Research Articles (Biotechnology)
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Item Unveiling novel contrasting photosynthetic responses in medicago truncatula under combined drought stress and phoma medicaginis infection(Taylor & Francis, 2024) Maiza, Nourhene; Ludidi, Ndiko; Mnafgui, WiemForage legumes face simultaneous abiotic and biotic stresses, causing substantial yield losses. This study explores the combined impacts of drought and Phoma medicaginis infection on the growth and photosynthetic activity of Medicago truncatula contrasting lines TN6.18 and F83005.5. The tolerant TN6.18 line exhibits superior tolerance to combined drought and P. medicaginis infection, manifesting in minimal leaf area reduction, the highest number of healthy leaves, increased carotenoids content, a consistently high and stable photosynthesis rate, and enhanced performance of photosystems PSI and PSII. On the contrary, the sensitive F83005.5 line shows pronounced leaf chlorosis, particularly under drought stress, and decreased pigment levels under the combination of drought and P. medicaginis infection stresses (combined stress). Moreover, the drought-stressed F83005.5, experiences reduced hydration and photosynthetic performance, linked to diminished gas exchange and chlorophyll fluorescence parameters. Chlorophyll fluorescence revealed more severe PSI impairment than PSII under combined stress. In conclusion, understanding the Pm8 infection-drought interaction enhances insights into M. truncatula resistance mechanisms to the combination of these stresses.Item Afriplex GRTTM extract attenuates hepatic steatosis in an in vitro model of NAFLD(Public Library of Science, 2024) Gabuza, Kwazi; Mabuda, Thendo Innocent; Patel, OelfahCurrently, it is acknowledged that vitamin E, insulin sensitizers and anti-diabetic drugs are used to manage non-alcoholic fatty liver disease (NAFLD), however, these therapeutic interventions harbour adverse side effects. Pioglitazone, an anti-diabetic drug, is currently the most effective therapy to manage NAFLD. The use of natural medicines is widely embraced due to the lack of evidence of their negative side effects. Rooibos has been previously shown to decrease inflammation and oxidative stress in experimental models of diabetes, however, this is yet to be explored in a setting of NAFLD. This study was aimed at investigating the effects of an aspalathin-rich green rooibos extract (Afriplex GRTTM) against markers of hepatic oxidative stress, inflammation and apoptosis in an in vitro model of NAFLD. Oleic acid [1 mM] was used to induce hepatic steatosis in C3A liver cells. Thereafter, the therapeutic effect of Afriplex GRTTM, with or without pioglitazone, was determined by assessing its impact on cell viability, changes in mitochondrial membrane potential, intracellular lipid accumulation and the expression of genes and proteins (ChREBP, SREBF1, FASN, IRS1, SOD2, Caspase-3, GSTZ1, IRS1 and TNF-α) that are associated with the development of NAFLD.Item Heterocyclic (pyrazine)carboxamide Ru(II) complexes: structural, experimental and theoretical studies of interactions with biomolecules and cytotoxicity†(Royal Society of Chemistry, 2024) Tsaulwayo, Nokwanda; Sibuyi, Nicole Remaliah Samantha; Meyer, MervinTreatments of N-(1H-benzo[d]imidazol-2-yl)pyrazine-2-carboxamide (HL1) and N-(benzo[d]thiazol-2-yl)pyrazine-2-carboxamide carboxamide ligands (HL2) with [Ru(p-cymene)Cl2]2 and [Ru(PPh3)3Cl2] precursors afforded the respective Ru(ii) complexes [Ru(L1)(p-cymene)Cl] (Ru1), [Ru(L2)(p-cymene)Cl] (Ru2), [Ru(L1)(PPh3)2Cl] (Ru3), and [Ru(L2)(PPh3)2Cl] (Ru4). These complexes were characterized by NMR, FT-IR spectroscopies, mass spectrometry, elemental analyses, and crystal X-ray crystallography for Ru2. The molecular structure of complex Ru2 contains one mono-anionic bidentate bound ligand and display pseudo-octahedral piano stool geometry around the Ru(ii) atom. The interactions with calf thymus DNA (CT-DNA) and bovine serum albumin (BSA) were investigated by spectroscopic techniques. The experimental binding studies suggest that complexes Ru1-Ru4 interact with DNA, primarily through minor groove binding, as supported by molecular docking results. Additionally, these complexes exhibit strong quenching of the fluorescence of tryptophan residues in BSA, displaying static quenching. The in vitro cytotoxicity studies of compounds Ru1-Ru4 were assessed in cancer cell lines (A549, PC-3, HT-29, Caco-2, and HeLa), as well as a non-cancer line (KMST-6). Compounds Ru1 and Ru2 exhibited superior cytotoxicity compared to Ru3 and Ru4.Item Phytonanotherapeutic applications of plant extract-synthesized silver nanoparticles in wound healing—a prospective overview(Springer, 2024) Oselusi, Samson Olaitan; Sibuyi, Nicole Remaliah Samantha; Madiehe, Abram MadimabeChronic wounds continue to pose severe threats to public health and the global economy. This is because the healing process is hindered by several factors, such as bacterial infections, comorbid conditions, age, and lifestyle. Medical wound therapy is currently based on long-term antibiotic use, and its activity has been limited by various factors, including treatment efficacy, toxicity, and increased risk of opportunistic infections. The advent of novel techniques such as nanotechnology can provide sustainable platforms for developing reliable, cost-effective, and innovative wound healing interventions. In this context, plant extract-synthesized silver nanoparticles (AgNPs) have become attractive to the clinical community because of their wide range of biological properties, such as antibacterial, anti-inflammatory, and wound healing effects. These AgNPs could be used in the development of better dressings for wounds.Item Intervertebral disc degenerative disease in South Africa: a case-control analysis of selected gene variants(Springer Science and Business Media B.V., 2024) Pearce, Keenau; Less, Stephanie; Benjeddou, MongiBackground: Intervertebral disc (IVD) degenerative disease is a multifactorial disease for which genetics plays an integral role. Several genes, and their variants, associated with the development and progression of IVD degenerative disease have been identified. While several studies have investigated these genes in Asian and European populations, no available evidence exists for the South African population. Therefore, this study aimed to investigate these parameters. Methods and results: Biological samples were collected in the form of buccal swabs from patients and DNA was extracted using a standard salt-lysis protocol. DNA purity and quantity was assessed by spectrophotometry, and subsequent genotyping was performed using the MassARRAY®System IPLEX extension reaction. For associations between variants and the presence of IVD degenerative disease, odds ratios (OR), confidence intervals (CI), chi-squared analysis and logistic regression was calculated. Age and sex were adjusted for, and Bonferroni’s correction was applied. This study found statistically significant associations for five of the evaluated single nucleotide polymorphisms (SNPs) with IVD degenerative disease, whereby IL-1α rs1304037 and rs1800587, ADAMTs-5 rs162509, and MMP-3 rs632478 demonstrated increased odds of a positive diagnosis for IVD degenerative disease, while decreased odds of IVD degenerative disease were seen for GDF-5 rs143383. Conclusion: To the best of our knowledge, this study represents the first of its kind to investigate the association of gene variants associated with IVD degenerative disease within the South African population. This study has shown that 5 of these gene variants were significantly associated with the presence of IVD degenerative disease, reflecting their integral roles in development and possible progression of the disease.Item Novel buffer for long-term preservation of DNA in biological material at room temperature(Taylor and Francis Ltd., 2024) Kasu, Mohaimin; Ristow, Peter Gustav; Burrows, Adria MichelleThe collection and preservation of biological material before DNA analysis is critical for inter alia biomedical research, medical diagnostics, forensics and biodiversity conservation. In this study, we evaluate an in-house formulated buffer called the Forensic DNA Laboratory-buffer (FDL-buffer) for preservation of biological material for long term at room temperature. Human saliva stored in the buffer for 8 years, human blood stored for 3 years and delicate animal tissues from the jellyfish Pelagia noctiluca comb jelly Beroe sp., stored for 4 and 6 years respectively consistently produced high-quality DNA. FDL-buffer exhibited compatibility with standard organic, salting out and spin-column extraction methods, making it versatile and applicable to a wide range of applications, including automationItem Liposomal-naringenin radiosensitizes triple-negative breast cancer mda-mb-231 cells in vitro(John Wiley and Sons Inc, 2024) Pearce, Keenau; Cairncross, Samantha; Benjeddou, MongiNaringenin has shown great promise in the realm of cancer therapeutics, demonstrating excellent cytotoxic action toward cancer cells and the enhanced effects of radiation therapy in vitro. However, the medicinal value of naringenin is severely limited clinically by poor bioavailability. Thus, multiple drug-delivery strategies for overcoming this limitation have been developed, of which liposomes are considered the most suitable due to their amphiphilic, modifiable, and biocompatible characteristics. In this study, we investigated the role of naringenin and liposomal-delivered naringenin as adjuncts to radiotherapy in the MDA-MB-231 triple-negative breast cancer cell line in vitro. Liposomal-naringenin was synthesized by thin-film hydration and extrusion and was characterized by spectrophotometry, dynamic light scattering, and zeta potential. The effects of free-from naringenin and liposomal-naringenin were evaluated toward MDA-MB-231 cell viability when combined with varying doses of radiation. Additionally, cell growth patterns, morphology, and colony formation were evaluated. The analysis demonstrated IC50 values of 387.5 and 546.6 µg/ml for naringenin and liposomal-naringenin, respectively. Naringenin and liposomal-naringenin significantly lowered cell viability, proliferation, and colony formation dose-dependently, as compared to radiation in isolation. The findings presented herein concur with previous accounts of the radiosensitizing potential of naringenin and further highlight the considerable biomedical application of liposomal-naringenin within the realm of radiotherapy.Item Discovering new genes for alfalfa (Medicago sativa) growth and biomass resilience in combined salinity and Phoma medicaginis infection through GWAS(Switzerland: Frontiers Media S.A, 2024) Wiem Mnafgui; Ndomelele Ndiko Ludidi; Gerhard Basson3Salinity and Phoma medicaginis infection represent significant challenges for alfalfa cultivation in South Africa, Europe, Australia, and, particularly, Tunisia. These constraints have a severe impact on both yield and quality. The primary aim of this study was to establish the genetic basis of traits associated with biomass and growth of 129 Medicago sativa genotypes through genome-wide association studies (GWAS) under combined salt and P. medicaginis infection stresses. The results of the analysis of variance (ANOVA) indicated that the variation in these traits could be primarily attributed to genotype effects. Among the test genotypes, the length of the main stem, the number of ramifications, the number of chlorotic leaves, and the aerial fresh weight exhibited the most significant variation. The broad-sense heritability (H²) was relatively high for most of the assessed traits, primarily due to genetic factors. Cluster analysis, applied to morpho-physiological traits under the combined stresses, revealed three major groups of accessions. Subsequently, a GWAS analysis was conducted to validate significant associations between 54,866 SNP-filtered single-nucleotide polymorphisms (SNPs) and seven traits. The study identified 27 SNPs that were significantly associated with the following traits: number of healthy leaves (two SNPs), number of chlorotic leaves (five SNPs), number of infected necrotic leaves (three SNPs), aerial fresh weight (six SNPs), aerial dry weight (nine SNPs), number of ramifications (one SNP), and length of the main stem (one SNP). Some of these markers are related to the ionic transporters, cell membrane rigidity (related to salinity tolerance), and the NBS_LRR gene family (associated with disease resistance). These findings underscore the potential for selecting alfalfa genotypes with tolerance to the combined constraints of salinity and P. medicaginis infection.Item Insights into the effects of hydroxycinnamic acid and its secondary metabolites as antioxidants for oxidative stress and plant growth under environmental stresses(2024) Khawula, Sindiswa; Niekerk, Lee-Ann; Basson, Gerhard; Keyster, Marshall; Klein, AshwilPlant immobility renders plants constantly susceptible to various abiotic and biotic stresses. Abiotic and biotic stresses are known to produce reactive oxygen species (ROS), which cause comparable cellular secondary reactions (osmotic or oxidative stress), leading to agricultural productivity constraints worldwide. To mitigate the challenges caused by these stresses, plants have evolved a variety of adaptive strategies. Phenolic acids form a key component of these strategies, as they are predominantly known to be secreted by plants in response to abiotic or biotic stresses. Phenolic acids can be divided into different subclasses based on their chemical structures, such as hydroxybenzoic acids and hydroxycinnamic acids. This review analyzes hydroxycinnamic acids and their derivatives as they increase under stressful conditions, so to withstand environmental stresses they regulate physiological processes through acting as signaling molecules that regulate gene expression and biochemical pathways. The mechanism of action used by hydroxycinnamic acid involves minimization of oxidative damage to maintain cellular homeostasis and protect vital cellular components from harm. The purpose of this review is to highlight the potential of hydroxycinnamic acid metabolites/derivatives as potential antioxidants. We review the uses of different secondary metabolites associated with hydroxycinnamic acid and their contributions to plant growth and development.