Theses and dissertations (Applied Sciences)
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Item The in vitro delivery of Doxorubicin using biosynthesized versus chemically synthesized stealth site-specific Bimetallic Selenium-silver nanoparticles(2023) Malinga, Thoko Winnie; Kudanga, Tukayi; Mbatha, Londiwe SimphiweProblems related to the limitations of chemotherapeutic treatments compel the pressing necessity to develop a drug-delivery system that will specifically target tumor cells and have minimal or no harmful effects on normal/healthy cells. This study aimed to comparatively evaluate the ability of chemically versus biologically synthesized site-specific selenium-silver bimetallic stabilized folic targeted nanoparticles (SeAgChPEGFA NPs) to efficiently deliver doxorubicin (DOX) in cervical cancer cells (HeLa). The NPs were synthesized using a coreduction method chemically using sodium borohydride and polyvinylpyrrolidone, and biologically using fenugreek seed extract. Moreover, the NPs from both methods of synthesis were stabilized and functionalized using carbodiimide and adsorptionreaction procedures. The drug/DOX-loaded nanocomplexes (NCs) were prepared via anadsorption and amide bonding reaction process between the co-polymer stabilized NPs and DOX. The bimetallic NPs and their DOX-loaded NCs were characterized using ultraviolet- visible (UV-vis) spectroscopy, Fourier-transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), and zeta Sizer. The drug release, loading, and encapsulation capabilities were evaluated in an in vitro environment. The effects of the synthesized NCs on cell viability and programmed cell death analysis were evaluated by means of the 3-(4,5-Dimethylthiazol-2-yl)-2,5- diphenyltetrazolium bromide (MTT) assay and a dual staining technique in selected human non-cancer and cancer cell lines (HEK293 and HeLa cells), respectively. The NPs and their drug-loaded NCs were successfully formulated and characterized. The successful synthesis of the NPs was initially validated by the reaction mixtures’ change in colour from cloudy to red-orange and subsequently from yellow-gold to orange-brown, signifying the formation of SeAg NPs and F-SeAg NPs, respectively. The UV- spectroscopy revealed that the SeAg NPs absorbance peaks were between 260 nm and 320 nm, while the FTIR verified the stabilization and functionalization of the NPs by revealing the presence of carbodiimide and amide bonds. All the resultant NPs and their drug-loaded NCs were shown asspherical withthe NPs appearing predominantly monodispersed and the NCs as groups. The sizes of the chemically and biosynthesized NPs ranged between 103.5 nm and 138.8 nm and that of the DOX-loaded NCs ranged between 154.9 nm and 158.7 nm respectively. The DOXloaded chemically- and biologically-synthesized NCs showed good stability with zeta measurements of 53.1 ± 2.3 mV and 57.4 ± 1.9 mV, respectively. The encapsulation efficiency (EE%) and drug loading (DL%) percentages of the chemically synthesized NCs were calculated to be 84% and 26%, respectively, while the percentages of the biosynthesized NCs were 87% and 22%, respectively. The cytotoxicity and anticancer activities of the BMNPs/NCsfrom both methods of synthesis were cell-specific and concentration-dependent. Overall, the encapsulation of DOX to the eco-friendly formulated BNPs enhanced the biocompatibility, bioavailability, and therapeutic effects ofthe drug in tumor cells, with limited harm to the healthy cells, thus showing promise as alternative delivery systems for targeted cancer treatment. The findings indicated that both the chemically synthesized and biosynthesized NPs showed great potential as anticancer drug-delivery modalities, with the biosynthesized SeAgChPEGFA@DOX NCs showing superior optical, surface charge stability, and drug encapsulation properties than the chemically synthesized SeAgChPEGFA@DOX NCs and free DOX. Moreover, among the studied synthesis methods, biosynthesis is reported to be eco-friendly and as a result the more ideal anticancer drug-delivery system with favourable features forfuture in vivo applications. Thus, future studies can encompass in vivo assessment of this eco-friendly system to further evaluate at a broader scale the bimetallic system’s efficacy and safety before using these NPs clinically.Item Enzymatic modification of Bambara groudnut protein for the production of hydrogels(2021) Ruzengwe, Faith Matiza; Kudanga, Tukayi; Amonsou, Eric OscarNatural polymer-based, especially plant protein hydrogels have recently been gaining attention because of their biodegradability and biocompatibility. Bambara groundnut is a potential source of protein in hydrogel production. However, the use of Bambara groundnut protein in such applications is limited because it is associated with the formation of inadequate crosslinks between polymer chains. Enzymatic treatment can potentially be used for improving the strength of Bambara groundnut protein hydrogel. In this study, the effect of laccase and transglutaminase (separately and in combination) on the microstructural, structural, rheological and mechanical properties of Bambara groundnut protein hydrogels was investigated for potential application in encapsulation and release of bioactive compounds. In the first part of this study, the effect of pH and NaCl concentration on the rheological and microstructural properties of Bambara groundnut protein gels were optimised using response surface methodology (RSM) to determine ideal starting conditions before enzymatic treatment. The effect of using crosslinking enzymes (transglutaminase and laccase) on the textural, rheological, structural and microstructural properties of Bambara groundnut protein hydrogels were then investigated. Since the effectiveness of enzymatic processes may be limited by using single enzymes, the use of a combination of enzymes was also investigated for the first time in gelation and optimised using RSM. Subsequently, encapsulation efficiency and release properties of the enzymatically crosslinked Bambara groundnut protein hydrogel were investigated using riboflavin as a model bioactive compound. The heat induced Bambara groundnut protein isolate (BPI) gels optimised for pH and NaCl prior to enzymatic treatment showed G’> G’’ over a frequency range of 0-100 rad s-1 . Although BPI gels displayed the characteristics of weak gels, slightly acidic conditions (pH 6) coupled with low NaCI concentration (0.5 M) promoted the formation of more rigid gels. These gels had the lowest water holding capacity and thiol content, suggesting the participation of disulphide linkages during network formation. Their microscopy images showed that the network was composed of porous homogeneous aggregates. Amino acid analysis showed that Bambara groundnut protein contains substantial amounts of amino acids including lysine, glutamic acid, cysteine and tyrosine with potential active sites for transglutaminase and laccase action. Laccase modification of Bambara groundnut protein caused a decrease in the gelation point temperature from approximately 85°C in the absence of laccase to 29°C at an activity of 3 U/g protein. Laccase treated samples showed a sharp increase in the G’ and G” values during the heating ramp as well as a wider gap between the moduli suggesting the formation of a more established network structure. The difference between G’ and G” increased to approximately 1 log and the dependency on angular frequency reduced suggesting improvement in the strength of the formed gels. Bambara groundnut protein crosslinking by laccase, was demonstrated by the decrease in thiol and phenolic content and crosslinking of amino acids (glutathione, cysteine and lysine) in model reactions. Microscopy images of the gel showed an increase in homogeneity and compactness of the lath sheet-like structure with increase in laccase activity up to 2 U/g protein. Transglutaminase crosslinking at 15 U/g protein resulted in the formation of hydrogels with well-organised network structures and small pores. Gel strength improved as observed from the highest G’ (6947 Pa) and hardness (5.60 N) recorded upon use of this activity. Transglutaminase-mediated crosslinking of BPI hydrogel was demonstrated by the reduction in amine and thiol groups and the formation of a new protein band (56 kDa) in crosslinked hydrogels. The combined use of transglutaminase and laccase showed a G’ > 10G” over a frequency range of 0 – 100 rad/s suggesting the dominance of the elastic behaviour. BPI hydrogel with the highest hardness (15.96 N) and encapsulation efficiency (98.8%) was formed at 15 and 0.5 U/g protein of transglutaminase and laccase activities, respectively. The lowest swelling capacity recorded in this hydrogel contributed to the lowest release kinetic constants in both simulated gastric fluid (0.51) and simulated intestinal fluid (0.73) in the presence of digestive enzymes which indicated that riboflavin release was due to diffusion and swelling. Overall, modification of Bambara groundnut protein using a combination of crosslinking enzymes increased the crosslinking density and promoted the formation of strong hydrogels. The hydrogels effectively encapsulated and prevented the early release of a heat sensitive compound (riboflavin) in the stomach while making it available in the small intestines. Therefore, the optimised enzyme combination of laccase and transglutaminase is a potential strategy for application in Bambara groundnut protein gelation.Item Microencapsulation of Bifidobacterium animalis and Lactobacillus casei using resistant starch from Vigna unguiculata(2020) Rengadu, Danielle; Mellem, John JasonThe use of functional foods is increasing globally with individuals aiming to maintain a healthy gut causing an increasing trend associated with probiotics in the health sector. Probiotics are live microorganisms that aid in improving the digestive system and gut health, however, the main problem associated with probiotics are ensuring a safe delivery through transition to the colon in harsh gastrointestinal conditions. For probiotics to be considered effective to the host a growth of Log 7 is essential in the colon, thus the need for microencapsulation. Therefore, this study was aimed at analysing resistant starch isolated from cowpea as an encapsulation material for Lactobacillus casei and Bifidobacterium animalis, for beverage application. Five different cultivars of cowpea (Bechuana white, Fahari, PAN 311, TVU 11424 and DT129-4) were analysed to determine the amount of resistant starch yielded as well as structural and physicochemical properties to determine the most suitable cultivar for the encapsulation process. The resistant starch percentage obtained was found in the range of 9.42-13.74%, with DT129-4 yielding the most resistant starch. The structural and physicochemical results obtained showed that the resistant starch isolated from cowpea has the potential for microencapsulation with cultivar DT129-4 exhibiting the most favourable results. Resistant starch was used as an encapsulating medium for Lactobacillus casei (RSL), Bifidobacterium animalis (RSB) and for a combination of the two probiotic microorganisms (RSLB) at a ratio of 1:1. The encapsulation yield after freeze drying were between 81.55-88.78% with the viability of the microcapsules under simulated gastrointestinal conditions also observed. The microcapsules were added to apple juice and the viability and stability of the microcapsules examined over 28 d. The final viability for microcapsules in the juice at the end of 28 d for RSL, RSB and RSLB were 7.53, 6.98 and 7.46 Log CFU/mL. This study shows that that resistant starch from cowpea has great potential as an encapsulating membrane within the nutraceutical beverage manufacturing industry.Item Characterisation and application of bambara protein-polysaccharide complex coacervates in encapsulation of bioactive compounds(2019) Busu, Nyasha M.; Amonsou, Eric OscarBambara groundnut (Vigna subterranea) is a leguminous crop that is indigenous to Africa. In South Africa, the legume is cultivated in KZN, Limpopo and Mpumalanga where it is considered a traditional food. Bambara groundnut is a good source of protein (15 – 28 %) and contains substantial amounts of starch. The legume thrives well in areas of low agricultural input. Despite its good protein content, bambara groundnut is mostly cultivated in rural areas for by subsistence farmers. In recent years, there has been increased interest in bambara groundnut protein as an alternative protein source. The purpose of this study is to investigate the complexation behavior of bambara protein with gum Arabic and test the application of the formed complexes in encapsulation and delivery of bioactive compounds. In the first part of this study, four protein fractions extracted at different pH including the salt-solubilisation method were complexed with gum Arabic. The protein content as well as physicochemical properties (SDS-PAGE, FTIR, Zeta potential, SEM) of the protein fractions and resulting bambara protein-gum Arabic (BPI-GA) complexes were then investigated. In subsequent parts of the study, bambara protein extracted by the salt-solubilisation method was complexed with gum Arabic. The influence of ionic strength and biopolymer mixing ratio on complex formation was investigated. Subsequently, the emulsification properties, foaming properties, encapsulation efficiency and release properties of the formed complexes were also investigated under simulated gastric and intestinal pH conditions. The salt-soluble fraction showed the highest protein content (82%) whilst the lowest protein content (76%) was recorded at pH 2. The FTIR analyses revealed an increase in β-sheet content with decrease in pH of extraction. Complexation of the protein fractions with GA resulted in the optimal pHs of interaction shifting towards acidic regions (pHopt: 4.8 to 2.9) as pH of protein extraction became more acidic. Upon complexation, protein fractions produced coacervate yields ranging between 41 - 68%, with the pH 2 fraction recording the lowest (41%) yield. Further, addition of gum arabic seemed to broaden the turbidity profiles. When assessed by SEM, the particles appeared as spherical and aggregated structures between 100-200 nm.Item Production of oligosaccharides from lignocellulosic biomass(2020) Arumugam, Nanthakumar; Pillai, Santosh Kumar Kuttan; Singh, SurenLignocellulosic biomass is the most abundant plant material present on earth which is primarily composed of cellulose, hemicellulose and lignin. The composition of lignocellulosic biomass varies depending on the type of plant material and the conditions at which the plant grow. Exploration of lignocellulose for the production of value-added compounds including all types of platform chemicals, biofuels and bioactive compounds is gaining momentum. However, extensive research needs to the carried out to minimize the cost of production to make the processing of this biomass more viable. In the last two decades, several agricultural biomass types have been studied to facilitate the production of biochemicals and biofuels at a low cost. Biomass such as peanut shells, bambara, cowpea and sorghum are some of the indigenous crops of South Africa that are yet to be explored for value addition. Therefore, this study was designed to characterize the underutilized agro-residues such as peanut shell, bambara, cowpea and sorghum biomass for the enzymatic production of prebiotic xylooligosaccharides (XOS) and their application.Item Characterisation of Opuntia phenolic extracts and enzymatic modification of selected compunds(2019) Aruwa, Christiana Eleojo; Kudanga, Tukayi; Amoo, Stephen O.Opuntia species are utilised as local medicinal interventions for chronic diseases and as food sources. The phytochemical profile varies within and across Opuntia species and has been related to differences in cultivar and geographical location. Macromolecular antioxidant (MA) fractions are also largely ignored from most conventional extractive processes compared to the well-known extractable polyphenol fractions. This study characterised subtropical spineless cladode, fruit pulp and peel extracts and selected phenolic compounds for enzymatic modification using a laccase from Trametes pubescens. MA extracts were also characterised in comparison with extractable fractions. The effects of drying methods and extraction solvent on extract yields and bioactivities were also studied. Extracts were assayed for phenolic content and antioxidant activities were determined using standard 2,2’-diphenyl-1-picrylhydrazyl (DPPH), 2,2,-azinobis3-ethylbenzthiazoline-6-sulfonic acid (ABTS) and ferric reducing antioxidant power (FRAP) assays. Antimicrobial activities and mode of antibacterial action were assessed against type-bacterial cultures. Minimum inhibitory concentration (MIC) values were recorded for the extracts and compounds. Compound profiling was achieved using liquid chromatography-time of flight-mass spectrometry (LC-TOF/MS) in negative ionisation mode. Antibacterial and antioxidant activities were higher in MA, hydrolysed and hydroalcoholic cladode and fruit extracts than in aqueous fractions. Ethanolic, methanolic and hexane extracts of freeze-dried Opuntia cladode, MA and peel samples showed higher total phenolic content, and in vitro antioxidant and antimicrobial activities than the oven-dried extracts. Cladode extracts inhibited growth of both Gram-positive and Gram-negative microorganisms (MIC range of 25 to 250 mg/mL). Likewise, fruit extracts inhibited both Gram-positive and Gram- negative microorganisms (MIC range of 2.5 to 18.75 mg/mL). Cladode and fruit extract profiles showed the presence of mainly phenolic acids and flavonoid derivatives. Isovitexin 7-O- xyloside-2"-O-glucoside, polyhydroxypregnane glycoside and neohancoside C in Opuntia cladode, and pinellic acid in Opuntia fruit were identified for the first time in this study. Some compounds, however, remained unidentified. Thereafter, selected Opuntia cladode and fruit phenolic compounds (isorhamnetin and luteolin) were used for enzymatic (laccase) transformation after preliminary screening reactions. Laccase-catalysed oxidation of luteolin in a monophasic system containing sodium acetate buffer (pH 5.0) and ethanol (50%, v/v) as co- solvent, resulted in the production of a dimer (m/z 569, M=570). Using a similar approach, oxidative coupling of isorhamnetin produced two main products, IP1 which was a dimer (m/z 629, M=630) and IP2 (m/z 457, M=458) which was most likely a result of coupling of an oxidative cleavage product and the isorhamnetin monomer. Dimers showed up to two-fold improvement in antioxidant and antimicrobial activities, compared to their respective substrates. The synthesised products showed a bactericidal mode of action as demonstrated by time-kill and bacterial cell integrity assays. The bactericidal action was further confirmed by scanning electron microscopy (SEM) which showed that treatment of bacterial cells with the synthesised compounds resulted in deformed, pitted, broken or fragmented cells, indicating strong bactericidal action. In conclusion, this study showed that Opuntia fruit pulp, peel and cladode extractable and MA extracts have potential as sources of phenolic compounds with antioxidant and antimicrobial activities. Laccase catalysis has potential to transform the phenolic compounds into coupling products with higher biological activities. The synthesised products have potential for application in the food, nutraceutical and other relevant industries.Item Occurrence of vancomycin resistant enterococci (VRE) in two Durban wastewater treatment plants for effluent reuse(2019) Madu, Chibuzor Ezinne; Stenström, Thor-Axel; Reddy, Poovendhree; Adegoke, Anthony AyodejiThe presence of enterococci in improperly treated wastewater leads to pollution of the recipient water bodies which directly or indirectly affects the humans especially when antibiotic resistant strains are involved. In 2017 the World Health Organization listed vancomycin resistant enterococci (VRE) among those with highest priority for further surveillance and research, both among humans and in the receiving aquatic environment. The purpose of this study is to determine how efficient the WWTPs are in removing both vancomycin-resistant enterococci (VRE) and vancomycin-sensitive enterococci (VSE) from wastewater. One hundred (60 wastewater and 40 river) samples were collected from July 2016 to June 2017 which covered the warm and cold seasons of South Africa. Primary isolation and enumeration were carried out on Slanetz and Bartley agar supplemented with and without vancomycin (6 µg/mL) for vancomycin resistant enterococci (VRE) and total enterococci (TE) respectively. Presumptive enterococci were selected using Gram staining, growth on bile aesculin agar, catalase and pyrase tests. The presumptive enterococci isolates (202 VRE and 67 VSE) were confirmed and speciated using polymerase chain reaction (PCR). The identified Enterococcus isolates were subjected to antibiotic susceptibility testing (AST) to examine their resistance profile against fifteen antibiotics including vancomycin. Antibiotic resistance genes (van, tet and emeA) were detected by PCR. The TE and VRE counts of the two WWTPs influents ranged from 6.1 to 7.2 log10 CFU/100 mL (for TE) and 4.3 to 6.7 log10 CFU/100 mL (for VRE) while the effluent concentration of Plant II contained 1.5 to 4.4 log10 CFU/100 mL and 0.9 to 3.4 log10 CFU/100 mL for TE and VRE respectively. Neither TE nor VRE was detected in Plant I effluent. The TE and VRE counts of the recipient river samples were higher than the effluents. There were no visible seasonal effects based on the counts. The removal efficiencies in the two plants ranged from 95 to 100%, where chlorination played a major role. Two hundred and sixty- nine (202 VRE and 67 VSE) isolates were identified by PCR as Enterococcus. The most abundant species was E. faecium followed by E. faecalis while other species include E. hirae, E. gallinarum, E. durans, E. casseliflavus and E. cecorium. MALDI-TOF and PCR were used in parallel for the identification of the isolates, which resulted in 80.1% agreement for genus identification. The AST results showed that a large percentage (39 to 98%) were resistantto all other antibiotics except amoxicillin/clavulanic acid and imipenem to which the isolates showed high sensitivity. Four van genes (vanA, vanB, vanC1, vanC2/3) and 4 tet genes (tetK, tetL, tetM, tetO), and also the multidrug efflux pump gene, emeA were detected among the 269 enterococci isolates with vanA and tetL being the most prevalent. At least one virulence gene (ace, asa1, cylA, efaA, esp, gelE and hyl) occurred in 74% (67/88) of the isolates. The result showed that the two WWTPs are efficient in removing both enterococci and VRE from their influents. Thus these effluents had little or no effect to enterococci count of their interlinked recipients. Also, a majority of the isolates are not only antibiotic resistant strains but are also virulent. They therefore pose risk to public health.Item Utilization of shrimp waste for the recovery of valuable bioactive compounds(2018) Dlamini, Nosihle; Permaul, KugenShrimp waste is a major by-product of crustacean processing and represents an interesting source of bioactive molecules. In addition, its use increases the sustainability of processing fishery products. The present study reports a process developed for recovering bioactive molecules from shrimp waste through the use of chemical methods. The samples of shrimp were confirmed to be from the species Haliporoides triarthrus. The recovery of chitin was 30% of the processing waste and 30-60% chitosan (CH) from chitin. CH was characterized by FTIR analysis and exhibited a degree of deacetylation (DDA) of 72%. From the demineralization extract, CaCO3 was extracted and confirmed by FTIR. Based on a kinetic study of acid hydrolysis, it was demonstrated that chitin can be quantitatively hydrolysed into glucosamine (GlN), N-acetyl glucosamine (GlcNAc) and their respective oligomers with 32% hydrochloric acid at 60oC and qualitatively from CH with 32% hydrochloric acid at 80oC. The oligomer mixed fractions were desalted by activated charcoal extraction and the components of each fraction were analysed by TLC and HPLC. Chitooligosaccharides (COS) and N-acetly chitooligosaccharides (NAcCOS) with degrees of polymerization (DP) ranging from 2 to 6 were obtained from CH and chitin, respectively. The antimicrobial activities of chitosan, COS and NAcCOS were investigated against five gram-negative bacteria and five gram-positive bacteria. Chitosan exhibited stronger bacteriostatic effects against gram- positive bacteria than gram-negative bacteria in the presence of 1% chitosan. The oligomers showed no bacteriostatic or bactericidal effects on all tested bacteria. A total 30.74± 0.078 µg.g-1 astaxanthin was extracted with 90% acetone from the species; Haliporoides triarthrus and TLC analysis indicated that the species contained both astaxanthin and its esters. Chitosan films were obtained by solution casting of blends of chitosan with glycerol, polyethylene glycol 200 (PEG-200) and polyethylene glycol 600 (PEG-600) as plasticizers. Films were characterized by FTIR, XRD diffraction, TGA, and SEM analysis. The tensile strength and elongation at break properties of the films were also evaluated. CH films and CH/GLY blended films were translucent in appearance and the CH/PEG 200 and CH/PEG 600 films were opaque. The CH films yielded mechanically resistant films without the use of a plasticizer. These data point to the feasibility of an integrated process for isolating highly bioactive molecules, such as oligosaccharides, with a broad spectrum of applications from shrimp processing waste.Item Anti-inflammatory, anti-oxidant and wound-healing properties of selected South Africa medicinal plants(2017) Mzindle, Nonkululeko Betty; Odhav, BhartiSouth Africa has a wide range of medicinal plants that are used traditionally by black Zulu South Africans for the treatment of a range of illnesses, including inflammatory ailments; disease conditions caused by oxidative stress and wound healing. It has been indicated that bioactive compounds isolated from plants contribute to their anti-inflammatory, antioxidant and wound healing properties; hence, herbal remedies have been widely used traditionally in many countries in the management and treatment of wounds. Inflammation is the main condition that relates to a variety of diseases affecting most of the world’s population. It is the body’s immune response to infection and injury and is induced by the release of pro-inflammatory mediator’s —prostaglandins and leukotrienes—following wound occurrence. Wounds result in disruption of living tissue caused by oxidative stress. Anti-inflammatory agents, antioxidants, and antimicrobials play an important role in the wound healing process and they prevent aggravated wound conditions.Controlling inflammation during wound repair is important to minimize any additional complications that may result; hence, chemical agents such as non-steroidal anti-inflammatory drugs (NSAIDS), synthetic antioxidantsand steroids are frequently used. These drugs block the enzymes that are responsible for prostaglandin synthesis in inflammation, react with free radicals thereby interfering with oxidation process as a result affect one or more phases of wound healing. The use of these drugs, however, has been limited as they can cause detrimental side effects when used over long periods of time.There is, consequently, a need to find alternative natural therapeutic drugs. Studies on medicinal plants confirmed that herbal drugs exhibit fewer side effects in comparison with chemical agents and are more cost-effective.Thus the aim of this study was to investigate South African medicinal plants, for anti-inflammatory, antioxidant and wound healing properties. Dissolved extracts of thirty-eight medicinal plants were evaluated for theiranti-inflammatory activity using the 5-lipoxygenase assay as well as free radical scavenging activity using the 1; 1-diphenyl-2-picrylhydrazyl (DPPH) assay.Their safety was evaluated using brine shrimp lethality assay. Proliferation and viability of fibroblast cells was determined by the3-(4, 5-dimethylthiazolyl)-2, 5-diphenyltetrazolium bromide(MTT) assay furthermore a scratch wound assay was used to study the properties of wound healing in vitro and to confirm the anti-inflammatory activities of the dissolved extracts. Migration rate was evaluated quantitatively by an image analyzer. Methanol was chosen for extraction because it completely dissolves extracts. Anova was used for statistical analysis. Almost all aqueous extracts were found to be effective in inhibiting lipoxygenase enzyme when compared to nordihydroguaiaretic acid (NDGA). Aqueous extracts exhibited remarkably high percentage inhibition of lipoxygenase with most above 100% when compared to methanolic extracts. Amaranthus dubius and Portulaca oleracea were found to have good biological activities in the inhibition of 5-lipoxygenase enzymes when compared to the other plants. However, Galinsoga parviflora and Syzygium cordatumwere least effective in inhibiting enzyme activity with percentages as low as -2% and 34% respectively. Percentage inhibitions for methanolic extracts were lower than that of aqueous extracts. Amaranthus spinosus had the highest percentage inhibition among all the methanolic extracts andGalinsoga parviflorahad the lowest. The methanolic plant extracts were found to be more effective in scavenging DPPH free radicals than the corresponding aqueous extracts. All the methanolic extracts exhibited free radical scavenging ability in the range of 60%–104%. Asystasia gangetica, Ficus sur, Heteropyxis natalensis, Hibiscus sabdariffa, Pelargonium sp. showed notably higher scavenging abilities, ranging from 101%–104% compared to Rutin. Methanolic extracts of Heteropyxis natalensis and Hibiscus sabdariffa exhibited scavenging ability even at the lowest concentration of 10μg/ml. Furthermore, aqueous extracts displayed remarkably lower activities than methanolic extracts with thirty-one extracts having a scavenging capacity ranging from 22%—59%. None of the extracts were found to be detrimental to brine shrimp. Almost all the extracts were shown to stimulate the growth of fibroblast cells except the methanolic extract of Solanum nodiflorum, which was shown to be killing the cells at high concentrations with a percentage viability of 46%.As the concentration decreased, however, the viability of cells with this extract increased to 143%. An increase in the number of fibroblast cells was observed in the scratched area of the treated cells and a significant migration rate was also noted with some of the extracts. Aqueous extracts of Sonchus oleraceus (86%), Justicia flava (85%) and Dichrostachys cinerea (85%) and methanolic extracts of Senna occidentalis and Hibiscus sabdariffa were found to have the highest migration rate compared to untreated cells that served as a control. No cell migration was observed with methanolic extract of Solanum nodiflorum.Instead, the extract was found to be toxic to the cells. Some of the plants evaluated in this study have been studied for either anti-inflammatory, antioxidantand wound healing properties in vivo, however, no work has been conducted to demonstrate a correlation between anti-inflammatory, antioxidant and wound healing properties of plant species in vitro. The current study was, therefore, conducted to review medicinal herbs considered as anti-inflammatory, antioxidants and wound healing agents as well as collecting evidence for their effectiveness and pharmacological mechanisms in modern science. In the plant species investigated Amaranthus dubius, Asystasia gangetica, Bidens pilosa, Buddleja saligna, Carpobrotus dimidiatus, Chenopodium album, Dichrostachys cinerea, Emex australis, Ficus sur, Guilleminea densa, Hibiscus sabdariffa, Physalis viscose, Syzygium cordatum, Taraxacum officinale and Tulbaghia violacea demonstrated good anti-inflammatory and wound healing properties.In conclusion the results from this study demonstrated promising anti-inflammatory and antioxidantactivities as well as wound healing properties,furthermoreit was aslo shown that the plant extracts were not toxic to the cells hencethis suggested that the plants investigated, can be used as substitutes or to formulate wound healing agents that are safe to use in primary healthcare.Item Assessment of a biological nutrient removal process for the remediation of edible oil effluent(2002-05-10) Mkhize, Sandile Psychology; Bux, FaizalEutrophication is a natural process that is greatly aggravated by the action of man in the natural environment. Deterioration of South Africa's natural water resources results directly or indirectly from the discharge of industrial effluent rich in nutrient nitrogen and phosphorus. The South African edible oil refmeries generally discharge poor quality effluent which impacts negatively on the water resources and wastewater treatment installations. The main aim of this study was to assess the capacity of a laboratory scale effluent treatment process that will produce final effluent of acceptable quality with regards to organic load and phosphate concentration prior to its discharge into the municipal sewerage system. The study was conducted in three stages: wastewater characterization, treatability studies, and laboratory scale treatment investigations. After analysing various effluent parameters, treatability studies were conducted using an aerobic-anaerobic sequencing batch reactor with a total hydraulic retention time of 24 hours. The results showed an average of 75 % reduction of COD and more than 90 % removal of fats, oils and grease (FOG). Based on the results of effluent characterisation and treatability studies, a laboratory scale activated sludge effluent treatment process was designed and operated with two bioreactors (aerobic and anaerobic) in series. The system was operated for a period of one-month resulting in 70 % removal of COD and 4% reduction in phosphate (P04-P). After some structural and operational changes from the original design configuration, the system was the operated continuously for the duration of the study period. An optimum COD removal of 75 % and 107 mgll P04-P reduction was achieved during the last operational phase of the system. More than 95 % reduction in fats, oils and grease (FOG) had been achieved in both semi-continuously and continuously operated systems.b.7