983 resultados para medicinal plants toxicity
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In the Andean highlands, indigenous environmental knowledge is currently undergoing major changes as a result of various external and internal factors. As in other parts of the world, an overall process of erosion of local knowledge can be observed. In response to this trend, some initiatives that adopt a biocultural approach aim at actively strengthening local identities and revalorizing indigenous environmental knowledge and practices, assuming that such practices can contribute to more sustainable management of biodiversity. However, these initiatives usually lack a sound research basis, as few studies have focused on the dynamics of indigenous environmental knowledge in the Andes and on its links with biodiversity management. Against this background, the general objective of this research project was to contribute to the understanding of the dynamics of indigenous environmental knowledge in the Andean highlands of Peru and Bolivia by investigating how local medicinal knowledge is socially differentiated within rural communities, how it is transformed, and which external and internal factors influence these transformation processes. The project adopted an actor-oriented perspective and emphasized the concept of knowledge dialogue by analyzing the integration of traditional and formal medicinal systems within family therapeutic strategies. It also aimed at grasping some of the links between the dynamics of medicinal knowledge and the types of land use systems and biodiversity management. Research was conducted in two case study areas of the Andes, both Quechua-speaking and situated in comparable agro-ecological production belts - Pitumarca District, Department of Cusco (Southern Peruvian Highlands) and the Tunari National Park, Department of Cochabamba (Bolivian inner-Andean valleys). In each case study area, the land use systems and strategies of 18 families from two rural communities, their environmental knowledge related to medicine and to the local therapeutic flora, and an appreciation of the dynamics of this knowledge were assessed. Data were collected through a combination of disciplinary and participatory action-research methods. It was mostly analyzed using qualitative methods, though some quantitative ethnobotanical methods were also used. In both case studies, traditional medicine still constitutes the preferred option for the families interviewed, independently of their age, education level, economic status, religion, or migration status. Surprisingly and contrary to general assertions among local NGOs and researchers, results show that there is a revival of Andean medicine within the younger generation, who have greater knowledge of medicinal plants than the previous one, value this knowledge as an important element of their way of life and relationship with “Mother Earth” (Pachamama), and, at least in the Bolivian case, prefer to consult the traditional healer rather than go to the health post. Migration to the urban centres and the Amazon lowlands, commonly thought to be an important factor of local medicinal knowledge loss, only affects people’s knowledge in the case of families who migrate over half of the year or permanently. Migration does not influence the knowledge of medicinal plants or the therapeutic strategies of families who migrate temporarily for shorter periods of time. Finally, economic status influences neither the status of people’s medicinal knowledge, nor families’ therapeutic strategies, even though the financial factor is often mentioned by practitioners and local people as the main reason for not using the formal health system. The influence of the formal health system on traditional medicinal knowledge varies in each case study area. In the Bolivian case, where it was only introduced in the 1990s and access to it is still very limited, the main impact was to give local communities access to contraceptive methods and to vaccination. In the Peruvian case, the formal system had a much greater impact on families’ health practices, due to local and national policies that, for instance, practically prohibit some traditional practices such as home birth. But in both cases, biomedicine is not considered capable of responding to cultural illnesses such as “fear” (susto), “bad air” (malviento), or “anger” (colerina). As a consequence, Andean farmers integrate the traditional medicinal system and the formal one within their multiple therapeutic strategies, reflecting an inter-ontological dialogue between different conceptions of health and illness. These findings reflect a more general trend in the Andes, where indigenous communities are currently actively revalorizing their knowledge and taking up traditional practices, thus strengthening their indigenous collective identities in a process of cultural resistance.
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Multidrug resistance pumps (MDRs) protect microbial cells from both synthetic and natural antimicrobials. Amphipathic cations are preferred substrates of MDRs. Berberine alkaloids, which are cationic antimicrobials produced by a variety of plants, are readily extruded by MDRs. Several Berberis medicinal plants producing berberine were found also to synthesize an inhibitor of the NorA MDR pump of a human pathogen Staphylococcus aureus. The inhibitor was identified as 5′-methoxyhydnocarpin (5′-MHC), previously reported as a minor component of chaulmoogra oil, a traditional therapy for leprosy. 5′-MHC is an amphipathic weak acid and is distinctly different from the cationic substrates of NorA. 5′-MHC had no antimicrobial activity alone but strongly potentiated the action of berberine and other NorA substrates against S. aureus. MDR-dependent efflux of ethidium bromide and berberine from S. aureus cells was completely inhibited by 5′-MHC. The level of accumulation of berberine in the cells was increased strongly in the presence of 5′-MHC, indicating that this plant compound effectively disabled the bacterial resistance mechanism against the berberine antimicrobial.
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"Issued June 5, 1909."
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Includes index.
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Most ethnopharmacological studies overlook food plants, yet many edible plants, also have medicinal value. I documented plants that are used as both food and medicine by the Totonac of Zapotitlan de Mendez, Mexico and recorded the presence of selected secondary compounds, and physical characteristics in these plants. Photoactivity, antimicrobial, and antifungal assays also were performed. The presence of these properties were compared among food/medicine plants, food, medicinal, and randomly selected plants. I predicted that a higher percentage of medicinal plants would contain the secondary compounds, physical characteristics, and bioactivity compared to the other groups. Phenolics and cyanogenic glycosides in the medicinal group were significantly greater than in the food/medicine group. The food plants did not differ greatly from the medicinal plants. This research indicates that including food plants in ethnomedical studies could provide a more complete knowledge of peoples therapeutic resources and practices. ^
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One-third of botanical remedies from southern Italy are used to treat skin and soft tissue infections (SST's). Methicillin-resistant Staphylococcus aureus (MRSA), a common cause of SSTIs, is responsible for increased morbidity and mortality from infections. Therapeutic options are limited by antibiotic resistance. Many plants possess potent antimicrobial compounds for these disorders. Validation of traditional medical practices is important for the people who rely on medicinal plants. Moreover, identification of novel antibiotics and anti-pathogenic agents for MRSA is important to global healthcare.^ I took an ethnopharmacological approach to understand how Italian medicinal plants used for the treatment of SSTIs affect MRSA growth and virulence. My hypothesis was that plants used in folk remedies for SSTI would exhibit lower cytotoxicity and greater inhibition of bacterial growth, biofilm formation and toxin production in MRSA than plants used for remedies unrelated to the skin or for plants with no ethnomedical application. The field portion of my research was conducted in the Vulture-Alto Bradano area of southern Italy. I collected 104 plant species and created 168 crude extracts. In the lab, I screened samples for activity against MRSA in a battery of bioassays. Growth inhibition was analyzed using broth microtiter assays for determination of the minimum inhibitory concentration. Interference with quorum-sensing (QS) processes, which mediate pathogenicity, was quantified through RP-HPLC of δ-toxin production. Interference with biofilm formation and adherence was assessed using staining methods. The mammalian cytotoxicity of natural products was analyzed using MTT cell proliferation assay techniques.^ Although bacteriostatic activity was limited, extracts from six plants used in Italian folk medicine (Arundo donax, Ballota nigra, Juglans regia, Leopoldia comosa, Marrubium vulgare, and Rubus ulmifolius ) significantly inhibited biofilm formation and adherence. Moreover, plants used to treat SSTI demonstrated significantly greater anti-biofilm activity when compared to plants with no ethnomedical application. QSI activity was evident in 90% of the extracts tested and extracts from four plants ( Ballota nigra, Castanea saliva, Rosmarinus officinalis, and Sambucus ebulus) exhibited a significant dose-dependent response. Some of the plant remedies for SSTI identified in this study can be validated due to anti-MRSA activity.^
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Diminishing cultural and biological diversity is a current global crisis. Tropical forests and indigenous peoples are adversely affected by social and environmental changes caused by global political and economic systems. The purpose of this thesis was to investigate environmental and livelihood challenges as well as medicinal plant knowledge in a Yagua village in the Peruvian Amazon. Indigenous peoples’ relationships with the environment is an important topic in environmental anthropology, and traditional botanical knowledge is an integral component of ethnobotany. Political ecology provides a useful theoretical perspective for understanding the economic and political dimensions of environmental and social conditions. This research utilized a variety of ethnographic, ethnobotanical, and community-involved methods. Findings include data and analyses about the community’s culture, subsistence and natural resource needs, organizations and institutions, and medicinal plant use. The conclusion discusses the case study in terms of the disciplinary framework and offers suggestions for research and application.
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Helicobacter pylori is a spiral, Gram negative, mobile, and microaerophilic bacteria recognized as a major cause of gastritis, ulcer, gastric cancer, and gastric low grade, B cell, mucosa – associated lymphoid tissue (MALT) lymphoma, constituting an important microorganism in medical microbiology. Its importance comes from the difficulty of treatment because the requirement of multiple drugs use, besides the increasing emergence of resistant and multiresistant strains to antibiotics used in th e clinic. In order to expand safe and effective therapeutic options , chemical studies on medicinal plants by obtaining extracts, fractions, isolated compounds or essential oils with some biological activity has been intensified . Given the above, the objective was to evaluate the inhi bitory activity of organic extracts derived from Syzygium cumini and Encholirium spectabile, with antiulcer history, and the essential oil, obtained from S. cumini, against H. pylori (ATCC 43504) by the disk diffusion method, for qualitative evaluation, an d determination of minimum inhibitory concentration (MIC) using the broth microdilution method, for quantitative analysis. Also was evaluated the extracts in vitro toxicity by a hemolytic assay using sheep red blood cells, and VERO and HeLa cells using the MTT assay to analyze cell viability. The extracts of both plant used in antimicrobial assays did not inhibit bacterial growth, however the essential oil of S. cumini (SCFO) proved effective, showing MIC value of 205 μg/mL (0.024 % dilution of the original oil). In the hemolytic assay, the same oil shows moderate toxicity, by promote 25% hemolysis at 1000 μg/mL. Regarding the cytotoxicity in cell culture, the SCFO, at 260 μg/mL, affected the cell viability around 80% of HeLa and 50% of VERO cells. So the oi l obtained from S. cumini leaves has antimicrobial activity against H. pylori and cytotoxicity potential, suggesting a source of new molecule drug candidates, since new stages of toxicity in vitro and in vivo, as well, chemical characterization be evaluate d. Moreover, the development of a prospective drug delivery system can result in a prototype to be used in preclinical tests.
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The therapeutic use of medicinal plants has contributed since antiquity in a beneficial way for health. However, many species lacks of scientific evidence which provide basis for their use in therapeutic practice. In this context is the Genipa americana L. species (Rubiaceae), popularly known as jenipapo and used to treat syfilis, ulcer and hemorrhagic disturbs. It's also used against bruising, as tonic and as aphrodisiac. Due this species lacks toxicological studies, the aim of this study was to evaluate the toxicity in vivo (acute and sub-chronic toxicity) and in vitro (cytotoxicity) of the hydroethanolic extract from G. americana fruits. The hydroethanolic extract of G. americana fruits was prepared by maceration. A preliminary phytochemical analysis was performed to assess the presence of secondary metabolites in the extract. The cytotoxicity study of the extract (0.1, 1.0, 10, 100 and 1000 mg / 100 ul) were performed against normal cells (3T3) and tumor (786-0, HepG2 and B16), analyzed by the MTT assay. To evaluate the acute (single dose of 2000 mg / Kg) and subchronic (100, 500 and 1000 mg / kg for 30 days) toxicity Swiss mice of both sexes were used. At the end of the experiment, blood samples and organs were collected for analysis. Data between groups were compared by t test or ANOVA with Dunnett's post-test with 5% significance level. The phytochemical study of the extracts mainly indicated the presence of iridoids. Results for cytotoxicity tests showed up to 70% inhibition of B16 cell line at a dose of 1000 mg / 100 ul, and up to 29% inhibition of 786-0 at a dose of 10 ug / 100 ul. The extract did not cause death in 3T3 and HepG2 cells. During the in vivo assays, there were no animal deaths. Analysis of blood samples revealed that the animals submitted to the evaluation of acute toxicity had changes in AST and ALT, and that the animals evaluated for subchronic toxicity showed changes in the relative wet weight of the kidney and plasma urea concentration. No differences were observed between groups on histopathological evaluation of the collected organs. Despite the changes found in the in vivo toxicity tests, using the criteria described by the OECD Guidelines, it is suggested that the hydroethanolic extract of the fruits of the G. americana is classified as low toxicity. The cytotoxicity of the extract suggests that they have potential against melanoma cell lines (B16).
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The therapeutic use of medicinal plants has contributed since antiquity in a beneficial way for health. However, many species lacks of scientific evidence which provide basis for their use in therapeutic practice. In this context is the Genipa americana L. species (Rubiaceae), popularly known as jenipapo and used to treat syfilis, ulcer and hemorrhagic disturbs. It's also used against bruising, as tonic and as aphrodisiac. Due this species lacks toxicological studies, the aim of this study was to evaluate the toxicity in vivo (acute and sub-chronic toxicity) and in vitro (cytotoxicity) of the hydroethanolic extract from G. americana fruits. The hydroethanolic extract of G. americana fruits was prepared by maceration. A preliminary phytochemical analysis was performed to assess the presence of secondary metabolites in the extract. The cytotoxicity study of the extract (0.1, 1.0, 10, 100 and 1000 mg / 100 ul) were performed against normal cells (3T3) and tumor (786-0, HepG2 and B16), analyzed by the MTT assay. To evaluate the acute (single dose of 2000 mg / Kg) and subchronic (100, 500 and 1000 mg / kg for 30 days) toxicity Swiss mice of both sexes were used. At the end of the experiment, blood samples and organs were collected for analysis. Data between groups were compared by t test or ANOVA with Dunnett's post-test with 5% significance level. The phytochemical study of the extracts mainly indicated the presence of iridoids. Results for cytotoxicity tests showed up to 70% inhibition of B16 cell line at a dose of 1000 mg / 100 ul, and up to 29% inhibition of 786-0 at a dose of 10 ug / 100 ul. The extract did not cause death in 3T3 and HepG2 cells. During the in vivo assays, there were no animal deaths. Analysis of blood samples revealed that the animals submitted to the evaluation of acute toxicity had changes in AST and ALT, and that the animals evaluated for subchronic toxicity showed changes in the relative wet weight of the kidney and plasma urea concentration. No differences were observed between groups on histopathological evaluation of the collected organs. Despite the changes found in the in vivo toxicity tests, using the criteria described by the OECD Guidelines, it is suggested that the hydroethanolic extract of the fruits of the G. americana is classified as low toxicity. The cytotoxicity of the extract suggests that they have potential against melanoma cell lines (B16).
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Natural resources like plants are currently used all over developed and under developed countries of the world as traditional home remedies and are promising agents for drug discovery as they play crucial role in traditional medicine. The use of plants for medicinal purpose usually varies from country to country and region to region because their use depends on the history, culture, philosophy and personal attitudes of the users (Ahmad et al., 2015). The use of plants and plant products as drugs predates the written human history (Hayta et al., 2014). Plants are a very important resource for traditional drugs and around 80% of the population of the planet use plants for the treatment of many diseases and traditional herbal medicine accounts for 30-50% of the total medicinal consumption in China. In North America, Europe and other well-developed regions over 50% of the population have used traditional preparations at least once (Dos Santos Reinaldo et al., 2015). Medicinal plants have been used over years for multiple purposes, and have increasingly attract the interest of researchers in order to evaluate their contribution to health maintenance and disease’s prevention (Murray, 2004). Recently between 50,000 and 70,000 species of plants are known and are being used in the development of modern drugs. Plants were the main therapeutic agents used by humans from the 19th century, and their role in medicine is always topical (Hayta et al., 2014). The studies of medicinal plants are rapidly increasing due to the search for new active molecules, and to improve the production of plants or bioactive molecules for the pharmaceutical industries (Rates, 2001). Several studies have been reported, but numerous active compounds directly responsible for the observed bioactive properties remain unknown, while in other cases the mechanism of action is not fully understood. According to the WHO 25% of all modern medicines including both western and traditional medicine have been extracted from plants, while 75% of new drugs against infective diseases that have arrived between 1981 and 2002 originated from natural sources, it was reported that the world market for herbal medicines stood at over US $60 billion per year and is growing steadily (Bedoya et al., 2009). Traditional medicine has an important economic impact in the 21st century as it is used worldwide, taking advantage on the low cost, accessibility, flexibility and diversity of medicinal plants (Balunas & Kinghorn, 2005).
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Thymus plants comprise distinct species with claimed health properties [1], commonly associated to their essential oils and phenolic compounds. Albeit that, the phenolic composition and the biological activities of many Thymus species remain unclear. This work aimed to elucidate the phenolic composition and antioxidant properties of aqueous extracts from Thymus herba barona, Thymus caespetitus and Thymus fragrantissimus. The aqueous extracts of the three Thymus species were evaluated for their total phenolic compounds by an adaptation of the Folin-Ciocalteu method [2], and individual phenolic compounds were identified by high performance liquid chromatography associated with electrospray mass spectrometry (HPLC-DAD-ESI-MSn) in the negative mode. The antioxidant activity of each extract was carried out by DPPH● scavenging assay and ferric reducing antioxidant power assays [3]. Total phenolic compounds in the three extracts ranged from 236±27 (T. caespetitus) to 273±17 μg GAE/mg (T. fragrantissimus). Similarly to other Thymus species [1,4], these extracts were rich in caffeic acid derivatives (characteristic UV spectra maxima at 290 and 328 nm) and mainly composed of rosmarinic acid (MW 360). Other caffeic acid derivatives included salvianolic acid K (MW 556) and 3′-O-(8″-Z-caffeoyl)rosmarinic acid (MW 538). High amounts of the flavone luteolin-O-glucuronide ([M-H]− at m/z 461→285) were found in T. caespetitus while the others species contained moderate amounts of this compound. T. herba barona, T. caespetitus and T. fragrantissimus extracts showed high DPPH radical scavenge ability (EC50 values 11.6±0.9, 13.8±0.6 and 10.9±1.2 μg/mL respectively), as well as high reducing power (EC50 values of 35.1±4.5, 39.3±2.7 and 32.4±4.3 μg/mL, respectively), that were comparable to those of reference compounds. This work is an important contribution for the phytochemical characterization and the antioxidant capacity of these three Thymus species.