Kabo Masisi

The rapid evolution of pathogens, particularly viruses, poses a continuous threat to global public health, necessitating the development of highly scalable and cost-effective vaccine platforms. Plant-based virus-like particles (VLPs) have emerged as a transformative approach in vaccinology, leveraging the innate capacity of plant systems to produce highly immunogenic, non-infectious, and structurally authentic viral mimics. VLP-based recombinant antigens contained within the plant tissues (particularly in seeds) show better stability and can be transported and stored at ambient temperatures, without the requirement of a cold chain framework, and edible vaccines offer needle-free vaccine administration. Plant-based expression systems use natural cellular structures such as plant cell walls and seed endosperms to encase antigens, functioning as a natural shield against digestion and thermal degradation. Grain host plants are inimitably adapted for prolonged storage owing to natural seed desiccation wherein recombinant antigens accumulate within vacuoles or intracellular protein bodies segregated from active degradation. By simply cultivating more plants, vaccine production can be scaled up while transient plant expression systems speed up production within a few weeks, which is critical for quick responses to emerging new disease outbreaks. By genetic modification, plants can be used to express several antigens, facilitating the development of multi-component vaccines against many diseases at a single shot. Recently, plant-derived VLP vaccines, principally targeting influenza and hepatitis viruses, have been shown to elicit robust immune responses through the expression of their surface antigens in plants such as lettuce, potato, and tobacco (Nicotiana benthamiana). Despite their potential, significant challenges persist, including the achievement of consistent dosing, the attainment of high and reproducible expression levels, and the navigation of complex regulatory frameworks for plant-derived pharmaceuticals which remain unsolved. The current review focuses on recent developments in the production of plant-based influenza and hepatitis vaccines and explores the advantages, challenges, and application of such vaccines in combating these infections.

Edible wild fruits are valuable sources of bioactive phytochemicals with potential for use in the pharmaceutical industry. This study evaluated the phytochemical composition, antioxidant activity and antimicrobial activity of seven wild fruits from Botswana, namely Grewia bicolor Juss., Grewia cana Sond., Grewia flava DC., Mimusops zeyheri Sond., Vangueria infausta Burch., Ximenia americana L. and Ximenia caffra Sond. Fruit pulps were extracted using methanol, ethanol and distilled water. Phenols, terpenoids, tannins and saponins with varying concentrations across the fruits were identified. Ximenia caffra had the highest total phenolic (23.378 ± 2.11 mg gallic acid equivalent/g dry weight (GAE/g DW)) and flavonoid content (3.84 ± 0.1 mg quercetin acid equivalent/g dry weight QAE/g DW)). Antioxidant activity ranged from 1.34 ± 0.09–9.14 ± 0.07 mg GAE/g DW, via 1,1-diphenyl-2picrylhydrazyl (DPPH) and 0.28 ± 0.05–6.72 ± 0.1 mg ascorbic acid equivalent/g dry weight (AAE)) via 2,2’-azino-bis (3-ethylbenzothiazoline-6-sulfonate (ABTS) assays, with higher activity noted in Ximenia sp and M. zeyheri. Methanolic extracts of Ximenia sp and M. zeyheri exhibited potent antibacterial activity against Staphylococcus aureus and Escherichia coli, with values from 9.67–4.33 mm and in vitro antibacterial activity (IC50) from 1.58–6.53 mg/mL. No in vitro antifungal activity was observed against Rhizopus oryzae and Aspergillus niger. Multivariate analysis showed a significant positive correlation among antioxidant, antimicrobial activity and phytochemical content. This study addresses the gap in comparative data in relation to wild edible fruits of Botswana and what influences their bio-functionality. These results highlight these fruits' antibacterial and antioxidant potency, suggesting further study into the isolation and purification of their bioactive compounds.

Influenza viruses constantly evolve due to sporadic antigenic shifts and point mutations, which undermine vaccine effectiveness. Newly drifted pathogenic variants make current vaccines inadequate against circulating strains, requiring frequent updates to vaccine formulations. On the other hand, hepatitis viruses such as HAV, HBV, and HCV can cause acute and chronic infection of the liver, leading to liver cirrhosis and cancer. Currently, there is no vaccination for HCV, and access to vaccines for HAV and HBV is also limited in developing countries. Plant-derived vaccines against influenza virus afford many advantages over egg-derived conventional methods. Plant virus-like particles (pVLPs) are non-infectious, contain virus structural features with high flexibility, and can be tailored to meet specific biotechnological needs. pVLPs are preferable for vaccine development due to being economically viable and can be produced more rapidly and with fewer complications. Recombinant antigens contained within the plant tissues (particularly in seeds) show better stability and can be transported and stored at ambient temperatures, without the requirement of a cold chain framework. Edible plant-derived oral vaccines offer needle-free vaccine administration. By simply cultivating more plants, vaccine production can be scaled up while transient plant expression systems speed up production within a few weeks, which is critical for quick response to emerging new disease outbreaks. By genetic modification, plants can be used to express several antigens, facilitating the development of multi-component vaccines against many diseases at a single shot. Nicotiana benthamiana has been extensively utilized as a plant-based expression platform to generate recombinant influenza vaccine antigens, including hemagglutinin (HA). Plant-derived hepatitis vaccines, principally targeting HBV, have been shown to elicit robust immune responses in preclinical studies and early clinical trials through the expression of HBV surface antigen in plants such as lettuce, potato, and tobacco. However, challenges such as achieving consistent dosing, obtaining sufficiently high, reproducible, and stable expression levels, and circumventing regulatory hurdles for the use of plant-based pharmaceuticals remain. The current review focuses on recent developments in the production of plant-based influenza and hepatitis vaccines, and explores the advantages, challenges, and application of such vaccines in combating these infections.

The aim of this study was to evaluate the total content of flavonoids and phenols, in vitro antioxidant and cytoprotective effects of Sclerocarya birrea fruit exocarp extracts. The fruit exocarp was extracted sequentially in Hexane, Chloroform, Ethyl acetate, and Methanol and the antioxidant properties were evaluated using in vitro antioxidant assays and cytoprotective effects against H ₂ O ₂ -induced cell death using HeLa cells. Molecular docking using Autodock 4.2.6 was used to assess the binding interactions of Sclerocarya birrea compounds to the antioxidant enzymes. The total flavonoid and total phenolic contents were in the order Methanol > Ethyl acetate > Chloroform > Hexane ( P < 0.05) of Sclerocarya birrea fruit exocarp extracts. The antioxidant properties using DPPH, ABTS, and Ferric reducing antioxidant power, and total antioxidant capacity assays revealed significantly higher ( P < 0.05) antioxidant activity in the Methanol > Ethyl acetate > Chloroform > Hexane. Using WST-1 assay, H ₂ O ₂ -induced cell loss was effectively reduced by preincubating HeLa cells with Ethyl acetate > Methanol > Chloroform > Hexane ( P < 0.05) extracts. Methanol and Ethyl acetate extracts also significantly increased ( P < 0.05) the activities of Superoxide dismutase, Catalase and reduced Glutathione. Amongst the identified compounds, Myricetin 3-o-α- rhamsoside (C8) emerged as the best compound to bind to both SOD and CAT with binding energies of − 9.1 and − 8.8 kcal/mol respectively. C8 formed hydrogen bonds and electrostatic interactions with SOD and CAT to act as an agonist. Our findings suggest that Methanol and Ethyl acetate Sclerocarya birrea fruit exocarp extracts improved antioxidant capacity and thus have the potential to be developed into antioxidant products that will alleviate oxidative stress linked diseases.

Background: Repeated heating of cooking oils induces the overproduction of reactive oxygen species with an overwhelmed cellular antioxidant defense system, resulting in oxidative stress, the known cause of cardiovascular diseases. Elaeodendron transvaalense is a medicinal plant believed to have phytochemicals that help ameliorate the effects of oxidative stress. Objective: This study investigated the pro-oxidant effects of repeatedly heated sunflower oil and the possible ameliorative potential of Elaeodendron transvaalense leaf powder in Sprague Dawley rats. Methods: Four groups of male Sprague Dawley rats were fed for 4-weeks a standard diet supplemented without (a) control or with (b) 15% (w/w) repeatedly heated sunflower oil (RHSO), (c) 15% (w/w) non-heated sunflower oil, (d) 15% (w/w) RHSO and 1.5% ETLP. Results: Endogenous antioxidants: Catalase and SOD activities were observed to rise significantly (p <0.05) in Group 2 when compared to Group 1 and Group 3 respectively. A significant decline in the SOD and catalase activities was observed in group 4 fed RHSO + ETLP. No significant differences were observed in the body, liver, and kidney weights of Group 2 when compared with Groups 1, 3 and 4 respectively, and no significant differences were observed when comparing Group 4 to Groups 1, 2 and 3. The levels of Lipid profiles; Low-density Lipoproteins (LDL), Total cholesterol (TC), and Triglycerides (TG) were observed to rise significantly (p <0.05) in Group 2 when compared to Group 1 and 3, while their significant (p <0.05) decline was observed in Group 4 fed with RHSO + ETLP. The levels of HDL showed no significant difference across all groups because the p-values for the difference between groups exceeded the null hypothesis (p <0.05). Conclusion: The findings of this experiment indicate the possible ameliorative potential of ETLP observed in the significantly (p <0.05) reduced SOD and catalase activities. A significant (p <0.05) decline in the TC, TG, and LDL to desirable levels further indicated the ameliorative effects.

Cell culture underpins virus isolation and virus neutralisation tests, which are both gold-standard diagnostic methods for foot-and-mouth disease (FMD). Cell culture is also crucial for the propagation of inactivated foot-and-mouth disease virus (FMDV) vaccines. Both primary cells and cell lines are utilised in FMDV isolation and propagation. Widely used cell lines for FMDV and isolation and propagation include baby hamster kidney cells (BHK-21), swine kidney cells (IB-RS-2), foetal goat tongue (ZZ-R 127), foetal porcine kidney cells (LFBKvB6), bovine kidney cells (BK), human telomerase reverse transcriptase bovine thyroid (hTERT-BTY) and porcine kidney-originating PK-15 or SK 6 cell lines. This review highlights how different receptors and molecules—integrins, heparan sulphate (HS), and the Jumonji C-domain containing Protein 6 (JMJD6)—found on the surface of different cell types contribute to differences experienced with susceptibility and sensitivity of the cells to infection with different serotypes of FMDV. This review specifically focuses on Southern African territory (SAT) serotypes, which are unique to the Southern African context and are often under-investigated in cell line development for FMDV isolation and propagation.

Cancer is the third leading cause of premature death in sub-Saharan Africa. Cervical cancer has the highest number of incidences in sub-Saharan Africa due to high HIV prevalence (70% of global cases) in African countries which is linked to increasing the risk of developing cervical cancer, and the continuous high risk of being infected with Human papillomavirus In 2020, the risk of dying from cancer amongst women was higher in Eastern Africa (11%) than it was in Northern America (7.4%). Plants continue to provide unlimited pharmacological bioactive compounds that are used to manage various illnesses, including cancer. By reviewing the literature, we provide an inventory of African plants with reported anticancer activity and evidence supporting their use in cancer management. In this review, we report 23 plants that have been used for cancer management in Africa, where the anticancer extracts are usually prepared from barks, fruits, leaves, roots, and stems of these plants. Extensive information is reported about the bioactive compounds present in these plants as well as their potential activities against various forms of cancer. However, information on the anticancer properties of other African medicinal plants is insufficient. Therefore, there is a need to isolate and evaluate the anticancer potential of bioactive compounds from other African medicinal plants. Further studies on these plants will allow the elucidation of their anticancer mechanisms of action and allow the identification of phytochemicals that are responsible for their anticancer properties. Overall, this review provides consolidated and extensive information not only on diverse medicinal plants of Africa but on the different types of cancer that these plants are used to manage and the diverse mechanisms and pathways that are involved during cancer alleviation.

: Treating diseases such as Muscular dystrophy (MD) and HIV/AIDS pose several challenges to the rapidly evolving field of regenerative medicine. Previously, stem cell therapy has been said to affect the clinical courses of HIV/AIDS and MD, but, in practice, eradication or control of these diseases was not achievable. The introduction of gene editing into stem cell therapy has stimulated HIV/AIDS and MD cell therapy research studies substantially. Here, we review current methods of treating HIV/AIDS and MD using stem cell therapy. This review also details the use of different types of cells and methods in cell therapy and the modeling of new cell-based therapies to treat Duchenne muscular dystrophy. We speculate that the effective use of stem cell therapy in conjunction with other treatment therapies , such as steroids and rehabilitation , could improve livelihood.

Plants continue to provide unlimited pharmacologically active compounds that can treat various illnesses, including cancer. The Solanaceae family, besides providing economically important food plants, such as potatoes and tomatoes, has been exploited extensively in folk medicine, as it provides an array of bioactive compounds. Many studies have demonstrated the anticancer potency of some of the compounds, but the corresponding molecular targets are not well defined. However, advances in molecular cell biology and in silico modelling have made it possible to dissect some of the underlying mechanisms. By reviewing the literature over the last five years, we provide an update on anticancer mechanisms associated with phytochemicals isolated from species in the Solanaceae plant family. These mechanisms are conveniently grouped into cell cycle arrest, transcription regulation, modulation of autophagy, inhibition of signalling pathways, suppression of metabolic enzymes, and membrane disruption. The majority of the bioactive compounds exert their antiproliferative effects by inhibiting diverse signalling pathways, as well as arresting the cell cycle. Furthermore, some of the phytochemicals are effective against more than one cancer type. Therefore, understanding these mechanisms provides paths for future formulation of novel anticancer drugs, as well as highlighting potential areas of research.