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The effects of elevated carbon dioxide concentrations on the physiological and biological characteristics of Portulacaria afra
No full textA research report submitted in partial fulfilment of the requirements for the degree Master of Science to the Faculty of Science, School of Animal, Plant and Environmental Sciences, University of the Witwatersrand, Johannesburg, 2023There is a concern that rising atmospheric carbon dioxide (CO₂) concentrations may affect the medicinal or nutritional profile of medicinal plants. Portulacaria afra (P. afra) is a medicinal plant used by traditional healers to treat various skin conditions. The aim of this study was to determine whether elevated CO2 concentrations will affect the physiological and medicinal properties of the leaves, stems, and roots of P. afra. This was achieved by measuring the physiological, phytochemical, antioxidant, and antimicrobial activity of the various plant parts, which were exposed to ambient (420 ppm) and elevated (600 ppm) CO₂ concentrations and comparing them to samples grown in greenhouse conditions. The plant samples were placed in a Conviron climate stimulator for three months. Three harvests were completed during thistime. The physiological properties measured include the weight of the various plant parts as well as the chlorophyll content within the leaves. The phytochemical profile of the plant was examined through a set of standard colour tests (qualitative analysis) and the determination of the total flavonoid content (quantitative analysis) in all three plant parts exposed to the various treatments. The antioxidant activity was determined by analysing the scavenging activity of the extracts against 1,1 diphenyl-2- picrylhydrazel (DPPH) and hydrogen peroxide (H2O2) with the use of a spectrophotometer. The antimicrobial activity determined the extracts’ ability to inhibit the growth of six microorganisms related to skin conditions. The results of this study revealed that there was a 65% and 39% increase in the weight of the leaves and roots, which were exposed to 600 ppm, respectively. A higher phytochemical presence was recorded in plants exposed to 600 ppm. There was a significant increase in flavonoid presence and flavonoid content in the methanolic and hot water plant samples that were exposed to elevated CO2.The leaves, stems, and roots of P. afra exhibit strong scavenging activity against DPPH and even more so towards H2O2. The strongest antioxidant activity was 13 exhibited by the methanolic leaf extracts which were exposed to 600 ppm, against H2O2 (0.2±0.7 mg/ml). The antimicrobial activity of all three plant parts was relatively constant between the different treatments. Despite the relatively weak antimicrobial activity of P. afra (MIC values > 1000 (µg/ml), a notable increase in the antimicrobial activity of the leaves against Cutibacterium. acnes were observed in samples exposed to 600 ppm of CO₂. Portulacaria afra is a medicinal plant that exhibits great resilience towards elevated atmospheric CO2 concentrations. The phytochemical and biological properties in this study displayed either no change or an increase in activity, which suggests that P. afra may continue to provide relief against certain ailments in the future despite rising atmospheric CO2 concentrationsTL (2024
The effects of concurrent extreme temperature and water deficit on the phytochemical profile and phytopharmacological activities in Portulacaria afra Jacq
No full textThis thesis is submitted in fulfillment of the requirements for the degree of Doctor of Philosophy in Animal, Plant and Environmental Sciences Faculty of Science, University of the Witwatersrand, Johannesburg, South Africa 2024In nature, all plants are exposed to stress which are mostly biotic and abiotic stress factors. Previous studies have demonstrated the impact of various abiotic stress factors on the production of secondary metabolites in therapeutic plants. Plant responses to stressors brought on by a combination of antagonistic abiotic factors have shown to be phenomenal compared to when plants are exposed to single a factor. According to latest climate change models, it is believed that plants would suffer unique or demanding concurrent abiotic stresses in the years to come. South Africa has been experiencing increasing temperatures over last 40 years and
being regarded as a climate change ‘hot spot’ by the Intergovernmental Panel on Climate Change (IPCC). Therefore, it is critical to conduct research on the impact of climate change on the bioactive compounds in therapeutic plants. The overarching aim of this study was to establish and scientifically document, for the first time to our knowledge, the phytochemical profile, medicinal properties and phytopharmacological attributes of Portulacaria afra, a widely renowned medicinal plant used for treating several skin conditions and oral infections which also includes the assessment of the effects of concurrent extreme temperatures and water
deficit/drought on species’ biological activities.
In this study, South African Portulacaria afra plants were selected from healthy parent plants and propagated from cuttings. Samples were allowed to grow and establish a root system in the greenhouse for up to three months. After three months, 180 potted plant samples were exposed to treatments and not watered for up to 144 hours (6 days), and 45 control samples were placed under 25oC (ambient) and watered every second day with 500ml of water. The control samples
were kept at 25°C maximum night-time temperature (7pm to 5am) and 27°C maximum day time temperature. Plants undergoing treatment (coded as treatment A, B, C, D) were treated as follows: A and B were exposed to 0/10ºC (night/day) and 5/15ºC (night/day) respectively, while C and D were exposed 20/40°C (night/day) and 35/45°C (night/day), respectively. Five potted plants were harvested in each treatment three times for up to 6 days (144hrs). Sample harvesting was scheduled episodically every 48hrs (48, 96, 144) and were then airdried under 40°C for 2 to 3 days.
The aqueous (water) extracts at a temperature of 60°C, alongside methanol, n-hexane, and ethyl acetate extracts were derived from the leaves, stems, and roots. The extracts were then used to investigate the phytochemical composition, antibacterial efficacy, antioxidant capacity and antidiabetic potential. The qualitative phytochemical screening encompassed the preliminary assessment of saponins, flavonoids, glycosides, quinones, phenols, terpenoids, steroids, phytosteroids, volatile oil, carbohydrates, amino acids, and coumarins. The quantitative analyses were performed to determine the total phenolic content (TPC), total flavonoid content (TFC), while the antioxidant assays were performed to determine the reducing, scavenging and chelating abilities against DPPH, H2O2 and metal (Iron) chelating. The antibacterial activities against gram-negative Escherichia coli and gram-positive Staphylococcus aureus, Streptomyces griseus were assessed through agar well diffusion assay. The antidiabetic potential was evaluated using In vitro inhibitory α-amylase assay. Chemical profiling of various extracts from the leaves, stems, and roots of P. afra was conducted to identify and quantify some secondary metabolites. The methanolic leaf extracts exhibited a notable presence of quinones, phenols, steroids, and coumarins, whereas the aqueous leaf extracts contained moderate presence of saponins, terpenoids, quinones, and coumarins. Ethyl acetate leaf extracts were characterized by a strong presence of tannins and a moderate presence of phytosteroids. Conversely, n-hexane leaf extracts showed considerable saponin levels, moderate tannins, and terpenoids. Significantly strong presence of secondary metabolites was observed in methanolic stem extracts, particularly terpenoids, steroids, phenols, and coumarins. Notably, coumarins, known for their anticancer properties, were prominently present in methanolic leaf and stem extracts, with a moderate presence in root extracts, hinting at potential pharmaceutical applications and future roles in public health. Aqueous stem extracts exhibited strong glycoside presence, while ethyl acetate and n-hexane stem extracts exhibited few fewer secondary metabolite groups, ranging from moderate to weak presence.
Distinctive chemical profiles were observed in root extracts, with ethyl acetate extracts showing significantly stronger quinone presence. Methanolic root extracts displayed moderate presence of coumarins and glycosides, whereas aqueous root extracts showed a low glycoside presence. The highest total phenolic contents (TPCs) and total flavonoid contents (TFCs) were found in methanol stem extracts and aqueous root extracts, respectively. Notably, aqueous root extracts exhibited the highest TPC and TFC among all root extracts. Antibacterial activity assays showed a wide range on inhibitory effects of n-hexane extracts from leaf, stem, and root against test microorganisms. Ethyl acetate leaf extracts demonstrated considerable inhibitory efficacy against Staphylococcus aureus, while methanolic extracts showed zero zone of inhibition. Aqueous root extracts showed strong antibacterial activity against Staphylococcus aureus, whereas other extracts showed no significant activity. Inhibition zones ranged from 13 to 24 mm for the plant extracts. The assessment of antioxidant potential through DPPH, H₂O₂ scavenging, and metal chelating assays showed varied activity among extracts. Ethyl acetate root extracts showed the strongest H₂O₂ scavenging activity, while aqueous stem extracts showed the strongest antioxidant activity against DPPH radicals. Aqueous and n-hexane root extracts showed the strongest metal chelating ability. The in vitro antidiabetic activity showed that all plant parts were active against α-amylase, with the highest inhibitory action recorded from the methanolic leaf extracts, followed by the methanolic root extractsUniversity of Witwatersrand Post-Graduate Merit AwardNational Research FoundationMM202
The Impact of different levels of organic plant-based compost on the macro and micro elements, secondary metabolites and water soluble vitamins content of Moringa oleifera leaves
No full textA thesis submitted in fulfilment of the academic requirements for the degree of Doctor of Philosophy, to the Faculty of Science, School of Animal, Plant and Environmental Sciences, University of the Witwatersrand, Johannesburg, 2023.Moringa oleifera leaves are a high source of phytochemicals and nutrients inclusive of macro and micro elements, secondary metabolites and water-soluble vitamins. All the M. oleifera plant parts inclusive of its leaves have been widely utilised for nutritional and/ medicinal properties because of its high levels of minerals and phytochemicals. Studies have been conducted targeting the improvement of the quantity of M. oleifera nutrient content. However, with increased consumer awareness of high quality organic, consumer and environmentally safe products there is increased need to improve the quality of M. oleifera products. One of the major factors impacting the quality and quantity of M. oleifera leaf nutrients is cultivation practices. Particularly soil amendments applied to improve plant biomass have also been found to significantly improve nutrient content of M. oleifera leaves. However, the popularly used soil amendments which are in the form of synthetic fertilisers or animal based compost have raised environmental and product safety concerns. They contain, among other contaminants, traces of heavy metals and other toxins which are harmful to both the environment and consumers of the produce. Producers of herbal plants such as M. oleifera are looking for sustainable, environmental safe ways of improving the quantity and quality of the produce. Application of organic plant based compost was therefore investigated as a potential soil amendment source in improving M. oleifera nutrients in an organic, clean sustainable way, and thus improving the quality of the produce. The use of plant based compost to improve the nutritional content of M. oleifera grown in South Africa was reported in this thesis. The primary objective of the study was to assess the impact of the plant-based organic compost on the macro and micro elements composition, secondary metabolite accumulation and distribution and water soluble vitamins content in M. oleifera leaves. This work is novel and worth exploring as it seeks to investigate for the first time the correlation between the use of plant-based organic compost and quality improvement in terms of nutrient content of M. oleifera leaf biomass. Furthermore, this research is the first of its kind which looks at the impact of compost on the nutritional content encompassing, macro and micro nutrients, secondary metabolites and water soluble vitamins in M. oleifera grown in South Africa. In addition, the developed and validated high performance liquid chromatography (HPLC) method for the simultaneous quantification of five B vitamins was successfully used in the identification and quantification of the vitamins. Clay soil and M. oleifera seeds used in the study were obtained from the M. oleifera community farm in Hammanskraal, Gauteng, South Africa. The clay soil was amended with plant-based organic compost purchased from the local nursery store. The amendments achieved four treatment levels namely 15 % compost / soil amendment, 30 % compost / soil amendment, 45 % compost / soil amendment and 60 % compost / soil amendment. Moringa oleifera seeds used were obtained from the same farm. Plant samples were grown in the School of Animal, Plant and Environmental Sciences (APES), University of the Witwatersrand, greenhouse under ambient temperatures. Harvesting of the leaf biomass was done after six months and nutrient analysis was carried out. Analytical techniques such as Spectroscopy and Chromatography were used for the nutrient analysis. Presence and quantity of macro and micro elements in the soil and leaves was analysed using the Inductively Coupled Plasma Optical Emission spectroscopy (ICP-OES). Whilst, the Ultra high-performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight mass spectrometry (UHPLC-ESI-QTOF-MS) was used to determine plant metabolites, and for the quantification of water-soluble vitamins by coupling it with the diode array detector (DAD). The nutrient analysis revealed that the use of organic plant-based compost for the amendment of clay soil improved the quality of the soil and M. oleifera leaves harvested from each soil amendment. The addition of the organic plant-based compost improved the macro and micro nutrients. Comparison of the different compost levels revealed that addition of plant based compost increased the bioavailability of macro and micro nutrients in the soil and increased their accumulation in M. oleifera leaves. Metabolic fingerprinting of M. oleifera leaf samples using UHPLC-ESI-QTOF-MS followed by untargeted compound analysis exposed variation in the identified metabolites. Further use of multivariate analysis in the form of PCA clustered the samples into five distinct clusters indicating diversity in the distribution of secondary metabolite as influenced by the addition of plant-based compost to the soil. The developed HPLC method was suitable for the simultaneous quantification of five B vitamins based on the low LOD and LOQ values, recovery of 97.8- 99.58% and good linearity. Application of the validated method revealed that, the addition of plant based compost significantly improved the quantity of the tested vitamins (Vitamin B1, B2, B3, B6 and B9). The 30% plant-based organic compost and clay soil combination was identified and recommended as the best compost-soil combination in improving nutrients in M. oleifera leaf biomass. It had the highest level of macro and micro nutrients. Leaves harvested from this soil/compost combination had higher concentration of Ca (45 042.5 mg/Kg), Mg (17 430 mg/Kg), P (8802. 5 mg/Kg). In addition leaves, harvested from 30% compost treatment exhibited the highest number of identified secondary metabolites and had the highest concentration of two of the five tested water soluble vitamins. This knowledge will make great contribution in the M. oleifera industry in South Africa and worldwide particularly for farmers who are into organic M. oleifera production.MMM202
The effects of elevated carbon dioxide on the secondary metabolites and biological activities in Moringa oleifera Lam. and Moringa peregrina Forssk
No full textThis dissertation is submitted in fulfilment of the requirements for the degree of Master of Science, to the Faculty of Science, at the School of Animal, Plant and Environmental Sciences, University of the Witwatersrand, Johannesburg, 2023.Climate is crucial for the distribution and survival of medicinal plants as it can influence phytochemicals and regulatory hormones that are responsible for the normal growth and development, as well as their interactions with the environment. Thus, it is important to understand how climate change will impact these crucial plant compounds and hormones that play a significant role in the plant’s survival and development. With the increasing CO2 in the atmosphere, it is expected that climate change effects will be devastating to the world and Southern Africa. The present study intended to achieve two aims, the first being to investigate the impacts of elevated CO2 (eCO2) on the secondary metabolites and biological activities of two important Moringa species, Moringa oleifera Lam. (M. oleifera) and Moringa peregrina - (Forssk.) Fiori (M. peregrina). The second aim was to investigate how the use of M. oleifera leaf extract (MLE) based and commercial (PhytoStim®) biostimulants influence the productivity as well as the adaptability of M. oleifera and M. peregrina under elevated eCO2. The first set of three-month-old potted plant samples were exposed to 400 ppm (control), 600 ppm and 800 ppm for three months, respectively. The second set of plants were placed in the greenhouse and sprayed (foliar application) with 200 mL of M. oleifera leaf extract (MLE) and 200 mL commercial biostimulant PhytoStim® every second week for three months, respectively. The control samples were unsprayed. The third set of plants were exposed 600 ppm and 800 ppm (separately) and simultaneously sprayed with 200 mL of M oleifera leaf extract (MLE) and 200 mL commercial PhytoStim® (separately) every second week for three months to assess the influence of biostimulants on the adaptability of the Moringa species under eCO2. The control samples under 400 ppm were unsprayed. In this study, 80% methanolic extracts from all the above mentioned treatments of M. oleifera and M. peregrina were screened for 17 secondary metabolite groups (tannins, saponins, flavonoids, quinones, phenols, terpenoids, cardiac glycosides, coumarins, steroids, phlobatannins, anthracyanine, volatile oils, phytosterols, triterpenoids, proteins and amino acid, glycosides, carbohydrates) using qualitative methods. Quantitative analyses were performed to determine the total phenolic content (TPC), total flavonoid content (TFC), total tannin content (TTC) and total proanthocyanidin content (TPAC). The antioxidant assays were performed to determine the reducing, scavenging and chelating abilities against DPPH, H2O2 and metal (Iron) chelating. The antimicrobial activities against gram negative Escherichia coli and gram-positive Staphylococcus aureus, Streptomyces albulus were assessed by using the agar well diffusion assay. In the control samples, out of 17 screened secondary metabolites, four (phytosterols, volatile oils, anthocyanin and phlobatannins) were not detected in both species’ extracts. On average, M. peregrina showed higher total content of tannins, phenolics, flavonoids and proanthocyanidins. M. peregrina showed stronger antioxidant activity against iron chelating and H2O2, whilst M. oleifera showed stronger antioxidant activity against DPPH. Both M. oleifera and M. peregrina extracts displayed an acceptable bacterial growth inhibition capability (ZOI ≥10 mm) with only S. albulus being resistant to the control of M. oleifera. Qualitative phytochemical analysis indicated the presence of secondary metabolites such as tannins, saponins, flavonoids under 600 ppm and a slight decline under 800 ppm in both species. The quantitative analysis indicated an increase in the total content of phenols, flavonoids (flavanols), tannins, and proanthocyanidins. An increase in CO2 resulted in an increase in the activity of antioxidants and antibacterial for both species. On average, Moringa peregrina showed higher accumulation of secondary metabolites, higher antioxidant and antibacterial activities in comparison to Moringa oleifera. The foliar application of MLE and PhytoStim® showed an increase in some secondary metabolites and decrease in metabolites such as tannins and phenols in M. oleifera. The application of biostimulants (MLE and PhytoStim®) also resulted in an increase in TPC, TTC and TPAC in M. peregrina, with a decline in total contents of these compounds in M. oleifera. However, the decline did not negatively impact both species' pharmacological abilities (antioxidant and antimicrobial activities), as they exhibited stronger antioxidant and antimicrobial activities when compared to the untreated plants (control samples). The use of the above mentioned plant based biostimulants resulted in an enhanced adaptability as indicated by the increase in the accumulation of selected screened secondary metabolites plant
samples that exhibited signs of stress. The higher accumulation of secondary metabolites was observed under 600 ppm, in combination with PhytoStim® for either species. The combined CO2 and biostimulant treatments improved the total phenolic content (TPC) of both M. oleifera and M. peregrina significantly, with M. oleifera showing higher TPC content when compared to M. peregrina. On average, both M. oleifera and M. peregrina exhibited lower total flavonoid content (TFC), total tannin content (TTC) and total proanthocyanidins (TPAC), with M. oleifera showing higher contents of the above-mentioned phytochemicals in comparison to M. peregrina. The study also highlighted a decline in biological activities for all treatments, with the controls showing higher biological activities for both species. In the three antioxidant assays conducted, the leaf extracts of the controls had significant lower IC50 values for DPPH and H2O2, when compared to the stressed M. oleifera and M. peregrina. Antimicrobial assays also showed no significant difference in the bacterial inhibition capabilities of M. peregrina and M. oleifera under 600 ppm and 800 ppm with either biostimulant application. M. peregrina and M. oleifera controls showed high ZOI for the selected bacterium. The study has demostrated that biostimulants (MLE and PhytoStim®) enhanced the adaptability of both species under potential stress coursed by eCO2. The present study has demonstrated that the exposure to elevated CO2 could alter the accumulation and biological processes (such as antioxidant activity and antimicrobial activity) in both M. oleifera and M. peregrina. Moringa peregrina exhibited more tolerance to elevated CO2 when compared to Moringa oleifera and showed higher antioxidant and antimicrobial activity which might be attributed to the stronger presence of phytochemicals such as flavonoids, phenols and tannins. The data also suggests that both Moringa oleifera and M. peregrina can adapt to high levels of CO2 concentrations (~600 ppm), however, as medicinal plants, it might be difficult to sustain the acclimatisation and tolerance due to membrane oxidation and DNA damage. Therefore, foliar application of the biostimulants could enhance the adaptability and productivity of both species under high levels of CO2. This study may contribute towards better planning on conservation efforts to improve the chances of survival of the Moringa oleifera and M. peregrina and could aid with food security.National Research Foundation (NRF).MM202
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
The effect of electrically activated sodium bicarbonate solution on tomatoes.
Get PDFTomato (Lycopersicon esculentum Mill.) is an important commercial crop. High quality tomatoes for the local and export markets are grown hydroponically. In this study, the effect of electrically activated sodium bicarbonate and non-ionized sodium bicarbonate solutions on productivity and postharvest quality of hydroponically grown tomatoes was tested. Sodium bicarbonate is a ready source of bicarbonate. By using a novel technique obtained from Radical Waters (Pty) Ltd., ionized bicarbonate (anolyte) can be produced from sodium bicarbonate and applied to plants to stimulate photosynthesis, and improve yield and postharvest quality. The effect of ionized and non-ionized bicarbonate solutions on productivity and postharvest quality was studied by measuring the following: (1) Preharvest growth rate (leaf length, stem height and diameter); total yield; starch concentration in leaves; fruit count; leaf chlorophyll content; CO2-uptake; soluble solids and concentration of K+, Na+ and NO3¯ in leaves. (2) Postharvest rate of respiration and transpiration; ethylene production; total soluble solids content; ascorbic acid content; pH; fruit firmness; fruit mass; fruit diameter; longevity; concentration of K+, Na+ and NO3¯ at one-third towards maturity, two-thirds towards maturity, at maturity and during ripening, and rate of ripening at 12 and 23°C. During the preharvest period, plants treated with anolyte showed increased growth rate, starch concentration, chlorophyll content, soluble solids content and improved yield. During the growth period, the concentration of K+ and NO3¯ was higher in plants treated with anolyte than in plants treated with non-ionized sodium bicarbonate. The concentration of Na+ during the preharvest period was higher in plants treated with non-ionized sodium bicarbonate than in plants treated with anolyte. After harvest, fruits from plants treated with anolyte had a reduced rate of ethylene production, rate of respiration and transpiration, total increased soluble solids and ascorbic acid content than fruits from plants treated with non-ionized sodium bicarbonate. Fruits from plants treated with anolyte had reduced rate of ripening and were larger and heavier than fruits from plants treated with non-ionized sodium bicarbonate. Anatomical and ultrastructural studies revealed that treatment with anolyte stimulated cell growth and photosynthesis. These results were confirmed by comparing the CO2-uptake of treated and untreated plants. Application of anolyte stimulated photosynthesis, thus improving yield and fruit quality. Treatment with non-ionized sodium bicarbonate resulted in salt- stress and calcium deficiency. Some of the fruits on plants treated with non-ionized sodium bicarbonate suffered from blossom-end rot due to salt-stress.Prof. C.S. Whitehea
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
An ethnobotanical study of indigenous knowledge of the medicinal plants used by traditional healers in the rural communities of Nkomazi Local Municipality, Mpumalanga province
No full textA research report submitted in partial fulfilment of the requirements for the degree Master of Science to the Faculty of Science, School of Animal, Plant and Environmental Sciences, University of the Witwatersrand, Johannesburg, 2023Traditional medicine continues to significantly impact many people’s lives amid all the advancements in modern medicine. Many rural communities in Mpumalanga province depend on indigenous traditional medicines to manage various ailments. The available research on the traditional usage of medicinal plants among rural communities in Mpumalanga is highly fragmented and under-researched. The decline of medicinal plant populations has led stakeholders to take various initiatives to counteract over-exploitation, including cultivation as a viable conservation approach. However, the scientists' inadequate understanding of the acceptance of cultivated medicinal plants by traditional healers is one of the issues contributing to the failure of medicinal plant cultivation programs. Consequently, this study aimed to document medicinal plants utilised by the Nkomazi Local Municipality's traditional healers and assess opportunities and constraints for medicinal plant conservation in the Nkomazi Local Municipality. The ethnobotanical data was obtained through semi-structured questionnaires and guided field walks with traditional healers. Individual interviews were conducted with ten traditional healers from eight villages across Nkomazi during field visits between July 2021 and February 2022. The study employed qualitative and quantitative approaches to understand traditional healers' perspectives concerning the ethnobotanical significance and medicinal plant conservation. The study found that the indigenous knowledge of medicinal plants in the Nkomazi Local Municipality is diverse, encompassing 111 species from 59 different families employed to treat 70 ailments. Most of the reported medicinal plants for this study are of Least Concern. Additionally, the top fourteen most reported species in the Nkomazi Local Municipality included commercially valuable plants such as Psidium guajava, Ricinus communis, Sclerocarya birrea, Aloe ferox, Aloe maculata, Leonotis leonurus, and Moringa oleifera. Most of the Nkomazi Local Municipality's traditional healers did not know about protected plant species and the National Environmental Management Act (NEMA). Traditional healers were aware of the decline in wild populations of medicinal plants, which they attributed to various factors such as overharvesting. Diviner’s and herbalist perception of using cultivated plants did not differ significantly (2=0.4762, df=1, P= 0. 490). The study provided a comprehensive inventory of medicinal plants utilised by Nkomazi traditional healers and essential data for future assessments of the use local use of indigenous medicinal plants.National Research Fund (NRF)TL (2024)MM202
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