Preliminary investigation of the neuroprotective potentials of Crossyne guttata in MPP+-induced toxicity in SH-SY5Y

Parkinson's disease (PD) is a movement disorder caused by the gradual and sustained loss of dopaminergic neurons in the substantia nigra pars compacta (SNpc). There is presently no permanent treatment for PD, thus the need for more investigations into complementary and alternative medicine capable of inhibiting neuronal damage. This study investigates the potential neuroprotective activity of Crossyne guttata, a plant commonly found in the western and southern Cape of South Africa in 1-methyl-4-phenylpyridinium (MPP+)-induced, in vitro model of PD, using the SH-SY5Y neuroblastoma cells.Methodology: The optimal concentration of Crossyne guttata aqueous extract (CGE) that showed no toxicity on cells and the concentration of MPP+ that reduced cell viability to about 50% was determined using the 3-(4,5-dimethyithiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays. Following this SH-SY5Y cells were pretreated with 10 μg/ml of CGE for 2 hours before the addition of 2000 μM of MPP+ and cell survival was determined. Furthermore, morphological changes associated with treatments were observed under the light microscope.Results: Results show that CGE did not reduce cell viability in the cells at all concentrations tested, while MPP+ showed a dose-dependent reduction in cell viability. Also, pretreatment of cells with CGE extract improved cell survival as well as cell morphology by inhibiting toxicity induced by MPP+.Conclusion: Findings from this study suggest that CGE may be a potential neuroprotective agent in PD and thus make a case for further investigation into the mechanism(s) of action as well as bioactive components of the plant eliciting such effects.Keywords: Crossyne guttata, Medicinal plants, 1-methyl-4-phenylpyridinium (MPP+), Cell viabilit

Antioxidant and apoptosis-inhibition potential of Carpobrotus edulis in a model of parkinson’s disease

Background: Parkinson’s disease (PD) is a neurological disorder resulting from the progressive loss of dopaminergic neurons. There is currently no known cure for PD, thus the search for complementary and alternative medicines capable of halting the degeneration of dopaminergic neurons is plausible. Carpobrotus edulis (CE) is an indigenous plant used in South African traditional medicine used for the treatment of a number of disease conditions including tuberculosis, diabetes mellitus and constipation. It has been suggested that CE contains bioactive compounds which are responsible for its acclaimed medicinal potential. No studies have been reported on the potential benefit of CE to the nervous system. This study was therefore done to evaluate the protective effects of CE against 1-methyl-4-phenylpyridinium (MPP+)-induced toxicity in the dopaminergic SH-SY5Y cell line, as well as its underlying mechanism. Methods: In this study, SH-SY5Y cells were treated with varying concentrations of CE and MPP+ respectively to determine the optimal concentrations of MPP+ and CE for further experiments. Thereafter, SH-SY5Y cells were pre-treated with 30 μM of CE before exposure to 2 mM of MPP+ to induce cellular damage. Cell viability was evaluated using the MTT assay, intracellular reactive oxygen species (ROS) production was determined using flow cytometry and the Hoechst nuclear staining was used to visualize apoptosis. Caspases 3/7 and 9 activity was assessed using commercially available kits. Results: MPP+ treatment induced marked cell viability, increased the number of condensed nuclei and apoptotic cells, increased ROS production, initiated caspase 9 and activated caspase 3/7 in SH-SY5Y cells. The observed effects of MPP+-induced toxicity were attenuated by the pre-treatment of SH-SY5Y cells with 30 μM of CE. Conclusion: The protective effects of CE against MPP+-induced toxicity in SH-SY5Y cells may be attributed to its antioxidant and anti-apoptotic properties

Response to letter to the Editor: The therapeutic strategy of drug re-positioning to induce autophagic cell death in brain malignancy

We thank Dr Yoshida for his valuable comments and interest in our study which describes the anti-cancer activity of DS00329, a novel derivative of the anti-psychotic drug phenothiazine, in glioblastoma multiforme (GBM) [1]. We appreciate the information provided by Dr Yoshida that illustrates that the activation of autophagy is an important mechanism by which neurochemical compounds and dopamine receptor D4 antagonists inhibit GBM proliferation [2]. Furthermore, we agree with him that levels of p62/SQSTM1 is an important indicator of the autophagic state of cells and that, in addition to our results showing an increase in LC3-11, it would be important to determine the impact of DS00329 on p62/SQSTM1 levels in glioblastoma cells. Indeed, increased LC3‐II levels can be associated with either enhanced autophagosome synthesis or reduced autophagosome turnover

Stem Bark Extracts of Ficus exasperata protects the Liver against Paracetamol induced toxicity in Wistar Rats

Ficus exasperata is an important medicinal plant with a wide geographical distribution in Africa particularly in Nigeria. In this study, aqueous stem bark extracts of Ficus exasperata were administered to investigate its hepatoprotective effects on Paracetamol induced liver toxicity in Wistar rats. A total of Twenty Five Wistar rats were randomly divided into five groups labeled A-E and kept in a well ventilated room. Group A served as control and were treated with distilled water. Rats in groups B-E were all treated with Paracetamol (800mg/kg body weight) but rats in group C, D and E were however pretreated with Silymarin (50 mg/kg bw), 100mg/kg bw aqueous stem bark extracts of Ficus exasperata and 200mg/kg bw aqueous stem bark extracts of Ficus exasperata respectively one hour before Paracetamol administration for fourteen days. Animals were sacrificed twenty four hours after the last treatment. Blood samples were collected into heparinized bottles for biochemical estimation of liver enzymes and the liver was harvested for routine histological examination. Paracetamol produced significant changes in biochemical parameters (increases in serum Alanine Aminotransferase (ALT), Aspartate Aminotransferase (AST), Alkaline Phosphatase (ALP), with a reduction in Total protein) and Liver histology (damage to hepatocytes). Pretreatment with Silymarin and aqueous stem bark extracts of Ficus exasperata significantly prevented the biochemical and histological changes induced by Paracetamol in the liver. In conclusion, our histological and biochemical findings indicate that aqueous stem bark extracts of Ficus exasperata possesses hepatoprotective properties

The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

The past 2 years, during which waves of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants swept the globe, have starkly highlighted health disparities across nations. Tegally et al. show how the coordinated efforts of talented African scientists have in a short time made great contributions to pandemic surveillance and data gathering. Their efforts and initiatives have provided early warning that has likely benefited wealthier countries more than their own. Genomic surveillance identified the emergence of the highly transmissible Beta and Omicron variants and now the appearance of Omicron sublineages in Africa. However, it is imperative that technology transfer for diagnostics and vaccines, as well the logistic wherewithal to produce and deploy them, match the data-gathering effort