Dynamic changes in radiological parameters, immune cells, selected miRNAs, and cytokine levels in peripheral blood of patients with severe COVID‑19

The present study aimed to investigate the dynamic changes in peripheral blood leucocyte subpopulations, cytokine and miRNA levels, and changes in computed tomography (CT) scores in patients with severe coronavirus disease 2019 (COVID-19) (n=14) and age-matched non-COVID-19 volunteers (n=17), which were included as a reference control group. All data were collected on the day of patient admission (day 0) and on the 7th, 14th and 28th days of follow-up while CT of the lungs was performed on weeks 2, 8, 24 and 48. On day 0, lymphopenia and leucopenia were detected in most patients with COVID-19, as well as an increase in the percentage of banded neutrophils, B cells, and CD4+ Treg cells, and a decrease in the content of PD-1low T cells, classical, plasmacytoid, and regulatory dendritic cells. On day 7, the percentage of T and natural killer cells decreased with a concurrent increase in B cells, but returned to the initial level after treatment discharge. The content of different T and dendritic cell subsets among CD45+ cells increased during two weeks and remained elevated, suggesting the activation of an adaptive immune response. The increase of PD-1-positive subpopulations of T and non-T cells and regulatory CD4 T cells in patients with COVID-19 during the observation period suggests the development of an inflammation control mechanism. The levels of interferon γ-induced protein 10 (IP-10), tumor necrosis factor-α (TNF-α) and interleukin (IL)-6 decreased on day 7, but increased again on days 14 and 28. C-reactive protein and granulocyte colony-stimulating factor (G-CSF) levels decreased gradually throughout the observation period. The relative expression levels of microRNA (miR)-21-5p, miR-221-3p, miR-27a-3p, miR-146a-5p, miR-133a-3p, and miR-126-3p were significantly higher at the beginning of hospitalization compared to non-COVID-19 volunteers. The plasma levels of all miRs, except for miR-126-3p, normalized within one week of treatment. At week 48, CT scores were most prominently correlated with the content of lymphocytes, senescent memory T cells, CD127+ T cells and CD57+ T cells, and increased concentrations of G-CSF, IP-10, and macrophage inflammatory protein-1α.

Treatment of Acute Respiratory Distress Syndrome Caused by COVID-19 with Human Umbilical Cord Mesenchymal Stem Cells

This study aimed to identify the impact of mesenchymal stem cell transplantation on the safety and clinical outcomes of patients with severe COVID-19. This research focused on how lung functional status, miRNA, and cytokine levels changed following mesenchymal stem cell transplantation in patients with severe COVID-19 pneumonia and their correlation with fibrotic changes in the lung. This study involved 15 patients following conventional anti-viral treatment (Control group) and 13 patients after three consecutive doses of combined treatment with MSC transplantation (MCS group). ELISA was used to measure cytokine levels, real-time qPCR for miRNA expression, and lung computed tomography (CT) imaging to grade fibrosis. Data were collected on the day of patient admission (day 0) and on the 7th, 14th, and 28th days of follow-up. A lung CT assay was performed on weeks 2, 8, 24, and 48 after the beginning of hospitalization. The relationship between levels of biomarkers in peripheral blood and lung function parameters was investigated using correlation analysis. We confirmed that triple MSC transplantation in individuals with severe COVID-19 was safe and did not cause severe adverse reactions. The total score of lung CT between patients from the Control and MSC groups did not differ significantly on weeks 2, 8, and 24 after the beginning of hospitalization. However, on week 48, the CT total score was 12 times lower in patients in the MSC group (p ≤ 0.05) compared to the Control group. In the MSC group, this parameter gradually decreased from week 2 to week 48 of observation, whereas in the Control group, a significant drop was observed up to week 24 and remained unchanged afterward. In our study, MSC therapy improved lymphocyte recovery. The percentage of banded neutrophils in the MSC group was significantly lower in comparison with control patients on day 14. Inflammatory markers such as ESR and CRP decreased more rapidly in the MSC group in comparison to the Control group. The plasma levels of surfactant D, a marker of alveocyte type II damage, decreased after MSC transplantation for four weeks in contrast to patients in the Control group, in whom slight elevations were observed. We first showed that MSC transplantation in severe COVID-19 patients led to the elevation of the plasma levels of IP-10, MIP-1α, G-CSF, and IL-10. However, the plasma levels of inflammatory markers such as IL-6, MCP-1, and RAGE did not differ between groups. MSC transplantation had no impact on the relative expression levels of miR-146a, miR-27a, miR-126, miR-221, miR-21, miR-133, miR-92a-3p, miR-124, and miR-424. In vitro, UC-MSC exhibited an immunomodulatory impact on PBMC, increasing neutrophil activation, phagocytosis, and leukocyte movement, activating early T cell markers, and decreasing effector and senescent effector T cell maturation.

A novel NCI-H69V small cell lung cancer functional mini-tumor model for future treatment screening applications

Small cell lung cancer (SCLC) is aggressive and despite multiple clinical trials, its standard of care is unchanged for the past three decades. In vitro cancer models are crucial in chemotherapy development, and three-dimensional (3D) models aim to bridge the gap between two-dimensional (2D) flat cultures and in vivo testing. Functional 3D spheroids can better represent the in vivo situation and tumor characteristics than 2D models. An NCI-H69V SCLC mini-tumor model was developed in a clinostat-based rotating bioreactor system. Spheroid growth and viability were characterized for 30 days, and the ideal experimental window with mature and metabolically stable spheroids was determined. Application of the model for anticancer treatment screening was validated with the standard chemotherapeutic drug irinotecan, for an exposure period of 72 h. The following parameters were measured: soluble protein content, planar surface area measurements, intracellular adenosine triphosphate and extracellular adenylate kinase levels, and glucose consumption. Histological morphology of the spheroids was observed. The established model proved viable and stable, while treatment with irinotecan caused a decrease in cell growth, viability, and glucose consumption demonstrating reactivity of the model to chemotherapy. Therefore, this NCI-H69V SCLC functional spheroid model could be used for future anticancer compound screening.

Effect of functional excipients on the dissolution and membrane permeation of furosemide formulated into multiple-unit pellet system (MUPS) tablets

The effect of functional excipients (i.e. chitosan, sodium lauryl sulphate, NaHCO₃, and CaCO₃) formulated in multiple-unit pellet system (MUPS) tablets has been investigated on the dissolution and permeability of furosemide, a BCS class IV compound. Spherical beads were produced and compressed into MUPS tablets. MUPS tablet formulations were evaluated for hardness, disintegration, mass variation, friability, and dissolution (pH 1.2, pH 4.6, and pH 7.4). Ex vivo permeability studies were conducted across excised pig tissues (pyloric antrum and duodenal region) on selected experimental MUPS tablet formulations. Histological analysis was conducted on the tissues after exposure to selected experimental MUPS tablet formulations. Dissolution results in the 0.1 M HCl (pH 1.2) showed the highest effect of the excipients on furosemide release. Dissolution parameters showed increased dissolution of furosemide for the MUPS tablet formulations containing functional excipients: a 4.5-10-fold increase in the AUC values, the %_max showed a 60-70% increase and up to a 19-fold increase in DRi was seen. Permeability results revealed a 2.5-fold higher cumulative percentage transport for selected formulations. The results proved that functional excipients incorporated into beads, compressed into MUPS tablet formulations increased furosemide release as well as permeation across excised intestinal tissues.

Comparison of RPMI 2650 cell layers and excised sheep nasal epithelial tissues in terms of nasal drug delivery and immunocytochemistry properties

Nasal drug administration has been identified as a potential alternative to oral drug administration, especially for systemic delivery of large molecular weight compounds. Major advantages of nasal drug delivery include high vascularity and permeability of the epithelial membranes as well as circumvention of first-pass metabolism. RPMI 2650 cell layers (in vitro cell model) and excised sheep nasal mucosal tissues (ex vivo sheep model) were evaluated with regard to epithelial thickness, selected tight junction protein expression (i.e. claudin-1, F-actin chains, zonula occludin-1), extent of p-glycoprotein (P-gp) related efflux of a model compound (Rhodamine-123, R123) and paracellular permeation of a large molecular weight model compound (FITC-dextran 4400, FD4). The cell model grown under liquid cover conditions (LCC) was thinner (24 ± 4 μm) than the epithelial layer of the sheep model (53 ± 4 μm), whereas the thickness of cell model grown under air liquid interface (ALI) conditions (53 ± 8 μm) compared well with that of the sheep model. Although the location and distribution of tight junction proteins and F-actin differed to some extent between the cell model grown under ALI conditions and the sheep model, the extent of paracellular permeation of FD4 was similar (P_app = 0.48 × 10^-6 cm.s^-1 and 0.46 × 10^-6 cm.s^-1, respectively). Furthermore, the bi-directional permeation of R123 yielded the same efflux ratio (ER = 2.33) in both models. The permeation results from this exploratory study indicated similarity in terms of compound permeation between the RPMI 2650 nasal epithelial cell line and the excised sheep nasal epithelial tissue model.

Molecular mechanisms and associated cell signalling pathways underlying the anticancer properties of phytochemical compounds from Aloe species (Review)

Naturally occurring components from various species of Aloe have been used as traditional folk medicine since the ancient times. Over the last few decades, the therapeutic effects of extracts and phytochemical compounds obtained from Aloe vera have been proven in preclinical and clinical studies. Recently, compounds from other Aloe species apart from Aloe vera have been investigated for the treatment of different diseases, with a particular focus on cancer. In the present review, the effects of phytochemical compounds obtained from different Aloe species are discussed, with a specific focus on the effects on cell signalling in cancer and normal cells, and their selectivity and efficacy. This information will be useful for the application of Aloe-derived compounds as therapeutic agents, either alone or in combination with other standard drugs for cancer treatment.

Anticancer Potential of Sutherlandia frutescens and Xysmalobium undulatum in LS180 Colorectal Cancer Mini-Tumors

Colorectal cancer remains to be one of the leading causes of death worldwide, with millions of patients diagnosed each year. Although chemotherapeutic drugs are routinely used to treat cancer, these treatments have severe side effects. As a result, the use of herbal medicines has gained increasing popularity as a treatment for cancer. In this study, two South African medicinal plants widely used to treat various diseases, Sutherlandia frutescens and Xysmalobium undulatum, were evaluated for potential activity against colorectal cancer. This potential activity for the treatment of colorectal cancer was assessed relative to the known chemotherapeutic drug, paclitaxel. The cytotoxic activity was considered in an advanced three-dimensional (3D) sodium alginate encapsulated LS180 colorectal cancer functional spheroid model, cultured in clinostat-based rotating bioreactors. The LS180 cell mini-tumors were treated for 96 h with two concentrations of each of the crude aqueous extracts or paclitaxel. S. frutescens extract markedly decreased the soluble protein content, while decreasing ATP and AK per protein content to below detectable limits after only 24 h exposure. X. undulatum extract also decreased the soluble protein content, cell viability, and glucose consumption. The results suggested that the two phytomedicines have potential to become a source of new treatments against colorectal cancer.

Permeation enhancement effects of leaf materials from different aloe species on in vitro and ex vivo nasal epithelial models

Introduction: The nasal route of drug administration offers an alternative way for oral drug delivery and has the benefit of avoiding first-pass metabolism through drug delivery directly into the systemic circulation. The drug absorption enhancing effects of selected aloe leaf materials have been shown across various delivery routes, but their efficacies in this regard across nasal epithelia have not yet been investigated. The aim of this study was to determine the effects of gel and whole leaf extract materials from three selected aloe species (Aloe vera, Aloe ferox and Aloe muth-muth) on FITC-dextran 4400 permeation across two nasal epithelial models. Methods: Permeation of FITC-dextran 4400 and histological studies were conducted on both RPMI 2650 cell layers and excised sheep nasal mucosa, while toxicity studies were conducted using a neutral red assay on the RPMI 2650 cell model. Results: Significantly increased (P ≤ 0.05) apparent permeability coefficient (Papp) values of FITC-dextran 4400 in the presence of the aloe materials as compared to the control were found with all three aloe species at the highest concentrations (1.5% and 3% w/v) in the RPMI 2650 cell line, while only Aloe muth-muth at the highest concentration exhibited significantly (P ≤ 0.05) higher Papp values across the excised tissue model. Histological and neutral red analysis showed that Aloe vera materials exhibited detrimental effects, Aloe muth-muth only showed slight effects on cell viability and Aloe ferox exhibited no effect on the nasal epithelium. Conclusion: This in vitro study showed for the first time the potential of Aloe ferox and Aloe muth-muth leaf materials to enhance nasal drug delivery without causing damaging effects on the epithelium, while Aloe vera enhanced nasal drug delivery with detrimental effects as determined by means of cytotoxicity assays and histological analysis.

Characterization of an Alginate Encapsulated LS180 Spheroid Model for Anti-colorectal Cancer Compound Screening

Colorectal cancer is one of the leading causes of cancer-related deaths. A main problem for its treatment is resistance to chemotherapy, requiring the development of new drugs. The success rate of new candidate cancer drugs in clinical trials remains dismal. Three-dimensional (3D) cell culture models have been proposed to bridge the current gap between in vitro chemotherapeutic studies and the human in vivo, due to shortcomings in the physiological relevance of the commonly used two-dimensional cell culture models. In this study, LS180 colorectal cancer cells were cultured as 3D sodium alginate encapsulated spheroids in clinostat bioreactors. Growth and viability were evaluated for 20 days to determine the ideal experimental window. The 3- (4,5- dimethylthiazol- 2- yl)-2,5-diphenyltetrazolium bromide assay was then used to establish half maximal inhibitory concentrations for the standard chemotherapeutic drug, paclitaxel. This concentration was used to further evaluate the established 3D model. During model characterization and evaluation soluble protein content, intracellular adenosine triphosphate levels, extracellular adenylate kinase, glucose consumption, and P-glycoprotein (P-gp) gene expression were measured. Use of the model for chemotherapeutic treatment screening was evaluated using two concentrations of paclitaxel, and treatment continued for 96 h. Paclitaxel caused a decrease in cell growth, viability, and glucose consumption in the model. Furthermore, relative expression of P-gp increased compared to the untreated control group. This is a typical resistance-producing change, seen in vivo and known to be a result of paclitaxel treatment. It was concluded that the LS180 sodium alginate encapsulated spheroid model could be used for testing new chemotherapeutic compounds for colorectal cancer.

Treatment of Skin Disorders with Aloe Materials

The skin is the largest organ and functions as a barrier to protect the underlying tissues against the elements and pathogens, while also fulfilling many physiological roles and biochemical functions such as preventing excessive water loss. Skin disorders vary greatly in terms of origin, severity, symptoms and affect persons of all ages. Many plants have been used for medicinal purposes since ancient times including the treatment of skin disorders and diseases. Aloe represents one of the earliest medicinal plant species mentioned in antique scriptures and even in rock art dating back thousands of years. Different Aloe species and materials have been used in the prevention and treatment of skin related disorders. Aloe vera is the most commonly used Aloe species for medicinal purposes. Some of the most prominent skin related applications and disorders that Aloe materials have been investigated for are discussed in this paper, which include cosmetic, radiation, cancer, wound and antimicrobial applications. Both in vitro and in vivo studies are included in the discussions of this paper and comprehensive summaries of all these studies are given in tables in each section. Although some contradictory results were obtained among studies, certain Aloe materials have shown excellent efficacy and exhibited potential for the treatment of skin related disorders and cosmetic applications.

Capsaicin and Piperine as Functional Excipients for Improved Drug Delivery across Nasal Epithelial Models

The fruit from various pepper plants has been employed for the seasoning of food, as perfuming agents, and also as traditional medicines. Phytochemicals isolated from different pepper species have been found to modulate the pharmacokinetics of orally administered drugs. This study investigated the possibility to apply capsaicin and piperine (extracted alkaloids) as modulators for drug delivery across the nasal epithelium. Both a nasal epithelial cell line (RPMI 2650) and excised sheep nasal tissue were used as models to investigate the effects of the selected pepper compounds on drug permeation. FITC-dextran 4400 (MW 4400 Da) was used as a large molecular weight marker compound for paracellular transport, while rhodamine 123 was used as a marker compound that is a substrate for P-glycoprotein-mediated efflux. From the permeation results, it was clear that capsaicin inhibited P-glycoprotein efflux to a larger extent, while piperine showed drug permeation enhancement via other mechanisms. The cell cytotoxicity studies indicated that capsaicin was noncytotoxic up to a concentration of 200 µM and piperine up to a concentration of 500 µM as indicated by cell viability above 80%. The histological analysis of the excised nasal tissue and cultured RPMI 2650 cell layers indicated that some damage occurred after treatment with 200 µM capsaicin, but no changes were observed for piperine up to a concentration of 50 µM.

Models used to screen for the treatment of multidrug resistant cancer facilitated by transporter-based efflux

PURPOSE

Efflux transporters of the adenosine triphosphate-binding cassette (ABC)-superfamily play an important role in the development of multidrug resistance (multidrug resistant; MDR) in cancer. The overexpression of these transporters can directly contribute to the failure of chemotherapeutic drugs. Several in vitro and in vivo models exist to screen for the efficacy of chemotherapeutic drugs against MDR cancer, specifically facilitated by efflux transporters.

RESULTS

This article reviews a range of efflux transporter-based MDR models used to test the efficacy of compounds to overcome MDR in cancer. These models are classified as either in vitro or in vivo and are further categorised as the most basic, conventional models or more complex and advanced systems. Each model's origin, advantages and limitations, as well as specific efflux transporter-based MDR applications are discussed. Accordingly, future modifications to existing models or new research approaches are suggested to develop prototypes that closely resemble the true nature of multidrug resistant cancer in the human body.

CONCLUSIONS

It is evident from this review that a combination of both in vitro and in vivo preclinical models can provide a better understanding of cancer itself, than using a single model only. However, there is still a clear lack of progression of these models from basic research to high-throughput clinical practice.

Transplantation of placenta-derived multipotent cells in rats with dimethylhydrazine-induced colon cancer decreases survival rate

Transplantation of placenta-derived multipotent cells (PDMCs) is a promising treatment method for many diseases. However, the impact of PDMCs on colon cancer has not yet been studied. PDMCs were obtained from rat placentas by culturing tissue explants. Colon cancer was experimentally induced in male albino Wistar rats by administering 20 mg/kg dimethylhydrazine (DMH) once a week for 20 consecutive weeks. The administration of the PDMCs was performed at the 20th week after the first DMH injection. The number and size of each tumour lesion were calculated in the 5th week after transplantation. The tumour type was determined by standard histological methods. To study the engraftment of PDMCs in the body of rats, the cells were transduced with enhanced green fluorescent protein. Cell engraftment was determined by assessing the presence of EGFP by PCR and immunohistochemistry. Survival of all rats was monitored daily. Allogeneic transplantation of PDMCs to rats at middle phase of DMH-induced colon carcinogenesis did not significantly influence the number of neoplasms and the parameters of mean and total tumour area, but led to an increase in size of the most invasiveness tumours. Intravenous allogeneic transplantation of PDMCs reduced the survival rate of rats with colon cancer by 17 days. PDMCs from rats engrafted into tissues of the normal intestine, tumours, lungs, liver, and spleen of rats for five weeks after intravenous transplantation. These results suggest that intravenous allogeneic transplantation of PDMCs promotes colon cancer progression and has a negative impact on survival of rats.

Placenta-derived multipotent cells have no effect on the size and number of DMH-induced colon tumors in rats

Transplantation of placenta-derived multipotent cells (PDMCs) is a promising approach for cell therapy to treat inflammation-associated colon diseases. However, the effect of PDMCs on colon cancer cells remains unknown. The aim of the present study was to characterize PDMCs obtained from human (hPDMCs) and rat (rPDMCs) placentas and to evaluate their impact on colon cancer progression in rats. PDMCs were obtained from human and rat placentas by tissue explant culturing. Stemness- and trophoblast-related gene expression was studied using reverse transcription-polymerase chain reaction (RT-PCR), and surface markers and intracellular proteins were detected using flow cytometry and immunofluorescence, respectively. Experimental colon carcinogenesis was induced in male albino Wistar rats by injecting 20 mg/kg dimethylhydrazine (DMH) once a week for 20 consecutive weeks. The administration of rPDMCs and hPDMC was performed at week 22 after the initial DMH-injection. All animals were sacrificed through carbon dioxide asphyxiation at week 5 after cell transplantation. The number and size of each tumor lesion was calculated. The type of tumor was determined by standard histological methods. Cell engraftment was determined by PCR and immunofluorescence. Results demonstrated that rPDMCs possessed the immunophenotype and differentiation potential inherent in MSCs; however, hPDMCs exhibited a lower expression of cluster of differentiation 44 and did not express trophoblast-associated genes. The data of the present study indicated that PDMCs may engraft in different tissues but do not significantly affect DMH-induced tumor growth during short-term observations.