Extensive research has already been performed on Aloe vera therefore it is important that researchers include other aloe species, such as Aloe marlothii and Aloe ferox, in studies involving aloe plant materials (Loots et al., 2007:6891). The use of natural products has regained popularity and in recent years the demand for alternative medication has risen considerably (Walji & Wiktorowicz, 2013:86). The hydration state of the human skin is fundamental for its normal functioning (Verdier-Sévrain & Bonté, 2007:75), with healthy skin possessing a water content higher than 10% (w/v) (Blank, 1952:439). This demonstrates the importance of the topical application of skin moisturisers as part of basic skin care regime (Verdier-Sévrain & Bonté, 2007:75). The first part of this project focused on the in vivo skin hydration effects of the precipitated polysaccharide components of A. vera, A. ferox and A. marlothii leaf gel materials (3% (w/v)) after single (30, 90 and 150 min after application) and multiple applications (twice daily application over a period of four weeks) on healthy volunteers, respectively. The anti-erythema effects of these aloe materials on sodium lauryl sulphate irritated skin were also examined. The skin hydration effects of the aloe materials were determined with the Corneometer® CM 825 and Visioscan® VC 98 during the short term study (single application) and longer term study (multiple applications). In addition, as an indirect measurement of skin hydration, the Cutometer® dual MPA 580 was used to measure skin elasticity during the longer term study. To determine the anti-erythema effects of the aloe materials when applied to irritated skin areas, the haemoglobin content of the skin was measured with a Mexameter® MX 18. The results from the in vivo study indicated that A. ferox gel material dehydrated the skin, whereas A. vera and A. marlothii gel materials hydrated the skin during the short term study. Results from the longer term study showed that all the aloe leaf materials have skin dehydration effects, probably due to the aloe absorbing moisture from the skin into the applied gel layer upon drying. From the anti-erythema study, it was seen that A. vera and A. ferox materials had the potential to reduce erythema on the skin similar to that of the positive control group (i.e. hydrocortisone gel) after six days of treatment. The skin possesses exceptional barrier properties which can mostly be ascribed to the outermost layer of the skin, the stratum corneum (SC). Due to the physical barrier the skin has against drug permeation, the delivery of drug molecules into and across the skin continues to be challenging (Lane, 2013:13) and to overcome this barrier, penetration enhancers can be used to efficiently deliver drugs across the skin (Barry, 2002:522). The aim of the second part of this project was to determine the skin penetration enhancing effects of the gel and whole leaf materials of A. vera, A. marlothii and A. ferox. Ketoprofen was used as the marker compound and a high performance liquid chromatography (HPLC) method was developed and validated to determine the amount of ketoprofen present in the samples. Prior to the skin diffusion studies, membrane release studies were performed to test whether the solutions containing different concentrations of the aloe leaf materials (i.e. 3.00%, 1.50% and 0.75% (w/v)) released ketoprofen from their gel-like structures. From these studies, it was evident the 0.75% (w/v) concentration had the highest average percentage ketoprofen release, which was subsequently chosen as the concentration for the aloe leaf materials tested in the transdermal skin diffusion studies. The in vitro permeation study was conducted across dermatomed (400 μm thick) skin in Franz diffusion cells. Tape stripping was performed after completion of the diffusion studies to determine the concentration ketoprofen present in the SC-epidermis and epidermis-dermis layers of the skin. Results from the in vitro permeation study showed that A. vera gel enhanced the flux of ketoprofen to the highest extent (20.464 μg/cm2.h) when compared to the control group (8.020 μg/cm2.h). Aloe marlothii gel (12.756 μg/cm2.h) and A. ferox whole leaf material (12.187 μg/cm2.h) also enhanced the permeation of ketoprofen across the skin compared to the control group. A. vera gel material was the most efficient transdermal drug penetration enhancer of the selected aloe species investigated. In order to determine by which mechanism the aloe leaf materials enhanced the skin permeation of ketoprofen (Hadgraft et al., 2003:141), the permeation profiles were analysed using a non-linear curve-fitting procedure (Díez-Sales et al., 1991:3) to obtain α, β and kp values. A change in the α-value indicated the aloe leaf material influenced the partition coefficient (K), whereas a change in β indicated the aloe leaf material influenced the diffusivity (D) (with the assumption that h, the diffusional path length is constant) (Otto et al., 2010:278). The calculated α-values indicated the drug permeation enhancing effect of A. vera gel can be ascribed to an increased partitioning of the drug into the skin. The calculated β-values showed A. ferox whole leaf altered the diffusion characteristics of the skin for ketoprofen. The tape stripping results showed A. marlothii whole leaf delivered the highest concentration of the ketoprofen into the SC-epidermis and epidermis-dermis layers of the skin. / PhD (Pharmaceutics), North-West University, Potchefstroom Campus, 2014

Extensive research has already been performed on Aloe vera therefore it is important that researchers include other aloe species, such as Aloe marlothii and Aloe ferox, in studies involving aloe plant materials (Loots et al., 2007:6891). The use of natural products has regained popularity and in recent years the demand for alternative medication has risen considerably (Walji & Wiktorowicz, 2013:86). The hydration state of the human skin is fundamental for its normal functioning (Verdier-Sévrain & Bonté, 2007:75), with healthy skin possessing a water content higher than 10% (w/v) (Blank, 1952:439). This demonstrates the importance of the topical application of skin moisturisers as part of basic skin care regime (Verdier-Sévrain & Bonté, 2007:75). The first part of this project focused on the in vivo skin hydration effects of the precipitated polysaccharide components of A. vera, A. ferox and A. marlothii leaf gel materials (3% (w/v)) after single (30, 90 and 150 min after application) and multiple applications (twice daily application over a period of four weeks) on healthy volunteers, respectively. The anti-erythema effects of these aloe materials on sodium lauryl sulphate irritated skin were also examined. The skin hydration effects of the aloe materials were determined with the Corneometer® CM 825 and Visioscan® VC 98 during the short term study (single application) and longer term study (multiple applications). In addition, as an indirect measurement of skin hydration, the Cutometer® dual MPA 580 was used to measure skin elasticity during the longer term study. To determine the anti-erythema effects of the aloe materials when applied to irritated skin areas, the haemoglobin content of the skin was measured with a Mexameter® MX 18. The results from the in vivo study indicated that A. ferox gel material dehydrated the skin, whereas A. vera and A. marlothii gel materials hydrated the skin during the short term study. Results from the longer term study showed that all the aloe leaf materials have skin dehydration effects, probably due to the aloe absorbing moisture from the skin into the applied gel layer upon drying. From the anti-erythema study, it was seen that A. vera and A. ferox materials had the potential to reduce erythema on the skin similar to that of the positive control group (i.e. hydrocortisone gel) after six days of treatment. The skin possesses exceptional barrier properties which can mostly be ascribed to the outermost layer of the skin, the stratum corneum (SC). Due to the physical barrier the skin has against drug permeation, the delivery of drug molecules into and across the skin continues to be challenging (Lane, 2013:13) and to overcome this barrier, penetration enhancers can be used to efficiently deliver drugs across the skin (Barry, 2002:522). The aim of the second part of this project was to determine the skin penetration enhancing effects of the gel and whole leaf materials of A. vera, A. marlothii and A. ferox. Ketoprofen was used as the marker compound and a high performance liquid chromatography (HPLC) method was developed and validated to determine the amount of ketoprofen present in the samples. Prior to the skin diffusion studies, membrane release studies were performed to test whether the solutions containing different concentrations of the aloe leaf materials (i.e. 3.00%, 1.50% and 0.75% (w/v)) released ketoprofen from their gel-like structures. From these studies, it was evident the 0.75% (w/v) concentration had the highest average percentage ketoprofen release, which was subsequently chosen as the concentration for the aloe leaf materials tested in the transdermal skin diffusion studies. The in vitro permeation study was conducted across dermatomed (400 μm thick) skin in Franz diffusion cells. Tape stripping was performed after completion of the diffusion studies to determine the concentration ketoprofen present in the SC-epidermis and epidermis-dermis layers of the skin. Results from the in vitro permeation study showed that A. vera gel enhanced the flux of ketoprofen to the highest extent (20.464 μg/cm2.h) when compared to the control group (8.020 μg/cm2.h). Aloe marlothii gel (12.756 μg/cm2.h) and A. ferox whole leaf material (12.187 μg/cm2.h) also enhanced the permeation of ketoprofen across the skin compared to the control group. A. vera gel material was the most efficient transdermal drug penetration enhancer of the selected aloe species investigated. In order to determine by which mechanism the aloe leaf materials enhanced the skin permeation of ketoprofen (Hadgraft et al., 2003:141), the permeation profiles were analysed using a non-linear curve-fitting procedure (Díez-Sales et al., 1991:3) to obtain α, β and kp values. A change in the α-value indicated the aloe leaf material influenced the partition coefficient (K), whereas a change in β indicated the aloe leaf material influenced the diffusivity (D) (with the assumption that h, the diffusional path length is constant) (Otto et al., 2010:278). The calculated α-values indicated the drug permeation enhancing effect of A. vera gel can be ascribed to an increased partitioning of the drug into the skin. The calculated β-values showed A. ferox whole leaf altered the diffusion characteristics of the skin for ketoprofen. The tape stripping results showed A. marlothii whole leaf delivered the highest concentration of the ketoprofen into the SC-epidermis and epidermis-dermis layers of the skin. / PhD (Pharmaceutics), North-West University, Potchefstroom Campus, 2014

Submitted by Emanuel Varela Cardoso (emanuel.varela@ufcg.edu.br) on 2018-06-21T23:28:14Z No. of bitstreams: 1 OSCAR GOMES DA SILVA NETO – DISSERTAÇÃO (UAEMa) 2015.pdf: 1645990 bytes, checksum: e448fc8b851a203983ccd784d8234090 (MD5) / Made available in DSpace on 2018-06-21T23:28:14Z (GMT). No. of bitstreams: 1 OSCAR GOMES DA SILVA NETO – DISSERTAÇÃO (UAEMa) 2015.pdf: 1645990 bytes, checksum: e448fc8b851a203983ccd784d8234090 (MD5) Previous issue date: 2018-06-21 / A ecografia é um dos métodos de diagnóstico por imagem mais versátil e difundido na atualidade, de aplicação relativamente simples, basear-se no fenômeno de interação de uma onda mecânica com os tecidos corporais, ou seja, observa as propriedades mecânicas dos tecidos ao longo da propagação da onda pelos mesmos, necessitando de um gel de acoplamento acústico para aumentar o contato entre a pele e o aparelho. A Aloe vera (Aloe barbadensis Miller) é uma planta suculenta perene, que desenvolve um tecido de armazenamento de água no interior das folhas, o gel, para sobreviver em zonas áridas de pluviosidade baixa ou irregular. Desta forma, este trabalho objetivou a extração do gel de Aloe vera, com subsequente análise de suas propriedades físicas, químicas e biológicas. Foram realizados testes de avaliação da sua funcionalidade para aquisição de imagens por ecografia e, por fim, realizado estudo comparativo com imagens ecográficas adquiridas com o gel de Aloe vera e com o gel comercial atualmente utilizado. O gel de Aloe Vera a 100% foi extraído da própria planta, processado e caracterizado por espectroscopia na Região do Infravermelho com Transformada de Fourier (FTIR), espectroscopia por Energia Dispersiva de raios X (EDS), Ensaio de Citotoxicidade e Ecografia. As análises foram realizadas no Laboratório de Desenvolvimento e Avaliação de Biomateriais (CERTBIO). O gel de Aloe vera quando utilizado para fins de obtenção de imagem, apresentou resultado igual ou superior às imagens obtidas com o gel comercial, podendo ter ocorrido devido a menor resistência oferecida pelo mesmo e consequentemente maior condutividade, provavelmente pela maior quantidade de íons livres, permitindo a diminuição da impedância do transdutor em relação à pele, promovendo a propagação do ultrassom desde o transdutor até os órgãos avaliados. Com base nos resultados obtidos nos ensaios de Espectroscopia na Região do Infravermelho com Transformada de Fourier, Espectroscopia por Energia Dispersiva de raios X, Citotoxicidade e Exames Ecográficos, pode-se concluir que os materiais apresentam características semelhantes, indicando que o gel de Aloe vera possa ser utilizado em exames de ultrassonografia. / Ultrasound is a diagnostic methods for more versatile and widespread image today, relatively simple application, be based on the interaction phenomenon of a mechanical wave with body tissues, ie observe the mechanical properties of tissues along the Wave propagation through the same, necessitating an acoustic coupling gel to increase the contact between the skin and the device. Aloe vera (Aloe barbadensis Miller) is a succulent perennial plant which develops a water storage tissue sheets within the gel, to survive in arid zones of low rainfall or irregular. Thus, this study aimed to extract the gel of Aloe vera, with subsequent analysis of their physical, chemical and biological properties, as well as evaluation tests were carried out of its functionality for image acquisition by ultrasound and finally performed study comparison with ultrasound images acquired with the gel of Aloe vera and commercial gel currently used. The gel of Aloe Vera 100% was extracted from the plant itself, processed and characterized by Spectroscopy in Infrared Region Fourier Transform (FTIR) Spectroscopy Energy Dispersive X-ray (EDS), Cytotoxicity and ultrasound test. The analyzes were performed at the Development Laboratory and Biomaterials Assessment (CERTBIO). The Aloe vera gel when used for the purpose of obtaining image presented results equal to or better than the images obtained with the commercial gel and this may be due to lower resistance of the same and therefore higher conductivity and this can probably allow the reduction of the impedance of the transducer relative to the skin, promoting the propagation of ultrasound from the transducer to the evaluated organs. Since based on the results obtained in tests spectroscopy in the infrared Fourier transform spectroscopy, by Energy Dispersive X-ray, ultrasound examinations and cytotoxicity, it can be concluded that the materials have similar characteristics indicative that the aloe vera gel may be used on ultrasound examination.

This study aims to evaluate the effect of a drug in order to avoid the appearance of side effects of human pulp fibroblasts. The groups were divided into: CTR with culture medium with fibroblasts; CL, FTL only; AA, Aloe vera with distilled water; AL, Aloe vera with distilled water and FTL; HA, calcium hydroxide P.A. With distilled water; HL, calcium hydroxide P.A. With distilled water and FTL; HAA, calcium hydroxide P.A. With Aloe vera and distilled water; HAL, calcium hydroxide P.A. With Aloe vera, distilled water and FTL. Cytotoxicity evaluation was performed with the MTT reagent at 24, 48 and 72 h, for the evaluation of genotoxicity the micronucleus test was used in 24 h. At 24 h, the CL group presented a greater media of cellular viability, and the HA showed lower mean but stimulated greater number of cell division. At 48 h, the CL group presented a higher medium of cellular viability of high genotoxicity, and the HAL showed lower mean. The AL group showed a higher percentage of surviving cells in 72 h with statistic different from the HA and HL groups (p <0.05). (P <0.001) and to the AA group (p <0.01). The AL group exhibited high genotoxicity with significant results when the CTR group (p <0.001) and the AA group (p <0.01). It is concluded that Aloe vera allowed a greater cell viability in human pulp fibroblasts in the presence of calcium hydroxide, with the increase of the genotoxicity increase in this association. Calcium hydroxide and an FTL showed higher cytotoxicity. / Este estudo objetiva avaliar in vitro o efeito da Aloe vera associada a medicamento de uso endodôntico combinados ou não a FTL em fibroblastos pulpares humanos FP6. Os grupos foram divididos em: CTR com meio de cultura com fibroblastos; CL, apenas FTL; AA, Aloe vera com água destilada; AL, Aloe vera com água destilada e FTL; HA, hidróxido de cálcio P.A. com água destilada; HL, hidróxido de cálcio P.A. com água destilada e FTL; HAA, hidróxido de cálcio P.A. com Aloe vera e água destilada; HAL, hidróxido de cálcio P.A. com Aloe vera, água destilada e FTL. A avaliação da citotoxicidade sucedeu-se com o reagente MTT em 24, 48 e 72 h e, para avaliação da genotoxicidade utilizou-se o teste de micronúcleo em 24 h. Em 24 h, o grupo CL apresentou a maior média de viabilidade celular, e o HA mostrou menor média mas estimulou maior número de divisão celular. Em 48 h, o grupo CL apresentou a maior média de viabilidade celular apesar da elevada genotoxicidade, e o HAL mostrou menor média. O grupo AL demonstrou maior percentual de células sobreviventes em 72 h com diferença estatística dos grupos HA e HL (p<0,05). O grupo AL exibiu alta genotoxicidade tendo resultados significantes quando em comparação com o grupo CTR (p<0,001) e ao grupo AA (p<0,01). Conclui-se que a Aloe vera permitiu uma maior viabilidade celular em fibroblastos pulpares humanos na presença do hidróxido de cálcio, contudo houve aumento da genotoxicidade nessa associação. Já o hidróxido de cálcio e a FTL apresentaram maior citotoxicidade.

Department of Food Science and Technology / MSCPNT

The present study aims at the isolation and identification of diverse phenolic polyketides from Aloe vera (L.) Burm.f. and Aloe plicatilis (L.) Miller and includes their 5-LOX/COX-1 inhibiting potency. After initial Sephadex-LH20 gel filtration and combined silica gel 60- and RP18-CC, three dihydroisocoumarins (nonaketides), four 5-methyl-8-C-glucosylchromones (heptaketides) from A. vera, and two hexaketide-naphthalenes from A. plicatilis have been isolated by means of HSCCC. The structures of all polyketides were elucidated by ESI-MS and 2D 1H/13C-NMR (HMQC, HMBC) techniques. The analytical/preparative separation of 3R-feralolide, 3′-O-β-d-glucopyranosyl- and the new 6-O-β-d-glucopyranosyl-3R-feralolide into their respective positional isomers are described here for the first time, including the assignment of the 3R-configuration in all feralolides by comparative CD spectroscopy. The chromones 7-O-methyl-aloesin and 7-O-methyl-aloeresin A were isolated for the first time from A. vera, together with the previously described aloesin (syn. aloeresin B) and aloeresin D. Furthermore, the new 5,6,7,8-tetrahydro-1-O-β-d-glucopyranosyl- 3,6R-dihydroxy-8R-methylnaphtalene was isolated from A. plicatilis, together with the known plicataloside. Subsequently, biological-pharmacological screening was performed to identify Aloe polyketides with anti-inflammatory potential in vitro. In addition to the above constituents, the anthranoids (octaketides) aloe emodin, aloin, 6′-(E)-p-coumaroyl-aloin A and B, and 6′-(E)-p-coumaroyl-7-hydroxy-8-O-methyl-aloin A and B were tested. In the COX-1 examination, only feralolide (10 µM) inhibited the formation of MDA by 24%, whereas the other polyketides did not display any inhibition at all. In the 5-LOX-test, all aloin-type anthranoids (10 µM) inhibited the formation of LTB4 by about 25–41%. Aloesin also displayed 10% inhibition at 10 µM in this in vitro setup, while the other chromones and naphthalenes did not display any activity. The present study, therefore, demonstrates the importance of low molecular phenolic polyketides for the known overall anti-inflammatory activity of Aloe vera preparations.

A babosa (Aloe vera (L.) Burm. f.), família Asphodelaceae, reconhecida e explorada mundialmente pela indústria farmacêutica e cosmética devido aos princípios medicinais de seus compostos fenólicos e principalmente ao gel de polissacarídeos específicos, foi submetida a dois experimentos interligados. O primeiro, refere-se a micropropagação no qual foram avaliados tratamentos de desinfestação de ápices caulinares, multiplicação in vitro e condições de aclimatação ex vitro. O segundo experimento refere-se ao cultivo das plantas em areia lavada e irrigada com solução nutritiva, em condições controladas de casa de vegetação, onde foram testados os efeitos de doses (105; 210 e 315 ppm) de nitrogênio avaliados aos 90; 180 e 270 dias de cultivo. Os efeitos foram avaliados em função dos teores foliares dos macronutrientes e dos micronutrientes boro, cobre, ferro manganês e zinco, de proteínas totais solúveis (PTS), de açúcares redutores (AR) e açúcares totais solúveis (ATS) e sobre o crescimento por meio do índice de área foliar (IAF), da taxa de assimilação líquida (TAL), taxa de crescimento relativo (TCR), taxa de crescimento absoluto (TCA) e incrementos de massas de matérias fresca (IMMF) e seca (IMMS). Todos os dados foram analisados estatisticamente. Em relação a micropropagação, a eficiência de desinfestação foi aumentada em torno de 40% na obtenção de ápices caulinares verdes em início de brotação quando as plantas colhidas a campo foram previamente desinfestadas por lavagem com solução de hipoclorito de sódio com 0,5% de cloro ativo ou com solução de dicloroisocianurato de sódio (Sumaveg®) 0,66%. p.v-1 e os ápices caulinares submetidos a imersões alternadas nas soluções dos dois produtos utilizados. A fase multiplicativa da microproagação em meio MS apresentou um rendimento de 1:5,3 a cada intervalo de 30 dias de multiplicação. A partir de 136 ápices caulinares desinfestados, verdes, em início de brotação, foram obtidas 40.495 microplantas. Classificadas em pequenas, médias e grandes, foram submetidas a condições de aclimatação observando-se que bandejas de 64 células com 40 cm3 de substrato apresentaram economia em torno de 50% de substrato e em espaço físico na casa-de-vegetação com micro-aspersão e exaustão de ar em sistema \"pad-house\", e durante o processo de aclimatação e transporte das microplantas aclimatadas. Em relação ao cultivo das plantas em doses de nitrogênio, apesar de algumas variáveis responderem melhor à dose de 105 ppm e outras à dose de 315 ppm, a dose de 210 ppm de nitrogênio favoreceu as melhores respostas para os teores de açúcares totais solúveis (504,21 mgATS.g-1 de MMS), que são diretamente relacionados ao conteúdo de polissacarídeos específicos, de interesse comercial da cultura de Aloe vera. Esses teores, por sua vez, foram propiciados pelos melhores valores de IAF, TCA, IMMF e IMMS, todos observados aos 270 dias de cultivo, ratificando a significância do fator tempo e da dose de 210 ppm de nitrogênio no cultivo dessa espécie vegetal. / Aloe vera (L.) Burm. f., family Asphodelaceae, worldwide renowned and explored by pharmaceutics and cosmetics industries due to its phenolics bearing medicinal principles and mainly to the specific polysaccharides present in the gel, was submitted to two interlinked experiments. The first one refers to apical shoot micropropagation evaluating different disinfection treatments of the explants, the in vitro bud multiplication and ex vitro acclimatization of the microplants. The second one refers to cultivation in greenhouse of the micropropagated plants in washed sand and irrigated with nutritive solution, in the presence of three nitrogen rates (105, 210 and 315 ppm); the plant material was harvested at 90-, 180- and 270-day. All data were statistically analyzed. The effects of nitrogen were evaluated on the content of the macronutrients, the following micronutrients: B, Cu, Fe, Mn and Zn and total soluble proteins, reducing sugars, total soluble sugars; the growth of the Aloe vera plants was measured through the foliar area index, the rate of liquid assimilation, rates of relative and absolute growth and increases in the fresh and dry weights. In regards to micropropagtion, the efficiency of the disinfection process was increased by 40% when the plants harvested in the field were previously washed either with sodium hypochloride (0.5% active chlorine) solution or sodium dichloroisocyanurate (Sumaveg®) 0.66% w.v-1 solution and the apical shoots explants were afterwards alternatively treated with the two disinfectants. The multiplication phase in MS medium showed a rate of 1:5.3 of microplant production at each 30-day interval with a production of 40.495 microplants out of the 136 initial disinfected apical shoots. The microplants were classified as small, medium and large plants and acclimatized in polyethylene trays bearing 64 cells with 40 cm3 of substrate each cell, a 50% saving in terms of substrate amount and free space in the greenhouse equipped with micro-aspersion irrigation, pad-house and air exhaustion systems and also in the transport of the acclimatized microplants. In regards to the effect of nitrogen rates on the development of Aloe vera plants, besides the fact that the best responses were observed either to 105 ppm or 315 ppm nitrogen by some variables, at 210 ppm nitrogen rates the best result was obtained for total soluble sugars (504.21 mg.g-1DW); the sugars are directly related to specific polysaccharides of Aloe vera and are of great importance for the industries. On the other hand, these values were favored by the best values reached by the physiological variables studied in this work at 270-day validate the significance of the time factor and the 210 ppm N rates in the Aloe vera production system.

A babosa (Aloe vera (L.) Burm. f.), família Asphodelaceae, reconhecida e explorada mundialmente pela indústria farmacêutica e cosmética devido aos princípios medicinais de seus compostos fenólicos e principalmente ao gel de polissacarídeos específicos, foi submetida a dois experimentos interligados. O primeiro, refere-se a micropropagação no qual foram avaliados tratamentos de desinfestação de ápices caulinares, multiplicação in vitro e condições de aclimatação ex vitro. O segundo experimento refere-se ao cultivo das plantas em areia lavada e irrigada com solução nutritiva, em condições controladas de casa de vegetação, onde foram testados os efeitos de doses (105; 210 e 315 ppm) de nitrogênio avaliados aos 90; 180 e 270 dias de cultivo. Os efeitos foram avaliados em função dos teores foliares dos macronutrientes e dos micronutrientes boro, cobre, ferro manganês e zinco, de proteínas totais solúveis (PTS), de açúcares redutores (AR) e açúcares totais solúveis (ATS) e sobre o crescimento por meio do índice de área foliar (IAF), da taxa de assimilação líquida (TAL), taxa de crescimento relativo (TCR), taxa de crescimento absoluto (TCA) e incrementos de massas de matérias fresca (IMMF) e seca (IMMS). Todos os dados foram analisados estatisticamente. Em relação a micropropagação, a eficiência de desinfestação foi aumentada em torno de 40% na obtenção de ápices caulinares verdes em início de brotação quando as plantas colhidas a campo foram previamente desinfestadas por lavagem com solução de hipoclorito de sódio com 0,5% de cloro ativo ou com solução de dicloroisocianurato de sódio (Sumaveg®) 0,66%. p.v-1 e os ápices caulinares submetidos a imersões alternadas nas soluções dos dois produtos utilizados. A fase multiplicativa da microproagação em meio MS apresentou um rendimento de 1:5,3 a cada intervalo de 30 dias de multiplicação. A partir de 136 ápices caulinares desinfestados, verdes, em início de brotação, foram obtidas 40.495 microplantas. Classificadas em pequenas, médias e grandes, foram submetidas a condições de aclimatação observando-se que bandejas de 64 células com 40 cm3 de substrato apresentaram economia em torno de 50% de substrato e em espaço físico na casa-de-vegetação com micro-aspersão e exaustão de ar em sistema \"pad-house\", e durante o processo de aclimatação e transporte das microplantas aclimatadas. Em relação ao cultivo das plantas em doses de nitrogênio, apesar de algumas variáveis responderem melhor à dose de 105 ppm e outras à dose de 315 ppm, a dose de 210 ppm de nitrogênio favoreceu as melhores respostas para os teores de açúcares totais solúveis (504,21 mgATS.g-1 de MMS), que são diretamente relacionados ao conteúdo de polissacarídeos específicos, de interesse comercial da cultura de Aloe vera. Esses teores, por sua vez, foram propiciados pelos melhores valores de IAF, TCA, IMMF e IMMS, todos observados aos 270 dias de cultivo, ratificando a significância do fator tempo e da dose de 210 ppm de nitrogênio no cultivo dessa espécie vegetal. / Aloe vera (L.) Burm. f., family Asphodelaceae, worldwide renowned and explored by pharmaceutics and cosmetics industries due to its phenolics bearing medicinal principles and mainly to the specific polysaccharides present in the gel, was submitted to two interlinked experiments. The first one refers to apical shoot micropropagation evaluating different disinfection treatments of the explants, the in vitro bud multiplication and ex vitro acclimatization of the microplants. The second one refers to cultivation in greenhouse of the micropropagated plants in washed sand and irrigated with nutritive solution, in the presence of three nitrogen rates (105, 210 and 315 ppm); the plant material was harvested at 90-, 180- and 270-day. All data were statistically analyzed. The effects of nitrogen were evaluated on the content of the macronutrients, the following micronutrients: B, Cu, Fe, Mn and Zn and total soluble proteins, reducing sugars, total soluble sugars; the growth of the Aloe vera plants was measured through the foliar area index, the rate of liquid assimilation, rates of relative and absolute growth and increases in the fresh and dry weights. In regards to micropropagtion, the efficiency of the disinfection process was increased by 40% when the plants harvested in the field were previously washed either with sodium hypochloride (0.5% active chlorine) solution or sodium dichloroisocyanurate (Sumaveg®) 0.66% w.v-1 solution and the apical shoots explants were afterwards alternatively treated with the two disinfectants. The multiplication phase in MS medium showed a rate of 1:5.3 of microplant production at each 30-day interval with a production of 40.495 microplants out of the 136 initial disinfected apical shoots. The microplants were classified as small, medium and large plants and acclimatized in polyethylene trays bearing 64 cells with 40 cm3 of substrate each cell, a 50% saving in terms of substrate amount and free space in the greenhouse equipped with micro-aspersion irrigation, pad-house and air exhaustion systems and also in the transport of the acclimatized microplants. In regards to the effect of nitrogen rates on the development of Aloe vera plants, besides the fact that the best responses were observed either to 105 ppm or 315 ppm nitrogen by some variables, at 210 ppm nitrogen rates the best result was obtained for total soluble sugars (504.21 mg.g-1DW); the sugars are directly related to specific polysaccharides of Aloe vera and are of great importance for the industries. On the other hand, these values were favored by the best values reached by the physiological variables studied in this work at 270-day validate the significance of the time factor and the 210 ppm N rates in the Aloe vera production system.