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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.
171

Phytochemical analysis and antibacterial properties of aqueous and ethanol extracts of Brachylaena elliptica (Thurb.) dc. and Brachylaena ilicifolia (Lam.) Phill & Schweick

Sagbo, Idowu Jonas January 2015 (has links)
Resistance of human pathogenic bacterial strains results in selective pressure against known antibiotic. However, plant derived compounds that possess antibacterial potential are currently being investigated for treatment of wound infections in diabetic patients as they are inexpensive and non-toxic. Hence, this dissertation was designed to evaluate two medicinal plants (Brachylaena elliptica and Brachylaena ilicifolia) traditionally used in the treatment of various diseases such as diabetes, and its secondary complications in diabetic patients. The in vitro antioxidant activity of both plants were evaluated using DPPH (1, 1-diphenylhydrazl), ferric reducing power, ABTS (2, 2’-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid), NO (nitric oxide) and H2O2 (hydrogen peroxide) techniques. The antibacterial test and Minimum inhibitory concentration (MIC) was determined by agar dilution method against 5 bacteria strains (Pseudomonas aeruginosa, Staphylococcus aureus, Streptococcus pyogene, Proteus vulgaris and Proteus mirabilis) infecting wounds in diabetic patients using amoxicillin and ciprofloxacin as positive control. The phytochemical analyses were assessed using standard published methods. Identification of bioactive components in essential oils of both plants were assessed using GCMS. The aqueous and ethanol extracts of both plants were also evaluated to identify bioactive components using LC-MS. The results of the phytochemical analysis revealed the presence of phenols, tannins, flavanoids, flavanols, proanthocyanidins, saponins and alkaloids in both plants. Both plants indicated strong antioxidant activities which might be due to the presence of bioactive compounds. The aqueous and ethanol leaf extracts of both plants demonstrated appreciable broad spectrum activities against these wound pathogens with MIC ranging between 5 and 0.3 mg/ml. The GC-MS analysis of the essential oils of both plants revealed the presence of monoterpenes, oxygenated sesquiterpenes, phenolics and esters. The LC-MS analysis of the aqueous and ethanol leaf extracts of both plants showed that both plants are rich in alkaloids, terpenes, terpenoids, monoterpernoids, and flavanoids. Conclusively, this study has partially justified the ethnomedicinal use of B. elliptica and B.licifolia leaves for the treatment of various diseases, including diabetes and wound infections caused by bacteria in diabetic patients. These may be attributed to the presence of antioxidant compound such as phenols, flavanoids, saponins, tannins, alkaloids and other phytochemical compounds.
172

Ant-diarrheal Plants of Central Anatolia: Do They Inhibit Diarrhea-causing Bacteria?

Rose, Janna L 27 June 2011 (has links)
Infectious diarrhea results in 2 to 5 million deaths worldwide per year, and treatments that are safe, effective, and readily available are under investigation. The field of medicinal ethnobotany focuses on plants that are used by different cultural groups for treating various diseases and evaluates these plants for efficacy and cytotoxicity. In the present study, ethnobotanical research was conducted with Central Anatolian villagers in Turkey. Folk concepts and etiologies surrounding diarrhea were analyzed, as were salient plant-based remedies for diarrhea. Reviewing the literature, 91 plant species were described as anti-diarrheal in all of Turkey. In Central Anatolia, villagers described 35 species. For continued research via bactericidal and bacteriostatic bioassays, 15 plants were selected. Methanolic and aqueous extracts of medicinally used plant parts were evaluated for inhibitory properties against 10 diarrhea-causing bacteria in the first bioassay, and later 21 bacteria in a second assay utilizing spectrophotometry. The cytotoxic properties were also evaluated in an Alamar Blue Assay using HepG-2, PC-3, and SkMEL-5 human cell lines. While several extracts showed bactericidal and bacteriostatic properties, the methanolic extract of R. canina galls inhibited the most bacteria at the lowest concentrations. They were not cytotoxic. Thus, R. canina methanolic gall extracts were selected for bio-assay guided fractionation. Antibacterial activity was maintained in the third fraction which was composed of almost pure ellagic acid. The bioassay was repeated with standard ellagic acid, and the polyphenol retained potency in inhibiting multiple bacterial strains. Several other extracts showed promise for safe, effective anti-bacterial remedies for diarrhea.
173

Comparative study on the chemical constituents and bioactivity between radix astragali and radix hedysari

Liu, Jing 01 January 2011 (has links)
No description available.
174

The effect of nigella sativa oil on male reproductive function in male Wistar rats exposed to an obesogenic diet

January 2020 (has links)
Magister Scientiae (Medical Bioscience) - MSc(MBS) / Obesity is a growing public health concern globally, particularly in developed countries such as the United States (US). More than 30% of Americans are considered obese. In the past 20 years in America, incidence of obesity has increased significantly (Mokdad et al., 2003). As a consequence, the Centers for Disease Control (CDC) anticipates that 1 in 3 American adults will be diabetic by 2050 (Boyle et al., 2001; Hedley et al., 2004). The most important cause of obesity is poor nutrition, absence of physical exercise and unfavourable lifestyle changes (James et al., 2001).
175

Anticancer efficacy and mechanism of action studies of the potent plant cycloheptapeptide compounds mavacyocines

Xia, Yixuan 28 August 2020 (has links)
Over the past 200 years, much attention has been paid to natural products for their great contribution in the industry of drug development as many of them have been shown effective against various diseased conditions in humans by virtue of their structural diversity and biological potency. Therefore, they are undeniably a rich resource for the discovery of novel bioactive compounds. To date, many of the mainstay anticancer agents often lead to undesirable side effects and/or develop rapid emergence of drug resistance. Therefore, new therapeutic remedies are desperately needed. In fact, many active compounds are derived from macrocyclic natural products. The identification of their molecular targets may assist researchers to synthesize biological agents for combating particular diseased conditions. Cycloheptapeptides that modulate specific molecular pathways in suppressing the proliferation of cancer cells are potential candidates for anticancer therapeutics and/or chemopreventive agents. In the current research project, we have demonstrated that MV-A, a novel cycloheptapeptide with the unique amino acid DMCPA isolated from Maytenus variabilis (Loes.) C. Y. Cheng (Celastraceae), showed potent cytotoxic activities against a panel of human cancer cell lines, and is worthy for further investigation. Objectives--The objectives of this study were to i) evaluate the anticancer effect, ii) elucidate the mechanism of action, and iii) identify the binding target(s) of the natural cycloheptapeptide MV-A. Methods--We first carried out various kinds of cellular and animal studies for validating the in vitro and in vivo anticancer efficacy of MV-A. Next, we performed a number of bioassays to ascertain the inhibitory effect of MV-A on several major cancer-associated pathways, including apoptosis, cell cycle arrest, senescence and metastasis. The biochemical assays included sulforhodamine B colorimetric assay, flow cytometric analyses of apoptosis and cell cycle arrest, Western blotting, real-time polymerase chain reactions (qPCR) arrays, senescence-associated β-galactosidase staining, phospho-specific protein arrays, as well as migration and invasion staining experiments. Lastly, we also identified the potential protein targets of MV-A by biochemical means, particularly the drug affinity responsive target stability (DARTS) approach. Results--MV-A is a potent anti-proliferative agent against a variety of cancer cells. It inhibited the proliferation of the human colorectal carcinoma (CRC) HCT116 cells with an IC50 value of 2.28 nM. However, the application of MV-A at 2.68 nM did not induce significant apoptosis; rather it caused a notable cell-cycle arrest at the G1 phase. Moreover, the treatment with this compound (0.68 to 2.68 nM) led to a remarkable senescence in cancer cells as well as a mitigated cellular migration. Meanwhile, the expression levels of some components of the p16 cascade and PI3K-AKT pathway, so as several epithelial-to-mesenchymal transition (EMT) molecules were suppressed by MV-A. Furthermore, HSP90, calnexin, EF2, 14-3-3 and annexin A1 were identified as the direct binding targets of MV-A in our DARTS analysis.Conclusions--In the present study, our results indicated that the novel cycloheptapeptide MV-A inhibited proliferation and migration of CRC HCT116 cells via the induction of cellular senescence and modulation of multiple pathways, including the p16/Rb, PI3K-AKT and EMT signaling pathways. These results revealed a potential role of MV-A in cancer therapy. The direct binding targets of MV-A further uncovered its molecular actions against different diseased conditions. Our findings strongly support the development of MV-A as a therapeutic agent for combating cancerous pathologies, explicitly CRC.
176

Anticancer efficacy and mechanism of action studies of the potent plant cycloheptapeptide compounds mavacyocines

Xia, Yixuan 28 August 2020 (has links)
Over the past 200 years, much attention has been paid to natural products for their great contribution in the industry of drug development as many of them have been shown effective against various diseased conditions in humans by virtue of their structural diversity and biological potency. Therefore, they are undeniably a rich resource for the discovery of novel bioactive compounds. To date, many of the mainstay anticancer agents often lead to undesirable side effects and/or develop rapid emergence of drug resistance. Therefore, new therapeutic remedies are desperately needed. In fact, many active compounds are derived from macrocyclic natural products. The identification of their molecular targets may assist researchers to synthesize biological agents for combating particular diseased conditions. Cycloheptapeptides that modulate specific molecular pathways in suppressing the proliferation of cancer cells are potential candidates for anticancer therapeutics and/or chemopreventive agents. In the current research project, we have demonstrated that MV-A, a novel cycloheptapeptide with the unique amino acid DMCPA isolated from Maytenus variabilis (Loes.) C. Y. Cheng (Celastraceae), showed potent cytotoxic activities against a panel of human cancer cell lines, and is worthy for further investigation. Objectives--The objectives of this study were to i) evaluate the anticancer effect, ii) elucidate the mechanism of action, and iii) identify the binding target(s) of the natural cycloheptapeptide MV-A. Methods--We first carried out various kinds of cellular and animal studies for validating the in vitro and in vivo anticancer efficacy of MV-A. Next, we performed a number of bioassays to ascertain the inhibitory effect of MV-A on several major cancer-associated pathways, including apoptosis, cell cycle arrest, senescence and metastasis. The biochemical assays included sulforhodamine B colorimetric assay, flow cytometric analyses of apoptosis and cell cycle arrest, Western blotting, real-time polymerase chain reactions (qPCR) arrays, senescence-associated β-galactosidase staining, phospho-specific protein arrays, as well as migration and invasion staining experiments. Lastly, we also identified the potential protein targets of MV-A by biochemical means, particularly the drug affinity responsive target stability (DARTS) approach. Results--MV-A is a potent anti-proliferative agent against a variety of cancer cells. It inhibited the proliferation of the human colorectal carcinoma (CRC) HCT116 cells with an IC50 value of 2.28 nM. However, the application of MV-A at 2.68 nM did not induce significant apoptosis; rather it caused a notable cell-cycle arrest at the G1 phase. Moreover, the treatment with this compound (0.68 to 2.68 nM) led to a remarkable senescence in cancer cells as well as a mitigated cellular migration. Meanwhile, the expression levels of some components of the p16 cascade and PI3K-AKT pathway, so as several epithelial-to-mesenchymal transition (EMT) molecules were suppressed by MV-A. Furthermore, HSP90, calnexin, EF2, 14-3-3 and annexin A1 were identified as the direct binding targets of MV-A in our DARTS analysis.Conclusions--In the present study, our results indicated that the novel cycloheptapeptide MV-A inhibited proliferation and migration of CRC HCT116 cells via the induction of cellular senescence and modulation of multiple pathways, including the p16/Rb, PI3K-AKT and EMT signaling pathways. These results revealed a potential role of MV-A in cancer therapy. The direct binding targets of MV-A further uncovered its molecular actions against different diseased conditions. Our findings strongly support the development of MV-A as a therapeutic agent for combating cancerous pathologies, explicitly CRC.
177

Medicinal plant sales : a case study in Northern Zululand

Ndawonde, Busisiwe Gude January 2006 (has links)
A mini dissertation submitted in partial fulfillments for the degree of master of Environmental Education in the department of Comparative and Science Education at the University of Zululand, 2006. / Most tribes in South Africa still make use oftraditional medicines and use prescriptions ofherbs and other natural materials (Matsiliza and Barker 2001). Medicinal plants from Northern KwaZulu-Natal (KZN), particularly areas such as UIundi, Empangeni, Eshowe Mtubatuba and Nongoma are no exception and are a constituent of a traditional culture. The informal trade in indigenous plants for medicinal use (umuthi) is growing constantly (Mander, 1998). There are many reasons for this, including an expanding population coupled with modernisation of society that is hastened by the development of roads, improved communication methods and the migration of people from villages to cities. The prohibitive cost of modern medicines, together with the high rate of unemployment is forcing many people to revert to traditional medicines and even to gather and sell medicinal plants as a living. This results in over-exploitation of some plant species, sometimes to the brink ofextinction (Matsiliza and Barker 2001). This study aims at investigating the implications of plant harvests that are sold at bus ranks in northern KwaZuluNatal, and at identifYing target species for threatened plant programmes with the help of data gathered via direct interviews with medicinal plant sellers. It also aims at identifying and remedying knowledge gaps that may exist among plant gatherers about propagation techniques applicable to the medicinal plants they harvest.
178

Tropical host plant-insect relationships as guides to medicinally-active plants

Helson, Julie Elizabeth. January 2005 (has links)
No description available.
179

Circum-Mediterranean cultural heritage and medicial plant uses in traditional animal healthcare: a field survey in eight selected areas within the RUBIA project

Pieroni, Andrea, Giusti, M.E., de Pasquale, C., Lenzarini, C., Censorii, E., Gonzales-Tejero, M.R., Sanchez-Rojas, Cr. P., Ramiro-Gutierrez, J.M., Skoula, M., Johnson, C., Sarpaki, A., Della, A., Paraskeva-Hadjichambi, D., Hadjichambis, A., Hmamouchi, M., El-Jorhi, S., El-Demerdash, M., El-Zayat, M., Al-Shahaby, O., Houmani, Z., Scherazed, M. January 2006 (has links)
Yes / During the years 2003¿2005, a comparative ethnobotanical field survey was conducted on remedies used in traditional animal healthcare in eight Mediterranean areas. The study sites were selected within the EU-funded RUBIA project, and were as follows: the upper Kelmend Province of Albania; the Capannori area in Eastern Tuscany and the Bagnocavallo area of Romagna, Italy; Cercle de Ouezanne, Morocco; Sierra de Aracena y Picos de Aroche Natural Park in the province of Huelva, Spain; the St. Catherine area of the Sinai Peninsula, Egypt; Eastern and Western Crete, Greece; the Paphos and Larnaca areas of Cyprus; and the Mitidja area of Algeria. One hundred and thirty-six veterinary preparations and 110 plant taxa were recorded in the survey, with Asteraceae and Lamiaceae being the most quoted botanical families. For certain plant species the survey uncovered veterinary phytotherapeutical indications that were very uncommon, and to our knowledge never recorded before. These include Anabasis articulata (Chenopodiaceae), Cardopatium corymbosum (Asteraceae), Lilium martagon (Liliaceae), Dorycnium rectum (Fabaceae), Oenanthe pimpinelloides (Apiaceae), Origanum floribundum (Lamiaceae), Tuberaria lignosa (Cistaceae), and Dittrichia graveolens (Asteraceae). These phytotherapeutical indications are briefly discussed in this report, taking into account modern phytopharmacology and phytochemistry. The percentage of overall botanical veterinary taxa recorded in all the study areas was extremely low (8%), however when all taxa belonging to the same botanical genus are considered, this portion increases to 17%. Nevertheless, very few plant uses were found to be part of a presumed "Mediterranean" cultural heritage in veterinary practices, which raises critical questions about the concept of Mediterraneanism in ethnobotany and suggests that further discussion is required. Nearly the half of the recorded veterinary plant uses for mammals uncovered in this survey have also been recorded in the same areas in human folk medicine, suggesting a strong link between human and veterinary medical practices, and perhaps also suggesting the adaptive origins of a few medical practices. Since most of the recorded data concern remedies for treating cattle, sheep, goats, and camels, it would be interesting to test a few of the recorded phytotherapeuticals in the future, to see if they are indeed able to improve animal healthcare in breeding environments, or to raise the quality of dairy and meat products in the absence of classical, industrial, veterinary pharmaceuticals.
180

Traditional phytotherapy and trans-cultural pharmacy among Turkish migrants living in Cologne, Germany.

Pieroni, Andrea, Müenz, H., Akbulut, M., Husnu, K., Baser, K.H.C., Durmuskahya, C. January 2005 (has links)
No / This article reports on an ethnopharmaceutical field study carried out among Turkish migrants in Cologne, western Germany, which recorded 79 botanical taxa and 115 plant-based preparations, encompassing 167 folk phytotherapeutical uses, as well as a few other biological (animal and mineral derived) remedies. One-fourth of the recorded remedies were represented by food¿medicines. Half of the ingredients quoted came originally from Turkey; only a few plants were gathered from the wild or cultivated in the Cologne area. This article discusses the Turkish migrants¿ frequent use of aerial parts of Sideritis species, the fruits of Pistacia terebinthus and the seeds of Peganum harmala from the perspective of modern phytopharmacology, phytotherapy and toxicology. It considers cultural adaptation related to the use of folk pharmaceuticals by analysing the ingredients of the Turkish folk pharmacopoeia and comparing them with those of the Turkish medical ethnobotany and of the phytotherapy of the host country (Germany). Only one third of the remedies mentioned by Turkish migrants living in Cologne are also known in German evidence-based phytotherapy, and less than 10% of the recorded phytotherapeutic uses are common to both pharmacopoeias. This article concludes by suggesting hypotheses on future changes affecting the knowledge and use of medicinal plants within the Turkish community of Cologne.

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