Thèse de doctorat--Sciences naturelles--Faculté des sciences de Paris, 1910. N°: 1385. / Notes bibliogr.

No description available.

MOURA, Andrea Felinto. Bioprospecção de compostos isolados de Combretum fruticosum com potencial antiproliferativo em células tumorais in vitro. 2015. 93 f. Dissertação (Mestrado em Farmacologia) - Universidade Federal do Ceará. Faculdade de Medicina, Fortaleza, 2015. / Submitted by denise santos (denise.santos@ufc.br) on 2015-04-10T13:48:06Z No. of bitstreams: 1 2015_dis_afmoura.pdf: 6953565 bytes, checksum: 6f2070977fb0341e1279b7a9f7cdf7b1 (MD5) / Approved for entry into archive by denise santos(denise.santos@ufc.br) on 2015-04-10T13:49:27Z (GMT) No. of bitstreams: 1 2015_dis_afmoura.pdf: 6953565 bytes, checksum: 6f2070977fb0341e1279b7a9f7cdf7b1 (MD5) / Made available in DSpace on 2015-04-10T13:49:27Z (GMT). No. of bitstreams: 1 2015_dis_afmoura.pdf: 6953565 bytes, checksum: 6f2070977fb0341e1279b7a9f7cdf7b1 (MD5) Previous issue date: 2015 / The use of substances from natural products has grown over the years, being the basis of therapeutic products. Lignans are molecules with large pharmaceutical use, which has aroused interest in search of new drugs to treat diseases. Much interest has been focused on their effectiveness as an antineoplastic agent. Thus, the aim of this study was to evaluate the in vitro anticancer potencial of compounds isolated from ethanolic extract of Combretum fruticosum, as well as, to study the possible mechanisms of action of a dibenzylbutyrolactone type lignan, trachelogenin, in colorectal cancer cells. The fractionation of the ethanolic extract of C. fruticosum resulted in the isolation of seven compounds: three triterpenes, two mixtures of β-sitosterol and stigmasterol steroids and two lignans Among them, the lignan, trachelogenin showed higher cytotoxic activity, with IC50 values ranging from 0.8 to 32.4 µM in glioblastoma (SF-295) and leukemic (HL-60) cells, respectively. While in normal cells (3T3-L1 and PBMC cells) the IC50 values were greater than 64.3 µM. The antiproliferative profile of different times of incubation was performed in SF-295 and HCT-116 cells. The cytotoxic effect on SF-295 cells was only observed after 72 hours of incubation, whereas in HCT-116 cells, this effect was observed after 48 hours, and it was enhanced after 72 hours of incubation. Before these results, analyzing cell cycle profile, membrane integrity, phosphatidylserine externalization and expression of proteins related to cell death by apoptosis in HCT-116 cells, it was not observed significantly changed, suggesting that the antiproliferative effect of this lignan is not related to mechanisms of cell death such as apoptosis and/or necrosis. Autophagy seems to be one of the cell death mechanisms involved in the antiproliferative effect of trachelogenin, because we observed an increase on number and size of acidic vesicular organelles (AVO) as well as the expression of proteins recruited during autophagy (LC3 A and B-II and Beclin-1) in cells treated with trachelogenin, although this seems not to be the only process involved. Therefore, we conclude that trachelogenin showed potent antitumor activity in vitro, and this effect may be related to the induction of autophagy. However, further tests should be conducted to confirm these proposals and to evaluate its mechanism of action and the therapeutic potential of this molecule better. / A utilização de substâncias derivadas de produtos naturais tem crescido com o passar dos anos, formando a base dos produtos terapêuticos. As lignanas são moléculas com amplo uso farmacêutico, o que tem despertado interesse na pesquisa e busca de novos fármacos no tratamento de doenças. Muito interesse tem sido focado na sua eficácia como agente antineoplásico. Com isso, o objetivo desse trabalho foi avaliar o potencial anticâncer in vitro de compostos isolados a partir do extrato etanólico dos talos da Combretum fruticosum, bem como, estudar os possíveis mecanismos de ação da trachelogenina, uma lignana do tipo dibezilbutirolactona, em células de câncer colorretal (HCT-116). O fracionamento do extrato etanólico da C. fruticosum resultou no isolamento de sete compostos: três triterpenos, duas misturas dos esteroides β-sitosterol e estigmasterol e duas lignanas. Dentre eles, a trachelogenina mostrou maior atividade citotóxica, apresentando valores de CI50 que variaram de 0,8 a 32,4 µM em células tumorais de glioblastoma (SF-295) e leucêmicas (HL-60), respectivamente, após 72 horas de incubação. Enquanto que, para células não tumorais (3T3-L1 e CMSP) esses valores foram maiores que 64,3 µM. O perfil antiproliferativo em diferentes períodos de incubação foi realizado em células SF-295 e HCT-116. O efeito citotóxico em células SF-295 foi observado apenas após 72 horas de incubação, enquanto que, em células HCT-116, esse efeito foi observado após 48 horas, sendo intensificados após 72 horas de incubação. Diante desses resultados, em células HCT-116, a análise do perfil do ciclo celular, integridade de membrana, externalização da fosfatidilserina e expressão de proteínas relacionadas ao processo de morte celular por apoptose não apresentou alterações significativas, sugerindo que o efeito antiproliferativo desta lignana não está relacionado com processos de morte por apoptose e/ou necrose. A autofagia parece estar envolvida no mecanismo antiproliferativo da trachelogenina, visto que foi possível verificar um aumento do número e do tamanho de organelas vesiculares ácidas (AVOs) bem como um aumento da expressão de proteínas recrutadas durante a autofagia (LC3 A e B II e Beclina-1) nas células tratadas com a trachelogenina, embora não pareça ser o único processo envolvido. Logo, podemos concluir que a trachelogenina apresentou potente atividade anticâncer in vitro, e este efeito pode estar relacionado com a indução da autofagia. No entanto, outros testes devem ser realizados para confirmar as propostas acima apresentadas e para uma melhor avaliação do mecanismo de ação e do potencial terapêutico desta molécula.

In maximizing South Africa's floral diversity, plant propagators have begun exploiting the rich array of indigenous plants, especially those with horticultural potential. Plants previously unavailable to the professional and amateur gardeners alike, are legally becoming common-place in nurseries. However, in promoting the trade of indigenous plants to nursery-owners, rapid, easy and cost effective methods of propagating these plants need to be established. Combretum bracteosum is one such indigenous plant, the aesthetic appeal thereof exhibits great potential for ornamentation, especially when flowering. In facilitating the introduction of Combretum bracteosum into nurseries, small gardens or even pots, investigations carried out aimed to determine and analyse quick and easy methods of propagating this plant. Of the various propagation techniques considered, only one, micropropagation, required specialized skill and training prior to carrying out the relevant procedures and protocols. The two other techniques used, which are accessible to most plant propagators, were seed germination and propagation from cuttings. Propagation by seed germination yielded less than optimal results from a commercial perspective. Although the hard pericarp surrounding the embryo did not impose any dormancy inducing mechanisms, such as the restriction of water uptake or the leaching of an inhibitory compounds, it did act as a mechanical barrier to the emerging radicle and roots. Recommendations for optimal Combretum bracteosum seed germination would be to remove the protective pericarp completely, incubate imbibed embryos in complete darkness at 25°C. After radicle emergence the germinating embryos could be moved into an alternating light: dark cycle. A more viable and simpler alternative to seed germination, was propagation by stem cuttings. Treating the cuttings with 10% and 50% or 75% of the commercially available Kelpak concentrate (using the Soak Method and Quick-dip Methods respectively), provided the most promising results, with the rapid development of roots and subsequent vegetative growth. Synthetic hormones such as IBA and NAA were also applied to the cuttings both alone or in combination however, although callus growth was profuse, root development was slow and unsubstantial, if any at all. Therefore, in recommending a protocol for the successful rooting of Combretum bracteosum cuttings taken during spring, summer or early autumn, the application of Kelpak at either 10% (Soak Method) or 50% (Quick-dip Method) of the full strength solution, is advised. Subsequent to hormone treatment, the cuttings still required attention with regard to nutrient supplementation as well as atmospheric moisture and temperature regulation. Success in generating Combretum bracteosum plantlets was obtained by germinating the seed in vitro as well as stimulating axillary shoot elongation from nodal explants. Placing the sterilized Combretum bracteosum embryo onto a nutrient rich basal medium (containing no hormones) was sufficient to stimulate 100% germination. The frequent poor availability of the seed may hamper the use of in vitro seed germination for commercial propagation purposes. The use of nodal explants from in vitro germinated stock plants, is a rapid and reliable means of generating a large seedling stock. Nodal explants excised from the newly developed shoot were subsequently placed onto 0.5 mg.ℓ ¯¹ BA which encouraged axillary bud elongation. After elongation, the lateral shoots were removed and placed onto a rooting medium (1.0 mg.ℓ ¯¹ IBA). The more mature nodal explants, collected from parent plants growing in vivo, required either a BA: NAA hormone combination or Kelpak to stimulate axillary shoot elongation, with the latter being most successful. Root initiation followed the protocol described above. Once rooted plantlets were hardened off they displayed a strong and vigorous growth, which is desirable from a commercial perspective. Upon maturity, the habit of many indigenous trees and shrubs could become too big for confined spaces such as the urban garden. Therefore, determining a means of modifying the plants' habit in order to maintain its suitability as a smaller garden plant was important. Treating the Combretum bracteosum plants with a 50 mg.ℓ ¯¹ paclobutrazol soil drench proved most successful, with the desired effects being visible within a few weeks of initial application. No negative morphological or developmental effects were noted on plants treated with the dwarfing agent, conversely however, the treated Combretum bracteosum plants were compact and bushy, with considerable visual appeal and aesthetic attractiveness. / Thesis (Ph.D.)-University of Natal, Pietermaritzburg, 2001.

Please read the abstract (Summary) in the section, 00front of this document / Dissertation (MSc (Pharmacology))--University of Pretoria, 2008. / Pharmacology / MSc / unrestricted

Made available in DSpace on 2017-07-21T14:13:09Z (GMT). No. of bitstreams: 1 Priscilla Salles Brito.pdf: 3568412 bytes, checksum: 203c4f88befe2482f92c6c8ac2640e40 (MD5) Previous issue date: 2012-02-29 / PelleC1 is an isolated compound from the Combretum leprosum (Combretaceae) that is a shrub popularly known as "mofumbo". This plant is used in folk medicine for wound healing, in the haemorrhages treatment or as a sedative. Researches with the extract of the plant attribute analgesic and anti-inflammatory activity to Combretum leprosum when orally administered. Based on these, the aim of this study was to evaluate the topical antiinflammatory effect of the PelleC1 compound in a skin chronic inflammatory model in mice. The anti-inflammatory activity of the PelleC1 was evaluated in the model of mice ear chronic inflammatory model induced by repeated applications of 12-O-tetradecanoilforbol acetate. The topical application of PelleC1 (0.3 mg/ear) caused a significantly inhibition of ear edema induced by TPA from the 6th day of the experiment (38.12 ± 6.89%) and this effect was intensified during the experiment until the last day (9th day, reduction of 62.44 ± 6.34%). The analysis of ears weight confirmed this result.The ears treated with PelleC1 or with dexamethasone (0.05 mg/ear) had a significant reduction of 30.17 ± 2.96% and 30.88 ± 1.80%, respectively, on weight of the ears, when compared with the control group (24.03 ± 1.65 mg). Another important event in the skin inflammation is the infiltration of polymorphonuclear and mononuclear cells, which were indirectly evaluated by determining the activity of enzymes myeloperoxidase (MPO) and n-acetyl-D-glucosaminidase (NAG). The studied compound reduced the activity of MPO and NAG, 31,45 ± 4,59% e 39,31 ± 0,64%, respectively, when compared to the controls (0,29 ± 0,01 DO/Biopsy - MPO; 1,73 ± 0,06 DO/Biopsy – NAG). The histological analysis confirmed this result and showed that compound PelleC1 and dexamethasone were able to reduce the thickness increase of the epidermis in 59,85 ± 5,05% e 60,10 ±3,77%, respectively, when compared to the control group (71,13 ± 4,21 μm). The PelleC1 and dexamethasone also showed a reduction in cell proliferation verified by immunohistochemistry for proliferating cell nuclear antigen of 71,7 ± 4,4% e 66,3 ± 0,5 respectively, when compared with the control group (156,4 ± 8,5 cells/field). The obtained results suggest that the PelleC1 has potent topical anti-inflammatory activity, since it reduced swelling, cell migration and proliferation in chronic inflammatory processes on the skin. / O PelleC1 é um composto isolado da planta Combretum leprosum (Combretaceae), arbusto popularmente conhecido como “mofumbo”. Esta planta é utilizada na medicina popular para a cicatrização de feridas, no tratamento de hemorragias e como sedativo. As pesquisas realizadas com os extratos atribuem à Combretum leprosum atividade analgésica e anti-inflamatória quando administrado por via oral. Desta forma, o objetivo desse trabalho foi avaliar o efeito anti-inflamatório tópico do composto PelleC1 em modelo de inflamação crônica na pele de camundongos. A atividade anti-inflamatória do composto PelleC1 foi avaliada no modelo de inflamação crônica na orelha induzida por aplicações repetidas de 12-Otetradecanoilforbol acetato. A aplicação tópica do PelleC1 inibiu de forma significativa o edema da orelha a partir do 6º dia de experimento (38,12 ± 6,89%) e este efeito foi intensificado no decorrer do experimento até o último dia (9º dia, redução de 62,44 ± 6,34%). A redução do edema foi confirmada pela análise do peso das orelhas no término da experimentação. As orelhas tratadas com PelleC1 (0,3 mg/orelha) ou com dexametasona (0,05 mg/orelha) tiveram redução significativa no peso das orelhas de 52,34 ± 5,13% e 53,57 ± 3,12%, respectivamente, quando comparados com o grupo controle (24,03 ± 1,65 mg). Outro evento importante na inflamação cutânea é a infiltração de polimorfonucleares e células mononucleares, que foram avaliadas indiretamente pela determinação da atividade das enzimas mieloperoxidase (MPO) e Nacetil-D-glucosaminidase (NAG). O composto estudado reduziu a atividade da MPO e da NAG, 31,45 ± 4,59% e 39,31 ± 0,64%, respectivamente, quando comparados aos controles (0,29 ± 0,01 DO/Biópsia da MPO; 1,73 ± 0,06 DO/Biópsia da NAG). A análise histológica confirmou a inibição da migração celular e também mostrou redução importante do processo de hiperproliferação celular na epiderme pelo composto PelleC1 e pela dexametasona em 59,85 ± 5,05% e 60,10 ± 3,77%, respectivamente, quando comparados ao grupo controle (71,13 ± 4,21 μm). Além disso, a imunohistoquímica com antígeno nuclear de proliferação celular mostrou que o tratamento com PelleC1 reduziu a proliferação celular, assim como a dexametasona (71,7 ± 4,4% e 66,3 ± 0,5, respectivamente), quando comparados com o grupo controle (156,4 ± 8,5 células/campo). Os resultados obtidos sugerem que o composto PelleC1 possui potente atividade anti-inflamatória por via tópica, visto que conseguiu reduzir o edema, a migração e a proliferação celular em processos inflamatórios crônicos na pele.

Made available in DSpace on 2017-07-21T14:13:10Z (GMT). No. of bitstreams: 1 Stefanie Nolte.pdf: 1509773 bytes, checksum: dbef289d8b9a1e611bef15b9a6d2f33c (MD5) Previous issue date: 2013-02-21 / Introduction: Psoriasis is a skin inflammatory disease characterized by keratinocytes hyperproliferation and their incomplete differentiation in the epidermis. Treatment aims to reduce the psoriatic plaques formation; however, many therapeutic regimens do not produce satisfactory results. Searching for new alternatives, this study evaluated the possible effect of the TTHL compound, isolated from the ethanolic extract of Combretum leprosum, on HaCaT proliferation.Methods: The cellular viability was assessed 24 hours after the treatment with different concentrations of TTHL through MTT and neutral red methods. To evaluate the TTHL anti-proliferative activity, the cells were treated with different concentrations of TTHL, in alternate days (96 hours) and analyzed through MTT and Cyquant methods. The cell cycle was evaluated by flow citometry. The possible toxicity by the topical application of the TTHL (0.3 mg/ear) was assessed in vivo, through skin atrophy, by measuring ear thickness of animals and histology.Results: The MTT assay showed, after 24 hours, that TTHL presents cytotoxic activity in HaCaT cells, at the concentrations of 5, 7, 9 and 10 μM, decreasing, respectively, 53.54, 89.53, 89.69 and 90.30 ± 5.84% the cellular viability compared to the control group. The neutral red assay, in the same concentrations, decreased 39.83%, 48.67%, 47.78% and 50.44 ± 4.42%, respectively. In the cellular proliferation assay, the 5, 7 and 10 μM concentrations decreased 24.27%, 59.25% and 82.30% ± 5.96% the cells number, as showed in the MTT method, and 30.30%, 59.59% e 90.90% ± 6.03% as showed in the Cyquant method. The cell cycle assay showed that, at the concentrations of 5, 7 and 10 μM, the non-viable cells number was higher and statistically significant when compared to the control group. Through the skin atrophy assay was possible to conclude that TTHL does not cause atrophy.Conclusion: TTHL is capable of reducing cell viability. These data suggest that TTHL might be a possible tool for the treatment of hyperproliferative diseases, among them, psoriasis. However, additional studies are needed to verify the action mechanism and triterpene safety. / Introdução: A psoríase é uma doença inflamatória cutânea caracterizada pela hiperproliferação e diferenciação incompleta de queratinócitos na epiderme. O tratamento tem como objetivo reduzir a formação de placas psoriáticas, porém muitos regimes terapêuticos não produzem resultados satisfatórios. Buscando alternativas, este trabalho avaliou o possível efeito do composto TTHL, isolado do extrato etanólico de Combretum leprosum, sobre a proliferação de HaCaT. Métodos: A viabilidade celular foi avaliada 24 horas após o tratamento com diferentes concentrações de TTHL, através do método de MTT e vermelho neutro. Para avaliar a atividade antiproliferativa, as células foram tratadas com diferentes concentrações de TTHL, em dias alternados e analisadas através do método de MTT e Cyquant. O ciclo celular foi avaliado por citometria de fluxo. A possível toxicidade pela aplicação tópica do TTHL foi avaliada in vivo, pelo ensaio de atrofia cutânea, através da medida da espessura da orelha dos animais e histologia. Resultados: No ensaio de MTT, após 24 horas, o TTHL, apresentou atividade citotóxica nas células HaCaT, nas concentrações de 5, 7, 9 e 10 μM, diminuindo, respectivamente em 53,54, 89,53, 89,69 e 90,30 ± 5,84% a viabilidade celular quando comparado ao grupo controle. No ensaio de vermelho neutro, essas mesmas concentrações diminuíram 39,83%, 48,67%, 47,78% e 50,44 ± 4,42%, respectivamente. No ensaio de proliferação celular, nas concentrações de 5, 7 e 10 μM, observou-se diminuição de 24,27%, 59,25% e 82,30% ± 5,96% no número de células, conforme o método de MTT e 30,30%, 59,59% e 90,90% ± 6,03% conforme o método de Cyquant. No ensaio de ciclo celular observou-se que nas concentrações de 5, 7 e 10 μM o número de células não viáveis foi maior e estatisticamente significante quando comparado com o grupo controle. Através do ensaio de atrofia cutânea foi possível concluir que o TTHL não causa atrofia. Conclusão: O TTHL é capaz de diminuir a viabilidade celular. Esses dados sugerem que o TTHL possa ser uma possível ferramenta para o tratamento de doenças hiperproliferativas, dentre elas, a psoríase. Entretanto, estudos adicionais são necessários para verificar o mecanismo de ação e segurança do triterpeno.

Made available in DSpace on 2015-05-14T13:00:19Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 2908035 bytes, checksum: 4dbd755d009a041e3acce2fdd866be83 (MD5) Previous issue date: 2011-02-25 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The species Combretum fruticosum (Loefl.) Stuntz belongs to the Combretaceae family and is popularly known as pente de macaco or mufumbo , it´s a neotropical plant, which can be found from Mexico until Argentina. This work describes the isolation and structural identification of a few chemical constituents of Combretum fruticosum (Loefl.) Stuntz aerial parts, with the objective of increasing the chemotaxonomic knowledge of the genus Combretum, as well as the family Combretaceae, besides doing biological studies with the isolated substances from this species. The phytochemical study of the Combretum fruticosum (Loefl.) Stuntz aerial parts led to the isolation of the compounds α-amyrin and β-amyrin (CF1), betulinic acid (CF2), α-spinasterol (CF3), spinasterol glycoside acetate (CF4), 132- hydroxy-(132-S)-phaeophytin-a (CF5) and 24-methylene cycloartanyl phydroxycinnamate (CF6). All of them reported for the first time on the genus, except for CF2. These compounds were identified by analysis of data obtained from spectroscopic methods such as infrared and NMR of 1H and 13C, with the aid of two dimensional techniques, besides comparison with literature data. On the biological study of Combretum fruticosum (Loefl.) Stuntz an evaluation of the antimicrobial activity from its crude extract has been made by the essay on agar diffusion against the bacteria and fungi Staphylococcus aureus, Enterococcus faecalis, Klebsiella pneumoniae, Pseudomonas aeruginosa, Escherichia coli, Candida parapsilosis, Candida albicans, Candida krusei and Candida glabrata, which demonstrated antimicrobial activity against the fungus Candida krusei and the bacteria Pseudomonas aeruginosa, Staphylococcus aureus and Enterococcus faecalis. Besides this essay, the evaluation of antitumoral activity in vitro with the substances CF1, CF2, CF3 and CF4 against Sarcoma 180 and K562 cells has been made, which did not show any citotoxic activity on concentrations until 200 μg/mL. / A espécie Combretum fruticosum (Loefl.) Stuntz , pertence a família Combretaceae e é conhecia popularmente por pente de macaco ou mofumbo ; é uma planta neotropical, que ocorre desde o México até a Argentina. O presente trabalho descreve o isolamento e identificação estrutural de alguns constituintes químicos das partes aéreas de Combretum fruticosum (Loefl.) Stuntz, com o objetivo de ampliar o conhecimento quimiotaxonômico do gênero Combretum, bem como da família Combretaceae; além de realizar estudos biológicos com as substâncias isoladas desta espécie. O estudo fitoquímico das partes aéreas de Combretum fruticosum (Loefl.) Stuntz levou ao isolamento das substâncias α-amirina e β-amirina (CF1), ácido betulínico (CF2), α-espinasterol (CF3), espinasterol glicosilado acetilado (CF4), 132-hidroxi-(132-S)-feoftina A (CF5) e o 24-metileno cicloartanil phidroxicinamato (CF6).Todos relatados pela primeira vez no gênero com exceção de CF2. Estes compostos foram identificados através da análise de dados obtidos por métodos como Infravermelho, RMN de 1H e 13C uni e bidimensionais, além de comparação com valores da literatura. No estudo biológico de Combretum fruticosum (Loefl.) Stuntz. realizou-se a avaliação da atividade antimicrobiana do extrato etanólico bruto através do ensaio de difusão em Agar frente as bactérias e fungos: Staphylococcus aureus, Enterococcus faecalis, Klebsiella pneumoniae, Pseudomonas aeruginosa, Escherichia coli, Candida parapsilosis, Candida albicans, Candida krusei e Candida glabrata, onde demonstrou-se atividade antimicrobiana contra o fungo Candida krusei e contra as bactérias Pseudomonas aeruginosa, Staphylococcus aureus e Enterococcus faecalis. Além deste ensaio, também foi realizada a avaliação da atividade antitumoral in vitro das substâncias CF1, CF2, CF3 e CF4 frente as células da linhagem Sarcoma 180 e K562, onde observou-se ausência de atividade citotóxica em concentrações até 200 μg/mL.

Please read the abstract is the 00front of this document. / Thesis (PhD (Paraclinical))--University of Pretoria, 2005. / Paraclinical Sciences / unrestricted

Given the drawbacks associated with the use of antibiotics as feed additives and the imminent banning of its use in the European Union, the aim of this project was to develop an extract that could be used as an alternative feed additive in poultry production. The desired extract preferably had to be rich in antibacterial activity to control proliferation of undesired microorganisms, and antioxidant activity to boost the immune system of the poultry. A number of trial extraction procedures were employed on dried leaf material samples to identify the best extraction method. In preliminary extraction studies, direct extraction was performed on leaf samples from the Lowveld National Botanical Gardens (LNBG) and from University of Pretoria Botanical Garden (UP). The principle aim of preliminary studies was to identify the solvents that extracted high antibacterial and antioxidant activity while also extracting large quantities of material. The secondary objective was to test for differences in activities between samples collected from LNBG and UP. Five extractants of varying polarities; acetone, ethanol, ethylacetate, dichloromethane and hexane were used. Antibacterial activity of all extracts was quantified by a serial dilution microplate technique while bioautography was used in qualitative analysis of the antibacterial active compounds. ATCC strains of Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli and Enterococcus faecalis were used as test organisms. Qualitative antioxidant activity was determined by using a DPPH assay on TLC plates. Results from preliminary extraction studies showed larger quantities of material were present in extracts from the LNBG sample than in the UP sample. Two major antioxidant compounds (Rf values of 0.85 and 0.35 in EMW solvent system) were seen on DPPH sprayed TLC plates, while bioautography showed the presence of a number antibacterial active compounds in the acetone, ethanol and ethylacetate extracts with Rr values ranging between 0.85 and 0.56 on TLC plates developed in the EMW solvent system. MIC values of the extracts tallied with the results from bioautography. The acetone, ethanol and ethyl acetate extracts had the highest antibacterial activity while the hexane extracts had the lowest activity with average MIC value of 0.55 mg/ml for both the LNBG and UP samples. MIC values as low as 0.04 mg/ml were measured in the acetone and ethylacetate extracts of the LNBG sample against S. aureus and E. faecalis. Based on results from preliminary extraction studies, hexane was identified as a possible pretreatment solvent for application in enrichment procedures, acetone and ethanol were chosen as the main extractants and only the LNBG sample was used for future work. Enrichment procedures were employed along two pathways; the first pathway involved the use of hexane "wash" as a pretreatment procedure prior to extraction with acetone or ethanol. The second pathway involved the use of various mixtures of acetone in water and ethanol in water as extractants. The rationale of using these various ratios was an attempt to identify solvent mixtures that would selectively extract the bioactive components or otherwise selectively remove inactive material. A serial dilution microplate method was used to determine Minimum Inhibitory Concentrations (MICs) and the Trolox Equivalent Antioxidant Capacity (TEAC) assay was used to quantify antioxidant activity of all extracts. The optimal extract was the one developed by pretreatment with a single direct extraction with hexane prior to extraction with acetone. It had a TEAC value of 2.3, an increase in TEAC value of 283% compared to that of the crude acetone extract. The average MIC of the crude acetone extract against ATCC stains of S. aureus, Ps. aeruginosa, E. coli and E. faecalis had dropped from 0.15 mg/ml to 0.08 mg/ml in the optimal extract (an improvement in antibacterial activity of 87.5%). Since the optimal extract is intended for commercial application in poultry production, its antibacterial activity was tested against Campylobacter jejuni, Clostridium perfringens, Salmonella enteritidis, E. coli and multi drug resistant E. coli isolated from chickens. Its in vitro toxicity was ascertained using the brine shrimp assay and the MTT cytotoxicity assay on monkey kidney cells. The optimal extract was effective against Campylobacter jejuni and Clostridium perfringens with MIC values ranging from 40 µ/ml to 80 µ/ml. It was also active against multi-resistant strains of E. coli and Salmonella enteritidis (MIC values of 125 µ/ml for both strains). LC50 results from the brine shrimp assay and the MTT cytotoxicity assay on monkey kidney cells gave values of 863 µ/ml and 226 µ/ml respectively indicating low toxicity. These results meant that though in some cases the MICs of the optimal extract were higher than befitting of typical antibiotics, due to its relatively low toxicity, large quantities of the extract may possibly be feed to achieve the desired activity without causing any toxicity in the poultry. The major antioxidant compound was isolated by silica gel column chromatography. The isolated compound was identified by nuclear magnetic resonance and mass spectroscopy as combretastatin BS (2', 3', 4-trihydroxyl, 3, S, 4'-trimethoxybibenzyl), previously isolated from the seeds of C. kraussii and also from C. woodii leaves. Famakin (2002) showed this compound to be the major antibacterial compound in C. woodii leaves. Combretastatin BS (CBS) demonstrated in vitro cytotoxicity in the MTT assay on monkey kidney cells with an LC50 value of 1 0 µ/ml. In vitro cytotoxicity of CBS could be due to its antimitotic activity. The TEAC value of 7.9 found in this study means that combretastatin BS has about 8 times the antioxidant capacity of vitamin E. This is the first report of the antioxidant activity of any of the combretastatins. Tolerance of broiler chickens to the optimal extract was assessed at clinically inferred doses of 2 mg/kg, Smg/kg and 10 mg/kg . After 21 days of infeed-dosing with the optimal extract, none of the chickens died or showed any behavioral signs of toxicity. There were no statistically significant differences in weight gain between broilers fed the optimal extract and the positive and negative control. There was also no positive correlation between weight gain and amount of the optimal extract incorporated in feed. Although the optimal extract did not result in significant growth promotion relative to the positive and negative control, 2 mg/kg dose regimens showed the best Feed Conversion Ratio (FCR), with a 6.2% improvement compared to the negative control. The positive control was the only other feed regimen to provide a positive FCR with an improvement of 1.73% compared to the negative control. Because purchase of feed could represent up to 80% of costs of broiler production, this is an important finding. If these results can be confirmed, the product may therefore have commercial value. Repetition of the experiment with lower doses of the optimal extract on poultry challenged with bacterial infections is required to confirm the commercial applicability of this product. Copyright / Dissertation (MSc (Paraclinical Science))--University of Pretoria, 2004. / Paraclinical Sciences / unrestricted