Theses And Dissertations

Permanent URI for this collectionhttp://hdl.handle.net/20.500.11837/231

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Anatomy and Morphology of Glandular and Non-glandular trichomes of Pteronia incana in relation to their essential oil production
(University of Fort Hare, 2000-01) Mayekiso, Buyisile
The morphology and anatomy of the non-glandular. and glandular trichomes present on both abaxial and adaxial surfacea as well as on the stem surface of Pteronia incana were examined using light, scanning electron microscopy and transmission electron microscopy. The non-glandular trichomes were thread-like structures with elongated fibrous ends having a tubular basal cells. They occurred in greater abundance in both young and mature leaves and in stems. The fibrous ends of non-glandular trichomes seemed to be shielding the epidermal layer, the glandular trichome and the stoma. The electron micrograph of non-glandular trichomes showed that both trichomes originated from a single epidermal cell by anticlinal division. As the trichome matured, the cells at the end of the trichome became dehydrated and formed a thread-like fibre. Structurally, these fibrous ends were similar in composition to the components of the suberized cell walls
Development of conservation methods for Gunnera perpensa L.: an overexploited medicinal plant in the Eastern Cape, South Africa.
(University of Fort Hare, 2014) Chigor, Chinyere Blessing
In South Africa, many plants which are used in traditional medicines are collected from wild populations. The high demand for trade and use of these medicinal plants place an enormous pressure on their natural populations, especially because they are indiscriminately harvested. The most affected of these plant species are those harvested from their underground parts, among which is Gunnera perpensa L. Gunnera perpensa is of considerable ethnobotanical interest in traditional medicine because of its wide usage. The rhizomes are widely used and indiscriminately collected in large quantities from the wild to meet the ever increasing demand in traditional medicine markets. As a result, this valuable medicinal plant species is being endangered. According to the Red List of South African Plants, the conservation status of G. perpensa has been listed as ‘declining’. The ethnobotanical survey conducted as part of this research confirms the plant species as threatened. It is, therefore, important to develop propagation and conservation strategies for this medicinal plant. Clonal propagation of G. perpensa was conducted using varying lengths of the rhizome (1, 2, 3, 4 and 5 cm) segments as propagules. While regeneration was possible with all the rhizome lengths, most of the growth parameters were significantly higher in the 5 cm rhizomes than the other rhizome segments. The appropriate planting depth for the rhizomes was also determined and 4 or 5 cm planting depths were found appropriate. No significant difference was observed in the growth parameters amongst the planting depths; nevertheless, 4 cm depth gave higher growth and yield. The results of this study show that regenerating G. perpensa through rhizome segments is an efficient method for obtaining plant material for medicinal purposes. Seed germination is an important determinant in the distribution and survival of a plant species. It therefore becomes essential to study the germination requirements of G. perpensa seeds. The effects of light, temperature conditions, leaching, scarification, pre-chilling and chemical substances such as gibberellic acid and KNO3 were investigated in the germination of the seeds. The optimum temperature for germination in this study was 25oC under light conditions. Overall, germination of G. perpensa seeds was poor and irregular, but mechanical scarification significantly improved the percentage germination from 4% to 32% compared to untreated seeds (control), with a mean germination time (MGT) of 56 days. This was followed by 7 day leaching with 26% germination and MGT of 44 days. Antimicrobial and antioxidant activities were evaluated between two different plant parts of G. perpensa, for their potential in plant part substitution. The plant parts (roots and leaves) were extracted in differing polarity solvents. These were screened for antibacterial activity against ten bacterial species including Bacillus subtilis and Staphylococcus aureus. The plant extracts presented some activity against the bacterial strains with zones of inhibition varying from 8 to 25 mm and MIC values ranging from 2.5 to 10 mg/ml. The highest activity against the tested bacteria was obtained with the methanol leaf extract with inhibition zone of 25 mm against Serratia mercescens. Gunnera perpensa extracts were also screened for antifungal activity against four fungal species. All the plant extracts exhibited high antifungal activity against Candida krusei and Absidia corymbifera with MIC values ranging from 0.15 to 0.62 mg/ml. The ability of the extracts of G. perpensa to inhibit the growth of several bacteria and fungi is an indication of the broad-spectrum antimicrobial potential of this plant that further validates its use for the treatment of various ailments. The phytochemical evaluation of the studied plant species indicated that the observed activities might largely be due to their high flavonoid and phenol contents, with a contributing effect from their alkaloids and saponins. The highest flavonoid content (434.09 mg Quercetin/g) was recorded in acetone rhizome extract, followed by methanol leaf extract (432.22 mg Quercetin/g). In the antibacterial and some of the antioxidant assays, the leaves of this plant demonstrated higher activity than the rhizomes, while in the antifungal assay the two plant parts exhibited similar activities suggesting their potential in plant part substitution. The harvesting of leaves as a conservation strategy is certainly more sustainable than the destructive use of the roots of this threatened plant species. Micropropagation is a useful technique for rapid clonal multiplication of plant material which could alleviate the pressure on the wild plant populations as well as potentially provide plant materials for use. This study did develop a successful decontamination method and the efficient means for eliminating detrimental browning of G. perpensa explants and media. The result demonstrated that ascorbic acid or activated charcoal was required as media supplements to reduce the browning effect. This information provides an important starting point for the development of a successful micropropagation protocol for the conservation of G. perpensa. This research further highlights the need to conserve our indigenous plant resources before they become extinct, since some of them could be pharmacologically active and perhaps contain novel compounds that are biologically active against some diseases.
Evaluation of the medicinal potentials of Bulbine abyssinica A. Rich in the management of diabetes mellitus in the Eastern Cape, South Africa.
(University of Fort Hare, 2016) Kibiti, Cromwell Mwiti; Afolayan, A.J.
Diabetes mellitus is a chronic physiological carbohydrate metabolic disorder with significant impact on the economy, quality of life and life expectancy in South Africa. Herbal medicine has become the alternative therapy in the management of this disease. However, their safety and effectiveness have not been investigated. To address this, one of the plants used in Eastern Cape Province, South Africa, Bulbine abyssinica A. Rich (Asphodelaceae), was evaluated. Bulbine abyssinica is one of the species used in the management of diabetes mellitus. This plant was mentioned during an ethnobotanical survey conducted in Nkonkobe municipality of the Eastern Cape Province. Though a decoction prepared from the whole plant is used in the treatment of diabetes mellitus, the mechanism of action and its safety has not been elucidated. Thus, this research work was designed to contribute to the understanding of the possible mechanism of action of B. abyssinica as an antidiabetic medicinal plant and its toxic potentials to the users. The aqueous extract exhibited remarkable inhibitory activity on α-amylase (estimated inhibitory concentration (IC)50 value of 3.28 μg/ml), while the acetone extract exhibited weak inhibitory activity. The acetone extract exhibited notable α-glucosidase inhibitory activity (IC50 value of 4.27 μg/ml) while aqueous extract had significantly weak activity. The Lineweaver-Burk double reciprocal plots revealed that the aqueous extract exerts noncompetitive inhibition on the α-amylase activity while the acetone extract exerts a near competitive inhibitory pattern on the α-glucosidase activity. The extracts from the plant possessed high free radical scavenging activities, with acetone extract exhibiting the highest activities in all assay models used except with ferric reducing power and nitric oxide (NO) scavenging ability. The aqueous extract exhibited the highest ferric reducing power and nitric oxide radical mopping strength while the essential oil exhibited the highest scavenging activities with 1,1-diphenyl-2-picrylhydrazyl (DPPH) and relatively high ferric reducing power and nitric oxide scavenging ability. The acetone extract and the essential oil of this species exhibited higher albumin denaturation inhibition than the aqueous extract while the latter showed the greatest membrane lysis protection. The essential oil, acetone and aqueous extracts from this plant significantly inhibited the growth of Shigelle flexneri, Pseudomonas aeruginosa, Staphylococcus aureus and Enterococcus faecalis. Klebsiella pneumonia, Proteus vulgaris and Streptococcus pyogens growth were inhibited by acetone and aqueous extracts. The essential oil also showed inhibitory activity against Proteus vulgaris. However, the extracts were active against the growth of only three fungi species. The essential oil showed significant inhibitory activity against Trichophyton rubrum. The aqueous extract inhibited the growth of Microsporum gypseum while the acetone extract was active against Microsporum canis, and Microsporum gypseum.
Implication of tillage, texture and mineralogy on the sieving efficiency, physical-based soil organic matter and aggregate stability of some soils in Eastern Cape Province, South Africa.
(University of Fort Hare, 2015) Peter, Prince Chinedu
Soil structure and its associated physical properties are essential soil components. Soil texture and mineralogy are inherent soil properties that influence soil management. This study assessed the implication of tillage, texture and mineralogy on soil sieving, aggregate stability indices and physical fractions of organic matter in soils of Eastern Cape Province of South Africa. An Iris FTLVH – 0200 digital electromagnetic sieve shaker (Filtra Vibraciόn SL Spain), was used to determine settings for sieving efficiency. Mean weight diameter (MWD), water stable aggregate (WSA), state of aggregation (SA), dispersion ratio (DR), water dispersible clay (WDC), clay dispersion ratio (CDR), clay flocculation index (CFI), and potential structural deformation index (PSDI) were aggregate stability indices evaluated to check for sensitivity in evaluating aggregate stability of soils under two tillage systems and physical fractions of carbon and nitrogen in soils of Eastern Cape Province. The T4I3P2 and T4I4P3 settings were sensitive under tillage and T4I1P4, T3I4P3 and T4I4P3 were sensitive under mineralogical considerations for sieving efficiency. The total carbon in soils under conventional tillage (CT) was 17.7 g/kg and in soils under no tillage (NT) it was 15.8 g/kg. The total carbon content in the clay fraction of soils under CT was 24.1 % higher than the total carbon content in the clay fraction of soils under NT. The total nitrogen content in the clay fraction of soils under CT was 5.4 % higher than the total nitrogen content in the soils under NT. The total carbon in the sandy loam (SL) textured soils was 17.4 g/kg and in the sandy clay loam (SCL) textured soils it was 17.1 g/kg. The total nitrogen in SL soils was 3.7 g/kg and in SCL soils it was 3.7 g/kg. The clay fraction had higher total carbon than other fractions in Sl and SCL soils. The higher values of nitrogen were observed in the silt fraction for SL soils and clay fraction for SCL soils. The total carbon in the soils dominated with kaolinite was 17.3 g/kg and in quartz dominated soils the value was 16.9 g/kg. The total nitrogen in the soils dominated with kaolinite was 3.7 g/kg and in the soils dominated with quartz the value was 3.7 g/kg. For soils under NT the WDC was 135.8 g/kg and for soils under CT it was 139.7 g/kg. The ASC was 72.5 for soils under NT and 92.0for soils under CT. The DR was 0.9 for soils under NT and 0.8 for soils under CT. The CFI was 0.5 for soils under NT and 0.5 for soils under CT. The CDR was 0.5 for soils under NT and 0.5 for soils under CT. The MWDw was 1.6 mm for soils under NT and 1.4 mm for soils under CT. The MWDd was 4.0 mm for soils under NT and 4.0 for soils under CT. The % WSA > 0.25 mm was 61.7 % for soils under NT and 56.2 % for soils under CT. The PSDI was 55.2 % for soils under NT and 61.15 % for soils under CT. The SA was 43.2 % for soils under NT and 37.89 % for soils under CT. The WDC was 125.7 g/kg for SCL soils and 151.4 g/kg for SL soils. The CDR was 0.5 for both SCL and SL soils. The DR was 0.9 for SCL soils and 0.8 for SL soils. The CFI was 0.5 for both SCL and SL soils. The ASC was 56.2 g/kg for SCL soils and 115 g/kg for SL soils. The MWDw was 1.5 mm for SCL soils and 1.4 mm for SL soils. The MWDd was 3.6 mm for SCL soils and 3.6 mm for SL soils. The % WSA > 0.25 mm was 53.0 % for SCL soils and 62.5 % for SL soils. The PSDI was 59.2 % for SCL soils and 59.7 % for SL soils. The SA was 33.6 % for SCL soils and 45.2 % for SL soils. The WDC was 313.3 g/kg for kaolinitic soils and 120.7 g/kg for quartz dominated soils. The CDR was 0.5 for kaolinitic soils and 0.5 for quartz dominated soils. The DR was 0.9 for kaolinitic soils and 0.8 for quartz dominated soils. The CFI was 0.5 for kaolinitic soils and 0.5 for quartz dominated soils. The ASC was 110.0 g/kg for kaolinitic soils and 101.7 g/kg for quartz dominated soils. The WSA > 0.25 mm was 57.3 % for quartz dominated soils and 68.4 % for kaolinitic soils. The MWDw was 1.6 mm for quartz dominated soils and 0.8 mm for kaolinitic soils. The MWDd was 3.6 mm for quartz dominated soils and 3.4 mm for kaolinitic soils. The PSDI was 56.3 for quartz dominated soils and 76.0 for kaolinitic soils. It was concluded that Tillage, texture and mineralogy influenced the result of the sieving operation using Iris FTLVH – 0200 digital electromagnetic sieve shaker (Filtra Vibraciόn SL Spain). Sieving efficiency attained for these soils varied with tillage and mineralogy. The aggregate size composition and distribution in soils of these ecotopes are a function of mineralogy rather than tillage. Tillage influenced Nitrogen in the physical fractions of these soils. Changes in nitrogen content due to tillage were expressed more in the silt fraction of the soils. Soils in these ecotopes showed tendency for slow nitrogen accumulation. Texture influenced the accumulation of carbon and nitrogen in these soils. Clay fraction was prominent in determining the amount of carbon and nitrogen in these soils. Tillage influenced the sensitivity of different aggregate stability indices in these soils. The indices WSA > 0.25 mm, SA, and MWDw were sensitive to detect differences in macro aggregate stability among tillage system in these soils. Micro aggregate stability indices were generally not sensitive in detecting expected differences among tillage systems in these soils. The micro aggregate stability indices DR and ASC were more sensitive in soils of different texture. The macro aggregate stability indices MWDw, MWDd and PSDI were not sensitive to detect difference in stability with texture. The SA and WSA > 0.25 mm indices were sensitive to detect differences in the stability of the soils with texture. The micro aggregate stability indices DR and WDC were sensitive in soils of different mineralogy. Clay fraction influenced the carbon content of these soils irrespective of mineralogy. The soils responded to different indices differently under different conditions of tillage, texture and mineralogy. Therefore caution must be exercised in adopting any index; it is however suggested to use the response of more than one index for any given conclusion. Further research on site specific measures to improve soil nitrogen retention in these soils is suggested to forestall green house gas emission. Also proper delineation of these ecotopes according to carbon response to tillage, texture and mineralogy for enhanced carbon sequestration measures is recommended.
Integrating natural sciences and indigenous knowledge systems for rural economic development: a model for rural enterprise development, health and nutrition initiatives in the Eastern Cape, South Africa
(University of Fort Hare, 2008) Lupuwana, Pumezo
This study demonstrated that the demographic profile of the Eastern Cape Province portrayed high levels of poverty and underdevelopment in the mostly rural population. This is despite the fact that the Eastern Cape is characterized by a rich endowment of natural resources, hosting a wide range of natural plant species, numerous rivers, water springs from mountains and no less than six biomes due to the variety of climatic conditions prevalent in the Province. In contrast, the natural resources found in the Province were regarded to have a high potential to grow and transform the economy of the Province. In this study, the integrated approach was conceptualized, developed and implemented in action within the rural communities selected with varying degrees of success, as a function of the material and objective socio-economic conditions prevailing in each community. A model for rural enterprise development based on agricultural production utilizing the principles of Community-Public-Private Partnerships was conceptualized and executed with the assistance of specialist professionals from various disciplines and organizations. Case studies structured on the basis of methodologies derived from the integration of natural sciences and indigenous knowledge systems were conducted to demonstrate the feasibility of the conceptual framework of the study as indicated by the following case studies. The first case study undertaken was the development of agricultural enterprises in the selected rural communities in joint ventures through the commercial production of food and vegetable crops for local markets and to provide nutrition for the rural communities as the first line of therapy against the HIV/AIDS infection and other diseases associated with malnutrition. The second case study was the establishment of an agricultural enterprise in partnership between rural communities, government agencies and agricultural specialist for the commercial production of grain crops, namely, Sorghum alternating with Wheat to satisfy the demand of local markets for these crops. The third case study was the establishment of a community-based enterprise through the commercial production of two Pelargonium plant species, namely, Pelargonium reniforme and P. sidoides. The two species had a high market demand in the pharmaceutical industry; hence, the plant species were domestically cultivated to satisfy the industry demand and to ensure the survival of the plant species. The enterprise succeeded in sustaining the livelihoods of the rural communities and conserving the plant species. The fourth case study was the commercial production of essential oil-producing plants in six selected rural communities providing employment for some of the members of these communities even though the initial phase of the start-up enterprise was a trial cultivation to determine the suitability of the environmental and climatic conditions for the propagation of the selected essential-producing plants. The demand for essential oils in local and international markets was determined to relatively high. The incorporation of Indigenous Knowledge Systems of the rural communities in the planning and implementation processes in the areas of Commercial Agricultural Production and Primary Health Care resulted in a gradual paradigm shift on the part of rural communities from a dependence mindset to one of self-reliance that is critical for sustainable rural economic development and the improvement of rural livelihoods. An integrated approach in the strategic planning and execution that involved the rural communities by government stakeholders, the academic community and other stakeholders from the Private Sector was piloted. The recognition of Indigenous Knowledge Systems by all the relevant stakeholders and their essential role in rural enterprise development, food production and primary health care as a pre-requisite for a successful transformation agenda was highlighted as never before. An all-inclusive approach that accorded the rural communities the status of equal partnership had a positive impact on most aspects of planning and implementing programmes for sustainable rural economic development and biodiversity conservation. Working in partnership with rural communities was found to be a challenge; hence, an understanding of the sub-cultures and the social dynamics that often manifested themselves in the form of internecine conflicts became necessary for successfully initiating the research programme in the rural communities. Furthermore, recognition of the rural communities as an integral part of the solution towards biodiversity conservation and the sustainable exploitation of natural resources was found to be a critical component for an effective strategy to ensure the continued survival of the endangered plant species. This attitude underpinned the co-operation of the rural communities and the overarching goals of rural transformation towards the consistent and sustainable improvement of rural livelihoods. The
Nutritional value and cultivation requirements of cleome gynandra l.: a wild vegetable growing in the Eastern Cape province, South Africa.
(University of Fort Hare, 2015) Sowunmi, Linda Ifeanyichukwu; Afoloyan, A.J.
South Africa has wide ranges of plants among which are leafy vegetables growing in the wild. These wild vegetables have been reported to have high nutritive and medicinal potentials. Yet, there is still high prevalence of malnutrition and micronutrients deficiencies among the low income bracket of the population. Effective utilization of wild vegetables has been proposed as part of the solutions to address the problem of dietary deficiencies among the populace. Their importance is mainly as relish to accompany and complement starch based diets. They are also known to serve as supplements for food which have the potential to improve the health status of its consumers in many rural communities. Cleome gynandra L. (Capparaceae) is one of the underutilized species mentioned during asurvey conducted in Nkonkobe municipality of the Eastern Cape Province, South Africa. The plant is an erect annual herb with alternate, palmately compound leaves and its petals are white, pink or lilac. It grows as a weed in this part of the Province and is usually gathered from the wild for food and medicine. It is commonly found on wastes land, road sides and on grass lands. Therefore, this research work was designed to contribute to the possible domestication of this wild vegetable in order to explore the nutritive and therapeutic potentials which would broaden the food base in the Eastern Cape Province.
Pharmacological studies of foeniculum vulgare (mill.) and Lippia javanica (burm. F.) Spreng. used as spices in Nkonkobe Municipality of the Eastern Cape province, South Africa
(University of Fort Hare, 2015) Asowata-Ayodele, Abiola Mojisola
Spices are of great importance in the indigenous culinary and traditional medicine systems of the people of Nkonkobe Municipality of the Eastern Cape, South Africa. The present investigation evaluated the ethnopharmacological potentials of two indigenous South African spices- Foeniculum vulgare and Lippia javanica. The pharmacological investigations on these two plant species include ultra-morphology, nutrient and mineral analysis, evaluation of the essential oil, phytochemical and antioxidant assays, antimicrobial, anti-inflammatory as well as anti-urolithiatic assay of the acetone and aqueous extracts of the two plants. The species were selected for study as the most cited plants after an ethnobotanical survey conducted on the indigenous knowledge of plants used as spices and medicine in Nkonkobe Municipality, Eastern Cape of South Africa. Among the plants cited Foeniculum vulgare (Apiaceae) and Lippia javanica (Verbenaceae) stood out as the most commonly used spices. Others were members of the families; Solanaceae, Apiaceae, Amaryllidaceae, Amaranthaceae and Lamiaceae. Ultra-morphological studies conducted on the leaves of the two selected plants using scanning electron microscope revealed the presence of non-glandular and glandular trichomes, stomata and crystals. The leaf surfaces of these herbs may serve as secretory sites where aromatic secondary metabolites are produced. Analyses of the proximate, mineral, vitamin and anti-nutrients contents of these two spices showed that both species are good sources of these phytochemicals and may be used to enrich the human diet. Lippia javanica possesses lower lipid (0.50%), fibre (5%) and carbohydrate (64.96%) contents than Foeniculum vulgare. On the other hand, protein (20.54%), ash (11.60%) and moisture content (11.69%) were higher in Foeniculum vulgare than in Lippia javanica. Foeniculum vulgare showed higher N (3286 mg/100g), Mg (386.7 mg/100g), K (3187 mg/100g) and Na (1383 mg/100g) content while Lippia javanica was higher in Ca (1833 mg/100g), Zn (4.7 mg/100g), Cu (0.9 mg/100g) and Fe (78.4 mg/100g). Vitamins A and E were also higher in Lippia javanica (1.31 mg/100g; 2.52 mg/100g) while Foeniculum vulgare (0.45 mg/100g) had higher vitamin C content. No significant differences were observed in the phytate, oxalate and tannin contents of the two spices, but saponin and cyanide were significantly lower in Lippia javanica (268.5 mg/100g; 8.45 mg/100g) than in Foeniculum vulgare (1855 mg/100g; 10.5 mg/100g). Evaluation of the essential oil component, cytotoxicity and antimicrobial activities of both fresh and dried leaves of Lippia javanica and Foeniculum vulgare revealed that the dried samples yielded more oil and also contain more chemical than the fresh samples of both plants. The overall antimicrobial activity evaluated using susceptibility and microdilution assays revealed that the oils of F. vulgare and L. javanica exhibited high antifungal and antibacterial activity, compared to the reference drugs. In addition, essential oil from fresh leaves of both spices was less toxic compared to the oil from the dried leaves. Polyphenolic evaluation of the aqueous and acetone extracts of the plants revealed that the acetone extract had higher phenol, flavanol, flavonoid and proanthocyanidin contents than the aqueous extracts. The total phenolic content of acetone and aqueous extracts were 4.49 ± 0.411 mg/g and 3.73 ± 0.498 mg/g tannic acid equivalent (TAE) respectively for Lippia javanica. The same trend was also observed in Foeniculum vulgare with total phenolic content of acetone and aqueous extracts were 4.22 ± 0.325 mg/g and 4.17 ± 0.651 mg/g tannic acid equivalent (TAE) respectively. Further assessment of the antioxidant activity of the solvent extracts revealed that both plants exhibited promising free radical scavenging potentials against 1,1 diphenyl-2-picrylhydrazyl (DPPH), 2, 2’-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid (ABTS), reducing power, lipid peroxidation, nitric oxide, phosphomolybdate and hydrogen peroxide. Antimicrobial activities of the acetone and aqueous extracts of the two plants revealed moderate antibacterial and antifungal activities. They inhibited the growth of Microsporium canis and Trichophyton rubrum that were not susceptible to the standard antifungal drug used as control. The assay revealed that both acetone and aqueous extracts of both plants had the ability to inhibit protein denaturation and maintain membrane stability. The in-vitro anti-urolithiatic assay revealed that Lippia javanica and Foeniculum vulgare exhibited moderate inhibitory effects. These findings support the folkloric uses of Foeniculum vulgare as a good source of anti-urolithiatic drug. This is the first documentation of the in-vitro evaluation of anti-urolithiatic potentials of Foeniculum vulgare and Lippia javanica. This study has revealed that the two species possess high antioxidant, antimicrobial, anti-inflammatory and anti-urolithiatic properties. These could account for the high importance placed on these two plants as spices among the people of Nkonkobe Municipality of the Eastern Cape, South Africa.

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