Magister Pharmaceuticae - MPharm / Syzygium cordatum is a medicinal plant indigenous to South Africa and Mozambique, commonly used to treat stomach aches, diabetes, respiratory problems and tuberculosis. In spite of the folklore use, adequate scientific data to credit its widespread traditional use is lacking. The objectives of this study were: to evaluate and validate scientifically the successful therapeutic claims by traditional medicine practitioners that Syzygium cordatum is effective in treating diarrhoea and diabetes; to determine the effects of the plant extract on gastrointestinal transit of a charcoal meal in mice; to determine the effects on castor oilinduced intestinal fluid accumulation; to determine the safety profile of the plant by carrying out acute toxicology study and to carry out preliminary screening of the active compounds present in the plant using standard phytochemical analytical procedures. The aqueous leaf extract of Syzygium cordatum (3.125 -50mg/kg, p.o) significantly reduced the faecal output caused by castor oil (0.7ml). All the doses used, reduced faecal output from 100% produced by castor oil to between 40 and 61%. S.cordatum (6.25 – 50mg/kg, p.o) significantly and in a dose dependent manner, delayed the onset of castor oil-induced diarrhoea. / South Africa

The South African commercial forest industry is almost exclusively reliant on plantations of exotic trees, of which Eucalyptus spp. make up almost 50 %. Botryosphaeria spp. are important canker pathogens in these Eucalyptus plantations in South Africa. However, exotic plantations and their pathogens cannot be viewed separately from the related native flora. This study showed the importance of extending our knowledge on pathogens that occur on related native and exotic hosts, and which can pose a threat by cross infection between these host groups. In Chapter 1, a review of the literature concerning Botryosphaeria spp. that occur on Eucalyptus in its native range and exotic plantations is presented. It is clearly shown that Botryosphaeria spp. are important pathogens on Eucalyptus in exotic plantations worldwide, causing various symptoms on this host. Botryosphaeria spp. are also important canker pathogens in Eucalyptus plantations in South Africa. Traditional identification of this group of fungi, based on morphological characteristics, led to much confusion about their identity. However, in recent studies morphological characteristics were combined with DNA sequence data to distinguish and identify these fungi. Based on these data a few revisions have been done and new Botryosphaeria spp. were described on Eucalyptus. Botryosphaeria spp. recognised as pathogens on Eucalyptus in South Africa include B. dothidea, B. parva and B. eucalyptorum. Future studies should be focused on correct identification of Botryosphaeria spp. that occur on Eucalyptus, which is the first step towards preventing the spread of this group of pathogens and developing management strategies to control disease outbreaks. During the study on Botryosphaeria spp. on Syzygium cordatum, isolates of two Botryosphaeria spp. appeared to be undescribed. One of the undescribed species was represented by only one isolate and it was not named. The other species was described as the new Botryosphaeria anamorph within Lasiodiplodia, namely L. gonubiensis. This species grows endophytically on native S. cordatum in South Africa and is the first species in Lasiodiplodia to be found on native trees in the country. Identification of the new species was based on conidial and cultural morphology and DNA sequence data of the rDNA internal transcribed spacers, ITS1 and ITS2. Identification and description of L. gonubiensis is presented and discussed in Chapter 2. In total nine Botryosphaeria spp. were isolated from native Syzygium cordatum in South Africa. These include B. parva, B. ribis, B. lutea, B. australis, B. rhodina, B. dothidea, Fusicoccum mangiferum, Lasiodiplodia gonubiensis and an unknown Botryosphaeria sp. The isolates related to B. ribis, B. parva and F. mangiferum were the most abundant, while only one isolate represented B. dothidea. Species were identified based on morphological characteristics of their anamorphs combined with ITS rDNA sequence data. Some species, such as B. parva and B. ribis, could not be distinguished based on morphology or ITS rDNA data. A PCR-RFLP fingerprinting technique was, therefore, used to distinguish isolates of these two species. Once again this technique has proven useful and reliable in identification of Botryosphaeria isolates, including cryptic species. However, isolates of closely related B. lutea and B. australis could not be distinguished using this technique. It could be of interest to develop PCR-RFLP identification system that could be used in identification of the latter species. Identification and characterization of Botryosphaeria spp. are presented in Chapter 3. Isolates of all Botryosphaeria spp., obtained from native Syzygium cordatum in this study, caused lesions on the stems of Eucalyptus camaldulensis and S. cordatum in trials conducted under greenhouse conditions. Except for Fusicoccum mangiferum, all the other Botryosphaeria spp. were more pathogenic on Eucalyptus than on S. cordatum. The most pathogenic species on Eucalyptus were B. rhodina, B. ribis and B. lutea, whileF. mangiferum and B. ribis were the most pathogenic on S. cordatum. Botryosphaeria dothidea and L. gonubiensis were the least pathogenic on both hosts. The results obtained from this trial clearly show that Botryosphaeria spp. on S. cordatum pose a potential threat to exotic Eucalyptus plantations. Future study should be conducted under field conditions to evaluate data obtained in greenhouse trials. These results were presented and discussed in Chapter 4. The results presented in this study provide the first detailed information on Botryosphaeria spp. on the native Myrtaceae in South Africa. Most of the species isolated from Syzygium cordatum are not known on Eucalyptus in the country. All of the Botryosphaeria spp. obtained in this study are pathogenic to Eucalyptus, and thus pose a threat to this host. Large number of B. ribis, B. parva and F. mangiferum isolates obtained from the native S. cordatum could imply their origin in this region. Further sampling is needed on myrtaceous trees native to the Southern African region, as well as on Eucalyptus. Population studies on the most abundant and most pathogenic Botryosphaeria spp., should provide more information on the movement and origin of these pathogens. The results from this study also highlights the need for quarantine measures to avoid the introduction of new Botryosphaeria spp. or new strains that can be more pathogenic to either native or cultivated plants. Please cite as follows Pavlic, D 2004, Botryosphaeria species on native South African Syzygium cordatum and their potential threat to Eucalyptus , MSc dissertation, University of Pretoria, Pretoria, viewed yymmdd < http://upetd.up.ac.za/thesis/available/etd-02062006-112938/ > / Dissertation (MSc)--University of Pretoria, 2007. / Microbiology and Plant Pathology / MSc / Unrestricted

Syzygium cordatum is a medicinal plant indigenous to South Africa and Mozambique, commonly used to treat stomach aches, diabetes, respiratory problems and tuberculosis. In spite of the folklore use, adequate scientific data to credit its widespread traditional use is lacking. The objectives of this study were: to evaluate and validate scientifically the successful therapeutic claims by traditional medicine practitioners that Syzygium cordatum is effective in treating diarrhoea and diabetes / to determine the effects of the plant extract on gastrointestinal transit of a charcoal meal in mice / to determine the effects on castor oilinduced intestinal fluid accumulation / to determine the safety profile of the plant by carrying out acute toxicology study and to carry out preliminary screening of the active compounds present in the plant using standard phytochemical analytical procedures. The aqueous leaf extract of Syzygium cordatum (3.125 -50mg/kg, p.o) significantly reduced the faecal output caused by castor oil (0.7ml). All the doses used, reduced faecal output from 100% produced by castor oil to between 40 and 61%. S.cordatum (6.25 &ndash / 50mg/kg, p.o) significantly and in a dose dependent manner, delayed the onset of castor oil-induced diarrhoea.

Syzygium cordatum is a medicinal plant indigenous to South Africa and Mozambique, commonly used to treat stomach aches, diabetes, respiratory problems and tuberculosis. In spite of the folklore use, adequate scientific data to credit its widespread traditional use is lacking. The objectives of this study were: to evaluate and validate scientifically the successful therapeutic claims by traditional medicine practitioners that Syzygium cordatum is effective in treating diarrhoea and diabetes / to determine the effects of the plant extract on gastrointestinal transit of a charcoal meal in mice / to determine the effects on castor oilinduced intestinal fluid accumulation / to determine the safety profile of the plant by carrying out acute toxicology study and to carry out preliminary screening of the active compounds present in the plant using standard phytochemical analytical procedures. The aqueous leaf extract of Syzygium cordatum (3.125 -50mg/kg, p.o) significantly reduced the faecal output caused by castor oil (0.7ml). All the doses used, reduced faecal output from 100% produced by castor oil to between 40 and 61%. S.cordatum (6.25 &ndash / 50mg/kg, p.o) significantly and in a dose dependent manner, delayed the onset of castor oil-induced diarrhoea.

Free radicals have been implicated in the progression of various diseases, such as cancers and cardiomyopathies. When the body is overburdened with free radicals and endogenous antioxidants become depleted, oxidative stress ensues with resultant damage to biomolecules. During oxidative stress high levels of reactive oxygen species are generated, cellular viability decreases, and apoptosis and lipid peroxidation are induced. Supplementation with exogenous supplements rich in antioxidants, such as herbal remedies containing polyphenols, could result in increased protection against oxidative stress. The aim of the study was to assess the effect of Burkea africana and Syzygium cordatum in a cellular oxidative stress model for the potential development of an antioxidant supplement. Crude aqueous and methanolic extracts were prepared by solvent maceration, while a polyphenolic-rich extract was created through liquid-liquid extraction. Polyphenolic content and antioxidant activity was assessed in cell-free systems. Polyphenolic content was determined through the Folin-Ciocalteau and aluminium trichloride methods, while antioxidant activity was assessed by the Trolox Equivalence Antioxidant Capacity and 1,1-diphenyl-2-picrylhydrazyl radical assays. Identification of phytochemical classes was done through thin layer chromatography and biochemical reactions. Inherent cytotoxicity of samples was determined in four cell cultures (3T3-L1 pre-adipocytes, C2C12 myoblasts, normal human dermal fibroblasts and U937 macrophage-like cells) using the neutral red uptake assay. The effect on oxidative stress was assessed in 2,2`-azobis-(2-methylpropionamidine) dihydrochloride-exposed U937 macrophage-like cells with regards to reactive oxygen species generation, cytotoxicity, apoptosis, lipid peroxidation and GSH depletion. Both B. africana and S. cordatum showed enrichment of polyphenols from the aqueous extract, to methanolic extract, to polyphenolic-rich extract. Antioxidant activity showed the same trend, which correlated well with the increased concentration of polyphenols, such as catechin, gallic acid and myricetin. Samples indicated toxicity in the 3T3-L1 and C2C12 cell lines, though no toxicity was noted in the U937 cell line and normal human dermal fibroblast cultures. Free radical-induced generation of reactive oxygen species, cytotoxicity, lipid peroxidation and apoptosis was successfully reduced by crude extracts of B. africana and the polyphenolic-rich extracts of both plants between concentrations of 10 and 20 ìg/ml. The crude extracts of S. cordatum were mostly ineffective in reducing these parameters, even though cell viability was increased. B. africana pre-treatment decreased reduced glutathione concentrations significantly in a dose-dependent manner, while the methanolic and polyphenolic-rich extract of S. cordatum increased concentrations moderately. Polyphenolic-rich extracts of B. africana and S. cordatum had the most potent decrease in oxidative stress-related parameters in the present study, which could be attributed to the polyphenolic content and antioxidant activity. Limited cytotoxicity was apparent in two of the four cell lines tested; further isolation and purification needs to be carried out to assess the bioactive constituents which do not elicit a toxic response. Further investigation through the use of quantitative structure–activity relationship modeling could give more insight on conformational and chemical changes that need to be brought about to modify the bioactive phytochemicals for reduced cytotoxicity, but increased antioxidant activity. Copyright / Dissertation (MSc)--University of Pretoria, 2013. / Pharmacology / unrestricted

Pentachlorophenol, (PCP) is an organochlorine compound which was first developed in the 1930’s. PCP is said to be the most toxic of the chlorophenols and is classified as a hazardous substance and a probable human carcinogen. PCP has proven to be cytotoxic to a number of cell lines translating to its effect on various organs. The aim of the study was to assess organochlorine-induced hepatotoxicity in a mechanistic manner using an in-house developed procedure. Also, the possible hepatoprotective effect of methanolic extracts of the bark of two medicinal plants, Burkea africana (BA) and Syzygium cordatum (SC), as well as the known hepatoprotective agent, N-acetyl cysteine (NAC), were investigated. In addition to PCP, two of its major metabolites, tetrachloro-1,2-hydroquinone (TCHQ) and tetrachloro-1,4-benzoquinone (TCBQ) were also evaluated. A hepatocarcinoma cell line (HepG2) was used to investigate the effect of these compounds on different parameters of cellular function. Cytotoxicity was assessed using the neutral red uptake assay. Cytochrome P4501A1 (CYP1A1) activity was determined using ethoxy-resorufin-O-deethylation as surrogate. Generation of reactive oxygen species (ROS) was investigated by measuring dichlorofluorescein diacetate cleavage. Effects on mitochondrial membrane potential were determined using JC-1 staining, whilst necrosis was investigated by assessing plasma membrane integrity using propidium iodide (PI)staining. The degree of apoptotic death was determined by quantifying caspase-3 activity. Assays were repeated with an additional 1 h pre-treatment of the cells with either NAC, SC or BA in order to investigate whether these compounds were able to protect against the toxicity induced by PCP and its metabolites. The IC50 values of PCP, TCHQ and TCBQ were 68.0, 144.0 and 129.4 μM, respectively. All three test compounds induced CYP1A1 activity with PCP being the most potent. TCBQ produced extensive ROS generation. TCHQ also induced ROS generation, whilst PCP appeared to have no significant effect on ROS generation. All test compounds caused mitochondrial depolarization. None of the test compounds caused an increase in necrotic cell death. PCP, TCHQ and TCBQ had negligible effects on apoptosis. Both SC and BA alleviated the toxic effects observed in cells treated with PCP. Minor increases in viability occurred in cells pre-treated with plant extracts prior to exposure to both metabolites. NAC, as well as both plant extracts, greatly reduced CYP 1A1 activity induced by PCP. NAC, SC and BA exacerbated CYP1A1 induction in cells exposed to concentrations of TCBQ and TCHQ that initially produced little or no effect on CYP1A1 activity. Contrarily, decreased CYP1A1 activity was observed in cells exposed to concentrations of TCBQ and TCHQ where extensive induction of CYP1A1 occurred. NAC, as well as both plant extracts, suppressed ROS generation in cells exposed to all test compounds. In cells exposed to PCP and TCBQ more extensive mitochondrial depolarization was seen when pre-treated with NAC and plant extracts than when exposed to the compounds alone. Negligible effects were seen in pre-treated cells exposed to TCHQ. BA and SC caused increases in necrotic death in cells exposed to the test compounds. NAC, BA and SC had negligible effects on the changes in caspase-3 activity induced by the test compounds. From the results it is proposed that PCP induces its own metabolism by increasing CYP1A1 activity. It also causes mitochondrial insult which could lead to the opening of the mitochondrial permeability transition pore and subsequent release of cytochrome C, activation of caspases and eventually apoptotic cell death. With regard to TCHQ and TCBQ, results suggest that extensive ROS generation caused damage to various cellular macromolecules and that this could be the main cause of their toxicity. NAC, SC and BA appeared to alleviate toxicity in certain instances. Further investigation is required in order to assess them as possible hepatoprotective agents. Copyright / Dissertation (MSc)--University of Pretoria, 2011. / Pharmacology / unrestricted