliatum mostraram efeito antinociceptivo, enquanto H. caprifoliatum mostrou atividade do tipo antidepressiva. Além disso, verificou-se atividade de H. polyanthemum sobre o carrapato Rhipicephalus (Boophilus) microplus. Para essas espécies, é descrita a presença de benzopiranos, derivados de floroglucinol e flavonóides. Objetivos: Isolar compostos fenólicos lipofílicos de H. polyanthemum e o flavonóide hiperosídeo de H. caprifoliatum, assim como avaliar atividades biológicas de algumas dessas substâncias. Materiais e Métodos: Realizou-se a análise química através de técnicas cromatográficas (CC, CCD) e espectroscópicas (1H e 13C RMN). Hiperosídeo foi avaliado nos seguintes modelos comportamentais: potenciação do sono barbitúrico, atividade locomotora espontânea, placa quente, contorções induzidas por ácido acético e natação forçada. O efeito antinociceptivo de isobutiril-5,7-dimetóxi-2,2-dimetilbenzopirano (HP1), 7-hidróxi-6-isobutiril-5-metóxi-2,2-dimetil-benzopirano (HP2) e 5-hidróxi-6-isobutiril-7-metóxi-2,2-dimetil-benzopirano (HP3), foi investigado, assim como sua atividade acaricida através do teste de imersão de larvas. Resultados e Conclusões: Além dos benzopiranos HP1, HP2 e HP3, dois compostos não relatados para a espécie H. polyanthemum, a xantona 6- desoxijacareubina e um benzopirano de estrutura similar ao ácido eriostemóico, foram isolados de extrato obtido por fluido supercrítico. Hiperosídeo mostrou efeito depressor sobre o SNC, e efeito antiimobilidade, que parece ser mediado pelo sistema dopaminérgico, em ratos. HP1 apresentou efeito antinociceptivo mediado pela neurotransmissão opióide. Nos experimentos para investigação da atividade acaricida, os benzopiranos mostraram ser, pelo menos em parte, responsáveis pela toxicidade dos extratos sobre os ácaros. / The pharmacological effects of some Hypericum species are worldwide recognized, mostly by the comproved efficacy of H. perforatum as antidepressant. The south Brazilian species have been showing promissing results. Hypericum polyanthemum and H. caprifoliatum presented antinociceptive effect, while an antidepressant-like activity of H. caprifoliatum was reported. In addition, extracts from H. polyanthemum showed to be highly toxic to Rhipicephalus (Boophilus) microplus cattle tick. The chemical characterization reveals that these species are rich in benzopyrans, flavonoids and phloroglucinol derivatives. Objectives: To isolate lipophilic compounds from H. polyanthemum and the flavonoid hyperoside from H. caprifoliatum, as well as to carry out a biological evaluation of some of the isolated substances. Material and Methods: Chromatography and NMR spectroscopy techniques were performed for isolation and structure elucidation. Hyperoside was applied on behavior models, as the open field, pentobarbital sleeping potentiation, hot plate, acetic acid-induced writhing and the forced swimming test. The antinociceptive effect and the acaricide potential of 6-isobutyryl-5,7-dimethoxy- 2,2-dimethyl-benzopyran (HP1), 7-hydroxy-6-isobutyryl-5-methoxy-2,2-dimethylbenzopyran (HP2) and 5-hydroxy-6-isobutyryl-7-methoxy-2,2-dimethylbenzopyran (HP3) were also investigated. Results and conclusions: A benzopyran similar to the eriostemoic acid and the xanthone 6-deoxyjacareubin were isolated from the extract obtained by supercritical fluid. Hyperoside showed a central depressor effect and no toxicity signs. The present study provides evidences for the involvement of D2-like dopaminergic neurotransmission on the mechanism of hyperoside antidepressant-like action in rats. HP1 presented opioid-mediated antinociceptive effect. On larvae immersion test, the benzopyrans showed to account for the acaricide properties of H. polyanthemum extracts.

Orientador: Rosemary Adriana Chiérici Marcantonio / Resumo: O objetivo deste trabalho foi avaliar os efeitos da aPDT (antimicrobial photodynamic therapy), com o fotossensibilizador Hipericina-glucamina (Hy-g), ativado por LED âmbar (34,10 J/cm2), no tratamento e progressão da doença periodontal (DP) induzida experimentalmente em ratos. Dois estudos distintos foram conduzidos. No Estudo 1, foi avaliada a fetividade da aPDT como tratamento adjuvante à raspagem e alisamento radicular. Em um período de 15 dias, 60 ratos permaneceram com ligadura ao redor do segundo molar superior para indução da DP. No dia seguinte a sua remoção, os animais foram distribuídos entre 4 grupos experimentais (n =5): IDP (Indução da Doença Periodontal); RAR (Raspagem e Alisamento Radicular); aPDT e RAR+aPDT. Em 7, 15 ou 30 dias após a aplicação dos tratamentos os animais foram eutanasiados. Análises: histológica, histométrica, microtomográfica e estereométrica. No Estudo 2, após 7 dias de indução da DP, 30 ratos foram divididos em 3 grupos experimentais (n=5): Hy-g; LED e aPDT. Os animais foram eutanasiados em 7 ou 15 dias após a aplicação dos tratamentos. Análises: microtomográfica, histométrica, e imuno-histoquimica para Fosfatase Ácida Tartarato Resistente. Os dados foram submetidos a análise estatística (α=0,05). Como resultados, observamos que no Estudo 1 o grupo IDP apresentou alterações morfológicas mais severas do que os demais grupos devido ao processo inflamatório propagado pela DP. No período de 7 dias após os tratamentos, a análise estereométrica m... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: This research aims at evaluating the effect of aPDT (antimicrobial photodynamic therapy) using the Hypericin-glucamine (Hy-g) as photosensitizer, activated by LED amber (34.10 J/cm2), on the treatment of experimental induced periodontal disease (PD) in rats. Two different studies were conducted. In the Study 1, we assessed the effectiveness of aPDT as an adjunctive treatment to root scaling and straightening. The PD was induced in the second upper molar of 60 rats using ligature for 15 days. In the day after removing the ligature, the animals were divided randomly in 4 experimental groups (n=5): IPD (Induced Periodontal Disease); RAR (Root Scaling and Smoothing); aPDT; and RAR+aPDT. At 7, 15 or 30 days after applying the treatments, the animals were euthanized. Analyses: histological, histometric, microtomographic and stereometric. In the Study 2, after 7 days of inducting the PD, 30 rats were distributed into 3 experimental groups (n=5): Hy-g; LED e aPDT. The animals were euthanized after 7 or 15 days from the treatments. Analyses: microtomographic, histometric, and immunohistochemical for Resistant Tartarate Acid Phosphatase. All data was submitted to statistical analysis (α=0,05). The results from Study 1 indicated that the IPD group had more severe morphological changes than the other groups due to the inflammatory process disseminated by the PD. The stereometric analysis showed a significantly higher proportion of fibroblasts in the animals from the 7-days-after-treatmen... (Complete abstract click electronic access below) / Doutor

Espécies de Hypericum (Guttiferae) são mundialmente reconhecidas por seus efeitos farmacológicos, destacando-se H. perforatum pela atividade antidepressiva. O estudo com espécies brasileiras vem apresentando resultados promissores. Hypericum polyanthemum e H. caprifoliatum mostraram efeito antinociceptivo, enquanto H. caprifoliatum mostrou atividade do tipo antidepressiva. Além disso, verificou-se atividade de H. polyanthemum sobre o carrapato Rhipicephalus (Boophilus) microplus. Para essas espécies, é descrita a presença de benzopiranos, derivados de floroglucinol e flavonóides. Objetivos: Isolar compostos fenólicos lipofílicos de H. polyanthemum e o flavonóide hiperosídeo de H. caprifoliatum, assim como avaliar atividades biológicas de algumas dessas substâncias. Materiais e Métodos: Realizou-se a análise química através de técnicas cromatográficas (CC, CCD) e espectroscópicas (1H e 13C RMN). Hiperosídeo foi avaliado nos seguintes modelos comportamentais: potenciação do sono barbitúrico, atividade locomotora espontânea, placa quente, contorções induzidas por ácido acético e natação forçada. O efeito antinociceptivo de isobutiril-5,7-dimetóxi-2,2-dimetilbenzopirano (HP1), 7-hidróxi-6-isobutiril-5-metóxi-2,2-dimetil-benzopirano (HP2) e 5-hidróxi-6-isobutiril-7-metóxi-2,2-dimetil-benzopirano (HP3), foi investigado, assim como sua atividade acaricida através do teste de imersão de larvas. Resultados e Conclusões: Além dos benzopiranos HP1, HP2 e HP3, dois compostos não relatados para a espécie H. polyanthemum, a xantona 6- desoxijacareubina e um benzopirano de estrutura similar ao ácido eriostemóico, foram isolados de extrato obtido por fluido supercrítico. Hiperosídeo mostrou efeito depressor sobre o SNC, e efeito antiimobilidade, que parece ser mediado pelo sistema dopaminérgico, em ratos. HP1 apresentou efeito antinociceptivo mediado pela neurotransmissão opióide. Nos experimentos para investigação da atividade acaricida, os benzopiranos mostraram ser, pelo menos em parte, responsáveis pela toxicidade dos extratos sobre os ácaros. / The pharmacological effects of some Hypericum species are worldwide recognized, mostly by the comproved efficacy of H. perforatum as antidepressant. The south Brazilian species have been showing promissing results. Hypericum polyanthemum and H. caprifoliatum presented antinociceptive effect, while an antidepressant-like activity of H. caprifoliatum was reported. In addition, extracts from H. polyanthemum showed to be highly toxic to Rhipicephalus (Boophilus) microplus cattle tick. The chemical characterization reveals that these species are rich in benzopyrans, flavonoids and phloroglucinol derivatives. Objectives: To isolate lipophilic compounds from H. polyanthemum and the flavonoid hyperoside from H. caprifoliatum, as well as to carry out a biological evaluation of some of the isolated substances. Material and Methods: Chromatography and NMR spectroscopy techniques were performed for isolation and structure elucidation. Hyperoside was applied on behavior models, as the open field, pentobarbital sleeping potentiation, hot plate, acetic acid-induced writhing and the forced swimming test. The antinociceptive effect and the acaricide potential of 6-isobutyryl-5,7-dimethoxy- 2,2-dimethyl-benzopyran (HP1), 7-hydroxy-6-isobutyryl-5-methoxy-2,2-dimethylbenzopyran (HP2) and 5-hydroxy-6-isobutyryl-7-methoxy-2,2-dimethylbenzopyran (HP3) were also investigated. Results and conclusions: A benzopyran similar to the eriostemoic acid and the xanthone 6-deoxyjacareubin were isolated from the extract obtained by supercritical fluid. Hyperoside showed a central depressor effect and no toxicity signs. The present study provides evidences for the involvement of D2-like dopaminergic neurotransmission on the mechanism of hyperoside antidepressant-like action in rats. HP1 presented opioid-mediated antinociceptive effect. On larvae immersion test, the benzopyrans showed to account for the acaricide properties of H. polyanthemum extracts.

Espécies de Hypericum (Guttiferae) são mundialmente reconhecidas por seus efeitos farmacológicos, destacando-se H. perforatum pela atividade antidepressiva. O estudo com espécies brasileiras vem apresentando resultados promissores. Hypericum polyanthemum e H. caprifoliatum mostraram efeito antinociceptivo, enquanto H. caprifoliatum mostrou atividade do tipo antidepressiva. Além disso, verificou-se atividade de H. polyanthemum sobre o carrapato Rhipicephalus (Boophilus) microplus. Para essas espécies, é descrita a presença de benzopiranos, derivados de floroglucinol e flavonóides. Objetivos: Isolar compostos fenólicos lipofílicos de H. polyanthemum e o flavonóide hiperosídeo de H. caprifoliatum, assim como avaliar atividades biológicas de algumas dessas substâncias. Materiais e Métodos: Realizou-se a análise química através de técnicas cromatográficas (CC, CCD) e espectroscópicas (1H e 13C RMN). Hiperosídeo foi avaliado nos seguintes modelos comportamentais: potenciação do sono barbitúrico, atividade locomotora espontânea, placa quente, contorções induzidas por ácido acético e natação forçada. O efeito antinociceptivo de isobutiril-5,7-dimetóxi-2,2-dimetilbenzopirano (HP1), 7-hidróxi-6-isobutiril-5-metóxi-2,2-dimetil-benzopirano (HP2) e 5-hidróxi-6-isobutiril-7-metóxi-2,2-dimetil-benzopirano (HP3), foi investigado, assim como sua atividade acaricida através do teste de imersão de larvas. Resultados e Conclusões: Além dos benzopiranos HP1, HP2 e HP3, dois compostos não relatados para a espécie H. polyanthemum, a xantona 6- desoxijacareubina e um benzopirano de estrutura similar ao ácido eriostemóico, foram isolados de extrato obtido por fluido supercrítico. Hiperosídeo mostrou efeito depressor sobre o SNC, e efeito antiimobilidade, que parece ser mediado pelo sistema dopaminérgico, em ratos. HP1 apresentou efeito antinociceptivo mediado pela neurotransmissão opióide. Nos experimentos para investigação da atividade acaricida, os benzopiranos mostraram ser, pelo menos em parte, responsáveis pela toxicidade dos extratos sobre os ácaros. / The pharmacological effects of some Hypericum species are worldwide recognized, mostly by the comproved efficacy of H. perforatum as antidepressant. The south Brazilian species have been showing promissing results. Hypericum polyanthemum and H. caprifoliatum presented antinociceptive effect, while an antidepressant-like activity of H. caprifoliatum was reported. In addition, extracts from H. polyanthemum showed to be highly toxic to Rhipicephalus (Boophilus) microplus cattle tick. The chemical characterization reveals that these species are rich in benzopyrans, flavonoids and phloroglucinol derivatives. Objectives: To isolate lipophilic compounds from H. polyanthemum and the flavonoid hyperoside from H. caprifoliatum, as well as to carry out a biological evaluation of some of the isolated substances. Material and Methods: Chromatography and NMR spectroscopy techniques were performed for isolation and structure elucidation. Hyperoside was applied on behavior models, as the open field, pentobarbital sleeping potentiation, hot plate, acetic acid-induced writhing and the forced swimming test. The antinociceptive effect and the acaricide potential of 6-isobutyryl-5,7-dimethoxy- 2,2-dimethyl-benzopyran (HP1), 7-hydroxy-6-isobutyryl-5-methoxy-2,2-dimethylbenzopyran (HP2) and 5-hydroxy-6-isobutyryl-7-methoxy-2,2-dimethylbenzopyran (HP3) were also investigated. Results and conclusions: A benzopyran similar to the eriostemoic acid and the xanthone 6-deoxyjacareubin were isolated from the extract obtained by supercritical fluid. Hyperoside showed a central depressor effect and no toxicity signs. The present study provides evidences for the involvement of D2-like dopaminergic neurotransmission on the mechanism of hyperoside antidepressant-like action in rats. HP1 presented opioid-mediated antinociceptive effect. On larvae immersion test, the benzopyrans showed to account for the acaricide properties of H. polyanthemum extracts.

The research presented in this study combines natural product chemistry with organic / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2010.

El objetivo de esta investigación fue comprobar el efecto antidepresivo del extracto hidroalcohólico de las hojas de Hypericum laricifolium (Chinchango) enratones albinos. Se empleó el modelo de natación forzada modificada (FST) donde se sometió a todos los animales a una sesión de habituación que consistió en sumergirlos en una piscina cilíndrica durante 15 minutos; posteriormente fueron tratados cada 12 horas de la siguiente manera: Grupo 1(n=13) vehículo 5 ml/Kg, Grupo 2 (n=13) Diazepan 10mg/Kg, Grupo 3 (n=13) Hypericum l (n=13) 1% 100mg/Kg y Grupo 4 (n=13) Hypericum l 10% 1000mg /Kg .Veinticuatro horas después se realizo la sesión de evaluación sometiéndolos a la experiencia anterior, durante 5 minutos. Se registró el tiempo de inmovilidad, swimming (natación) y climbing (escalado) para cada animal. Para la prueba de suspensión de la cola (TST) los animales fueron tratados cada 12 hrs de la siguiente manera Grupo 1(n=11) vehículo 5 ml/Kg Grupo 2 (n=11) Fluoxetina 10mg/Kg Grupo 3 (n=11) Hypericum l (n=11) 1% 100mg/Kg Grupo 4 Hypericum l 10% 1000mg /Kg. Veinticuatro horas más tarde los ratones fueron suspendidos individualmente por el tercio distal de la cola (prueba de suspensión de la cola) registrándose el tiempo de inmovilidad durante 6 minutos. En el modelo de FST los grupos Hypericum 1 % y 10% mostraron una reducción en el tiempo de inmovilidad en relación al grupo control 170 y 167 seg vs 231 seg respectivamente; el tiempo de swimiming para el grupo Hypericum al 10% en relación al grupo control fue 112 vs 48 seg respectivamente; no observándose modificaciones en el tiempo de climbing. En la prueba de TST los animales con Hypericum l al 10% y fluoxetina mostraron una significativa reducción del tiempo de inmovilidad en relación al grupo control 65 y 42 seg vs 108 segundos. En conclusión el extracto hidroalcoholico de las hojas de Hypericum laricifolium presentó efecto antidepresivo en ratones observándose un mayor efecto a la concentración del 10%. / The objective of this research was to test the antidepressant effect of hydroalcoholic extract of the leaves of Hypericum laricifolium (Chinchango) in albino mice. In modified forced swimming test (FST) all animals were immerse in a cylindrical pool for 15 minutes (habituation session), then they were treated every 12 hours as follows: Group 1 (n = 13) Vehicle 5 ml / kg, Group 2 (n = 13) diazepam 10mg/kg, Group 3 (n = 13) Hypericum l (n = 13) 1% 100 mg / kg and Group 4 (n = 13) Hypericum l 10% 1000 mg / kg and four hours after the session was equal to the last experience, for 5 minutes. We recorded the time of immobility, swimming and climbing for each animal. In the tail suspension test (TST) the animals were treated every 12 hours as Group 1 (n = 11) Vehicle 5 ml / kg, Group 2 (n = 11) Fluoxetine 10mg/kg Group 3 (n = 11) Hypericum l (n = 11) 1% 100mg/kg Hypericum l Group 4 10% 1000 mg / kg. Twenty-four hours later the mice were individually suspended by the distal third of the tail (test suspension of the tail) the immobility time was recorded for 6 minutes. In the FST (Forced Swimming Test) Hypericum l groups 1% and 10% showed a reduction in the immobility time in relation to the control group 170, 167 vs 231 seconds respectively; swimiming time for the Hypericum l group and 10% compared to the control group was 112 vs 48 seconds respectively, no significant changes in the time of climbing. TST in animals with Hypericum l to 10% and fluoxetine showed a significant reduction of immobility time in relation to the control group 65, 42 vs 108 seconds. In conclusion, the hydroalcoholic extract of the leaves of Hypericum laricifolium have antidepressant effect in mice with a greater effect on the concentration of 10%.

Production of hypericine in explantate cultures of Hypericum perforatum Pavel Sazama Diploma thesis Charles university in Prague, Faculty of Pharmacy in Hradec Králové, Pharmacy Key words: St. John's Wort, precursors, hypericine, flavonoids, acetate, cinnamic acid, cinnamate, tyrosine, shikimic acid The goal of this work was to affect the production of hypericin (naphto-dianthrone), hyperoside and quercitrin (flavonoids) in the suspensional Hypericum perforatum explantate cell cultures. The method of precursor feeding was used. The precursors of naphtodianthrones and flavonoids were added into the medium in final concentrations 10 mg.l-1, 50 mg.l-1 and 100 mg.l-1. Samples were taken after 72 and 168 hours after adding the precursor. Potassium acetate, cinnamic acid, sodium cinnamate, tyrosine and shikimic acid were used as precursors. Cultures were cultivated on the Murashige and Skoog medium with the addition of the growth stimulator α-NAA. Concentration of hypericin, hyperosid and quercitrin was measured by HPLC analysis. The highest influence on the production of hypericin in cultures was detected after adding of tyrosine. The concetration of hypericin in cells raised in this experiment from 0,003% (control culture) to 0,03% (culture with tyrosine concen-tration of 100 mg.l-1). This...

Produtos naturais têm fornecido fármacos para uma grande variedade de doenças, como as parasitoses, que afetam aproximadamente 1 bilhão de pessoas. Os compostos fenólicos como a curcumina, as cumarinas e os benzopiranos, têm atraído considerável interesse visto que são reconhecidos pela ampla gama de atividades biológicas. Neste trabalho, foi realizada a hibridização molecular entre a curcumina e cumarina através da reação de Pechmann, que mostrou melhores resultados em aquecimento convencional que micro-ondas (90% de rendimento, 75 °C). O híbrido obtido, LASOM 135, apresentou forte atividade antioxidante frente a radicais peroxila (IC50 < 0,5 μM), mostrando que as duas porções farmacofóricas contribuíram para esta atividade biológica. Além disto, LASOM 135 apresentou atividade tripanomicida (IC50 = 11,8 μM). Os benzopiranos benzopyrans HP1 (6-isobutiril-5,7-dimetoxi-2,2-dimetil-benzopirano), HP2 (7-hidroxi-6-isobutiril-5-metoxi-2,2-dimetil-benzopirano) e HP3 (5-hidroxi-6-isobutiril-7-metoxi-2,2-dimetil-benzopirano), encontrados até o momento somente na planta nativa do Rio Grande do Sul Hypericum polyanthemum (Guttiferae), demonstram várias atividades biológicas, despertando considerável interesse no potencial terapêutico destas moléculas. Assim sendo, neste trabalho foi realizada a modificação estrutural de HP1, HP2 e HP3 através de aminação redutiva, se obtendo três derivados aminados inéditos com baixo a médio rendimento. Também se avaliou a atividade contra epimastigotas de Trypanosoma cruzi dos três benzopiranos, onde se elegeu HP2 como o protótipo para obtenção de novas moléculas tripanomicidas. Além disso, a atividade larvidicida em Aedes aegypti demonstro que os benzopiranos HP1, HP2 e HP3 são os responsáveis pela atividade larvicida do extrato n-hexano de H. polyanthemum. Tanto HP1 como o extrato demonstraram atividade reguladora do crescimento / Historically, natural products have been supplied drugs for a wide range of diseases, like the parasitic ones, which affect about 1 billion people. In this way, the phenolic compounds as curcumin, coumarins and benzopyrans, have attracted attention since they are recognized by their wide range of activities. In this study the molecular hybridization was performed between curcumin and coumarins through Pechmann reaction in conventional heating since it showed better results than the microwave one (90% yield, 75°C). The new hybrid, LASOM 135, presented strong antioxidant activity against peroxyl radicals (IC50 < 0.5 μM) indicating a synergism of the curcumin and coumarin pharmacophoric moieties. Besides, LASOM 135 presented trypanocide activity (IC50 = 11.8 μM). The benzopyrans HP1 (6-isobutyryl-5,7-dimethoxy-2,2-dimethyl-benzopyran), HP2 (7-hydroxy-6-isobutyryl-5-methoxy-2,2-dimethyl-benzopyran) and HP3 (5-hydroxy-6-isobutyryl-7-methoxy-2,2-dimethyl-benzopyran) are found until this moment only in the native plant to Rio Grande do Sul Hypericum polyanthemum (Guttiferae), and showed many biologic activities. Thus, in this study are described the achievement of three amino derivatives by structural modification of these molecules through reductive amination with a low to medium yield. The activity against epimastigotes of Trypanosoma cruzi was also evaluated by HP1, HP2 and HP3 and HP2 was elected as a hit to new trypanocide compounds. Besides, the larvicidal activity in Aedes aegypti was evaluated for the three benzopyrans. The benzopyrans demonstrated to be the responsible for the larvicidal activity of the extract. Both the HP1 as the extract demonstrated growth regulatory activity.

Due to the essential demands for novel anti-tuberculosis treatments for global tuberculosis control, this research investigated the antimycobacterial activity of Hypericum perforatum herb (commonly known as St. John’s wort, SJW), including a SJW methanol extract, purified major bioactive constituents of SJW: hypericin (Hpn), pseudohypericin (Phn) and hyperforin (Hfn). The SJW acidified methanol extract showed bactericidal activity against Mycobacterium JLS at 0.05 mg/ml culture. Purified compounds were tested at similar concentrations contained in the SJW methanol extract treatment. Among three purified bioactive compounds, only Hfn was bactericidal at 12 μg/ml. The other two compounds Phn and Hpn were not inhibitory or bactericidal at concentrations corresponding to the SJW methanol extract treatments. The Polysorbate surfactant Tween 80, which is commonly added to the mycobacterial cultures to prevent cell clumping, was found to have inhibitory effects on the antimycobacterial activities of SJW extract and hyperforin. The addition of Tween 80 (0.05% v/v) increased the minimum bactericidal concentration (MIC) of SJW methanol extract from 0.05 to 0.33mg /ml and from 12 to 80 μg/ml for Hfn. This inhibitory effect of Tween 80 on SJW is opposite to the effect of Tween 80 on the antimycobacterial activity of rifampin and isoniazid. These observations are also in conflict with the existing permeability barrier hypothesis. A hypothesis that hyperforin molecules were sequestered in the core of Tween 80 micelles was given out to explain the repression effect of Tween 80 on hyperforin activity. The effectiveness of Tween 60, Tween 40 and Tween 20 on SJW activity was also tested. Tween 60 and Tween 40 showed the similar dose-dependent inhibitory effect on SJW extract activity with Tween 80, while the inhibitory effect of Tween 20 is much weaker. A preliminary test was performed to detect the activity of SJW acidified MeOH extract and hyperforin on M. tuberculosis H37Rv strain. Results showed the MIC was 0.67mg SJW extract/ml and 200 μg Hfn /ml. In all, M. tuberculosis H37Rv stain is not that sensitive to SJW and hyperforin as other non-pathogenic strains tested in the present and previous studies.