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Evaluating the efficacy of curcumin derivatives on adipocyte dysfunction and adipocyte differentiation
(North-West University (South Africa), 2024) Moetlediwa, Marakiya Tiriwangani
The prevalence of obesity has increased worldwide, necessitating the need to explore novel therapeutic interventions as the existing treatment options may not always be safe and effective over the long term. As such, natural compounds such as curcumin, a natural polyphenol derived from the turmeric plant, have shown promise in combating obesity through its diverse pharmacological properties, including anti-adipogenic, anti-lipolytic, and anti-inflammatory effects. However, the therapeutic efficacy of curcumin is limited due to its poor pharmacokinetic profile. This has prompted the development of synthetic curcumin derivatives to overcome these limitations and enhance the anti-obesity potential of curcumin. Thus, this study aimed to evaluate the effects of iii curcumin and the three synthetic curcumin derivatives on adipocyte dysfunction and adipogenesis using in silico and in vitro experimental approaches. The three synthetic curcumin derivatives, namely two chloro curcumin derivatives (1A6 and 1A8) and an asymmetric curcumin derivative (1B8), were synthesized via a chemical reaction of 3-chloroacetylacetone (1A6 and 1A8) or acetylacetone (1B8) with boric oxide. Three spectroscopic techniques, including high resolution - mass spectrometry - electrospray ionization (HR-MS-ESI), fourier transform - infrared (FT-IR) spectroscopy, and proton nuclear magnetic resonance (1H-NMR) spectroscopy were used for the characterization of the synthesized curcumin derivatives. Thereafter, in silico computational tools such as Protox II and SwissADME were used to predict the toxicity and pharmacokinetic properties of curcumin and the three synthetic curcumin derivatives. Additionally, SwissTargetPrediction and similarity ensemble approach (SEA) online tools were used to identify potential biological targets of curcumin and three synthetic derivatives. Molecular docking and molecular dynamic simulation were also used to predict the binding affinities and molecular interactions of curcumin, 1A6, 1A8, and 1B8 with the selected target proteins involved in adipogenesis, lipid metabolism, and inflammation. In addition, the bioactivity of curcumin, 1A6, 1A8, and 1B8 was assessed in vitro in 3T3-L1 adipocytes induced with tumor necrosis factor alpha (TNFα), lipopolysaccharide (LPS), and palmitic acid (PA) combination treatment. Metabolic activity, lipolysis, and lipid accumulation were assessed using the adenosine triphosphate (ATP), glycerol release, and Oil Red O staining assays, respectively. Adiponectin (ADIPOQ) and interleukin 6 (IL-6) secreted levels were quantified using enzyme-linked immunosorbent assays and the expression of genes involved in lipid metabolism and inflammation was measured using quantitative real-time polymerase chain reaction (qRT-PCR).The three curcumin derivatives (1A6, 1A8, and 1B8) were synthesized with high purity and thermal stability, and their chemical structures were elucidated by HR-MS-ESI, FT-IR, and 1H-NMR spectroscopic techniques. In silico predictive screening showed that curcumin and the three synthetic curcumin derivatives (1A6, 1A8, and 1B8) similarly exhibit low toxicity, improved drug-like attributes, and favorable pharmacokinetic profiles. Molecular docking and molecular dynamic simulations showed that curcumin, 1A6, 1A8, and 1B8 similarly exhibit favorable binding scores to the predicted biological target proteins, with the most stable binding for peroxisome proliferatoractivated receptor gamma (PPARγ), cyclooxygenase 2 (COX2), and fatty acid synthase (FAS), which are key proteins involved in adipogenesis, inflammation, and lipid metabolism. TNFα, LPS, and PA combination treatment induced metabolic dysfunction in 3T3-L1 adipocytes by reducing metabolic activity, increasing iv lipolysis, decreasing lipid accumulation, reducing anti-inflammatory, and increasing pro-inflammatory markers. ATP assay showed that treatment with curcumin, 1A6, and 1A8 at 40 µM reduced metabolic activity, while lower concentrations of these compounds (1.25 - 20 µM) and 1B8 did not affect metabolic activity in 3T3-L1 adipocytes induced with TNFα, LPS, and PA combination.Similarly, lipolysis was attenuated by treatment with curcumin (5 - 20 µM), 1A6 (2.5 - 20 µM), and 1A8 (2.5 and 10 µM), while 1B8 had no effect. In contrast, treatment with curcumin and 1B8 (10 and 20 µM) increased lipid accumulation, while no effects were observed in cells treated with the chloro curcumin derivatives (1A6 and 1A8). The mRNA expression of the lipolytic gene, patatin-like phospholipase domain containing 3 (Pnpla3) was upregulated by treatment with 1B8 (20 µM). In contrast, acetyl-CoA carboxylase alpha (Acaca) mRNA expression was reduced by 1A6 (20 µM), while fatty acid synthase (Fasn) mRNA expression was also decreased by curcumin (10 µM), 1A6 (10 and 20 µM), and 1A8 (10 and 20 µM). Curcumin (10 and 20 µM), 1A6 (10 and 20 µM), 1A8 (20 µM), and 1B8 (10 and 20 µM) reduced cyclooxygenase 2 (Cox2) mRNA expression levels. Surprisingly, the results showed increased monocyte chemoattractant protein 1 (Mcp1) mRNA expression in cells treated with curcumin and 1A8 at 10 µM. In addition, treatment with curcumin (10 and 20 µM), 1A6 (10 and 20 µM), 1A8 (20 µM), and 1B8 (10 and 20 µM) decreased IL-6 secretion levels. This study suggests that curcumin and the three synthetic curcumin derivatives (1A6, 1A8, and 1B8) ameliorate adipocyte dysfunction by modulating lipid metabolism and inflammation and regulate adipogenesis by targeting key adipogenic and lipid metabolism proteins, thus exerting potential anti-obesity effects. Further experimental work is warranted to explore the anti???obesity potential and mechanism of action of the synthetic curcumin derivatives.
Effect of fulvic acid inclusion in broiler diets on growth performance, physiological and meat quality parameters
(North-West University (South Africa), 2024) Mokubung, Keamogetswe Constance; Marume, Upenyu
The use of non-conventional feed sources in poultry farming has a beneficial impact on sustainably improving nutrient supply in poor communities in South Africa. Fulvic acid (FA) is one of the feed resources which can promote animal performance by improving growth rate, immunity, feed efficiency and reducing the risk of infections, but its utility in broilers has not been fully assessed. This study was therefore, undertaken to investigate the effect of FA inclusion in broiler diets on growth performance, physiological and meat quality parameters. For six weeks, chickens were fed five isonitrogenous and isoenergetic experimental diets formulated as follows: negCON (T1): commercial diets without antibiotics, posCON (T2): commercial diet with antibiotics, FA1 (T3) commercial diet + 1% FA1, FA2 (T4): commercial diet + 2% FA and FA3 (T5): commercial diet with 3% FA. The feeding trial was conducted over 3 feeding phases, Starter (day 1-14); Grower (15-28) and Finisher ration (day 28-42). Birds fed the posCON diet had the highest (P < 0.05) ADFI (93.33 g) followed by those fed the FA2 (90.66 g) diet. Dietary inclusion on cumulative weight gain (CWG) in the final week revealed that birds fed the FA2 (1897.34 g) diet gained at the same level as those fed the posCON (1932.74 g) diets and birds in both treatments achieved similar final weights at the end of the feeding trial. Dietary inclusion treatments significantly influenced protein utilization and growth efficiency parameters in all the three growth phases apart from the protein efficiency ratio (PER) in the grower phase, the protein consumed (PC) and the specific growth rate (SPR) at the finisher phase. Chickens offered the negCON (44.05) diet had the highest platelet count, while broilers offered the FA3 diet had the lowest platelet count values. Birds fed the posCON, FA1 and FA2 diets had statistically similar values for platelet counts with FA3 having the least value. Dietary treatments significantly (P <0.05) affected the glucose concentration, symmetric dimethylarginine (SDMA), alanine transaminase (ALT), alkaline phosphatase (ALP), phosphorus and lipase concentration. The SDMA was observed to decline III with increasing levels of FA inclusion in diet with the birds fed the FA3 (6.87 μg/dL) diet having the lowest levels of SDMA compared with all other diets. Diet had a significant effect (P <0.05) on all measured carcass characteristic parameters apart from the dressing percentage, chilling loss percentage and the thigh index. Chickens fed the posCON diet (1959.27 g) obtained the highest slaughter weights, followed by those offered the FA2 diet (1942.10 g), while broilers offered the negCON diet had the lowest (1789.25 g) value. Chickens offered posCON (42.61) diet had statistically similar values for lightness as with those fed FA1 (42.62) and FA3 (42.54) diets. However, the birds fed the FA2 (41.90) diets appeared to have darker breast muscle compared to all other treatments. Findings from this study illustrate that the experimental diets cooperated with FA inclusion revealed an increase in total PUFA/SFA ratio compared to the control diets. However, diets consisting of FA reduced the total n-3/n-6 ratio in all the FA treatments with FA2 having a ratio of 5 in the n-3PUFA, resulting in a beneficial impact on the important fatty acid needed for human and animal health maintenance. Results showed that diet had no effect on latency to lie, feather and gait scoring test. The highest latency to lie was observed in broilers fed the positive control diet with the highest standing persistence observed in broilers fed FA2 followed by FA3. Diet showed no dietary influence on all micro and macro minerals apart from phosphorus, iron and molybdenum. Serum calcium levels were higher in all the diets containing FA compared to the control. FA inclusion in diets also increased calcium levels and ash concentration with increment levels. Overall, the inclusion of FA in broiler diets did not compromise the nutrient utilization efficiency, broiler performance, health status, meat quality traits, internal organs, carcass traits and bone development of broiler diets. Collectively, findings from this study may be useful in developing low-cost feed formulas that will benefit customers and enhance future chicken farming systems for growth performance, health status, carcass features, meat quality.
An assessment of genetic fingerprinting tools for typing of multidrug-resistant and biofilm forming Staphylococcus aureus
(North-West University (South Africa), 2024) Mbanga, B; Ateba, Collins Njie; Montso, Peter Kotsoana
Staphylococcus aureus is a ubiquitous organism that has been associated with foodborne and nosocomial infections that may be difficult to treat due to the development of multiple antibiotic resistances. Genetic variation may also impact disease severity and transmission in susceptible populations. The occurrence and genetic diversity of multidrug-resistant and biofilm-forming S. aureus from drinking water troughs, milk, and milking environments at the North-West University dairy farm, were determined. A cross-sectional study design was employed to collect 39 samples from different sampling sites. Samples were screened by culture and the identity of the isolates was confirmed by PCR amplification of the Gap gene. Confirmed isolates were subjected to the Kirby-Bauer antibiotic susceptibility test against 11 antibiotics and antibiotic resistance genes (ARGs) detection by PCR. The biofilm-forming potential of the isolates were determined phenotypically. Genetic fingerprinting assays including REP, ERIC, and RAPD-PCR were used to determine the genetic relatedness of the drug-resistant of S. aureus. Out of 144 putative isolates, 124 (86.11%) harboured the gap gene. These isolates showed varied resistance abilities to cefoxitin (51.25%) penicillin (32%) and clindamycin (24,22%). Three ARGs, namely, mecA, blaZ, and tetO were amplified in 31.14%, 21.95% and 3.65% of the isolates respectively. The dominant MAR phenotypes were CLI-PEN-TET-FOX and PEN-ERY-RIF-FOX each in 15.38% of the isolates. Proportions of 34.83%, 42.86%, and 61.29% of the S. aureus isolates were capable of producing biofilms at 4 ºC, 25 ºC, and 37 ºC respectively. PCR-based DNA fingerprinting grouped the 33 S. aureus isolates into 19 distinct profiles. The study findings revealed MDR and biofilm-forming strains of S. aureus with high genetic diversity from various sampling sites, which could serve as a reservoir for the dissemination of severe and difficult-to-treat infection in susceptible populations.
Effect of enzymes and polyethylene glycol addition to Kalahari melon (Citrullus lanatus)-based diets on egg production performance in layer chicken
(North-West University (South Africa), 2024) Mauwane, Mpho Darky; Marume, Upenyu; Motsei, Lebogang Ezra
The research is aimed to improve the nutritional quality of Kalahari melon meal (KM) in layer chicken diets by incorporating external digestive enzymes and polyethylene glycol. Chapter one outlines the study's context, issue at hand, rationale, and its intended goals and purposes. Chapter two presents a comprehensive view of layer chicken farming alongside the nutritional composition and significance of incorporating Kalahari melon in diets for chickens. It also provides a summary of the voids and contradictions discovered in the research and provides a comprehensive overview of poultry diets that contain exogenous feed enzymes. Chapters three, four and five studied the effect of polyethylene glycol and protease enzyme on FI, body weight changes, haematology and serum biochemistry, egg production parameters (internal and external), fatty acid profile, internal organs, and bone development. Five dietary treatments were formulated by including 10% KM, polyethylene glycol and protease enzyme in poultry diets. The following diet plans were developed: Control (commercial layer feed), 10%KM (10 %KM diet), PRO (10% KM diet + protease enzyme), PEG (10% KM diet + polyethylene glycol), KMEP (10% KM diet + protease enzyme + polyethylene glycol). A total of 150- leghorn layer hens at 18 weeks old were purchased for use in the research. The hens were distributed randomly among 5 different dietary plans using a completely randomized arrangement. Each of these plans consisted of 10 separate cages, with each cage housing 3 birds, serving as the experimental unit. Diets significantly affected (P< 0.05) average daily gain, average weekly feed intake, average daily feed intake and feed to egg ratio. The 10% Km diet had the high values for all parameters except for feed to egg ratio. The peg diet had the highest value for feed to egg ratio (31.59±2.16). The observation made on serum biochemical and haematological had no linear or quadratic responses (P >0.05). In comparison to other diets, the control diet exhibited elevated levels of lymphocytes, eosinophils, basophils, and red iii blood cells. The KM containing diets had high values(P>0.05) for all parameters in serum biochemistry except for blood urea nitrogen and ALKP. With regards to egg production indices (chapter 4), diet had no influence (P>0.05) on all egg production indices apart from the NFEI (P<0.05), with the highest value in PRO diet followed by the KMEP diet. With all other parameters, the KM containing diets, whether with feed additives or not appeared to have better performances compared to the control diet while the PEG diet seemed to supress the performance of hens. Of all the diets containing KM oil cake, while the values of hens fed the PEG diet had similar performance as the control. The birds on the PRO diet experienced fewer cracked eggs in comparison to those on the KMEP and control diets. All egg external quality parameters, with the exception of the eggshell ratio, eggshell obtuse, breaking strength, and egg breadth, were unaffected by diet. The values for egg width and shell breaking strength (Shell BS) were highest (P < 0.05) in the commercial diet (Con), with the chickens fed the 10% KM diet following closely behind. The yolk index, haugh unit, albumen weight, and albumen ratio were the only internal parameters that were not influenced by diet. The hens fed the 10%KM diet had the highest (P < 0.05) yolk height (YH) and yolk weight (YWT).
Developing a regulatory framework for e-hailing services in South Africa
(North-West University, 2026) Dzawoma, I; Kilian, C. G; Gresse, E
Public transport has long reflected South Africa's social and economic inequalities. What started as an instrument of colonial control and apartheid segregation has developed into a complex regulatory environment struggling to keep pace with twenty-first-century innovations. This study examines how South Africa's transport law, often burdened by exclusion and informality, can adapt to the rise of e-hailing. This digital phenomenon has transformed both mobility and regulation. The e-hailing crisis, often visible as violent clashes and institutional paralysis, is not an isolated incident but the latest sign of longstanding governance failures in public transport. Chapter 1 sets the stage by presenting the research context, highlighting the 2024 National Land Transport Amendment Act and the 2025 Regulations as pivotal moments that finally legitimised e-hailing as a lawful form of public transport. This milestone comes after a decade of chaos, characterised by conflicts between metered taxi groups and e-hailing drivers, weak enforcement, and legal uncertainty. Thereafter, Chapter 2 traces the development of transport regulation from 1809 through to the post-apartheid era, showing how successive regimes each perpetuated a fragmented and unequal system. Chapter 3 explores how platform technologies have disrupted this legacy, revealing the "pacing problem" between rapid technological breakthroughs and sluggish legislative responses. It highlights, among other things, three linked issues in the e-hailing sector: distorted competition, insecure labour conditions, and increasing transport inequality. Chapters 4 to 6 serve as the analytical and prescriptive core of the thesis. Chapter 4 provides a doctrinal assessment of the National Land Transport Act, its 2024 Amendment, the 2025 Regulations, and the Economic Regulation of Transport Act. While these instruments introduce long-overdue legal clarity, they remain limited by narrow licensing provisions, inconsistent enforcement, and silence on key labour and pricing questions. Chapter 5 employs a functional comparative method, analysing regulatory models from Kenya, Tanzania, and India; jurisdictions that share similar developmental and institutional constraints. Their experiences with commission caps, fare corridors, and driver protection mechanisms offer valuable lessons for balancing innovation with accountability. Chapter 6 synthesises these insights into a proposed hybrid framework, combining competition oversight, minimum labour protections, and transport-justice measures to establish a stable, enforceable, and context sensitive regime. Ultimately, the study demonstrates that effective e-hailing regulation in South Africa requires more than legislative recognition: it demands an integrated approach that treats transport not merely as an economic service but as a governed public good. By drawing together historical, doctrinal, and comparative analyses, the thesis develops a realistic and actionable pathway for reform; one that aligns technological innovation with fair competition, safer working conditions, and equitable access to mobility.