Erratum for “Effect of aqueous leaf extract of Thunbergia laurifolia on alcohol-induced liver injury in rats”

Purpose: To investigate the antioxidant and anti-inflammatory effects of aqueous leaf extract of T. laurifolia against alcoholic liver injury in rats. Methods: Male Wistar rats were administered either normal saline, ethanol (EtOH), normal saline with low or high dose T. laurifolia leaf extract (TL-LD or TL-HD), EtOH with TL-LD or EtOH with TL-HD. Blood biochemical indices: hepatic malondialdehyde (MDA) levels, liver histopathology, hepatic cytochrome P450 2E1 (CYP2E1), nicotinamide adenine dinucleotide phosphate (NADPH) oxidase, and proinflammatory cytokines, including interleukin 1 beta (IL-1β) and tumor necrotic factor alpha (TNF-α) mRNA expressions, were determined using standard methods. Results: The leaf extract of T. Laurifolia decreased hepatic MDA levels, improved liver pathology and down-regulated mRNA expressions of CYP2E1, NADPH oxidase and pro-inflammatory cytokinesin ethanol-treated rats. Conclusion: These results demonstrate that aqueous extract of T. Laurifolia exerts hepatoprotective effect against alcoholic liver injury through a mechanism involving inhibition of oxidative stress and inflammation

Effect of aqueous leaf extract of Thunbergia laurifolia on alcohol-induced liver injury in rats

Purpose: To investigate the antioxidant and anti-inflammatory effects of aqueous leaf extract of T. laurifolia against alcoholic liver injury in rats. Methods: Male Wistar rats were administered either normal saline, ethanol (EtOH), normal saline with low or high dose T. laurifolia leaf extract (TL-LD or TL-HD), EtOH with TL-LD or EtOH with TL-HD. Blood biochemical indices: hepatic malondialdehyde (MDA) levels, liver histopathology, hepatic cytochrome P450 2E1 (CYP2E1), nicotinamide adenine dinucleotide phosphate (NADPH) oxidase, and pro-inflammatory cytokines, including interleukin 1 beta (IL-1β) and tumor necrotic factor alpha (TNF-α) mRNA expressions, were determined using standard methods. Results: The leaf extract of T. Laurifolia decreased hepatic MDA levels, improved liver pathology and down-regulated mRNA expressions of CYP2E1, NADPH oxidase and pro-inflammatory cytokinesin ethanol-treated rats. Conclusion: These results demonstrate that aqueous extract of T. Laurifolia exerts hepatoprotective effect against alcoholic liver injury through a mechanism involving inhibition of oxidative stress and inflammation

Effect of a heme oxygenase-1 inducer on NADPH oxidase expression in alcohol-induced liver injury in male Wistar rats

Purpose: To investigated the effect of hemin, a heme oxygenase-1 (HO-1) inducer, on nicotinamide adenine dinucleotide phosphate oxidase (NOX) expression in rats with alcohol-induced liver injury.Methods: Male Wistar rats were randomly divided into four groups consisting of the control group, the ethanol (EtOH) group, the EtOH + zinc protoporphyrin IX (ZnPP-IX) group and EtOH + hemin group. Hepatic NOX gene expression and immunohistochemistry of hepatic NOX1 and NOX4 were investigated in week 4.Results: EtOH significantly increased levels of NOX. An immunohistochemical study demonstrated a high number of immunopositive hepatocytes for NOX1 in the EtOH group and EtOH + ZnPP-IX group compared with the control group. Hemin administration downregulated NOX gene expression and lowered the number of immunopositive hepatocytes for NOX1. In contrast, ZnPP-IX (HO-1 inhibitor) administration caused upregulation of NOX gene expression and increased the number of immunopositive hepatocytes for NOX1.Conclusion: HO-1 inducer, hemin, alleviates oxidative stress-induced alcoholic liver injury by reducing NOX, especially NOX1.Keywords: NADPH oxidase, Immunohistochemistry, Heme oxygenase-1, Hemin, Reactive oxygen species, Alcohol-induced liver diseas

Immunofluorescence study of cytoskeleton in endothelial cells induced with malaria sera

Background: Endothelial cells (ECs) play a major role in malaria pathogenesis, as a point of direct contact of parasitized red blood cells to the blood vessel wall. The study of cytoskeleton structures of ECs, whose main functions are to maintain shape and provide strength to the EC membrane is important in determining the severe sequelae of Plasmodium falciparum malaria. The work investigated the cytoskeletal changes (microfilaments-actin, microtubules-tubulin and intermediate filaments-vimentin) in ECs induced by malaria sera (Plasmodium vivax, uncomplicated P. falciparum and complicated P. falciparum), in relation to the levels of pro-inflammatory cytokines. Methods: Morphology and fluorescence intensity of EC cytoskeleton stimulated with malaria sera were evaluated using immunofluorescence technique. Levels of tumour necrosis factor (TNF) and interferon (IFN)-gamma (γ) were determined using enzyme-linked immunosorbent assay (ELISA). Control experimental groups included ECs incubated with media alone and non-malaria patient sera. Experimental groups consisted of ECs incubated with malaria sera from P. vivax, uncomplicated P. falciparum and complicated P. falciparum. Morphological scores of cytoskeletal alterations and fluorescence intensity were compared across each experiment group, and correlated with TNF and IFN-γ. Results: The four morphological changes of cytoskeleton included (1) shrinkage of cytoskeleton and ECs with cortical condensation, (2) appearance of eccentric nuclei, (3) presence of “spiking pattern” of cytoskeleton and EC membrane, and (4) fragmentation and discontinuity of cytoskeleton and ECs. Significant damages were noted in actin filaments compared to tubulin and vimentin filaments in ECs stimulated with sera from complicated P. falciparum malaria. Morphological damages to cytoskeleton was positively correlated with fluorescence intensity and the levels of TNF and IFN-γ. Conclusions: ECs stimulated with sera from complicated P. falciparum malaria showed cytoskeletal alterations and increased in fluorescence intensity, which was associated with high levels of TNF and IFN-γ. Cytoskeletal changes of ECs incubated with complicated P. falciparum malaria sera can lead to EC junctional alteration and permeability changes, which is mediated through apoptotic pathway. The findings can serve as a basis to explore measures to strengthen EC cytoskeleton and alleviate severe malaria complications such as pulmonary oedema and cerebral malaria. In addition, immunofluorescence intensity of cytoskeleton could be investigated as potential prognostic indicator for malaria severity

Activation of nuclear factor kappa B in peripheral blood mononuclear cells from malaria patients

BACKGROUND: Malaria parasites and their products can activate a specific immune response by stimulating cytokine production in the host’s immune cells. Transcription nuclear factor kappa B (NF-κB) is an important regulator for the control of many pro-inflammatory genes, such as interleukin-1 (IL-1) and tumor necrosis factor (TNF). The activation and expression of NF-κB p65 in peripheral blood mononuclear cells (PBMCs) of malaria patients were investigated and correlated with the levels of IL-10 and TNF to study the nature of NF-κB p65 and its linkage to inflammatory cytokines. METHODS: The sample group comprised 33 patients admitted with malaria caused by Plasmodium vivax (n = 11), uncomplicated Plasmodium falciparum (n = 11), and complicated Plasmodium falciparum (n = 11). Peripheral blood was collected at admission and on day 7 for PBMC isolation. Healthy subjects were used as a control group. The expressions of NF-κB p65 in the PBMCs from malaria patients and the plasma levels of IL-10 and TNF were measured by using enzyme-linked immunosorbent assay (ELISA). The immunofluorescence technique was used to determine NF-κB nuclear translocation. RESULTS: At admission, patients with P. vivax and uncomplicated P. falciparum had significantly elevated phospho-NF-κB p65 levels in the PBMCs compared with those of healthy controls. However, patients with complicated P. falciparum malaria had decreased levels of phospho-NF-κB p65. On day 7 post-treatment, significantly increased phospho-NF-κB p65 was found in the PBMCs of patients with complicated P. falciparum, compared with healthy controls. The plasma level of IL-10 was elevated in day 0 in patients with complicated P. falciparum malaria and was found to be negatively correlated with phospho-NF-κB p65 level (r(s) = −0.630, p = 0.038). However, there was no correlation between phospho-NF-κB p65 expression and TNF level in patients with complicated P. falciparum malaria. CONCLUSIONS: This is the first report demonstrating alterations in NF-κB p65 activity in the PBMCs of malaria patients. The altered lower features of NF-κB p65 in the PBMCs of patients with complicated P. falciparum at admission could be due to a suppressive effect of high IL-10 associated with complicated P. falciparum malaria

Study of pulsatile pressure-driven electroosmotic flows through an elliptic cylindrical microchannel with the Navier slip condition

This paper aims to study an unsteady electric field-driven and pulsatile pressure-driven flow of a Newtonian fluid in an elliptic cylindrical microchannel with Navier boundary wall slip. The governing equations of the slip flow and distributions of electric potential and charge densities are the modified Navier-Stokes equations, the Poisson equation and the Nernst-Planck equations, respectively. Analytical and numerical analyses based on the Mathieu and modified Mathieu equations are performed to investigate the interplaying effects of pulsatile pressure gradients and the slip lengths on the electroosmotic flow

Overexpression of Sphingosine Kinase-1 and Sphingosine-1-Phosphate Receptor-3 in Severe Plasmodium falciparum Malaria with Pulmonary Edema

Pulmonary edema (PE) is a major cause of pulmonary manifestations of severe Plasmodium falciparum malaria and is usually associated with acute lung injury (ALI) and acute respiratory distress syndrome (ARDS). The sphingosine kinase-1 (SphK-1)/sphingosine-1-phosphate receptor-3 (S1PR-3) pathway has recently been reported to affect the pathogenesis of lung injury, but the expression of these proteins in the lungs of severe P. falciparum malaria patients has not been investigated. The cellular expression of SphK-1 and S1PR-3 in lung tissues from autopsied patients with P. falciparum malaria was investigated using immunohistochemistry (IHC). Lung tissues from patients who died of severe P. falciparum malaria were classified into two groups based on histopathological findings: those with PE (18 patients) and those without PE (non-PE, 19 patients). Ten samples of normal lung tissues were used as the control group. The protein expression levels of SphK-1 and S1PR-3 were significantly upregulated in endothelial cells (ECs), alveolar epithelial cells, and alveolar macrophages (AMs) in the lungs of severe P. falciparum malaria patients with PE compared to those in the non-PE and control groups (all p<0.001). In addition, the SphK-1 and S1PR-3 expression levels were significantly positively correlated in pulmonary ECs (rs=0.922, p<0.001), alveolar epithelial cells (rs=0.995, p<0.001), and AMs (rs=0.969, p<0.001). In conclusion, both the SphK-1 and S1PR-3 proteins were overexpressed in the lung tissues of severe P. falciparum malaria patients with PE, suggesting that SphK-1 and S1PR-3 mediate the pathogenesis of PE in severe malaria. Targeting the regulation of SphK-1 and/or S1PR-3 may be an approach to treat pulmonary complications in severe P. falciparum patients

Exploring pancreatic pathology in Plasmodium falciparum malaria patients.

Hypoglycaemia is an important complication of Plasmodium falciparum malaria infection, which can be lethal if not treated. A decrease in blood sugar (BS) level has been correlated with disease severity, parasitaemia and the use of certain antimalarial drugs. This study explored the relationship between pancreatic pathology, including the expressions of insulin and glucagon in the islets of Langerhans, and the BS levels in P. falciparum malaria patients. Pancreatic tissues from malaria patients were divided into three groups, namely those with BS  120 mg/dl. In P. falciparum malaria, pancreatic tissues showed numerous parasitised red blood cells (PRBCs) in the capillaries, oedema, acinar necrosis and the presence of inflammatory cells. The islet size and the expression of insulin were significantly increased in P. falciparum malaria patients with hypoglycaemia. In addition, insulin expression was positively correlated with islet size and negatively correlated with BS levels. This pioneer study documents an increase in insulin expression and an increase in islet size in hypoglycaemic patients with P. falciparum malaria. This could contribute to the pathogenesis of hypoglycaemia and provides evidence for the potential need to effectively manage the hypoglycaemia seen in malaria infection