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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
51

Genetic variation in Hypericum perforatum L. and resistance to the biological control agent Aculus hyperici liro / Gwenda Mary Mayo.

Mayo, Gwenda Mary January 2004 (has links)
"October 2004" / Includes bibliographical references (leaves 223-243) / xvi, 243 leaves : ill. (col.), maps, plates ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, School of Agriculture and Wine, Discipline of Plant and Pest Science, 2004
52

An investigation into the economic potential of hypericum production in Northern Natal.

De Jager, Ian. January 2003 (has links)
Hypericum is a most useful and versatile cut flower which within the last ten years has gained significant economic importance, recently having been included in the top fifty cut flowers on the Dutch Auctions. This study has investigated the cultural requirements of the crop, focusing on the following; propagation, insect and disease control, fertilisation, crop manipulation, marketing of the finished product, business theory and the interpretation of business theory. Propagation and multiplication techniques were investigated in order to reduce the reliance of external seedling growers and in so doing reducing the start up costs ofthe project. Insect and disease control were investigated as the import requirements for many countries are stringent. Contamination of the finished product results in the cargo being rejected at the port of entry. Insect and disease infestation reduce the quality and subsequently the return that is generated from the project. Fertilisation plays an important role in producing high quality sterns. Failure to fertilise the crop at the correct stage results in quality degradation, or additional expenditure on labour to groom the plants. Crop manipulation was investigated for the purpose of supplying crop into the market place on a sustained basis, ensuring optimal utilisation of resources whilst building customer loyalty. Product marketing plays an integral role in determining the success of a venture. Markets were evaluated in order to determine which markets would yield the greatest return on investment. Chapter three deals with various business theories that may be applied to the data and observations. Chapter four integrates business theory with the data and observations in an attempt to gain a meaningful picture of the economic potential of this proposed venture. The last chapter deals with a proposed strategy that the company should follow, having evaluated and integrated the business theory, data and observations. / Thesis (MBA)-University of Natal, Durban, 2003.
53

Chemical quality in two medicinal plants : St. John's wort and purple coneflower /

Gray, Dean E. January 2000 (has links)
Thesis (Ph. D.)--University of Missouri-Columbia, 2000. / Typescript. Vita. Includes bibliographical references (leaves 230-254). Also available on the Internet.
54

Chemical quality in two medicinal plants St. John's wort and purple coneflower /

Gray, Dean E. January 2000 (has links)
Thesis (Ph. D.)--University of Missouri-Columbia, 2000. / Typescript. Vita. Includes bibliographical references (leaves 230-254). Also available on the Internet.
55

Avaliação in vitro da atividade antiproliferativa de compostos isolados de espécies de Hypericum nativas do sul do Brasil

Pinhatti, Amanda Valle January 2013 (has links)
Devido ao grande avanço na descoberta de novos fármacos a partir de compostos naturais, tornou-se interessante avaliar o potencial antiproliferativo de moléculas isoladas de extratos de plantas. Este trabalho prioriza o estudo da atividade antitumoral de benzofenonas (carifenona A e carifenona B) e floroglucionóis (japonicina A e uliginosina B), isolados das espécies nativas do sul do Brasil, Hypericum carinatum e Hypericum myrianthum, respectivamente, bem como a associação destes com quimioterápicos utilizados na clínica. Os experimentos propostos foram realizados em modelos in vitro, utilizando diferentes tipos de linhagens tumorais humanas comercialmente disponíveis. Foi avaliado o efeito de diferentes doses destes compostos através de experimentos de viabilidade e sobrevivência celular, análise morfométrica nuclear (NMA) e citometria de fluxo. Na análise estatística foi utilizada a variância de uma via (ANOVA) seguida de teste post-hoc (Tukey). Os resultados foram expressos como média ± erro padrão da média (SEM), sendo valores de P menores do que 0,05 considerados significativos. Verificamos que nas linhagens de adenocarcinoma de ovário e colorretal e de glioblastoma (OVCAR-3, HT-29 e U-251) ocorreu uma diminuição significativa na viabilidade celular quando tratadas com a dose de 100μg/mL tanto de carifenona A como de carifenona B, enquanto os compostos japonicina A (50μg/mL) e uliginosina B (20μg/mL) só foram ativos na linhagem OVCAR-3. Dentre as associações com quimioterápicos, a única que apresentou efeito sinérgico foi a combinação de japonicina A e paclitaxel na linhagem OVCAR-3. A partir deste momento selecionamos a japoncina A para dar continuidade aos estudos. Este composto foi avaliado frente a outros tipos de linhagens tumorais, sendo ativa somente em células de adenocarcinoma de ovário e próstata (OVCAR-3 e PC-3). Na linhagem PC-3, a análise do ciclo celular demonstrou decréscimo da fase G1 e indução ao arraste da fase G2, assim como, através da técnica de NMA, foi verificado um aumento de células apoptóticas, quando as células foram tratadas com japonicina A. Estudos moleculares devem ser realizados para melhor entendimento do mecanismo de ação da japonicina A, composto que pode servir de modelo para o desenho de fármacos mais específicos para este tipo de neoplasia. / Due to the great progress in the discovery of new drugs from natural compounds, it has become interesting to evaluate the antiproliferative activity of molecules isolated from plant extracts. This work emphasizes the study of antitumor activity of benzophenones (cariphenone A and cariphenone B) and phloroglucionols (japonicin A and uliginosin B), isolated from Hypericum species native to southern Brazil, H. carinatum and H. myrianthum, respectively, as well as their association with chemotherapeutic drugs used in the clinic. The proposed experiments were performed in vitro using commercially available cell lines. The effect of different doses of these compounds were evaluated via cell viability and survival assay, nuclear morphometric analysis (NMA) and flow cytometry. One way analysis of variance (ANOVA) followed by post hoc tests (Tukey) were utilized for statistical analysis. Results were expressed as mean ± standard error of the mean (SEM), and P values less than 0.05 were considered significant. We found that in ovarian, colorectal (adenocarcinoma) and glioblastoma cell lines (OVCAR-3, HT-29 and U-251) a significant decrease in cell viability occurred when these were treated with a dose of 100μg/mL of cariphenone A and B, while compounds japonicin A (50μg/mL) and uliginosin B (20μg/mL) were active only in OVCAR- 3. Among the associations with chemotherapeutic agents, only japonicin A presented a synergistic effect with paclitaxel in the OVCAR-3 cell line. We then selected japonicin A for evaluation against other cell lines, but its effects were only observed in ovary and prostate adenocarcinoma cell lines (OVCAR-3 e PC-3). In PC-3, the cell cycle revealed a decreased in the G1 phase and induction of G2 arrest, the NMA showed an increase in apoptotic cells when cells were treated with japonicin A. More studies should be conducted to better understand the mechanisms of action of japonicin A, since this compound may serve as pharmacophore model for the design of more specific drugs to treat this tumor type.
56

Avaliação in vitro da atividade antiproliferativa de compostos isolados de espécies de Hypericum nativas do sul do Brasil

Pinhatti, Amanda Valle January 2013 (has links)
Devido ao grande avanço na descoberta de novos fármacos a partir de compostos naturais, tornou-se interessante avaliar o potencial antiproliferativo de moléculas isoladas de extratos de plantas. Este trabalho prioriza o estudo da atividade antitumoral de benzofenonas (carifenona A e carifenona B) e floroglucionóis (japonicina A e uliginosina B), isolados das espécies nativas do sul do Brasil, Hypericum carinatum e Hypericum myrianthum, respectivamente, bem como a associação destes com quimioterápicos utilizados na clínica. Os experimentos propostos foram realizados em modelos in vitro, utilizando diferentes tipos de linhagens tumorais humanas comercialmente disponíveis. Foi avaliado o efeito de diferentes doses destes compostos através de experimentos de viabilidade e sobrevivência celular, análise morfométrica nuclear (NMA) e citometria de fluxo. Na análise estatística foi utilizada a variância de uma via (ANOVA) seguida de teste post-hoc (Tukey). Os resultados foram expressos como média ± erro padrão da média (SEM), sendo valores de P menores do que 0,05 considerados significativos. Verificamos que nas linhagens de adenocarcinoma de ovário e colorretal e de glioblastoma (OVCAR-3, HT-29 e U-251) ocorreu uma diminuição significativa na viabilidade celular quando tratadas com a dose de 100μg/mL tanto de carifenona A como de carifenona B, enquanto os compostos japonicina A (50μg/mL) e uliginosina B (20μg/mL) só foram ativos na linhagem OVCAR-3. Dentre as associações com quimioterápicos, a única que apresentou efeito sinérgico foi a combinação de japonicina A e paclitaxel na linhagem OVCAR-3. A partir deste momento selecionamos a japoncina A para dar continuidade aos estudos. Este composto foi avaliado frente a outros tipos de linhagens tumorais, sendo ativa somente em células de adenocarcinoma de ovário e próstata (OVCAR-3 e PC-3). Na linhagem PC-3, a análise do ciclo celular demonstrou decréscimo da fase G1 e indução ao arraste da fase G2, assim como, através da técnica de NMA, foi verificado um aumento de células apoptóticas, quando as células foram tratadas com japonicina A. Estudos moleculares devem ser realizados para melhor entendimento do mecanismo de ação da japonicina A, composto que pode servir de modelo para o desenho de fármacos mais específicos para este tipo de neoplasia. / Due to the great progress in the discovery of new drugs from natural compounds, it has become interesting to evaluate the antiproliferative activity of molecules isolated from plant extracts. This work emphasizes the study of antitumor activity of benzophenones (cariphenone A and cariphenone B) and phloroglucionols (japonicin A and uliginosin B), isolated from Hypericum species native to southern Brazil, H. carinatum and H. myrianthum, respectively, as well as their association with chemotherapeutic drugs used in the clinic. The proposed experiments were performed in vitro using commercially available cell lines. The effect of different doses of these compounds were evaluated via cell viability and survival assay, nuclear morphometric analysis (NMA) and flow cytometry. One way analysis of variance (ANOVA) followed by post hoc tests (Tukey) were utilized for statistical analysis. Results were expressed as mean ± standard error of the mean (SEM), and P values less than 0.05 were considered significant. We found that in ovarian, colorectal (adenocarcinoma) and glioblastoma cell lines (OVCAR-3, HT-29 and U-251) a significant decrease in cell viability occurred when these were treated with a dose of 100μg/mL of cariphenone A and B, while compounds japonicin A (50μg/mL) and uliginosin B (20μg/mL) were active only in OVCAR- 3. Among the associations with chemotherapeutic agents, only japonicin A presented a synergistic effect with paclitaxel in the OVCAR-3 cell line. We then selected japonicin A for evaluation against other cell lines, but its effects were only observed in ovary and prostate adenocarcinoma cell lines (OVCAR-3 e PC-3). In PC-3, the cell cycle revealed a decreased in the G1 phase and induction of G2 arrest, the NMA showed an increase in apoptotic cells when cells were treated with japonicin A. More studies should be conducted to better understand the mechanisms of action of japonicin A, since this compound may serve as pharmacophore model for the design of more specific drugs to treat this tumor type.
57

Vliv abiotických elicitorů na obsah sekundárních metabolitů v in vitro kulturách rostlin - I. / The effect of abiotic elicitors on secondary metabolites content in plant cultures in vitro - I.

Teplá, Klára January 2021 (has links)
Plants are a source of a wide range of secondary substances, which due to their effects find use in many areas of focus. By a method called elicitation, we can achieve their higher and thus more efficient production. This diploma thesis aimed to determine whether the abiotic elicitor 2-(4-chlorophenyl)-N-(5-chloropyridin-2-yl)acetamide can positively affect the production of the flavonoid hyperoside in callus and suspension culture of Hypericum perforatum L. The elicitor was added to the in vitro cultures in three concentrations: C1 = 3,571.10-3 mol/l; C2 = 3,571.10-4 mol/l and C3 = 3,571.10-5 mol/l. A sample was taken at regular intervals after 6, 24, 48, 72 and 168 hours of elicitor treatment. Control samples were taken after 24 and 168 hours. The content of hyperoside produced was subsequently determined using High Performance Liquid Chromatography. Simultaneously, the amount of hyperoside released into the nutrient media of both plant cultures was also monitored. Maximum hyperoside production was recorded in suspension culture after 6 (17,7 µg/g DW) and 48 hours (3,69 µg/g DW) of elicitor treatment with the lowest concentration of C3 (3,571.10-5 mol/l). The content of hyperoside in the first case was 1770 % higher compared to the control sample. There was a significant release of hyperoside...
58

Estudo do mecanismo de ação antinociceptiva da uliginosina B / Study of the antinociceptive mechanism of action of uliginosin B

Stolz, Eveline Dischkaln January 2014 (has links)
Uliginosina B é um derivado acilfloroglucinol natural, isolado de espécies de Hypericum nativas da América do Sul. Estudos prévios demonstraram que a uliginosina B apresenta efeitos do tipo antidepressivo e antinociceptivo em baixas doses (até 15 mg/kg, i.p. ou v.o.) e, em doses elevadas (90 mg/kg, i.p.), prejudica a coordenação motora. A atividade antidepressiva depende da ativação da neurotransmissão monoaminérgica e envolve a regulação da homeostase através do balanço de Na+. A atividade antinociceptiva é mediada por receptores opioides e dopaminérgicos da família D2. O efeito atáxico depende da ativação de receptores opioides e dopaminérgicos. Os efeitos parecem ser decorrentes da sua capacidade de inibir a recaptação de monoaminas (especialmente dopamina) com consequente ativação de receptores opioides e monoaminérgicos. O objetivo deste estudo foi aprofundar o conhecimento sobre o mecanismo de ação antinociceptiva de uliginosina B, investigando o envolvimento da neurotransmissão monoaminérgica, glutamatérgica e purinérgica. O tratamento com uliginosina B aumentou a disponibilidade intersticial de dopamina e seu metabólito, ácido homovanílico (HVA), no estriado de ratos; dados que reforçam o papel da neurotransmissão dopaminérgica nos efeitos da uliginosina B. O papel das outras monoaminas e da neurotransmissão glutamatérgica foi investigado nos efeitos antinociceptivo e atáxico induzidos por uliginosina B. A ataxia (90 mg/kg, i.p.) foi completamente prevenida pelo tratamento prévio com pCPA (inibidor da síntese de serotonina) e MK-801 (antagonista do receptor glutamatérgico NMDA), mas não foi afetada pelo prétratamento com prazosina ou ioimbina (antagonistas de receptores adrenérgicos α1 e α2, respectivamente). A atividade antinociceptiva (15 e 90 mg/kg, i.p.) foi reduzida significativamente pelo pré-tratamento com pCPA e MK-801 e aumentada pelo prétratamento com prazosina e ioimbina, apenas na dose mais elevada (90 mg/kg, i.p.). A importância da neurotransmissão monoaminérgica para o efeito antinociceptivo da uliginosina B foi confirmada através da análise isobolar. A associação de uliginosina B com amitriptilina (inibidor da recaptação de monoaminas) ou clonidina (agonista adrenérgico α2) apresentou interação aditiva – dados sugestivos de substâncias com mecanismos de ação mediados pelas mesmas vias – enquanto a associação com morfina (agonista opioide) apresentou interação sinérgica – dados indicativos de um possível uso clínico, como adjuvante opioide na farmacoterapia da dor. O efeito antinociceptivo de uliginosina B (15 mg/kg, i.p.) também foi prevenido pelo tratamento prévio com DPCPX e ZM-241385 (antagonistas de receptores adenosinérgicos A1 e A2A, respectivamente). Este efeito esta relacionado, pelo menos em parte, com a capacidade da uliginosina B aumentar a hidrólise de AMP na medula espinhal e de ATP no córtex cerebral. A uliginosina B também inibiu in vitro a atividade da enzima Na+,K+-ATPase (isoformas α1 e α3). O conjunto de dados apresentados nesta tese evidencia a uliginosina B como um padrão estrutural multirreceptor promissor no desenvolvimento de fármacos com ação analgésica. Em suma, os efeitos antinociceptivo e atáxico induzidos pelo tratamento com uliginosina B são mediados pela ativação da neurotransmissão monoaminérgica, glutamatérgica, purinérgica e opióide, requisitadas com diferente grau de importância; e ainda envolvem o balaço iônico da Na+,K+-ATPase. / Uliginosin B is a natural acylphloroglucinol derivative obtained from Hypericum species native to South America. Previous studies have shown that uliginosin B presents antidepressant-like and antinociceptive effects at low doses (up to 15 mg/kg, i.p. or p.o.), and at high doses (90 mg/kg, i.p.) it impairs the motor coordination. The antidepressant-like activity seems to depend on the activation of monoaminergic neurotransmission and ionic balance of Na+. The antinociceptive effect is mediated by opioid and D2 dopamine receptors. The ataxic effect involves opioid and dopaminergic receptors activation. The uliginosin B effects appear to be a consequence of their ability to inhibit reuptake of monoamines (especially dopamine) with subsequent activation of opioid and monoaminergic receptors. The aim of this study was to deepen our knowledge about the mechanism of antinociceptive action of uliginosin B, investigating the involvement of monoaminergic, glutamatergic and purinergic neurotransmissions. Treatment with uliginosin B increased the interstitial availability of dopamine and its metabolite, homovanillic acid (HVA), in the striatum of rats; these data underscore the role of dopaminergic neurotransmission in the effects of uliginosin B. The role of other monoamines as well as the glutamatergic neurotransmission, were investigated in the antinociceptive and ataxic effects induced by uliginosin B. The ataxic effect (90 mg/kg, i.p.) was completely prevented by pre-treatment with pCPA (a serotonin synthesis inhibitor) and MK-801 (a NMDA glutamatergic receptor antagonist), but was not affected by pretreatment with prazosin or yohimbine (α1 and α2 adrenoceptor antagonists, respectively). The antinociceptive activity (15 and 90 mg/kg, i.p.) was significantly reduced by pretreatment with pCPA and MK-801 and increased by pretreatment with yohimbine and prazosin only at the highest dose (90 mg/kg, i.p.). The importance of monoaminergic neurotransmission for the uliginosin B antinociceptive effect was confirmed by isobolar analysis. The association between uliginosin B with amitriptyline (monoamine reuptake inhibitor) or clonidine (α2 adrenergic agonist) showed additive interaction - findings suggestive of substances with mechanisms of action mediated by the same pathways - while the association with morphine (opioid agonist) showed synergistic interaction - indicative of a possible clinical use as adjuvant to opioid pharmacotherapy of pain relief. The antinociceptive effect of uliginosin B (15 mg/kg, i.p.) was also prevented by pretreatment with DPCPX and ZM-241385 (A1 and A2A adenosinergic receptor antagonists, respectively). This effect is related, at least in part, to its ability of increases the AMP and ATP hydrolysis in the spinal cord and cerebral cortex synaptosomes, respectively. Moreover, uliginosin B inhibited the Na+,K+-ATPase activity (α1 and α3 isoforms) in vitro. The data set presented in this thesis pointed uliginosin B as a promising multirreceptor molecular pattern in the analgesic drug development. In summary, the antinociceptive and ataxic effects induced by uliginosin B were mediated by the activation of monoaminergic, glutamatergic, purinérgico and opioid neurotransmission and involves the ionic balance, required with different degree of importance.
59

Isolation, chemical characterisation and biological activity ofacylphloroglucinols from petroleum ether extract of Hypericum barbatumJacq. 1775 / Izolacija, hemijska karakterizacija i biološka aktivnost acilfloroglucinola izpetroletarskog ekstrakta Hypericum barbatum Jacq. 1775

Šibul Filip 19 February 2018 (has links)
<p>Within this doctoral thesis, eighteen new compounds, polycyclic polyprenylated<br />acylphloroglucinols, were isolated from petrol ether extract of <em>Hypericum barbatum</em><br />plant. The compounds are named hyperibarbins A&ndash;R. For hyperibarbins A&ndash;D,<br />cytotoxicity towards carcinogenic cells and antibacterial activity were evaluated. All<br />four compounds exhibited intermediate activity towards tumor cells in vitro. Although<br />inactive towards Gram negative bacteria, examined compounds have expressed<br />extraordinary bacteriostatic activity towards Gram positive bacterial strains.<br />Hyperibarbins C, E, N and K were, since having endoperoxide bridge in their structures,<br />tested for antiprotozoal activity, but shown intermediate activity towards the examined<br />parasite strains. All goals set for this doctoral thesis at the beginning have been fully<br />met, with isolation of new compounds, described andcompletely chemically<br />characterized for the first time.</p> / <p>U okviru ove doktorske disertacije izolovano je osamnaest novih jedinjenja, policikličnih&nbsp; poliprenilovanih acilfloroglucinola, iz petroletarskog ekstrakta biljke <em>Hypericum&nbsp; barbatum</em>. Imena jedinjenja su hiperibarbini A&ndash;R. Za hiperibarbine A&ndash;D, ispitana je&nbsp; citotoksičnost prema kancerogenim ćelijama i antibakterijska aktivnost. Sva četiri&nbsp; jedinjenja su ispoljila srednju aktivnost prema tumorskim ćelijama <em>in vitro</em>.&nbsp; Iako neaktivni&nbsp; prema Gram negativnim bakterijama, ispitana jedinjenja su ispoljila izuzetnu bakteriostatsku aktivnost prema sojevima Gram pozitivnih bakterija. Hiperibarbini C, E, N i K su, zbog posedovanja endoperoksidnog prstena u svojoj strukturi, testirana na antiprotozoalnu aktivnost, ali su pokazali srednju aktivnost prema ispitanim sojevima parazita. Svi ciljevi postavljeni na početku izrade ove doktorske disertacije su do kraja ispunjeni, sa izolacijom novih, prvi put opisanih i u potpunosti hemijski okarakterisanih jedinjenja.</p>
60

Επίδραση της πόσης αφεψημάτων των φυτών Rosmarinus sp. & Hypericum sp. στην από το μόλυβδο (Pb) επαγώμενη νευροτοξικότητα

Φερλέμη, Αναστασία - Βαρβάρα 27 October 2010 (has links)
Το περιβάλλον διαθέτει πλούτο παραγόντων, οι οποίοι επηρεάζουν με θετικό ή αρνητικό τρόπο την ανάπτυξη και τη λειτουργία των οργανισμών. Μεταξύ των μετάλλων, ο μόλυβδος (Pb) θεωρείται ο σημαντικότερος νευροτοξικός περιβαλλοντικός παράγοντας, με τις κυριότερες αρνητικές επιδράσεις του να αφορούν νεαρούς οργανισμούς ή οργανισμούς που βρίσκονται στα πρώτα στάδια ανάπτυξης. Το περιβάλλον, ωστόσο, διαθέτει και πολλούς παράγοντες οι οποίοι δύνανται να χρησιμοποιηθούν για τις ευεργετικές τους ιδιότητες. Τα τελευταία χρόνια το επιστημονικό ενδιαφέρον έχει στραφεί στην εξεύρεση φυτών και φυτικών συστατικών που θα μπορούσαν να δρουν ενάντια της νευροτοξικής δράσης των μετάλλων. Η ελληνική χλωρίδα είναι πλούσια σε κοινά και ενδημικά φυτά που διαθέτουν νευροπροστατευτικές ιδιότητες. Ο σκοπός της εργασίας ήταν η διερεύνηση της πιθανής συσσώρευσης του μολύβδου στον ολικό εγκέφαλο (-παρεγκεφαλίδα) ενήλικων μυών και της πιθανής επαγωγής νευροτοξικών δράσεων, εστιάζοντας στη διεργασία μνήμη/μάθηση και την ενεργότητα του ενζύμου ακετυλοχολινεστεράση, ύστερα από χορήγηση διαλύματος μολύβδου (500 ppm) για διάστημα 4 εβδομάδων. Επιπλέον, διερευνήθηκε η πολυφαινολική σύσταση και η πιθανή προστατευτική δράση ενάντια στο μέταλλο των αφεψημάτων δυο φυτών της ελληνικής χλωρίδας, του κοινού Rosmarinus officinalis (δενδρολίβανο) και του υπενδημικού Hypericum vesiculosum, ύστερα από χορήγηση των αφεψημάτων σε ενήλικους μύες, καθώς και μετά από συγχορήγησή τους με το μόλυβδο για χρονικό διάστημα 4 εβδομάδων. To Η. vesiculosum δεν έχει μελετηθεί ποτέ ξανά ως προς τη σύσταση και τις ιδιότητές του. Τα αποτελέσματά μας υποδεικνύουν ότι και τα δυο αφεψήματα έχουν πλούσιο πολυφαινολικό περιεχόμενο, και ιδιαιτέρως το H. vesiculosum που υπερισχύει του δενδρολίβανου. Επιπλέον, με τη χρήση δυο φασματομετρικών μεθόδων (Φασματομετρία Ατομικής Απορρόφησης/AAS, Φασματομετρία Μάζας με Πηγή Επαγωγικά Συζευγμένου Πλάσματος/ICP-MS) αποδείχτηκε ότι ο Pb συσσωρεύεται στον εγκέφαλο ενήλικων μυών και αυτή η συσσώρευση δεν επηρεάζεται σε σημαντικό βαθμό από την συγχορήγηση των δυο αφεψημάτων με το μέταλλο. Ακόμα, η μελέτη της μνήμης και της μάθησης με τη χρήση της δοκιμασίας της Παθητικής Αποφυγής και η μελέτη της ενεργότητας της AChE στον ολικό εγκέφαλο (-παρεγκεφαλίδα) και στην παρεγκεφαλίδα [SS (διαλυτό σε άλας) κλάσμα που περιέχει κυρίως την G1 ισομορφή της AChE και DS (διαλυτό σε απορρυπαντικό κλάσμα) που περιέχει κυρίως την G4 ισομορφή της AChE, η οποία είναι πολύ σημαντική για το νευρικό σύστημα] απέδειξε ότι (α) ο μόλυβδος ασκεί τις νευροτοξικές του επιδράσεις προκαλώντας γνωστικές βλάβες και δυσλειτουργία του χολινεργικού συστήματος. Η ελάττωση της ενεργότητας της AChE μπορεί να οφείλεται στην αποικοδόμηση των χολινεργικών νευρώνων του ιππόκαμπου και της παρεγκεφαλίδας. (β) Τα δυο αφεψήματα αναστέλλουν την AChE με το δενδρολίβανο να είναι πιο αποδοτικό ακολουθώντας ιστοειδική δράση. Η διαδικασία της μνήμης/μάθησης δε φάνηκε να επηρεάζεται από τα δυο αφεψήματα αν και το δενδρολίβανο έδειξε ένα θετικό αποτέλεσμα που δεν ήταν στατιστικά σημαντικό. (γ) Η συγχορήγηση καθενός από τα αφεψήματα με το διάλυμα του Pb προκάλεσε σημαντικές αλλαγές στην ενεργότητα της AChE (ειδικά στο DS κλάσμα) και το R. officinalis ήταν περισσότερο αποτελεσματικό από το H. vesiculosum. Ολοκληρώνοντας, η συγχορήγηση υποδεικνύει ότι και τα δυο αφεψήματα επηρέασαν με παρόμοιο θετικό τρόπο τη γνωστική λειτουργία σε σχέση με τη δυσλειτουργία που είχε προκαλέσει ο Pb. / There are many environmental factors that can affect positively or negatively both the development and the functions of organisms. Among heavy metals, lead (Pb) is considered to be the most neurotoxic environmental factor, which exerts its negative effects especially in young or developmental organisms. However, there are many environmentally-based factors that could be used for their beneficial properties. In recent years, scientists have turned their interest to the discovery of plants and phenols that could protect the neural system against the neurotoxic effects of heavy metals. Hellenic flora is very rich in common and endemic plants with possible neuroprotective properties. The aim of the present study was to investigate the possible accumulation of lead in adult mice brain and the induction of neurotoxic effects, with emphasis on learning/memory process and acetylcholinesterase (AChE) activity, after the consumption of a lead solution (500 ppm), for 4 weeks. Furthermore, we investigated the polyphenolic content and the possible neuroprotective effects of two beverages (2%w/v), one of the common Rosmarinus officinalis (rosemary) and one of the endemic Hypericum vesiculosum, against metal’s toxicity after consumption/coadministration of each beverage with the lead solution, for 4 weeks. H. vesiculosum has never been studied before for its phenolic content, nor for its biological actions. Our results showed that the two beverages are rich in polyphenols, with H. vesiculosum been richer than R. officinalis. Moreover, the use of two spectrometric methods (Atomic Absorption Spectrometry/AAS, Inductively Coupled Plasma-Mass Spectrometry/ICP-MS) indicated that lead accumulates in adult mice brain, which was not affected after its co-administration with each beverage. Furthermore, the study of cognitive function, as assessed by Passive Avoidance test and determination of AChE activity in whole mice brain and cerebellum, [SS (salt soluble) fraction which contains the G1 isoform of AChE; and DS (detergent soluble) fraction which contains the G4 isoform of AChE that is very important for the neural system], demonstrated that: (a) lead exerts its neurotoxic effects by causing learning and memory deficits and dysfunction of the cholinergic system. The decrease of AChE activity may be due to the degeneration of the cholinergic neurons in the hippocampus and cerebellum; (b) Both beverages inhibit AChE activity, with rosemary being more effective and tissue-specific, while no effect was observed on learning/memory, after consumption of the two beverages. Only rosemary showed a positive effect that wasn’t, however, statically important; (c) The co-administration of each beverage with the lead solution caused important changes in AChE activity (especially in the G4 isoform), and R. officinalis was more effective than H. vesiculosum. Both beverages showed similar protective effects against Pb-induced cognitive dysfunctions in mice.

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