O elevado índice de pessoas afetadas pela ansiedade tem levado os pesquisadores a buscarem novas alternativas de tratamento. A fitoterapia tem empregado medicamentos contendo algumas espécies de Passiflora, conhecidas popularmente como \"maracujá\". As folhas de P.alata oficializadas na Farmacopéia Brasileira e os órgãos aéreos de P.incarnata, inscrita em farmacopeias estrangeiras, são matéria-prima para a elaboração de diversos medicamentos fitoterápicos. No entanto, as semelhanças morfológicas entre plantas medicinais deste gênero geram erros e falsificações. Considerando este fato, constitui objetivo desta dissertação, o estudo farmacognóstico comparativo de folhas de cinco espécies medicinais: P.alata, P.caerulea, P.edulis, P.incarnata e P.quadrangularis. Embora a forma das folhas de P.alata e de P.quadrangularis seja similar, observam-se caracteres diferenciais como o número de nervuras laterais e glândulas peciolares. P.alata apresenta dois pares de glândulas e P.quadrangularis possui três pares. P.edulis e P.incarnata, espécies semelhantes morfologicamente, diferenciam-se na análise microscópica pelo tipo e frequência de tricomas; localização de estômatos. P.edulis caracteriza-se pela presença de tricomas tectores simples, pouco freqüentes e estômatos na face abaxial. P.incarnata exibe tricomas pluricelulares freqüentes e estômatos em ambas as faces. P.caerulea diferencia-se facilmente das anteriores pela folha provida geralmente de 5 lobos longos e estreitos; acresce-se o parênquima paliçádico que alcança até mais da metade da largura do mesofilo. Fotografias acompanham as descrições bem como as análises cromatográficas comparativas em camada delgada (CCD) e camada delgada de alta eficiência (HPTLC). O controle de qualidade das drogas vegetais é complementado com a quantificação da fração flavonoídica através de método espectrofotométrico e por HPTLC. / The high number of people suffering from anxiety has led reseachers to seek alternative kinds of treatment. Phytotherapy has used medicines containing a few species of Passiflora, popularly known in Portuguese as \"maracujá\". P alata leaves officially included in the Brazilian Pharmacopoeia and the aerial parts of P. incarnate, listed in foreign pharmacopoeia, are the raw materials to prepare several phytomedicines. However, the morphological similarities of medicinal plants of this kind may lead to errors and fraud. Bearing in mind this possibility, the purpose of this dissertation, is the comparative pharmacognostic study of leaves from five medicinal species - P.alata, P.caerulea, P.edulis, P.incarnata and P. quadrangularis. Although the shape of P.alata and P.quadrangularis leaves is similar, there are different characteristics such as number of side veins and petiolar glands. P.alata has two pairs of glands and P.quadrangularis has three pairs of glands. P.edulis and P.incarnata, which are species with similar structure, appear different in a microscopic analysis due to the types and frequency of their covering trichomes and stomata location: P.edulis typically has infrequent unicellular covering trichomes and stomata on its lower surface. P.incarnata has frequent pluricellular trichomes and stomata on both sides. P.caerulea can be easily distinguished from the aforementioned by its leaves, which are palmately divided in more than half their depth into five lobes; in addition to their palisade parenchyma, which extends to more than half their mesophyll width. Photomicrographs are enclosed with the descriptions, as well as thin layer chromatography and comparative high performance thin layer chromatography (HPTLC). Quality control of crude drugs is further completed with the amount of flavonoid fraction through spectrophotometry and HPTLC.

Diferentes tipos de terapias vêm sendo introduzidas como tratamento alternativo ao combate a diversos tipos de distúrbios humanos e entre eles, a utilização de chás com plantas medicinais vem se destacando pelo custo/benefício, facilidade de aquisição e administração. O objetivo deste estudo foi determinar os constituintes inorgânicos, avaliar a concentração dos elementos As, Ba, Br, Ca, Co, Cr, Cs, Fe, Hf, K, Mg, Mn, Na, Rb, Sb, Sc, Se, Ta, Th, Ti, U, V, Zn e Zr por análise por ativação neutrônica; o Cd, Cu, Ni e Pb pela espectrometria de emissão com plasma indutivamente acoplado e o Hg por espectrometria de absorção atômica com geração de vapor frio nas plantas medicinais e seus extratos cuja comercialização é regulamentada pela Agência Nacional de Vigilância Sanitária (ANVISA). A relevância dessas análises é justificada pela necessidade de contribuir para a recomendação destas plantas como fontes desses minerais na dieta. As técnicas utilizadas apresentaram sensibilidade adequada na obtenção da concentração de todos os elementos analisados, foram encontrados elementos considerados tóxicos em concentrações não prejudiciais ao organismo humano. Este estudo também possibilitou relacionar a concentração elementar nas espécies analisadas por meio das análises de coeficiente de correlação e da análise de agrupamento. Pode-se com isso, verificar a confirmação da similaridade no comportamento de grupos de elementos em relação à variação de suas concentrações observadas nas plantas e em seus extratos. Os elementos que exercem papel importante no metabolismo foram determinados em concentrações que podem auxiliar tanto no tratamento como na carência destes elementos no organismo, quando introduzido na dieta alimentar. / Different types of therapies have been introduced as an alternative treatment to combat different types of human disorders. Among them, the use of herbal teas has been highlighted by the cost/benefit, easiness of acquisition and administration. The aim of this study was to determine the inorganic constituents, and evaluate the element concentrations of As, Ba, Br, Ca, Co, Cr, Cs, Fe, Hf, K, Mg. Mn, Na, Rb, Sb, Sc, Se, Ta, Th, Ti, U, V, Zn and Zr by neutron activation analysis; and Cd, Cu, Ni and Pb, by atomic emission spectrometry, with inductively coupled plasma source and Hg, by atomic absorption spectrometry, with cold vapor generation in medicinal plants and their extracts, whose marketing was recently regulated by National Health Surveillance Agency (ANVISA). The relevance of these analyses is justified by the need of contributing to the recommendation of such plants as sources of minerals in the diet and, also, to verify if their concentrations cam pose some harm to the organism. The techniques showed adequate sensitivity in determining the concentration for most of the elements. Toxic elements were found in concentration not harmful to the human body. The results, also, allowed possible to correlate the elemental concentration in the analyzed species, by the determination the correlation coefficients and applications of cluster analysis. From these results it was confirmers in the groups of elements, regarding the variation of the concentrations observed in some plants and their extracts. The elements that play important roles in the human metabolism were determined in concentrations that can help both, to avoid the lack of these elements in the organisms, from the diet, and in treatment of disease.

Thesis (MSc. (Microbiology)) -- University of Limpopo, 2017 / This study was aimed at isolating and evaluating the antibacterial, antioxidant and cytotoxic effects of active compounds from selected medicinal plant species. The biological activities and cytotoxic effects of Commelina africana, Dombeya rotundifolia, Elephantorrhiza elephantina and Schkuhria pinnata were investigated based on their traditional uses. The plants were extracted with different solvents of varying polarities. Methanol was the best extractant with the highest yield. The presence of different phytoconstituents was screened using standard methods; this revealed the presence of terpenoids, flavonoids, tannins, and saponins. Meanwhile, the phytochemicals were screened on TLC, where different colours observed indicated the presence of different compounds. The total phenolic, tannin and flavonoid content were estimated using spectrophotometric methods. D. rotundifolia had the highest amounts of phenol, tannin and flavonoid content, while S. pinnata had the least. The antibacterial and antioxidant screening employed both qualitative and quantitative assays. Although not separated, this study demonstrated the antioxidant potential of D. rotundifolia extracts developed in BEA and CEF. D. rotundifolia also demonstrated the highest free radical scavenging and reducing power antioxidant potential. These activities could be attributed to the high phenolic, tannin and flavonoid content observed. All the selected plants had antibacterial potential against E. coli and P. aeruginosa. Only S. pinnata extracts were active against E. faecalis and S. aureus. The MIC values of the plants and ampicillin ranged from 0.02 to 2.50 mg/mL and 0.02 to 0.08 mg/mL, respectively. The plants were combined to determine any interaction effects in exhibiting antibacterial activity. Among all the possible combinations, combinations with S. pinnata had improved antibacterial activity. The effects of D. rotundifolia and S. pinnata extracts on the inhibition of the production of reactive oxygen species on LPS-induced RAW 264.7 macrophages was determined using the DCFHD-A assay. Both plants demonstrated anti-inflammatory potential by inhibiting the production of ROS in a dose-dependent manner. Cell viability assays revealed that S. pinnata had cytotoxic effects on African green monkey kidney (Vero) cells with the lowest LC50 (25 µg/mL). Bioassay guided fractionation and nuclear magnetic resonance spectroscopy of dichloromethane extracts of S. pinnata on column chromatography afforded isolation and characterisation of three sesquiterpene lactones. These were identified as 6-(2, 3- xxvi dihydroangeloylory)-6α-hydroxyinuviscolide, heliangolide and eucannabiolide. All three compounds had antibacterial, anti-inflammatory and cytotoxic effects. The compounds may serve as leads for synthesis of less toxic therapeutic antibacterial and anti-inflammatory drugs in the pharmaceutical industry. / National Research Foundation (NRF)

Thesis (M.Sc. (Biochemistry )) --University of Limpopo, 2007 / Refer to document / Medical Research Council (MRC), National Research Foundation (NRF) and University of Limpopo

Thesis (Ph.D. (Biochemistry)) --University of Limpopo, 2009 / Refer to document / National Research Foundation (NRF) and University of Limpopo

Thesis (Ph. D. (Botany)) -- University of Limpopo, 2014 / Refer to document

No description available.

Pseudomonas aeruginosa is an opportunistic, nosocomial pathogen for which antibiotic resistance and biofilm development is common. Quorum sensing communication is known to be a major controlling factor in virulence gene expression, biofilm development, antibiotic resistance factors, and specifically MexAB-OprM multi-drug efflux pump expression in P.aeruginosa. MexAB-OprM efflux pumps contribute to antibiotic resistance of tetracycline and other antibiotics in pseudomonads and other organisms. P.aeruginosa infections are problematic in cystic fibrosis and burn patients; it is also the number one causative agent of respiratory infections for intensive care unit patients. Present day antibiotics are losing the battle against these infections. In theory, quorum sensing inhibitors (QSI) reduce pathogencity of the organism; making it less virulent, thus allowing either the host immune system to clear the infection or use of a QSI in combination with an antibiotic to clear more persistent pathogens. For these reasons two alternative modes of treatment were explored in this study: quorum sensing inhibition by folk-medicinal plant extracts and an example of combination drug therapy, the “thyme-tetracycline effect”. Fifty folk-medicinal plant extracts were screened for potential anti-quorum sensing activity using two quorum sensing inhibition (QSI) reporter strains, Pseudomonas aeruginosa QSIS2 and Chromobacterium violaceum 12725. These were used to test specifically for C4-C6 and C12 HSL quorum sensing inhibition. Of the fifty plants tested, thirty plant families were represented. Eleven plant extracts (basil, chaparral, clove, cranberry, oregano, pomegranate, rosemary, sage, sassafras, thyme and witch hazel) showed C4 HSL quorum sensing inhibition as determined by both assays. Interestingly, five of the plants were from the Lamiaceae family. Thymus vulgaris (thyme), also from the Lamiaceae family, was chosen for further assessment. Previous research has shown that thyme extract can synergistically augment tetracycline activity against tetracycline-resistant Pseudomonas aeruginos, creating the “thyme-tetracycline effect.” Disc diffusion assay, thin layer chromatography (TLC), and TLC bioassay techniques were used to show that thymol is the active component in the thyme extract that augments tetracycline activity against resistant Pseudomonas. This study also showed that thymol is a potent C4 HSL quorum sensing inhibitor. The collective data suggests a potential mode of action for the thyme-tetracycline effect: thymol appears to prevent MexAB-OprM efflux pump gene expression. By blocking MexAB-OprM expression, tetracycline antibiotic accumulation can occur within the cell, thus allowing cellular damage.

University of Macau / Institute of Chinese Medical Sciences

University of Macau / Institute of Chinese Medical Sciences