Introduction: Despite the tremendous advances made with regard to synthetic organic medicinals within the last two decades, heavy reliance is still placed on plant products. This is especially true of the anthracene derivatives used medicinally as purgatives, and which are derived principally from senna, cascara, rhubarb, frangula and aloes. While particular attention has been paid to the chemistry of the former group in recent years, aloes has been largely neglected, possibly due to the fact that the Aloe species are confined largely to areas where extensive research facilities are lacking, such as Africa , India and the West Indies. Thus research in Europe has been confined largely to the lump aloes of commerce, derived from relatively few species. In 1953 a comprehensive report by Hodge (103) appeared on "The Drug Aloes of Commerce, with Special Reference to the Cape Species". Hodge observed that South Africa abounds in species just as abundant as A.ferox, (which is the prime source of Cape aloes), and advised that a systematic chemical survey might show certain of these to be not only higher yielders of bitter aloetic juice but also sources of a superior drug product. Consequently an investigation along these lines is presented here, and it is observed that several species apart from A.ferox not only contain aloin, but also yield a large volume of aloetic juice. Only pharmacologic studies can reveal if the juice of these species is as safe as that of A.ferox, but without doubt they could be used for the extraction of crystalline aloin. Concurrently, the distribution of the Aloe resins, said by some to be purgative themselves, has been studied. The investigation has revealed that the structurally similar compound homonataloin enjoys an equally wide distribution as aloin. However, almost invariably it is confined to small species yielding little aloetic juice, apart from which nothing is known regarding its pharmacologic properties. It is interesting to note that the resin distribution in the homonataloin-containing species is very similar to that of the aloin-containing species, but differs widely from. that of the species containing neither of these principles. Apart from aloin and homonataloin, aloinoside and chrysophanol also occur in Aloe species, and together with the resins, these indicate that when all the South African Aloe species have been investigated, they may well be of chemotaxonomic value. Within the comparatively short space of the last decade some work has been performed on aspects of the metabolism of such anthracene-containing species as Rheum, Rhamnus and Rumex. These investigations have shown that the anthracene derivatives are not merely waste products, but perform definite metabolic functions. The latter portion of this work has been devoted to this relatively neglected aspect of the Aloe species.

No description available.

A invasibilidade do capim-annoni-2 em agroecossistemas tem sido atribuída as suas características biológicas e relações ecológicas. A ecologia da germinação da espécie e a interação alelopática são pouco compreendidas. Este trabalho objetivou determinar a influência de fatores ambientais na germinação, a fitotoxicidade de extratos de capim-annoni-2, identificar e quantificar aleloquímicos fenólicos presentes em suas frações, determinar a influência da degradação da fitomassa e do solo na fitotoxicidade do extrato aquoso, monitorar a degradação dos compostos presentes nos extratos e identificar e quantificar aleloquímicos no solo de área contaminada. Foram realizados experimentos em laboratório utilizando materiais coletados a campo. As sementes germinaram em temperaturas constantes de 15 até 40 °C, mas as percentagens de germinação foram superiores a 94 % apenas em temperaturas alternadas. A exposição à luz aumentou a frequência de plântulas normais. A germinação aumentou com incremento no potencial de água e o número de plantas normais diminuiu com aumento na concentração de cloreto de sódio. A maior taxa de emergência foi observada com as sementes colocadas na superfície do solo, enquanto que nenhuma emergência ocorreu a 4 cm. Foram identificados e quantificados nove compostos fenólicos com potencial aleloquímico nas frações dos extratos de capim-annoni-2: ácido caféico, ácido cumárico, ácido ferúlico, ácido gálico, ácido vanílico, catequina, epicatequina, resveratrol e rutina. A ordem decrescente de fitotoxicidade geral dos extratos brutos no desenvolvimento de plântulas de trigo e alfafa foi acetato de etila, metanólico, aquoso e hexânico. Foi identificada correlação inversamente proporcional entre concentração de ácido vanílico e comprimento de radícula e total de plântulas de alfafa. A simulação da degradação da fitomassa e do solo ocasionou aumento na fitotoxicidade dos extratos sobre a germinação e o desenvolvimento de plântulas, comprovando a liberação dos aleloquímicos e a influência do solo no aumento de sua fitotoxicidade. Extratos etéreos da fitomassa e do solo incubados apresentaram modificações em seus respectivos cromatogramas do primeiro até o sétimo dia de incubação, enquanto a mistura de fitomassa + solo apresentou maiores modificações apenas entre o primeiro e o terceiro dia de degradação. Foram identificados quatro compostos fenólicos com potencial aleloquímico no solo da área infestada com capim-annoni-2: ácido cumárico, ácido ferúlico, catequina e epicatequina. A concentração destes compostos foi maior na superfície do solo e horizontalmente próximo às plantas de capim-annoni-2, evidenciando associação entre as concentrações dos aleloquímicos com a proximidade da planta. / The invasiveness of South African lovegrass in agroecosystems has been attributed to its biological characteristics and the ecological relations. The ecology of species germination and allelopathic interaction are poorly understood. The objective of this work was to determine the influence of environmental factors on germination, phytotoxicity of South African lovegrass extracts, to identify and quantify phenolic allelochemicals present in their fractions, to determine the influence of phytomass and soil degradation on the phytotoxicity of the aqueous extract, to monitor the degradation of the compounds present in the extracts and to identify and quantify allelochemicals in a infested soil. Experiments were carried out in the laboratory using materials collected in the field. Seeds germinated at constant temperatures of 15 to 40 ° C, but the percentages of germination were greater than 94 % only at alternating temperatures. Exposure to light increased the frequency of normal seedlings. Germination increased with increasing water potential and the number of normal plants decreased with increasing sodium chloride concentration. The highest emergence rate was observed with the seeds placed on the soil surface, whereas no emergence occurred at 4 cm. A total of nine phenolic compounds with allelochemical potential were identified in the fractions of extracts of South African lovegrass: caffeic acid, coumaric acid, ferulic acid, gallic acid, vanillic acid, catechin, epicatechin, resveratrol and rutin. The general decreasing order of general phytotoxicity of crude extracts in the development of wheat and alfalfa seedlings was ethyl, methanolic, aqueous and hexane acetate. An inversely proportional correlation was identified between vanillic acid concentration and root and total alfalfa seedlings length. The simulation of phytomass and soil degradation caused an increase in the phytotoxicity of the extracts on germination and seedling development, proving the release of the allelochemicals and the influence of the soil in the increase of its phytotoxicity. The ether extracts of the straw and soil showed changes in their chromatograms from the first to the seventh day of incubation, while the mixture of straw + soil showed greater changes only between the first and third day of degradation. Four phenolic compounds with allelochemical potential were identified in the South African lovegrass infested soil: coumaric acid, ferulic acid, catechin and epicatechin. The concentration of these compounds was higher at the soil surface and horizontally near the South African lovegrass plants, showing an association between concentrations of allelochemicals and plant distance.

The use of medicinal plants for healing and prevention diseases is one of the oldest practices of mankind. Among the many plants used in folk medicine, the Mimosa hostilis Benth known as jurema black popularly used in skin problems and inflammation in general. This study aimed to perform phytochemical screening and evaluate the antioxidant and antiinflammatory activity of hydroethanolic extract (HEE) and its fractions, hexane (HXF), chloroform (CLF), ethyl acetate (EAF) and hydromethanol (HMF) obtained from the inner bark of M.hostilis. For this, the HEE and their fractions were subjected to classic phytochemical trials which involved qualitative chemical reactions that resulted in the confirmation of metabolites belonging to the classes of flavonoids, tannins, xanthones, triterpenoids, free steroids, saponins and phenols. The total phenolic content was also performed using the Folin-Ciocalteu method which it was higher in EAF (527.71 ¡Ó 30.80 mg GAE.g-1). To evaluate the antioxidant activity were used kidnapping free radical DPPH (2,2-diphenyl-1-picryl-hydrazyl) and inhibition of lipid peroxidation quantified by the thiobarbituric acid reactive substances (TBARS). The HEE, EAF and HMF had a higher inhibition percentage of DPPH free radical with indices 95.84%, 94.66% and 95.40%, respectively. The HEE and EAF showed higher lipid peroxidation inhibition percentage when induced by AAPH, while HMF was higher when induce by FeSO4. The biological activity investigated was antiinflammatory by reducing of ear edema and myeloperoxidase (MPO) activity. Ear edema was induced by 12-O-tetradecanoylphorbol acetate (TPA, 1 Ýg/ear) and the HEE effect or their fractions was evaluated by co-administration there of in doses of 1.0 and 3.0 mg/ear, with TPA in the right ear. Left ear was administered only the vehicle (acetone). After 6 h, the ear sites were removed and the edema was expressed from the mass variation between left and right ear, as well the myeloperoxidase activity (MPO) was measured. Co-administration of HEE caused significant inhibition (p<0.001) swelling and MPO activity (p<0.05) at both doses. In turn, HXF, CLF, EAF and FHM reduced similarly edema at a dose of 3.0 mg/ear and percent inhibition de 78%, 71%, 75% and 65%, respectively. The FAE and FHM inhibited MPO activity at doses 1.0 and 3.0 mg/ear (FAE: 86% and 93% for 1.0 and 3.0 mg/ear [p<0.001], respectively; FHM: 40% and 52% for 1.0 and 3.0 mg/ear [p<0.05], respectively). The CLF caused inhibition at a dose of only 3.0 mg/ear (72%, p<0.05) and HXF did not significantly alter MPO activity induced by TPA. If taken together these results indicate that the HEE and its fractions have antioxidant and antiinflammatory, allowing future studies with this plant to obtain bioactive compounds. / O uso de plantas medicinais para cura e prevencao de doencas e uma das praticas mais antigas da humanidade. Uma das plantas utilizadas na medicina popular e a Mimosa hostilis Benth conhecida como jurema preta e usada popularmente em problemas de pele e inflamacoes em geral. O presente trabalho teve por objetivo realizar a triagem fitoquimica e avaliar a atividade antioxidante e anti-inflamatoria do extrato hidroetanolico (EHE) e das suas fracoes hexanica (FHX), cloroformica (FCL), acetato de etila (FAE) e hidrometanolica (FHM) obtidas das entrecascas da M. hostilis. Para isso, o EHE e suas fracoes foram submetidos a prospeccao fitoquimica classica a qual envolveu reacoes quimicas qualitativas que resultaram na confirmacao de metabolitos pertencentes as classes dos flavonoides, taninos, xantonas, triterpenoides, esteroides livres, saponinas e fenois. O teor de fenois totais tambem foi realizado utilizando-se o metodo de Folin-Ciocalteu cujo resultado foi maior na FAE (527,71 ¡Ó 30,80 mg de EAG.g-1). Para avaliar a atividade antioxidante foram utilizados os metodos de sequestro do radical livre (2,2-difenil-1-picril-hidrazil-DPPH) e da inibicao da lipoperoxidacao quantificada por meio das substancias reativas ao acido tiobarbiturico (TBARS). O EHE e as FAE e FHM tiveram um maior percentual de inibicao do radical livre DPPH com indices de 95,84%, 94,66% e 95,40% respectivamente. O EHE e FAE mostraram maior percentual de inibicao da peroxidacao lipidica quando induzida por AAPH enquanto a FHM, maior quando induzida por FeSO4. A atividade biologica investigada foi a anti-inflamatoria por meio da reducao do edema de orelha e pela atividade da mieloperoxidase (MPO). O edema de orelha foi induzido pelo 12-O-tetradecanoilforbol acetato (TPA, 1 Ýg/orelha) e o efeito do EHE ou das fracoes foi avaliado pela coadministracao dos mesmos, em doses de 1,0 e 3,0 mg/orelha, com o TPA na orelha direita. Na orelha esquerda foi administrado apenas o veiculo (acetona). Apos 6 h, os sitios de orelha foram retirados o edema expresso pela variacao da massa da orelha direita pela orelha esquerda, bem como a atividade de mieloperoxidase (MPO) foi mensurada. A coadministracao do EHE causou inibicao significativa (p<0,001) do edema e da atividade de MPO (p<0,05) em ambas as doses. Por sua vez, FHX, FCL, FAE e FHM reduziram o edema de forma semelhante na dose de 3,0 mg/orelha com percentuais de inibicao de 78%, 71%, 75% e 65%, respectivamente. A FAE e a FHM inibiram a atividade de MPO nas doses de 1,0 ou 3,0 mg/orelha (86% e 93% para 1,0 e 3,0 mg/orelha de FAE, respectivamente,p<0,001; 40% e 52% para 1,0 ou 3,0 mg/orelha de FHM respectivamente, p<0,05). A FCL causou inibicao apenas na dose de 3,0 mg/orelha (72%, p<0,05) e a FHX nao alterou significativamente a atividade de MPO induzida pelo TPA. Se considerados conjuntamente estes resultados indicam que o EHE e suas fracoes possuem acao antioxidante e anti-inflamatoria, viabilizando estudos futuros com esta planta para a obtencao de compostos bioativos.

The HIV-1 pandemic affects millions of people worldwide with approximately 70% of those affected residing in sub-Saharan Africa (SSA) relying on traditional medicines for treatment. The key aim of the study was to isolate and characterise an active phyto-pharmaceutical ingredient (API) from L. trigonus for use as a vaginal microbicide. The aerial parts of L. trigonus were oven-dried at 80°C, ground and then extracted with boiling water for 30 minutes. Aqueous extracts were screened using an HIV-1 neutralization assay in TZM bl cells. Chromatographic and spectroscopic techniques were used to purify, isolate and identify the API. The API (BP36-117-26464C) was identified as a polymeric macromolecule with IC50 = 0.04 μg/ml against HIV-1 HXB 2 subtype B. This activity is comparable to the ARV drug, enfuvirtide (IC50 = 0.02 μg/ml). The API consists of galacturonic acid polymer and a mixture of seven compounds. Its mode of action may involve inhibiting virus attachment. The activity of this precipitate (BP36-117-26464C) tested against HIV-1 subtype C pseudovirions and shown to compare favorably with that of enfuvirtide (T20). The water-soluble nature of this API and its mode of action identified it as a potential microbicide. In the current form, the precipitate (API) would be difficult to develop as an oral treatment for HIV, as high-molecular weight agents often have poor bioavailability following oral administration. However, large molecules with potent anti-HIV activity are ideal for topical use and potent development as a microbicide. / Life & Consumer Sciences / M.Sc (Life Sciences)

Traditionally, Sceletium tortuosum has been used as a medicine and for social and spiritual purposes. The genus is distributed in the south-western parts of South Africa. This project phytochemically analysed and characterised Sceletium plant extracts and determined if any extract showed anti-malarial properties. Extracts were prepared in ethanol and methanol and various compounds were purified using column chromatography with hexane and ethyl acetate as mobile phase. The structure of isolated compounds, including mesembrine, pinitol, sucrose, mesembrenone and obtusalin, was confirmed using NMR. The Plasmodium Lactate dehydrogenase assay was used to screen all extracts and mesembrine to show that four extracts showed antimalarial activity with activity values ranging between 1.47 μg/ml and 7.32 μg/ml, well below the 10 μg/ml cut off value. The study recommends extracting compounds from fresh plant material and further research as to anti-malarial activity of compounds isolated from Sceletium tortuosum / Life and Consumer Sciences / M. Sc. (Life Sciences)

The HIV-1 pandemic affects millions of people worldwide with approximately 70% of those affected residing in sub-Saharan Africa (SSA) relying on traditional medicines for treatment. The key aim of the study was to isolate and characterise an active phyto-pharmaceutical ingredient (API) from L. trigonus for use as a vaginal microbicide. The aerial parts of L. trigonus were oven-dried at 80°C, ground and then extracted with boiling water for 30 minutes. Aqueous extracts were screened using an HIV-1 neutralization assay in TZM bl cells. Chromatographic and spectroscopic techniques were used to purify, isolate and identify the API. The API (BP36-117-26464C) was identified as a polymeric macromolecule with IC50 = 0.04 μg/ml against HIV-1 HXB 2 subtype B. This activity is comparable to the ARV drug, enfuvirtide (IC50 = 0.02 μg/ml). The API consists of galacturonic acid polymer and a mixture of seven compounds. Its mode of action may involve inhibiting virus attachment. The activity of this precipitate (BP36-117-26464C) tested against HIV-1 subtype C pseudovirions and shown to compare favorably with that of enfuvirtide (T20). The water-soluble nature of this API and its mode of action identified it as a potential microbicide. In the current form, the precipitate (API) would be difficult to develop as an oral treatment for HIV, as high-molecular weight agents often have poor bioavailability following oral administration. However, large molecules with potent anti-HIV activity are ideal for topical use and potent development as a microbicide. / Life and Consumer Sciences / M.Sc (Life Sciences)

Cowpea (Vigna unguiculata) and moringa (Moringa oleifera) are nutritious and medicinal vegetables, but could also harbor harmful microbial contaminants. The main aim of the project was to determine the effect of each processing techniques on the microbiology, proximate nutrients and shelf life of these vegetables to produce nutritious, tasty, safe and long lasting vegetable products. The processing techniques used were: washing, blanching, and drying. Leaf samples were collected at each stage of processing and were analysed for total viable count, coliform count, yeast and mould count and nutritional content. Microbial plate analysis showed the presence, particularly on cowpea leaves, of yeasts and bacteria such as Pseudomonas, Klebsiella, Staphylococci, Streptococci, and enterobacter including enteropathogens such as Salmonella spp., Shigella dysenteriae and E coli. The presence of E.coli on the leaves was also confirmed using polymerase chain reaction-amplified ribosomal DNA analysis. The most effective processing technique which reduced microbial load to below SABS standards while retaining nutritional quality was the washing of the leaves twice with tap water followed by steam tunnel blanching at 94oC for 12 minutes. Oven drying the leaves at 60oC gave satisfactory and extended shelf life results. Proximate analysis comparison of the two leaf types showed that on average moringa leaves contained more ash (2.37 vs 1.1 g), protein (6,9 vs 3,6 g), fat (0,41 vs 0.2 g) and energy (305,1 vs 70KJ) but less dietary fibre (0,9 vs 7,5 g) than cowpea leaves. No significant differences were noted in these values following washing and steam blanching. These results indicate that washing of these leaves is effective as to reducing microbial load and maintaining proximate values in the short term (up to 4 days) but that oven drying is effective for longer-term storage. / Life and Consumer Sciences / M. Sc. (Life Sciences)

Cowpea (Vigna unguiculata) and moringa (Moringa oleifera) are nutritious and medicinal vegetables, but could also harbor harmful microbial contaminants. The main aim of the project was to determine the effect of each processing techniques on the microbiology, proximate nutrients and shelf life of these vegetables to produce nutritious, tasty, safe and long lasting vegetable products. The processing techniques used were: washing, blanching, and drying. Leaf samples were collected at each stage of processing and were analysed for total viable count, coliform count, yeast and mould count and nutritional content. Microbial plate analysis showed the presence, particularly on cowpea leaves, of yeasts and bacteria such as Pseudomonas, Klebsiella, Staphylococci, Streptococci, and enterobacter including enteropathogens such as Salmonella spp., Shigella dysenteriae and E coli. The presence of E.coli on the leaves was also confirmed using polymerase chain reaction-amplified ribosomal DNA analysis. The most effective processing technique which reduced microbial load to below SABS standards while retaining nutritional quality was the washing of the leaves twice with tap water followed by steam tunnel blanching at 94oC for 12 minutes. Oven drying the leaves at 60oC gave satisfactory and extended shelf life results. Proximate analysis comparison of the two leaf types showed that on average moringa leaves contained more ash (2.37 vs 1.1 g), protein (6,9 vs 3,6 g), fat (0,41 vs 0.2 g) and energy (305,1 vs 70KJ) but less dietary fibre (0,9 vs 7,5 g) than cowpea leaves. No significant differences were noted in these values following washing and steam blanching. These results indicate that washing of these leaves is effective as to reducing microbial load and maintaining proximate values in the short term (up to 4 days) but that oven drying is effective for longer-term storage. / Life and Consumer Sciences / M. Sc. (Life Sciences)