No description available.

No description available.

No description available.

No description available.

No description available.

No description available.

No description available.

No description available.

Due to the increasingly documented prevalence of diarrhoeal diseases in Malaysia, a number of water-related programmes have been implemented in an attempt to improve health status through the reduction of incidence of waterborne communicable diseases associated with poor public water supplies. The implicit assumption underlying these projects is that the enhancement of the physical infrastructure, and subsequent improvements in the quality of the water supply, will substantially reduce waterrelated disease. This thesis questions the veracity of this hypothesis, and therefore the justifiability of an emphasis upon engineering and urban infrastructural interventions. Research centred upon Port Dickson, a district which typifies existing water and sanitation conditions in much of semi-rural Malaysia. The specific objectives of the thesis were: to determine the measured burden of illness of waterborne disease within the district and to estimate levels of underreporting; to determine morbidity-related factors influencing the decision to seek medical treatment; to provide a demographic profile of the population experiencing diarrhoeal episodes; and to identify risk markers or predictors of morbidity. Burden of illness was measured by health services utilization, while values for underreporting and risk markers were derived from a 268 household diarrhoeal morbidity survey. Diarrhoeal incidence was estimated to be 12-16% annually, much higher than Malaysia's official average. This incorporated a rate of non-reporting of 19~, which was influenced by chronicity, duration and severity of episodes. Individuals found to be most at risk were young children and adults in their child-bearing years, minority racial groups, and those with poor water supply and sanitation infrastructure and inappropriate hygiene habits. While water quality was found to influence diarrhoeal rates, factors in addition to infrastructure - partially hygiene - were shown to play a greater role. Thus, it is suggested that the impact of water and sanitation improvement projects would likely be minimal, unless accompanied by complementary behavioural education programmes. The spatial bias of the aforementioned risk factors suggests a need to refocus intervention initiatives upon rural areas. / Thesis / Master of Arts (MA)

Diarrhoea is one of the killer diseases resulting from the dehydration and loss of electrolytes through profuse and excessive excretion of loose stool. The pathoaetiologies include infections, intestinal inflammation, imbalanced intestinal oxidative homeostasis and altered motility. Treatment with oral rehydration therapy (ORT) is a key intervention especially in secretory diarrhoea as supportive therapy. Symptomatic and non-symptomatic therapies directed at treating the intestinal tissues are available. However, these conventional treatments are still not sufficient in curing diarrhoea due to their associated hazards such as the development and spread of drugresistant pathogens, changes in normal intestinal bacteria flora and potential chronic toxicity. Therapies targeted at intestinal tissue include antimotility and antisecretory agents have adverse effects such as addictiveness, constipation and fatal ischaemic colitis. Many ethnopharmacological and ethnobotanical therapies for treating diarrhoea exist among different cultures. The aims of this study were to evaluate the biological activities of plant extracts against some diarrhoeal pathophysiologies. A literature search in English of published articles and books that discussed ethnobotanical uses of medicinal plants in southern Africa was conducted. A list of 230 medicinal plants used in South African traditional medicines for treating diarrhoea and associated complications was created. The list included family, genus, species, biological activities and bioactive isolates as well as the remedies for diarrhoea. Twenty seven species were selected to evaluate for antimicrobial, antioxidant and anti-inflammatory activities. Safety of the plants was determined by determining the cytotoxicity of the crude extracts against Vero African green monkey kidney cell lines using a standard method. Motility effects of Bauhinia galpinii (BGE) and <i<Combretum vendae (CVE) were determined by modulation of the contractility process of the isolated rat ileum induced by spasmogens. Phenolic compositions of the crude extract were determined using various standard methods and finally bioactivity guided isolation of antimicrobial and antioxidant compounds from BGE and CVE were carried out using open column chromatography. Identification and characterization of the isolated compounds was achieved by NMR, El-MS and UV spectroscopy. The non-polar fractions had good antimicrobial activities with MIC ranged between 19 - 1250 μg/ml while the polar fraction had moderate antimicrobial activities with MIC ranged between 39 - >2500 μg/ml. In general the non-polar fractions had a higher antimicrobial activity. The crude extracts contained wide range phenolic compounds with a total phenolic (7 4.91 ±1.26 to 467.04±15.82 mg GAE/g plant material), and total flavonoids (11.27±3.37 to 176±5.96 mg EQ/g plant material). The antioxidant activities were concentrated and potentiated in the polar fractions. The non-polar fractions had poor antioxidant activities with EC50 values ranging from 0.21 ±0.03 to 303.65±3.84 μg/ml for DPPH radical scavenging and 0.43±0.03 to 1709±91.44 μg/ml for ABTS radical scavenging. The crude extracts had selective COX-1 inhibitory activities ranging between 41.70 to 84.61% and had no COX-2 inhibitory activity. All the extracts tested had 15-LOX inhibitory capacity with LC50 values ranging between 0.86±0.27 and 111.44±37.28 1-μg/ml. The cytotoxicity results indicated a wide variation in toxic potential of the crude extracts with LC50 values ranging from 3.51 to 741.901-μg/ml. The BGE extracts had dual activities as spasmolytic by stimulating the spontaneous contractility and also agonised contractions induced by spasmogens but it inhibited K+ induced contraction. CVE had spasmodic activities through a multiple mechanisms inhibiting contractions induced by spasmogens and K+ in a dosedependent manner. Several bioactive xompoundswere isolated from the <i<Combretum vendae leaves, There were triterpenoids (ursol-12-en-28-oic acid, mixtures of corosolic acid and maslinic acid, and asiatic acid and arjunolic acid) as well as bibenzyls combretastatin 85-0-2'-β-D-glucopyranoside, combretastatin 81-0-2'-β-Dglucopyranoside and a flavonoid (apigenin) .. From Bauhinia galpinii the following bioactive compounds were isolated and characterized: β-3 ethoxy sitosterol, one new flavone (5, 7, 4' 5' tetrahydroxy-2'-methoxyflavone (isoetin 2'-methyl ether) or 5, 7, 2' 5' tetrahydroxy-4'-methoxyflavone (isoetin 4'-methyl ether)), 3, 5, 7, 3', 4'-pentahydroxyflavone and 3, 5, 7, 3', 4', 5'hexahydroxyflavone, quercetin-3-0-β-galactopyranoside and myriceti n-3-0-β-galactopyranoside The extraction protocol used in this work potentiated the antimicrobial activities in the non-polar fractions while antioxidant activities were potentiated in the polar fractions. This indicated that using polar solvents as extractant for treating infectious diarrhoea may not be quite effective unless some other antidiarrhoeal mechanisms are involved. Therefore, mixture of organic solvent (ethanol) and water can be recommended for broad-based activity. Bauhinia galpinii extracts had a dual- mechanism of action (prokinetic and relaxant) on gastro-intestinal motility, depending on the prevalent patho-physiological condition and Combretum vendae mediated spasmolytic effects on isolated rat ileum through multiple inhibitions of a wide range of contractile stimuli. Hence, the presence of multiple acting spasmolytic activities in the plant extract might be contributing towards its effectiveness in treating diarrhoea and abdominal spasm. The uses of these plants in traditional medicine need to be monitored closely because of the selective inhibition of COX-1 and its associated GIT injury, and the high toxicity potential of some of the extracts. Further work evaluating the antidiarrhoea mechanisms, identification and isolation of bioactive compounds, sub-acute and acute toxicity of the plant extracts is recommended. / Thesis (PhD)--University of Pretoria, 2013. / Paraclinical Sciences / unrestricted