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Abstract: Coronavirus disease (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged in late 2019 with severe respiratory failure and organ damage that later appeared as a pandemic disease. Worldwide, people’s mental and physical health and socioeconomic have been affected. Currently, with no promising treatment for COVID-19, the existing anti-viral drugs and vaccines are the only hope to boost the host immune system to reduce morbidity and mortality rate. Unfortunately, several reports show that people who are partially or fully vaccinated are still susceptible to COVID-19 infection. Evidence suggests that COVID-19 immunopathology may include dysregulation of macrophages and monocytes, reduced type 1 interferons (IFN-1), and enhanced cytokine storm that results in hypersecretion of proinflammatory cytokines, capillary leak syndrome, intravascular coagulation, and acute respiratory distress syndrome (ARDS) ultimately leading to the worsening of patient’s condition and death in most cases. The recent use of cell-based therapies such as mesenchymal stem cells (MSCs) for critically ill COVID-19 patients has been authorized by the Food and Drug Administration (FDA) to alleviate cytokine release syndrome. It protects the alveolar epithelial cells by promoting immunomodulatory action and secreting therapeutic exosomes to improve lung function and attenuate respiratory failure. As a result, multiple clinical trials have been registered using MSCs that aim to use various cell sources, and dosages to promote safety and efficacy against COVID-19 infection. In this review, the possibility of using MSCs in COVID-19 treatment and its associated challenges in their use have been briefly discussed.

Inclining mortality with a constant plummet in the survival rates associated with glioblastoma still stands as an inveterate predicament. The only promising therapy with temozolomide (TMZ) is now side-lined due to escalated resistance mediated by Poly (ADP-ribose) Polymerase-1 (PARP-1). In the light of this, the very study was designed to evaluate the potential of an active phyto component named naringin, in inhibiting PARP-1, using in silico and in vitro methods. Under in silico settings, inhibitor bound crystal structure of PARP-1, i.e., 4UND was retrieved and molecular docking studies were performed against naringin using Schrodinger software. In vitro cytotoxicity and apoptotic detection assay were performed using C6 glioma cells. Docking studies revealed high affinity and low binding energy at the inhibition site with good stability. An increase in cytotoxicity to C6 cells was observed with TMZ and naringin combination when compared to TMZ alone. Isobologram plot confirmed the synergistic effect of the drug combination. A significant increase in the number of apoptotic cells with combination drugs, as evaluated by acridine orange and ethidium bromide staining reassured the reversal of resistance. In conclusion, chemosensitivity to TMZ was restored by successful inhibition of PARP-1 using naringin and the drug combination was hence proven effective in reversing TMZ resistance.

Exosomes are extracellular vesicles with the diameter ranging from 50 to 100 nm and are found in different body fluids such as blood, cerebrospinal fluid (CSF), urine and saliva. Like in case of various diseases, based on the parent cells, the content of exosomes (protein, mRNA, miRNA, DNA, lipids and metabolites) varies and thus can be utilized as potential biomarker for diagnosis and prognosis of the brain diseases. Furthermore, utilizing the natural potential exosomes to cross the blood–brain barrier and by specifically decorating it with the ligand as per the desired brain sites therapeutics can be delivered to brain parenchyma. This review article conveys the importance of exosomes and their use in the treatment and diagnosis of brain/central nervous system diseases. Graphical abstract

Nanotechnology has now become a pivotal technology in medicine, capable of providing an innovative explanation for various unmet therapeutic needs. The core of nanomedicine is the development of diagnostic means and therapeutics into their nanoscopic form with the aid of different vehicles to achieve targeted drug delivery. These nanoparticles are typically less than 200 nm in diameter. Lipid nanoparticles, polymeric nanoparticles, inorganic nanoparticles, drug conjugates, and magnetic nanoparticles are a few examples of nanomedicines. Nanomedicines with their novel structural characteristics enhance the drug permeability, absorbability, and retention properties. They play a very important role in diagnostic imaging, tumor detection, photodynamic, and photothermal therapy. Physicochemical properties such as particle size, shape, and surface area show a greater influence on the absorption and elimination of nanomedicines. Besides several advantages, the major adverse effect of the nanomedicines is their toxicity. The smaller the size of the particle, the higher is its toxicity. In this chapter, we focus on the detailed pharmacokinetics, biodistribution, and toxicology of nanomedicines.

Considering the cognitive impairment induced by temozolomide (TMZ) in glioblastoma survivors, the present study was aimed to evaluate the protective effect of dehydrozingerone (DHZ) against TMZ-induced cognitive impairment (chemobrain) and C6 cell line-induced glioma in male Wistar rats. In both chemobrain and glioma models, TMZ was administered at a dose of 18 mg/kg i.v every 5th day and DHZ at a dose of 100 mg/kg p.o. daily. Additionally, glioma was induced by intracerebral injection of 5 × 104 C6 rat glioma cells in the cortex in the glioma model. Upon disease induction and treatment with TMZ + DHZ, spatial memory was assessed by the Morris water maze (MWM) test and episodic memory by the novel object recognition test (NORT). The induction of glioma was confirmed by histology of the cortex. Hippocampus and frontal cortex were subjected to antioxidant evaluation. Significant loss of spatial and episodic memory was observed with TMZ treatment which was significantly restored by DHZ. DHZ showed significant improvement in oxidative stress markers reversed the histopathological features in the cortex. TMZ-induced elevation of the glutathione level was also reversed by DHZ, indicating the role of DHZ in the reversal of TMZ resistance. In the glioma model, the improvement in cognition by DHZ correlated with the decrease in tumor volume. Altogether, the study results reveal the role of TMZ in worsening the memory and DHZ in reversing it, besides, improving its anticancer potential.