Photobiomodulation enhances the Th1 immune response of human monocytes

This study aims to evaluate the effects of photobiomodulation (PBM) on human monocytes, assessing the oxidative burst and ultimate fungicidal potential of these cells, as well as the gene expression at the mRNA level of CD68, CD80, CD163, CD204, IL-6, TNF-α and IL-10 in derived macrophages. Primary cultures of human monocytes were irradiated with an InGaAlP (660 nm)/GaAlAs (780 nm) diode laser (parameters: 40 mW, 0.04 cm², 1 W/cm²; doses: 200, 400 and 600 J/cm²). Cells were submitted to the chemiluminescence assay, and a microbicidal activity assay against Candida albicans was performed. Reactive oxygen species (ROS) and nitric oxide (NO) production were measured, and cell viability was assessed by the exclusion method using 0.2% Trypan blue reagent. Irradiated monocytes were cultured for 72 h towards differentiation into macrophages. Total RNA was extracted, submitted to reverse transcription and real-time PCR. The results were analysed by ANOVA and the Tukey test (α = 0.05). Irradiated monocytes revealed a significant increase in their intracellular and extracellular ROS (P < 0.001). The 660 nm wavelength and 400 J/cm² dose were the most relevant parameters (P < 0.001). The fungicidal capacity of the monocytes was shown to be greatly increased after PBM (P < 0.001). PBM increased the expression of TNF-α (P = 0.0302) and the production of NO (P < 0.05) and did not impair monocyte viability. PBM induces a pro-inflammatory Th1-driven response in monocytes and macrophages.

Tempol modulates the leukocyte response to inflammatory stimuli and attenuates endotoxin-induced sickness behaviour in mice

Background and aims: Lipopolysaccharide (LPS), an endotoxin, is a component of the outer membrane of Gram-negative bacteria that is able to activate the peripheral immune system, leading to changes in signalling pathways that act locally and systemically to achieve adaptive responses. Sickness behaviour is a motivational state in response to endotoxin exposure and includes depressed activity and a reduction of exploratory behaviour, potentially reorganising organism priorities to cope with infectious diseases. We hypothesised that 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl (Tempol) modulates the leukocyte response to endotoxins and decreases LPS-induced sickness behaviour in mice.Methods: The effects of Tempol on LPS-induced peritonitis and the respiratory burst of neutrophils primed with LPS and triggered by phorbol 12-myristate-13-acetate (PMA) were evaluated. To evaluate the effects of Tempol on sickness behaviour, the mice were submitted to an open field and forced swim tests.Results: Tempol (50-100 μM/10⁶ cells) decreased the respiratory burst of LPS-primed and PMA-stimulated neutrophils in vitro. In vivo, this nitroxide (30 and 100 mg/kg body weight) inhibited leukocyte migration to the peritoneal cavity after LPS administration in mice. Moreover, Tempol pretreatment (30 and 100 mg/kg body weight) before LPS administration also attenuated sickness behavioural changes.Conclusions: Together, these findings shed light on the mechanisms underlying the anti-inflammatory potential and confirm the therapeutic potential of nitroxides.

Parâmetros Nutricionais em Pacientes Oncológicos atendidos em um Centro de Referência no Sul de Minas Gerais, Brasil

Introdução: A orientação nutricional é de extrema importância para pacientes oncológicos, prevenindo deficiências nutricionais que podem gerar sérias complicações. Objetivo: Avaliar o perfil nutricional de pacientes oncológicos. Método: Estudo transversal, realizado em um Centro de Referência em Oncologia de Alfenas - MG. Para traçar o perfil nutricional de 52 pacientes oncológicos (n=52) durante o tratamento quimioterápico, foram utilizados métodos dietéticos e antropométricos (índice de massa corporal [IMC], prega cutânea tricipital [PCT], circunferência do braço [CB], circunferência muscular do braço [CMB] e percentagem da perda de peso [%PP]). Dados gerais de saúde dos pacientes foram também avaliados. Resultados: Houve predominância do sexo feminino (63%), faixa etária >50 anos (40% IC95% 27-53,7). O tipo de câncer correlacionou-se ao sexo (p<0,01). No sexo feminino, o de mama teve prevalência de 51%, seguido pelo uterino (18%). No masculino, a prevalência de câncer de próstata foi de 10% e, comum aos dois sexos, o câncer de pulmão, de 15%, sendo o mais prevalente no masculino (32%). Hipertensão arterial sistêmica foi a comorbidade mais reportada (75%) e enjoos, o efeito adverso mais comum (69%). As médias dos parâmetros IMC, PCT, CB e CMB não sofreram alterações significativas (p>0,05) ao final do tratamento, mas 40% dos pacientes tiveram um grave %PP, 23% não grave %PP, 4% mantiveram o peso e 33% apresentaram ganho de peso. Entre os pacientes avaliados, 48% usavam suplementos nutricionais. Conclusão: A orientação nutricional deve ser desenvolvida junto aos pacientes oncológicos, desde que se demonstrou um variado perfil nutricional em uma amostra heterogênea de pacientes.

Nitroxide 4-hydroxy-2,2',6,6'-tetramethylpiperidine 1-oxyl (Tempol) inhibits the reductase activity of protein disulfide isomerase via covalent binding to the Cys400 residue on CXXC redox motif at the a'active site

BACKGROUND AND AIM

Oxidative stress arising from inflammatory processes is a serious cause of cell and tissue damage. Tempol is an efficient antioxidant with superoxide dismutase-like activity. The purpose of this paper is to address the inhibition of protein disulfide isomerase (PDI), an essential redox chaperone whose active sites contain the Cys-Gly-His-Cys (CXXC) motif, by the nitroxide Tempol.

RESULTS

In the presence of Tempol (5-120 μM), the reductase activity of PDI was reversibly affected both in vitro and in activated mice neutrophils, with an IC₅₀ of 22.9 ± 10.8 μM. Inhibitory activity was confirmed by using both the insulin method and fluorescent formation of eosin-glutathione (E-GSH). The capacity of Tempol to bind the enzyme was determined by EPR and mass spectrometry. EPR Tempol signal decreased in the presence of PDI while remained unaffected when PDI thiols were previously blocked with NEM. When total protein was analyzed, 1 and 4 molecules of Tempol were bound to the protein. However, only one was found to be covalently bound to PDI at the a'active site. More specifically, Cys₄₀₀ was modified by Tempol.

CONCLUSION

We have shown that the nitroxide Tempol acts as an inhibitor of PDI through covalent binding to the Cys400 of the protein structure. Since PDI is coupled with the assembly of the NADPH oxidase complex of phagocytes, these findings reveal a novel action of Tempol that presents potential clinical applications for therapeutic intervention to target PDI knockdown in pathological processes in which this protein is engaged.

Low-level laser therapy stimulates the oxidative burst in human neutrophils and increases their fungicidal capacity

Low-level laser therapy (LLLT) is known to enhance mitochondrial electron transfer and ATP production; thus, this study asked whether LLLT could stimulate the oxidative burst in human neutrophils (PMN) and improve their ability to kill microorganisms. Blood from healthy human subjects was collected and PMN were isolated from the samples. PMN were treated in vitro with 660 nm or 780 nm CW laser light at 40 mW power and increasing energies up to 19.2 J and were subsequently incubated with Candida albicans cells. Generation of hydroxyl radicals, hypochlorite anions and superoxide anions by PMN were checked using fluorescent probes and chemiluminescence assays; a microbicidal activity assay against C. albicans was also performed. LLLT excited PMN to a higher functional profile, which was translated as superior production of reactive oxygen species (ROS) and increased fungicidal capacity. The most efficacious energy was 19.2 J and, interestingly, the 660 nm light was even more efficacious than 780 nm at increasing the respiratory burst of PMN and the fungicidal capacity. Human neutrophils (PMN) were stimulated in vitro with 660 nm or 780 nm CW laser light at 40 mW of power and a total energy of 19.2 J. Low-level laser therapy (LLLT) excited PMN to a higher functional profile, which was translated as a superior production of reactive oxygen species (ROS) such as hydroxyl radicals (HO^• ) and hypochlorite anions (ClO^- ) (Figure) and increased fungicidal capacity against Candida albicans cells.

Green banana pasta diet prevents oxidative damage in liver and kidney and improves biochemical parameters in type 1 diabetic rats

OBJECTIVE

In this study, the effects of a green banana pasta diet on the oxidative damage from type 1 diabetes mellitus (DM) were investigated.

MATERIALS AND METHODS

Formulations containing 25 (F25), 50 (F50), and 75% (F75) of green banana pasta were prepared and included in a 12-week diet of Wistar rats with alloxan-induced type 1 DM. The effects of these formulations in preventing oxidative damage in kidneys and liver homogenates of rats were evaluated using the TBARS assay (lipid peroxidation in liver) and the DNPH assay (protein oxidation in liver and kidneys). Furthermore, the effects of the formulations on the fasting glycemia, fructosamine levels, renal function (creatinine), liver function (enzymes aspartate aminotransferase [AST] and alanine aminotransferase [ALT]), and lipid profile (total cholesterol and fractions) in the serum of rats were evaluated in addition to the evaluation of the centesimal composition and microbiological analysis of the produced green banana pasta.

RESULTS

An F75 diet prevented hyperglycemia in diabetic rats (p < 0.05) compared to the diabetic rats fed a standard diet (commercial feed). Notably, the protein oxidation in both the liver and kidneys were prevented in diabetic rats on the F50 or F75 diets compared to the control group, whereas the lipid peroxidation was only prevented in the liver (p < 0.05). Moreover, all formulations prevented an increase in the amount of triglycerides in the serum of the rats. The F25 and F50 diet prevented the increase of cholesterol, and the F75-based diet of ALT and fructosamine (p < 0.05) supported the anti-hyperglycemic effects and the protection against oxidative damage.

CONCLUSION

The green banana pasta (F75) diet showed great potential for preventing complications associated with diabetes.

In vitro screening antibacterial activity of Bidens pilosa Linné and Annona crassiflora Mart. against oxacillin resistant Staphylococcus aureus (ORSA) from the aerial environment at the dental clinic

Currently multiresistant Staphylococcus aureus is one common cause of infections with high rates of morbidity and mortality worldwide, which directs scientific endeavors in search for novel antimicrobials. In this study, nine extracts from Bidens pilosa (root, stem, flower and leaves) and Annona crassiflora (rind fruit, stem, leaves, seed and pulp) were obtained with ethanol: water (7:3, v/v) and their in vitro antibacterial activity evaluated through both the agar diffusion and broth microdilution methods against 60 Oxacillin Resistant S. aureus (ORSA) strains and against S. aureus ATCC6538. The extracts from B. pilosa and A. crassiflora inhibited the growth of the ORSA isolates in both methods. Leaves of B. pilosa presented mean of the inhibition zone diameters significantly higher than chlorexidine 0.12% against ORSA, and the extracts were more active against S. aureus ATCC (p < 0.05). Parallel, toxicity testing by using MTT method and phytochemical screening were assessed, and three extracts (B. pilosa, root and leaf, and A. crassiflora, seed) did not evidence toxicity. On the other hand, the cytotoxic concentrations (CC50 and CC90) for other extracts ranged from 2.06 to 10.77 mg/mL. The presence of variable alkaloids, flavonoids, tannins and saponins was observed, even though there was a total absence of anthraquinones. Thus, the extracts from the leaves of B. pilosa revealed good anti-ORSA activity and did not exhibit toxicity.