• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 12
  • 7
  • 1
  • Tagged with
  • 21
  • 11
  • 10
  • 10
  • 7
  • 7
  • 6
  • 5
  • 5
  • 5
  • 5
  • 4
  • 4
  • 3
  • 3
  • 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.
1

Aspects of honeybush tea (Cyclopia species) propagation /

Mbangcolo, Mongezi Morrison. January 2008 (has links)
Thesis (MScAgric)--University of Stellenbosch, 2008. / Bibliography. Also available via the Internet.
2

Assessing the suitability of antibiotic resistance markers and the indirect ELISA technique for studying the competitive ability of selected Cyclopia Vent. rhizobia under glasshouse and field conditions in South Africa

Spriggs, AC, Dakora, FD 20 July 2009 (has links)
Abstract Background: Symbiotic N2 fixation in legumes is constrained by many factors, including the paucity of suitable soil rhizobia To maximise growth of legume species therefore often requires the application of effective rhizobia as inoculants. But where native strains out-compete introduced rhizobia for nodule formation, it is important that the competitiveness of selected strains is tested in the field and glasshouse prior to their recommendation as commercial inoculants. However the methodology for strain identification inside nodules has often proved difficult and thus limited this field of research. In this study, the suitability of the antibiotic resistance technique (both intrinsic low-resistance fingerprinting and high-resistance marking) and the serological indirect ELISA method were assessed for their ability to detect selected Cyclopia rhizobia under glasshouse and field conditions. The four rhizobial strains that were used, namely PPRICI3, UCT40a, UCT44b and UCT61a, were isolated from wild Cyclopia species growing in the Western Cape fynbos of South Africa. Results: The test strains formed two distinct groups with regard to their intrinsic resistance to the antibiotics streptomycin sulphate and spectinomycin dihydrochloride pentahydrate, making it impossible to use intrinsic antibiotic resistance to distinguish strains from within the same intrinsic resistance group. The use of strains marked with double antibiotic resistance was also investigated. A number of these strains lost their antibiotic marker tags after one plant passage; and some also lost their competitive ability. The indirect ELISA technique provided a more satisfactory method of identifying selected Cyclopia strains under both field and glasshouse conditions. The primary antibodies raised against strains UCT40a, UCT61a and UCT44b gave absorbance readings that were unambiguously negative (0.30 OD405), while those of strain PPRICI3 were ambiguous (0.50 OD405) with many false positive readings (1.0 A405). The indirect ELISA method showed a high level of analytical sensitivity in glasshouse experiments and there were no cross-reactions between the four test strains. The method was also suitable for detecting three of the four test strains in competition studies under field conditions, and can also be used to identify some strains under field conditions. Conclusion: The antibiotic marker method was found unsuitable for identifying Cyclopia rhizobia in competition experiments in both glasshouse and field conditions. However, the indirect ELISA technique was found suitable for identifying these strains in glasshouse studies. The method was also appropriate for identifying strains UCT40a, UCT44b and UCT61a, but not strain PPRICI3, in field competition studies.
3

Molecular phylogenetics of Cyclopia Vent.and its position within Podalyrieae (Fabaceae).

Du Toit, Nicole 21 April 2008 (has links)
The tribe Podalyrieae is a diverse and interesting group with most of its species found in the Cape Floristic Region (120 out of 128 species), the smallest floral kingdom and the subject of intense conservation interest. DNA sequence data from nuclear ribosomal internal transcribed spacer, including the 5.8s coding region, were used to reconstruct the phylogeny of this Cape Floral Clade. Results support a transfer of Cadia (Sophoreae) to Podalyrieae. Cyclopia is well imbedded in a paraphyletic Podalyriinae and not sister to the tribe as previously suggested. A broader concept of Podalyrieae, which include Podalyriinae, Xiphothecinae and Cadia is suggested. Dating the nodes of the phylogenetic tree using non-parametric rate smoothing with a fossil calibration point indicates that the root node of Podalyrieae (+ Cadia) is 34.35MYA. / Dr. M. van der Bank
4

Rôle morphogénétique de la crête neurale céphalique au cours du développement précoce de l'oeil / Morphogenetic role of cephalic neural crest during early development of the eye

Sghari, Soufien 29 October 2015 (has links)
La crête neurale céphalique (CNC) est une structure pluripotente à l'origine de la totalité du squelette de la face et de la voûte crânienne.
L'absence de la CNC est associée à des malformations du cerveau antérieur et des défauts oculaires qui reproduisent les malformations congénitales humaines: microcéphalie, holoprosencéphalie, aniridie, chambre antérieure manquante, colobome congénital, désorganisation du cristallin, agénésie des
paupières,
strabisme précoce (Alward 2000, Creuzet 2009, Williams and Bohnsack 2015). Dans notre étude, l'augmentation hétérochronique de la signalisation Bmp7 au niveau de la plaque préchordale (PPC) a engendré une perturbation de la migration de la CNC associée à une fusion des deux champs oculaires en un seul œil cyclope. Cette cyclopie, contrairement aux études antérieures (Chiang et al. 1996, Golden et al. 1999) est précédée par une perturbation de la constriction apicale au niveau des vésicules optiques (VO) au stade Hamburger-Hamilton (HH) 12 et qui est responsable de l'invagination dorsale des VO et leur séparation du reste du tube neural. Au niveau moléculaire, nous avons enregistré une augmentation de la signalisation Wnt1 très tot après le traitement (2h) dans la CNC. Cette augmentation s'étend rostralement ce qui suggère que Wnt1 pourrait etre impliqué dans la perturbation du développement oculaire. Pour tester cette hypothèse, nous avons tenté des expériences de sauvetage par l'inactivation de la signalisation Wnt1 par ARN interférence. Nous avons observé une amélioration du phénotype mais les yeux sont restés morphologiquement en hypotélorisme, c'est-à-dire trop proches. Des coupes coronales au stade E8 (32-33HH) ont montré que les yeux sont synophtalmiques, deux yeux dans un seul orbite, et sont restés fusionnés au télencéphale. Au niveau moléculaire, nous avons observé aussi une diminution de l'expression de Wnt2b au niveau des VO chez l'embryon cyclope et que cette diminution persiste malgré le sauvetage par Wnt1. Pour comprendre cette signalisation, nous avons tenté une deuxième expérience de sauvetage avec ARN interférence contre Wnt1 et un vecteur plasmidique exprimant Wnt2b dans le tube neural et les VO respectivement. Vers E8 l'embryon ressemble au contrôle mais avec persistance de fusion entre les VO et le télencéphale. L'hybridation in situ a montré une diminution du niveau d'expression de Foxg1 à 12HH dans la partie dorsale des VO au niveau de la frontière entre la partie rostrale du diencéphale et le télencéphale (RD/T) dans les deux tentatives de sauvetage ce qui suggère que ce gène pourrait être impliqué dans la séparation rostrale des VO du télencéphale. / Cephalic neural crest (CNC) is a pluripotent structure giving rise to entire skeleton of the face and skull. Absence of CNC is associated with forebrain and eye defects that mimic human congénital malformations: microcephaly, holoprosencephaly, aniridia, missing anterior chamber, coloboma, congenital dislocation of the lens, agenesis of eyelid and early strabismus. (Alward 2000 Creuzet 2009, Williams and Bohnsack 2015). In our study, heterochronic increased Bmp7 signaling in the prechordal plate (Pcp), caused disruption of CNC migration associated with fusion of two optical fields into one cyclopic eye. This cyclopia, unlike previous studies (Chiang et al. 1996, Golden et al. 1999), is preceded by a disturbance of the apical constriction in optic vesicles at Hamburger-Hamilton (HH)12 stage witch is responsible for dorsal invagination of OVs and their separation from the rest of the neural tube. At the molecular level, we recorded an increase in Wnt1 expression very early after treatment (2h) in CNC and this increase extends rostrally suggesting that Wnt1 could be involved in the disturbance of eye development. To test this hypothesis, we attempted rescue experiments by inactivating Wnt1 signaling by RNA interference and we observed an improvement of the phenotype but the eyes remained morphologically in hypotelorism, too close,. At E8 (32-33HH) stage the eyes are remained fused to the forebrain and are synophtalmic, two eyes in a single orbit,. We also observed a decrease in Wnt2b expression in OV in the cyclopic embryo and that this decline persists despite Wnt1 rescue. To understand Wnt2b signaling, we attempted a second rescue experience with RNA interference against Wnt1 and a plasmid vector expressing Wnt2b in the CNC and OV respectively. Coronal sections at E8 stage resemble the control but with persistence of dorsal fusion between OVs and telencephalon. In situ hybridization showed a decrease in Foxg1 expression at 12HH in the dorsal part of OVs in the RD/T boundry in the two rescue attempts suggesting that this gene may be involved in the separation of OVs at 12HH stage rostrally from the telencephalon.
5

Aspects of honeybush tea (Cyclopia species) propagation

Mbangcolo, Mongezi Morrison 12 1900
Thesis (MScAgric (Agronomy)--Stellenbosch University, 2008. / Honeybush (Cyclopia spp. Fabaceae) is indigenous to the fynbos botanical biome of the Eastern and Western Cape of South Africa. The increase in the international demand for honeybush tea for health benefits, concern over exploitation of wild populations and the lack of published agronomic information necessitated this study to evaluate different aspects of honeybush propagation. The main objectives of this study were to evaluate the effect of species and cutting position on rooting of cuttings of Cyclopia species using different rooting hormones, to evaluate the effect of an organic plant fertilizer and cutting position on growth and establishment of rooted cuttings and to study the influence of different seed pre-treatments on germination of Cyclopia species. Terminal and sub-terminal cuttings of C. intermedia and C. genistoides treated with different rooting hormones were rooted under day/night temperature controlled glasshouse conditions. Intermittent mist was used as means of moisture supply to the cuttings for 45-60 seconds daily every 30 minutes. C. genistoides rooted significantly better compared to C. intermedia as measured by rooting percentage, number of roots per cutting, length of longest root and mean root length during the summer season. The cutting position had a significant effect on rooting of the cuttings in summer compared to winter and spring season. The interactive effect of species, treatment and cutting position resulted into 86% of rooting in summer from the terminal cuttings of C. genistoides, while only 4% was recorded as the highest rooting percentage in both winter and spring seasons. The highest number of roots and the greatest root length per cutting were obtained with 2 and 4 g L-1 IBA from terminal cuttings of C. genistoides and these hormone concentrations were not significantly different to each other. To evaluate the effect of an organic plant fertilizer and cutting position on plant growth and establishment, rooted cuttings of two Cyclopia species (C. intermedia and C. genistoides) from two cutting positions (terminal and sub-terminal) were transferred to pots (576 cm3) and treated with Nitrosol fertilizer at application rates of 3.33 ml.L-1, 1.67 ml.L-1 and 0 ml.L-1 (control). Cyclopia plantlets were uniformly inoculated once with a symbiotic Rhizobium bacteria to improve the formation of nodules. Nitrosol® at 3.33 ml.L-1 significantly affected fresh and dry plant weight, fresh and dry root weight, number of shoots and nodules per plant compared to either 1.67 ml.L-1 or the control. Relative to species, C. genistoides performed better in terms of fresh and dry plant weight, fresh and dry root weight, and number of shoots and nodules per plant compared to C. intermedia. The origin of the cutting position did not significantly affect the above mentioned parameters. Plant mineral analysis revealed that most of the essential elements increased with increasing Nitrosol® application rates, with C. genistoides having higher levels of mineral elements than C. intermedia. This could be an indication of the differences between the two species in terms of nutrient uptake, utilization and distribution within the plant tissues. In the germination studies, seeds obtained from different seed sources of Cyclopia species were subjected to different pre-sowing treatments. Seed treatments were sulphuric acid (95%), hot water (100°C), water with smoke paper disk, and demineralised water (control). The study revealed that all the treatments had a significant effect on germination with the exception of eight year old seeds obtained from C. subternata (seed source two). Although hot water treatment improved germination compared to smoked paper disk and the control, seeds treated with hot water degenerated rapidly. The highest overall germination (77.33%) was found with one year old seeds compared to other seed sources older than one year. Although smoked paper disks generally did not improve germination compared to the control, in one year old seeds from seed source one, this treatment greatly influenced germination, suggesting that seed age might have influenced germination of these seeds. In terms of germination rate, germination generally started after four days in most treatments.
6

Evaluation of the phytoestrogenic activity of honeybush (Cyclopia)

Verhoog, Nicolette Jeanette Dorothy 03 1900 (has links)
Thesis (MSc (Biochemistry))--University of Stellenbosch, 2006. / The phytoestrogenic activity of Cyclopia, used to prepare honeybush tea, was evaluated and compared with that of the endogenous estrogen, 17-β-estradiol (E2) and the known phytoestrogen, genistein. Phytoestrogens are plant polyphenols much in demand in the nutraceutical market as they mediate an estrogenic effect through binding to estrogen receptor (ER) subtypes, ERα and ERβ.
7

Stability and clinical efficacy of honeybush extracts in cosmeceutical product

Gerber, Gezina Susanna Fredrika Wilhelmina January 2012 (has links)
The progression of skin ageing in individuals is multifaceted and provoked by various aspects, including hereditary and a variety of environmental causes, for instance UV (ultra violet) radiation, resulting in the morphological modifications in the dermal layer of the skin (Makrantonaki & Zouboulis, 2007:40) Transformations caused by ageing skin, in which degenerative alterations exceed regenerative alterations are recognised by the thinning and wrinkling of the epidermis in conjunction with the appearance of lines, creases, crevices and furrows, particularly emphasised in lines of facial expressions (Aburjai & Natsheh, 2003:990). For human beings to continue to exist in a terrestrial atmosphere, the loss of water from the skin must be cautiously synchronised by the epidermis, a task dependent on the multifaceted character of the stratum corneum (Rawlings & Harding, 2004:43). The stratum corneum (SC) is responsible for the main resistance to the penetration of most compounds; nevertheless the skin represents as an appropriate target for delivery. The target site for anti-ageing treatment includes the epidermal and dermal layers of the skin. Therefore, the need to apply fatty materials to the skin is practically intuitive and may perhaps be as old as man’s existence itself (Lodén, 2005:672). Natural therapies have been used for several decades for taking care of skin illnesses and a wide variety of dermatological disorders, such as inflammation, phototoxicity, atopic dermatitis and alopecia areata (Aburjai & Natsheh, 2003:988). Using the skin as an alternative route for the administration of honeybush extracts for the treatment of ageing skin may be beneficial. Tea contains more than 500 chemical compounds, including, tannins, flavonoids, amino acids, vitamins, caffeine and polysaccharides. Tea polyphenols (flavonoids) have proven anti-inflammatory, antioxidant, antiallergic, antibacterial and antiviral effects (Aburjai & Natsheh, 2003:990). Unfortunately using the skin as an alternative route for administering drugs (transdermal drug delivery) has numerous limitations. One of these limitations is the barrier function of the skin (Naik et al., 2000:319). Because of the skin’s outstanding ability to protect the body against unwanted substances from its surroundings, it is necessary to use methods to enhance drug penetration through the skin. The aim of this study was to formulate two 2% semisolid formulations containing two different honeybush extracts as the active ingredient, and to determine which of the formulations deliver mangiferin and hesperidin best to the target site (dermis). Cosmetic formulations of a natural origin, is designed to protect the skin against exogenous or endogenous harmful agents, as well as to balance the dermal homeostatis lipids altered by dermatosis and ageing (Aburjai & Natsheh, 2003:988). Stability tests over a three month period were also performed on the different formulations. To determine the stability of the different semi-solid formulations, the formulated products were stored at 25 °C/60% RH (relative humidity), 30 °C/60% RH and 40 °C/75% RH. HPLC analysis was used to determine the concentrations of the ingredients in all the formulated products. Other stability tests included appearance, pH, viscosity, mass loss, zeta potential and particle size determination. Unfortunately a change in colour, viscosity, zeta potential, mass loss, particle size and concentration of the ingredients in both the formulations, indicated that the products were unstable from the first month of stability testing. A 2% Cyclopia maculata cream as well as a 2% Cyclopia genistoides cream was formulated. Franz cell diffusion studies as well as membrane release studies were performed over a 12 h period, followed by tape stripping experiments to determine which semi-solid formulation delivered mangiferin and hesperidin the best to the dermal layer of the skin. The results of the different formulations were compared. Unfortunately there was no significant penetration by any of the honeybush extracts. Results were inconclusive and unquantifiable due to unconvincing penetration results. The antioxidant properties of both the extracts and the active ingredients were calculated. Antioxidant studies by the use of the TBA-assay method were done to determine whether the honeybush extracts, mangiferin and hesperidin as well as their semisolid formulations had any antioxidant activities. Both the honeybush extracts and the semisolid formulations showed promising results. Mangiferin and hesperidin did not show any antioxidant activity on their own, therefore the assumption can be confirmed that plants do function synergistically. A clinical study was also conducted to see whether honeybush extracts have the potential to hydrate the skin, counteracting the symptoms and signs of skin ageing. Clinical efficacy studies were done to determine whether the honeybush formulations had any skin hydrating effects in the treatment against skin ageing. The results were statistically inconclusive and variations between the subjects were very high due to skin variations at different skin sites. There was however a trend that Cyclopia genistoides performed the best. / Thesis (MSc (Pharmaceutics))--North-West University, Potchefstroom Campus, 2013.
8

Stability and clinical efficacy of honeybush extracts in cosmeceutical product

Gerber, Gezina Susanna Fredrika Wilhelmina January 2012 (has links)
The progression of skin ageing in individuals is multifaceted and provoked by various aspects, including hereditary and a variety of environmental causes, for instance UV (ultra violet) radiation, resulting in the morphological modifications in the dermal layer of the skin (Makrantonaki & Zouboulis, 2007:40) Transformations caused by ageing skin, in which degenerative alterations exceed regenerative alterations are recognised by the thinning and wrinkling of the epidermis in conjunction with the appearance of lines, creases, crevices and furrows, particularly emphasised in lines of facial expressions (Aburjai & Natsheh, 2003:990). For human beings to continue to exist in a terrestrial atmosphere, the loss of water from the skin must be cautiously synchronised by the epidermis, a task dependent on the multifaceted character of the stratum corneum (Rawlings & Harding, 2004:43). The stratum corneum (SC) is responsible for the main resistance to the penetration of most compounds; nevertheless the skin represents as an appropriate target for delivery. The target site for anti-ageing treatment includes the epidermal and dermal layers of the skin. Therefore, the need to apply fatty materials to the skin is practically intuitive and may perhaps be as old as man’s existence itself (Lodén, 2005:672). Natural therapies have been used for several decades for taking care of skin illnesses and a wide variety of dermatological disorders, such as inflammation, phototoxicity, atopic dermatitis and alopecia areata (Aburjai & Natsheh, 2003:988). Using the skin as an alternative route for the administration of honeybush extracts for the treatment of ageing skin may be beneficial. Tea contains more than 500 chemical compounds, including, tannins, flavonoids, amino acids, vitamins, caffeine and polysaccharides. Tea polyphenols (flavonoids) have proven anti-inflammatory, antioxidant, antiallergic, antibacterial and antiviral effects (Aburjai & Natsheh, 2003:990). Unfortunately using the skin as an alternative route for administering drugs (transdermal drug delivery) has numerous limitations. One of these limitations is the barrier function of the skin (Naik et al., 2000:319). Because of the skin’s outstanding ability to protect the body against unwanted substances from its surroundings, it is necessary to use methods to enhance drug penetration through the skin. The aim of this study was to formulate two 2% semisolid formulations containing two different honeybush extracts as the active ingredient, and to determine which of the formulations deliver mangiferin and hesperidin best to the target site (dermis). Cosmetic formulations of a natural origin, is designed to protect the skin against exogenous or endogenous harmful agents, as well as to balance the dermal homeostatis lipids altered by dermatosis and ageing (Aburjai & Natsheh, 2003:988). Stability tests over a three month period were also performed on the different formulations. To determine the stability of the different semi-solid formulations, the formulated products were stored at 25 °C/60% RH (relative humidity), 30 °C/60% RH and 40 °C/75% RH. HPLC analysis was used to determine the concentrations of the ingredients in all the formulated products. Other stability tests included appearance, pH, viscosity, mass loss, zeta potential and particle size determination. Unfortunately a change in colour, viscosity, zeta potential, mass loss, particle size and concentration of the ingredients in both the formulations, indicated that the products were unstable from the first month of stability testing. A 2% Cyclopia maculata cream as well as a 2% Cyclopia genistoides cream was formulated. Franz cell diffusion studies as well as membrane release studies were performed over a 12 h period, followed by tape stripping experiments to determine which semi-solid formulation delivered mangiferin and hesperidin the best to the dermal layer of the skin. The results of the different formulations were compared. Unfortunately there was no significant penetration by any of the honeybush extracts. Results were inconclusive and unquantifiable due to unconvincing penetration results. The antioxidant properties of both the extracts and the active ingredients were calculated. Antioxidant studies by the use of the TBA-assay method were done to determine whether the honeybush extracts, mangiferin and hesperidin as well as their semisolid formulations had any antioxidant activities. Both the honeybush extracts and the semisolid formulations showed promising results. Mangiferin and hesperidin did not show any antioxidant activity on their own, therefore the assumption can be confirmed that plants do function synergistically. A clinical study was also conducted to see whether honeybush extracts have the potential to hydrate the skin, counteracting the symptoms and signs of skin ageing. Clinical efficacy studies were done to determine whether the honeybush formulations had any skin hydrating effects in the treatment against skin ageing. The results were statistically inconclusive and variations between the subjects were very high due to skin variations at different skin sites. There was however a trend that Cyclopia genistoides performed the best. / Thesis (MSc (Pharmaceutics))--North-West University, Potchefstroom Campus, 2013.
9

Development of in vitro models to investigate the anti-inflammatory properties of Cyclopia Maculata and other South African herbal teas : a comparative study

Keet, Lana 04 1900 (has links)
Thesis (MSc)--Stellenbosch University, 2015. / ENGLISH ABSTRACT: Chronic inflammation is suggested to contribute to cancer development and therefore a potential target for chemoprevention. In the skin, keratinocytes and macrophages play an integral part in acute and chronic inflammation, with interleukin 1-α (IL-1α) and tumor necrosis factor α (TNF-α) as key cytokines governing this process. Green tea (Camellia sinensis) and the South African herbal teas, rooibos (Aspalathus linearis) and honeybush (Cyclopia spp.) displayed antiinflammatory effects in mouse and human skin. To further investigate the antiinflammatory properties of green tea and the herbal teas, rooibos and honeybush (C. subternata and C. maculata) herbal teas, suitable cell culture models were developed and validated utilising human keratinocytes (HaCaT) and monocyte (THP- 1) derived macrophages. Aqueous extracts of the green tea and unfermented herbal teas were prepared and their chemical composition determined by high performance liquid chromatography (HPLC) and the antioxidant activity characterised utilising different antioxidant assays. Green tea and rooibos exhibited similar antioxidant activities while C. maculata displayed the lowest overall antioxidant activity of all the extracts, despite possessing the highest mangiferin level, the major polyphenol in honeybush. The modulation of cytokine release was studied in (i) an UVB-induced pre-exposure HaCaT model monitoring the accumulation of IL-1α and (ii) a LPS stimulated THP-1 macrophage model monitoring the TNF-α release, utilising both a pre-exposure and co-exposure extract regimens. In the pre-exposure HaCaT inflammatory model the UVB-induced IL-1α was decreased by the green tea extract while a far weaker response was obtained with the rooibos extract. Both the honeybush extracts displayed a significant effect in the reduction of IL-1α with C. subternata exhibiting a slight increased protection at a lower extract concentration. In the pre-exposure THP-1 derived macrophage model, green tea and the herbal tea extracts inhibited TNF-α release in a dose dependent manner in the absence of an overt loss in cell viability and apoptosis at lower extract concentrations, suggesting a typical anti-inflammatory effect. In the co-exposure model, the different extracts also exhibited an anti-inflammatory effect at the lowest concentrations in the absence of apoptosis while at higher extract concentrations the effect was masked by a decrease in cell viability and increased apoptosis. C. maculata exhibit differential effects when considering the inhibition of cytokine production and, depending on the cell model, either exhibited a weaker or stronger effect when compared to C. subternata and rooibos. Phenolic diversity of the different teas is likely to explain the differential effects in the antioxidant assays and cell culture models with respect to the regulation of the production of the inflammatory markers. Proposed mechanism for the anti-inflammatory effects include the modulation of oxidative stress via various pathways and the subsequent down regulation of nuclear factor kappa β (NFκB) and activated protein-1 (AP-1) which are key regulators of cytokine production governing the inflammatory response. / AFRIKAANSE OPSOMMING: Kroniese inflammasie van die vel kan bydra tot die ontwikkeling van kanker en is dus ’n potensiële area om te teiken in die voorkoming van velkanker. Keratinosiete en makrofage speel ’n integrale rol in akute en chroniese inflammasie van die vel en TNF-α en IL-1α is die belangrikste sitokiene wat hierdie proses inisieer. Dit is bekend dat ekstrakte van groen tee (Camellia sinensis) en die Suid-Afrikaanse kruietees, rooibos (Aspalathus linearis) en heuningbos (Cyclopia spp.) ‘n anti-inflammatoriese effek op die vel van muise en mense het. Om die anti-inflammatoriese aktiwitieit van groen tee, rooibos en 2 heuningbos kruietees (C. subternata en C. maculata) verder te ondersoek en te definieer is geskikte selkultuurmodelle ontwikkel en gevalideer deur gebruik te maak van menslike keratinosiete (HaCaT) en monosiet (THP-1) afgeleide makrofage. Water ekstrakte van groen tee en ongefermenteerde kruietees is voorberei en die chemiese samestelling deur hoë druk vloeistof chromatografie (HDLC) bepaal. ‘n Verskeidenheid van antioksidant bepalingstoetse is gebruik om die antioksidant aktiwiteit van die ekstrakte te meet. Groen tee en rooibos het soortgelyke antioksidant aktiwiteite getoon, terwyl C. maculata die swakste algehele aktiwiteit getooon het, ten spyte van die teenwoordigheid van hoёr vlakke van mangiferin, die belangrikste polifenoliese verbinding in heuningbos. Modulasie van sitokiene is verder bestudeer in (i) ’n UVB-geïnduseerde vooraf-blootstelling HaCaT model, waartydens akkumulering van IL-1α gemonitor is en (ii) ‘n lipopolisakkaried (LPS)-gestimuleerde THP-1 makrofaag model, waar die vrystelling van TNF-α gemonitor is. Vir die THP-1 model is beide die voor en gelyktydige blootstelling benaderings vir die ekstrakte met LPS gebruik. In die keratinosiet model, waar die selle aan ekstrakte blootgestel is voor UVB bestraing, is IL-1α beduidend verlaag deur die groen tee ekstrak, terwyl ’n swakker reaksie gesien is met rooibos. Beide heuningbos ekstrakte het ’n beduidende invloed in die vermindering van IL-1α getoon, waar C. subternata ’n effense verhoogde beskerming teen selsterfte by ‘n laer ekstrakkonsentrasie toon. Blootstelling van die makrofage aan al vier ekstrakte voor LPS stimulasie (vooraf-blootstelling), het gelei tot inhibisie van TNF-α vrystelling op ’n dosis afhanklike wyse en die afwesigheid van apoptose en selsterftes by lae ekstrak konsentrasievlakke. Hierdie waarnemings dui op ’n tipiese antiinflammatoriese effek. In die gelyktydige-blootstelling model verlaag al die ekstrakte TNF-α vrystelling teen die laagste ekstrak konsentrasievlakke, in die afwesigheid van apoptose en met geen effek op seldood nie. Hoёr ekstrak konsentrasievlakke het sitotoksisiteit en verhoogde apoptose getoon, dus was die anti-inflammatoriese effek gemaskeer. C. maculata toon ‘n variërende effek met betrekking tot antioksidant aktiwiteit en die bekamping van sitokien produksie, afhangend van die model wat bestudeer is. Die verskeidenheid fenoliese verbindings teenwoordig in die verskillende tee ekstrakte is waarskynlik die rede vir die effekte wat waargeneem is tydens antioksidant toetsing en selkultuurmodelle. Die anti-inflammatoriese meganismes wat deur hierdie studie voorgestel word sluit die modulasie van oksidatiewe stres via verskeie metaboliese paaie in. Modulasie van oksidatiewe stres lei tot af-regulering van kernfaktor-kappaB (NF-κB) en aktiveerderproteïen- 1(AP-1), wat sleutel reguleerders van sitokien produksie tydens inflammatoriese respons is.
10

The use of rooibos (Aspalathus linearis) and honeybush (Cyclopia spp.) as wood alternative in red winemaking

De Wet, Alet 03 1900 (has links)
Thesis (MSc)--Stellenbosch University, 2015. / ENGLISH ABSTRACT: Wine knowledge has increased drastically in recent years with the aid of scientific experimentation. The producers of wine have increasingly incorporated new wine knowledge into the marketing and innovation of wine products. In parallel with the above, the consumer market has become more aware of winemaking practices and their influence on consumer health. The use of alternative methods and additives in wine are means by which producers have been able to create innovative wine products. This study focused on the addition of rooibos (Aspalathus linearis) and honeybush (Cyclopia spp.) plant material to red wine. Consumer liking, as well as descriptive sensory analysis (DSA) of different red wines made from a range of cultivars with the addition of rooibos and honeybush plant material, was investigated. Another aim of the study was to observe the effect of oxygen addition to red wines treated with rooibos and honeybush plant material. The consumer studies included a number of events where wines treated with rooibos and honeybush material were compared with other commercial wines. The results could not clearly indicate whether consumers liked or disliked the wine products with added rooibos and honeybush plant material. Further refinement of wines with the addition of rooibos and honeybush can serve as topics for future research. Focus on the potential health benefits which can be added to wine from rooibos and honeybush plant material, as a result of inherent antioxidants within both these species, may serve as a novel research topic. The DSA panels identified aroma descriptors that could be related to the addition of wood and leaf or only rooibos and honeybush wood to wine. The addition of oxygen to wines treated with rooibos and honeybush plant material indicated that aromas associated with these treatments are relatively stable in wine undergoing oxidation. This could possibly pave the way for future research on the topic of low sulphur dioxide containing wines. As a result of this study, a commercial wine product called “Rooibos wine” was developed and became available in retail. Further research on this topic and the impact of the addition of rooibos and honeybush material to wine may be of great benefit for the production of innovative wines with unique aroma profiles. / AFRIKAANSE OPSOMMING: Kennis oor wyn het oor die afgelope paar jaar vooruitgegaan met behulp van wetenskaplike eksperimentering. Wynprodusente sluit toenemend nuwe wynkennis in die bemarking en innovering van wynprodukte in. Parallel hiermee het die verbruikersmark baie meer bewus geword van wynbereidingspraktyke en die invloed daarvan op verbruikersgesondheid. Die gebruik van alternatiewe metodes en byvoegings in wyn is maniere waarop produsente innoverende wynprodukte kan skep. Hierdie studie het gefokus op die byvoeging van rooibos (Aspalathus linearis) en heuningbos (Cyclopia spp.) plantmateriaal by rooiwyn. Verbruikers se voorkeur, sowel as die beskrywende sensoriese analise (descriptive sensory analysis [DSA]) van diverse rooi wyn kultivars waarby rooibos en heuningbos plantmateriaal gevoeg is, is geanaliseer. Nóg ’n doelwit van die studie was om die effek van suurstofbyvoeging by rooiwyne wat met rooibos en heuningbos plantmateriaal behandel is waar te neem. Vir die verbruikerstudies is geleenthede aangebied waar wyne wat met rooibos en heuningbos materiaal behandel is met kommersiële wyne vergelyk is. Die resultate kon nie duidelik aandui of die verbruikers gehou het of nie van wynprodukte wat met rooibos en heuningbos behandel is. Verdere verfyning van wyne met bygevoegde rooibos en heuningbos kan as onderwerpe vir toekomstige navorsing dien. Die verhoogde gesondheidvoordele van wyn wat met rooibos en heuningbos plantmateriaal behandel is as gevolg van die inherente anti-oksidante eie aan die spesies, kan dien as fokus vir ʼn nuwe navorsingstema. Die DSA-panele het beskrywende terme vir aromas geïdentifiseer wat verband kan hou met die byvoeging van die hout/blaar of slegs die rooibos- en heuningboshout by die wyn. Die aromas in wyn wat met rooibos en heuningbos behandel is, is gevind om relatief stabiel te bly tydens oksidasie. Dit kan moontlik die weg baan vir toekomstige navorsing oor lae swaweldioksied-bevattende wyne. As gevolg van hierdie studie is ‘n kommersiële wynproduk, genaamd “Rooiboswyn”, ontwikkel en is dit in die handel beskikbaar. Verdere navorsing oor hierdie onderwerp en die impak van die byvoeging van rooibos en heuningbos materiaal by wyn sal moontlik van groot voordeel wees vir die produksie van innoverende wyne met unieke aroma profiele.

Page generated in 0.0406 seconds