Siparuna apiosyce (Mart.) A. DC, espécie vegetal aromática da família Monimiaceae Jussieu, encontrada no sudeste brasileiro, conhecida vulgarmente como \"limão-bravo\", é planta medicinal de uso popular. As folhas são empregadas em problemas gástricos e respiratórios. A espécie consta na primeira edição da Farmacopéia Brasileira, sob a denominação \"limoeiro-bravo\", sendo-considerada a folha, como parte usada. Efetuou-se análise macro e miscroscópica de folha e de caule para fins de identificação da droga inteira, em análises de rotina. O estudo microscópico incluiu folha, na forma pulverizada. Empregaram-se as técnicas usuais de análise. Elaboraram-se desenhos esquemáticos e em detalhe das estruturas microscópicas. As descrições são, igualmente, acompanhadas de fotografias e de fotomicrografias. Efetuou-se análise comparativa de folha e desta em mistura com caule, na proporção naturalmente encontrada no vegetal, tendo-se realizado a determinação de parâmetros físico e químico, abordagem fitoquímica e estudo cromatográfico em camada delgada de ambos. Realizou-se avaliação da atividade antimicrobiana dos extratos fluidos frente a Escherichia coli, Staphylococcus aureus e Candida albicans. Foi determinado o teor de óleo essencial presente em folha e em fruto da espécie. Considerando a comercialização da droga, na forma de extrato fluido, estes foram preparados, pelo processo de percolação fracionada (processo \"C\"), segundo a Farmacopéia Brasileira II, a partir das partes aéreas, anteriormente referidas. Efetuou-se a determinação comparativa, para ambos os extratos fluidos, de parâmetros físicos e químico e análise cromatográfica em camada delgada. Para o estudo químico foram elaborados os extratos hexânico, diclorometânico e etanólico, com vistas ao isolamento de componentes de folha e caule. Com o resíduo etanólico efetuou-se processo de extração de alcalóides. O resíduo hexânico e o resíduo bruto de alcalóides foram submetidos à separação por coluna cromatográfica. As frações resultantes foram cromatografadas em camada delgada, tendo sido reunidas aquelas de comportamento cromatográfico semelhante. Posteriormente, efetuaram-se procedimentos específicos para o isolamento de compostos. Entre os vários componentes obtidos, dois foram identificados, por via espectral, tendo sido o estigmasterol e o alcalóide noraporfínico asimilobina. Espectros das substâncias (I.V., RMN 1H, RMN 13C, RMN 13C - DEPT 135º e HETCOR) acompanham o trabalho. / Siparuna apiosyce (Mart.) A. DC., an aromatic medicinal specie of southest Brazil, commonly known as \"limão - bravo\", is traditionally used to treat gastric and pulmonary diseases. The leaves are included in the first edition of the Brazilian Pharmacopeia and officially named \"limoeiro-bravo\". Macro and microscopical descriptions and analysis were made, concerning leaves and twigs. It was performed by usual techniques. Photographies (macro and microscopical analysis) and drawings follow the descriptions. Comparative assays were made considering leaves and twigs with leaves. The author determined physical and chemical parameters, followed by phytochemical screening and thin layer chromatography profile. The respective fluid extrats were prepared by fractionated percolation, as directed under second edition of the Brazilian Pharmacopeia. Physical and chemical parameters and antimicrobial activity of fluid extract. were determined. Essential oil content of leaf and fruit were obtained. Twigs and leaves were extracted by percolation and successively with n-hexane, dichlorometane and ethanol. Extraction procedures for alkaloidal content was performed, with the ethanolic residue, by traditional methods. The hexanic residue and the concentrated alkaloidal phase were submitted to chromatographic column techniques. Specific procedures were applyed for the component isolation. Two compounds were identified by spectrometric determination: stigmasterol and the noraporphine asimilobine alkaloid. This work include RMN 1H, RMN 13C,DEPT 1350and HETCOR spectra.

Plinia edulis (Myrtaceae), popularmente conhecida como cambucá, é espécie medicinal empregada no tratamento de afecções da garganta por populações caiçaras. O trabalho teve como objetivo aprimorar o conhecimento da planta sob os aspectos farmacobotânicos, fitoquímicos e farmacológicos. O extrato hidroetanólico liofilizado, preparado com suas folhas, apresentou: classes de substâncias de interesse farmacológico (flavonóides 0,99% e taninos 31,35%); atividade antioxidante elevada no modelo de medida de produção do malonildialdeído, com Q1/2 de 0,21 µg/mL; atividade antiúlcera extremamente significativa no modelo de indução por etanol acidificado, reduzindo o Índice de Lesão Ulcerativa (81,5%), a Área Total de Lesão (97,9%) e a Área Relativa de Lesão (97,6%), comparativamente ao controle, com prévia administração de uma dose de 400 mg/kg, por via oral. O extrato não inibiu o crescimento de Aspergillus niger e Candida albicans na concentração de até 2.000 µg/mL e não inibiu o crescimento de Escherichia coli e Staphylococcus aureus na concentração de até 1.000 µg/mL. Na avaliação de toxicidade aguda, não provocou a morte de nenhum animal no período de ensaio, com uma concentração de até 5.000 mg/kg. A triagem fitoquímica da droga vegetal permitiu detectar flavonóides, taninos, saponinas e óleo volátil. O rendimento de óleo volátil, extraído de folhas frescas, foi de 0,02% (v/m) e sua análise evidenciou como componentes majoritários o epi-α-cadinol (21,72%), α-cadinol (20,22%) e trans-cariofileno (14,19%). As características macro e microscópicas importantes na identificação da droga vegetal foram: folhas cartáceas, lanceoladas, com 14 a 17 cm de comprimento e 4 a 6 cm de largura, nervura mediana evidente e pontos translúcidos no limbo; mesofilo dorsiventral, idioblastos arredondandos em número de 2 a 4 perpendiculares à face adaxial contendo drusas ou cristais prismáticos; folhas hipoestomáticas, com estômatos predominantemente anomocíticos; cavidades secretoras presentes em ambas as faces recobertas por um par de células com parede comissural ligeiramente sinuosa. Fotomicrografias ilustram o trabalho. / Plinia edulis (Myrtaceae), popularly known as cambucá, belongs to the medicinal species employed in the treatment of throat affections by the caiçaras (communities of fishermen families living on coastal towns). This work aims to improve the knowledge of the plant considering its pharmacobotanical, phytochemical and pharmacological aspects. The lyophilized hydroethanolic extract of the leaves showed substances with pharmacological interest (flavonoids 0.99% and tannins 31.35%); elevated antioxidant activity at malondialdehyde production measure model, with Q1/2 of 0.21 µg/mL; extremely significant antiulcer activity at the acidified ethanol induction model, being able to decrease the Ulcerative Lesion Indices (81.5%), the Total Lesion Area (97.9%) and the Relative Lesion Area (97.6%), comparatively to the control, with previous oral administration of 400 mg/kg. The extract did not inhibit either the growth of Aspergillus Niger and Candida albicans in a concentration of 2,000 µg/mL or the growth of Escherichia coli and Staphylococcus aureus in a concentration of 1,000 µg/mL. At the acute toxicity evaluation, no animals died at the oral administration assay of 5,000 mg/kg of extract. The phytochemical screening of the vegetal drug showed the presence of flavonoids, tannins, saponins and volatile oil. The content of volatile oil in fresh leaves was 0.02% (v/m) and the analysis showed, as main components, the epi-α-cadinol (21.72%), &#945-cadinol (20.22%) and trans-caryophyllene (14.19%). The most important characteristics to the vegetal drug identification were: chartaceous lanceolates leaves 14 to 17 cm long and 4 to 6 cm wide, evident midvein and translucent spots at the lamina, dorsiventral mesophyll, circular idioblasts in number of 2 to 4, perpendicularly to the adaxial surface, with druses or prismatic crystals, hypostomatic leaves, with anomocytic stomata predominantly, secretory cavities in both faces recovered by two cells with the comissural wall slightly sinuous. Photomicrographs illustrated the work.

Croton urucurana Baillon, comumente conhecida como \"sangra-d\'água\", é uma árvore medicinal do suldeste brasileiro utilizada como cicatrizante e antiinflamatório. A espécie carece de estudos botânicos, químicos e farmacológicos para que possa ser utilizada com segurança. O objetivo deste trabalho foi caracterizar a casca, a folha e o látex obtidos desta espécie, através de estudos farmacognósticos, isolando princípios ativos e verificando a toxicidade e as atividades antiúlcera e cicatrizante. Dentre as principais características macroscópicas podemos citar: (a) casca; enrolada com presença de manhas brancas, fratura fibrosa e sabor adstringente; (b) folha; simples, pubescente, cordiforme, peninérvea e ápice agudo. Quanto as características microscópicas temos: (a) casca; floema, pseudocórtex e periderme apresentado drusas, cristais prismáticos e amiloplastos; grande quantidade de esclereídes, células com taninos e laticíferos não articulados; (b) folha; mesofilo assimétrico com presença de grandes drusas; epiderme com pêlos estelares e estômas paracíticos. Na triagem fitoquímica foram encontrados alcalóides, esteróides, compostos fenólicos, taninos, saponinas e óleo essencial. O teor de taninos presente no látex é de 1,02%, determinado por gravimetria. Foram realizadas determinações físico-químicas (segundo Farmacopéia Brasileira) e cromatográficas das drogas (casca e folha) e de seus extratos. A taspina, um alcalóide cicatrizante, foi isolado do látex e identificado por I.V. e RM.N. O látex é altamente tóxico por via oral, e apresenta atividade cicatrizante e antiúlcera, verificado por ensaios com ratos Wistar. / Croton urucurana Baillon, commonly known as \"sangra-d\'água\", is a medicinal tree a southest brazilian, used for healing of wounds and antiinflammatory. There are not data about the botanical, chemical and pharmacological studies for the drug to used with safety. The objective of our search to was characterize to bark, the leaf and the latex obtained from this species, through pharmagnostics studies, active principle isolation and its toxicity, antiulcer and wound healing activities. the main macroscopic characteristics are: (a) bark, rolled up with presence of white spots, its fractures is fibrous and flavor astringent; (b) leaf; simple, puberulent, cordate, pinnately veined and acute apice. The microscopic characteristics have: (a) bark; phoem, pseudocortex and periderm with druses, prismatic crystals and starch; great amount of sclereids, cells with phenolic content and non-articulate laticifers; (b) leaf; asymmetric mesophyll with enormous druses of calcium oxalate, abundant in the palisade parenchyma; epidermis with stellate hairs and stomata paracytic. In the phytochemical screening there were detected alkaloids, steroids, phenolics compounds, tannins, saponins and essential Gil. The proportion of tannins presents in the latex is of 1,02%. The physical-chemical and chromatographic profiles (according to Farmacopéia Brasileira) of the drugs (bark and leaf) and of its extracts were determined. The taspine, a wound healing alkaloid, was isolated of the latex and identified by I.R. and M.N.R. The látex showed to be highly toxicant and to have a wound healing and antiulcer activity, assayed in Wistar rats.

Philodendron bipinnatifidum Schott é populannente conhecida como cipó-imbé, filodendro, imbé, guaimbé, banana-de-macaco, costela-de-Adão, entre outras denominações populares. Apesar de ser reconhecida como planta tóxica por muitos, existem relatos de sua utilização em erisipela, inflamações reumáticas, orquite; as folhas são aplicadas sobre úlceras. A raiz em pó é conhecida como purgativo drástico. Para as análises anatômicas foram utilizadas as partes aéreas floridas e as raízes aéreas de plantas adultas. A raiz aérea escora apresenta duetos secretores (resiníferos) de origem esquizógena, cilindro vascular lobado, laticíferos entre cordões de floema de tamanho conspícuo Na lâmina foliar, as epidermes em vista frontal apresentam cutícula espessa sem ornamentações, na face adaxial as células epidérmicas possuem paredes retas com ausência total de tricomas e estômatos. Na face abaxial as células são de contorno levemente sinuoso e ocorrem estômatos do tipo paracítico. O parênquima esponjoso mostra uma organização colunar das células do mesofilo e no meio deste, ocorrem grandes idioblastos contendo ráfides. No pedalo, como na nervura central e no caule, existem grandes cavidades de ar alongadas longitudinalmente, delimitadas por uma camada de células, entre as quais ocorrem idioblastos contendo ráfides que se projetam para o interior das mesmas. A triagem química revelou a presença de flavonóides, mucilagens, compostos esteroidais, alcalóides, saponinas (4,52% e 2,52%, para órgãos aéreos e raízes aéreas escoras, respectivamente) e taninos (5,46% e 21,13%, para órgãos aéreos e raízes aéreas escoras, respectivamente). O extrato fluido e a fração hidroalcoólica 50% foram ensaiadas através de indução aguda de úlcera por etanol e ácido clorídrico. Os resultados foram significativos apenas no nível de ulceração IH. Foi realizado teste de toxicidade aguda com os extratos fluidos liofilizados de órgãos aéreos e raízes aéreas escoras de P. bipinnatifidum Schott em dose única de 5000 mglkg, por via oral, em camundongos Swiss, machos e fêmeas, observados por um período de 14 dias. O ensaio de toxicidade subcrônica do extrato fluido liofilizado de raízes aéreas escoras foi realizado em dose diária de 800 mg/kg, por via oral, durante 38 dias consecutivos. Os resultados analisados em função da variação do peso dos animais, do consumo de água e ração e do peso relativo do baço, figado, rins e pulmões, não foi significativo, ou seja, nas condições experimentais não houve variação em relação ao controle. A atividade antiinflamatória foi avaliada, sendo os modelos utilizados: edema de pata induzido pela carragenina e dermatite induzida pelo óleo de cróton, no entanto, não foram obtidos resultados significativos. Os extratos liofilizados de órgãos aéreos e raízes aéreas escoras não apresentaram atividade antimicrobiana. / Philodendron bipinnatifidum Schott is populary known as Cipo-imbé, Filodendro, Imbé, Guaimbé, Banana-de-macaco, Costela-de-Adão, Bananeira do brejo. Nevertheless it is recognized as a toxic plant, there are reports about utilization in erysipela, rheumatic inflammations, orchits; the leaves are applied on ulcers. The powdered root is a drastic purgative. Aerial parts and aerial roots have been employed for the anatomic analyses. Phytochemical screening showed the presence of flavonoids, steroids, saponins, alkaloids, essential oilJs and mucilages. The crude extract and the 50% hydroalcoholic fraction were tested against ulcer through acute induction by ethanol and hydrochloric acid. Results were significant only at level mulceration. The acute toxicity was tested with the dose of 5000mg/kg, and the subchronic toxicity, with 800 mg/kg, of the crude extract, orally administred, and the subchronic toxicity was performed during 38 days. The weight variation ofthe animals, food and water consumption and the relative weight of the spleen, liver, kidneys and lungs, were not significant. The results of the antiinflammatory test were not significant.

隨著個人計算機運算能力的快速發展，虛擬藥物篩檢已被廣泛運用。目前運用於計算機輔助藥物虛擬篩選的化合物數據庫多為人工合成的數據庫，而用於天然產物藥物篩選的數據庫則較少報道。為了加速天然化合物的虛擬篩選，我們建立了包含約8000個天然產物的數據庫。他們中的大多數為傳統中藥。 / 為了驗證天然產物數據庫的可用性，其被用於篩選乙酰膽鹼酯酶抑製劑。該數據庫成功地確定了美國藥品監督管理局所批準的乙酰膽鹼酯酶抑製劑，如石杉鹼甲和他克林，表示該天然產物數據庫可以用於藥物虛擬對接篩選。 / 除了已知的乙酰膽鹼酯酶抑製劑，十二種植物化學物（大黃酸，大黃素，蘆薈大黃素，大黃酚，花椒毒素，珊瑚菜素，別異歐前胡素，歐前胡素，紫草素，乙酰紫草素，異戊紫草素和β，β-二甲基丙烯酰紫草素）被確定為新的乙酰膽鹼酯酶抑製劑。澱粉樣蛋白聚集可以導致神經細胞死亡；本研究中新發現的乙酰膽鹼酯酶抑製劑乙酰紫草素能夠阻止澱粉樣蛋白的聚集。除此之外，乙酰紫草素及其衍生物可以對抗過氧化氫誘導的神經細胞凋亡。其抗凋亡的活性作用是通過抑制活性氧的產生，以及保護線粒體膜電位的損失所實現的。亞鐵血紅素加氧酶在其神經細胞保護作用中起重要作用。 / 趨化因子受體4為跨膜G蛋白偶聯受體（GPCRs）。 CXCR4已被確定為一個新治療以及預防腫瘤轉移的新靶點。本研究利用分子對接篩選，從天然產物數據庫篩選選出CXCR4拮抗劑。通過分子對接和基於細胞的測定，黃芪甲苷，羥基紅花黃色素A和水飛薊賓已被確定為CXCR4拮抗劑。抗轉移的研究表明，黃芪甲苷和水飛薊賓抑制CXCL12誘導乳腺癌細胞的遷移和侵襲。此外，水飛薊賓也抑制CXCL12誘導的人臍靜脈內皮細胞管形成。另一方面，羥基紅花黃色素A對乳腺癌細胞的增殖表現出較強的抑製作用，因此很難進行抗轉移實驗。 / With the rapid advances in personal computing power, virtual drug screening has become increasingly popular. While there are numerous databases for synthetic compounds, there are few natural product databases that are specifically for in silico docking studies. To facilitate virtual docking on natural compounds, in-house Natural Products Database has been established, which contains approximately 8,000 naturally occurring chemicals so far. Most of them are documented Traditional Chinese Medicines. / In order to validate the usefulness of the database, in silico screening of acetylcholinesterase inhibitors (AChEIs) by virtual docking was performed. The database successfully identified the FDA-approved AChEIs such as huperzine and tacrine, indicating the in-house database is workable for natural products docking screening. / Apart from well-known AChE inhibitors, twelve phytochemicals (emodin, aloe-emodin, chrysophanol, rhein, xanthotoxin, phellopterin, alloisoimperatorin, imperatorin, shikonin, acetylshikonin, isovalerylshikonin and β, β-dimethylacrylshikonin) were identified as AChE inhibitors in this study that were not previously reported. Amyloid aggregation leads to toxic species that cause neuronal cell deaths, it was found that the newly identified AChEIs acetylshikonin and shikonin are able to prevent amyloid aggregation. A series of cell-based analysis were conducted for in vitro evaluation of the neuroprotective activities of the newly identified AChEIs. Acetylshikonin and its derivatives was found to prevent apoptotic cell death induced by hydrogen peroxide in human and rat neuronal SH-SY5Y and PC12 cells at 10 μM. Acetylshikonin exhibited the most potent anti-apoptotic activity through inhibition of reactive oxygen species (ROS) generation as well as protection of the loss of mitochondria membrane potential. Furthermore, acetylshikonin upregulates hemooxygenase 1(HO-1) which is a key step mediating its anti-apoptotic activity from oxidative stress in SH-SY5Y cells. / The C-X-C chemokine receptor type 4 (CXCR4) belongs to the class A family of seven transmembrane G protein-coupled receptors (GPCRs). CXCR4 has been identified as one of novel target against metastasis. A search for natural CXCR4 antagonists was conducted from natural product database by molecular docking for anti-metastasis study. Astragaloside IV, hydroxy safflower yellow A and silibinin have been identified as novel CXCR4 antagonists by both molecular docking and characterized by various cell-based assays. Anti-metastasis study showed that astragaloside IV and silibinin inhibited CXCL12-induced migration and invasion in breast cancer cells. In addition, silibinin also inhibited CXCL12-induced tube formation in human umbilical vein endothelial cells. On the other hand, hydroxy safflower yellow A exhibited a strong cytotoxicity on breast cancer cell proliferation, which is difficult to conduct anti-metastasis experiments. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Wang, Yan. / Thesis (Ph.D.) Chinese University of Hong Kong, 2013. / Includes bibliographical references (leaves 230-250). / Abstracts also in Chinese.

An estimated 13.9% of Americans currently meet criteria for an alcohol (ethanol; EtOH) use disorder (AUD). While there are 4 medications approved by the Food and Drug Administration (FDA) to treat AUD, these treatments have demonstrated poor clinical efficacy. Our ongoing research program encompasses a multi-tiered screening of a natural product library and validation process to provide novel information about the mechanisms underlying EtOH-induced changes in neurobiology and to identify novel chemical scaffolds to be exploited in the development of pharmacological treatments for AUD in a rodent organotypic hippocampal slice culture model. Initial screens of several natural product compounds identified 3 compounds which attenuate 48 h EtOH-induced cytotoxicity in vitro. As analogs of natural products can be developed to have enhanced therapeutic potential over parental structures, Study 1 sought to extend on prior findings via the screening of several natural product analogs for their ability to attenuate EtOH-induced cytoxicity. Nine natural produce analogs demonstrated potent cytoprotective effects against EtOH-induced toxicity at 48 h. Several reports suggest EtOH-induced neurotoxicity may be secondary to the induction of persistent neuroimmune activation, and isoflavonoids have been shown to have effects on neuroimmune signaling. Thus, Study 2 compared the effects of compound 9b, an isoflavonoid analog identified in Study 1, to daidzein (DZ), a prototypical isoflavonoid, in the same 48 h model, with the addition of a neuroimmune component. Specifically, culture media was collected to assess for the release of the neuroimmune mediators HMGB1, TNF-α, IL-6, and IL-10 via ELISA. Compound 9b and DZ protected against EtOH-induced cytotoxicity at 48 h. EtOH exposure significantly increased secretion of HMGB1 and IL-6 into culture media at 48h. Compound 9b and DZ attenuated these increases at all concentrations tested. These results suggest potential neuroimmune modulating properties of isoflavonoids which may contribute to their neuroprotective effects against EtOH in vitro. These findings highlight the potential applications DZ and the novel isoflavonoid analog 9b for use in the treatment of AUD.

Cyclotides are a family of small and macrocyclic proteins that have been found in Violacaee and Rubiaceae plant species. These proteins contain a cystine knot: two disulfides bonds together with their connecting peptide backbone form an embedded ring which is penetrated by a third disulfide bond. The cyclotides have been attributed a wide range of biological activities, which in combination with their chemical stability and structural plasticity have made them attractive tools for pharmaceutical applications. The sequence of eleven novel cyclotides, vibi A-K, from Viola biflora was determined by the use of both chemical (extraction and characterization) and molecular biology (cDNA analyses) approaches. A clear discrepancy in the results from the two methods was observed. Additionally, one novel cyclotide, vodo O, was isolated from Viola odorata. To correlate cytotoxic potency to sequence, vodo O and vibi D, E, G and H were tested on a lymphoma cell line. Based on the presence or absence of a cis-Pro bond, the cyclotides are divided into the Möbius and bracelet subfamilies. The bracelet proteins have a higher net charge and are more cytotoxic potent than the Möbius ones. To explore these differences, charged and hydrophobic residues in varv A (Möbius) and cycloviolacin O2 (bracelet) were chemically modified and tested for their cytotoxicity. The net-charge of the two proteins was not important for the potency. The Glu residue in cycloviolacin O2 was crucial, while this residue was of minor importance in varv A. Oxidation of the single Trp residue declined the potency significantly in both proteins. To evaluate how the surface properties correlate to the degree of cytotoxic potency, models of all cyclotides hitherto tested were constructed by homology modelling. Calculations showed that the membrane orientation of varv A and cycloviolacin O2 differed significantly, which might explain their difference in potency

Diarrhoea and related diseases are the most common causes of death in children, especially from developing countries, killing about 1.5 million children under the age of five yearly. In South Africa, diarrhoea is the third leading cause of death. This condition results from food and water sources infected with Campylobacter spp., Escherichia coli, Salmonella spp., Shigella spp., Giardia intestinalis and Cryptospondium parvum amongst others. Diarrhoea spreads through faeces-contaminated water. Hence, infection is more common when there is a short supply of clean drinking and cooking water. Waterborne diseases are common in rural communities of Bizana because the majority of rural dwellers depend largely on water from unprotected sources. Most of the pathogens that cause diarrhoea have developed resistance to several antibiotics. Therefore there is a need for new and safe antidiarrhoeal drugs. Most people in developing countries use traditional medicine to treat all kinds of diseases including diarrhoea and South Africa is no exception. Each cultural group in South Africa has different medical solutions for the prevention and curing of the same disease. The people from Pondoland (AmaMpondo), around Bizana have a strong tradition of using medicinal plants for the cure and prevention of several conditions including diarrhoea. Although several researchers have conducted different types of studies in many parts of South Africa to evaluate the efficacy of traditional medicine used in the treatment of diarrhoea, there is, however, still a lot of undisclosed data that should be collected. The aims of this research were to record and collect medicinal plants that are used for treating diarrhoea in Bizana, Pondoland in the Eastern Cape and evaluate them for their pharmacological properties. An ethnobotanical approach is one of several methods that have been useful in selecting plants for pharmacological research, yielding better results than other plant selection methods. Using questionnaires, this approach was used to record plants that are used for treating diarrhoea in Bizana for testing in pharmacological assays. From the completed questionnaires, nine plants were selected for bioassays based on their higher frequency index, and the fact that the plants have never been evaluated against diarrhoea causing-microorganisms. The study revealed 34 plant species belonging to 21 families as being used in treatment of diarrhoea in the study area. Psidium guajava was the most mentioned plant species. The dried, ground plant materials were each extracted non-sequentially using petroleum ether (PE), dichloromethane (DCM), 70% ethanol (EtOH) and water. Among all the extracts, 70% ethanol yielded the highest quantity of crude extract. The extracts were each evaluated for their antibacterial, anti-inflammatory and genotoxicity properties. For the antibacterial activity, the following diarrhoea causing microorganisms were used: Gram-positive Staphylococcus aureus and Gram-negative Campylobacter jejuni, E. coli and Shigella flexneri. A microdilution assay (for S. aureus, E. coli and S. flexneri) and the disk diffusion technique (for C. jejuni) were used for antibacterial testing. The extracts were also evaluated for their ability to inhibit cyclooxygenase (COX-1 and -2) enzymes. Genotoxicity was evaluated using the Salmonella microsome assay without S9 metabolic activation. Three strains of Salmonella typhimurium TA98, TA1535 and TA1537 were used. The evaluated plant extracts showed a broad spectrum of inhibitory activity with MIC values ranging from 0.098-12.5 mg/ml and mean zone inhibition percentage ranging from 0-73%. The best activity was exhibited by DCM extracts of Rapanea melanophloeos, EtOH extracts of Ficus craterostoma and Maesa lanceolata with MIC values of 0.098 mg/ml and EtOH extracts of Searsia chirindensis with 73% mean zone inhibition percentage. The inhibitory activity against COX-1 enzyme was higher than COX-2, with 19 plant extracts for the former and 7 for the latter. The highest inhibition of COX-1 was shown by EtOH extracts of F. craterostoma and the DCM extract of S. chirindensis at 100%. Highest percentage COX-2 inhibition was shown by water extracts of F. craterostoma and DCM extracts of Tecoma capensis with 99.5% and 99.0% respectively. None of the tested plant extracts were mutagenic, at all concentrations tested against all tester strains of the bacteria. The results of this study demonstrate that people still have a rich and diverse pool of knowledge concerning the uses of plants against diarrhoea. The data also show that plants form part of the cultural heritage of the communities in Pondoland. Therefore it is important to urgently save the people’s cultural heritage by recording the existing knowledge and confirming therapeutic uses of plants through scientific methods. This will prevent the information from vanishing together with the ageing knowledge holders. In light of the fact that the evaluated plants were selected based on their ethnobotanical use for treating diarrhoea, the activities reported here goes a long way in adding value to the plants used as part of traditional medicine. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2012.

Marine organisms are widely recognized sources of an impressive array of structurally unusual compounds. Marine natural products have exhibited interesting biomedical activities, provided targets for synthetic organic chemists, and afforded opportunities for elucidation of enzymatic mechanisms involved in biosyntheses of these molecules. Secondary metabolite pathways probably evolved to mediate interactions between organisms in their natural habitats; however, the ecological functions of natural products remain poorly understood for the vast majority of cases. In the present series of investigations, I evaluate the hypothesis that macroalgal natural products play a role in defending these organisms against potentially pathogenic microbes in the marine environment. Further, I combine these ecology-driven investigations with evaluation of algal natural products as sources of novel human drugs. This combined approach resulted in discovery of 15 novel natural products from two tropical red algae, Callophycus serratus and an unidentified crustose red alga. These new molecules included seven novel carbon-carbon connectivity patterns, not previously reported in the synthetic or natural product literature, illustrating the abundance of secondary metabolite diversity among marine macroalgae. Further, many compounds exhibited both biomedical and ecological activities, suggesting the synergistic potential of combined biomedical/ecological investigations in providing drug leads as well as insights into the natural functions of secondary metabolites. Bromophycolides and callophycoic acids, natural products from C. serratus, inhibited growth of the marine fungal pathogen Lindra thalassiae. Spatially-resolved desorption ionization mass spectrometry (DESI-MS) revealed that antifungal natural products were found at specific sites on algal surfaces. The heterogeneous presentation of antimicrobial chemical defenses on host surfaces suggests the potential importance of spatial scale in understanding host-pathogen interactions, and illustrates the capacity of mass spectrometry imaging in understanding chemically-mediated biological processes. Finally, assessment of antimicrobial chemical defenses among extracts from 72 collections of tropical red algae revealed that nearly all algae were defended against at least one marine pathogen or saprophyte and further suggested the untapped potential of ecological investigations in the discovery of novel chemistry.

The use of traditional medicine through the use of medicinal plants in Africa and especially in South Africa has long been considered an important characteristic of people's daily lives and socio-cultural heritage. Cotyledon Orbiculata is among the medicinal plants that are used by South African traditional practitioners for the treatment of epilepsy and painful conditions such as corns, warts, toothache, earache, boils and various other ailments. However, the claim of therapeutic successes of medicinal plants by traditional medicine practitioners are hardly subjected to scientific scrutiny. This study therefore, investigated the anti-epileptic property of Cotyledon Orbiculata by studying the effects of the methanol extract of the plant against chemically induced seizures by pentylenetetrazole, picrotoxin, bicuculline and N-methyl-DL-aspartic acid in mice. The study also investigated the analgestic effects of Cotyledon Orbiculata by studying the effect of the plant extract on pain induced by acetic acid and hot plate thermal stimulation.