Cytotoxic effect and oxidative damage of organic extract from Artemisia verlotorum in human cancer cell lines

Neste estudo, avaliamos os efeitos citotóxico e oxidativo dos extratos orgânico e aquoso de folhas da Artemisia verlotorum em linhagens celulares derivadas de câncer humano. Apenas o extrato orgânico demonstrou atividade citotóxica na linhagem celular de adenocarcinoma de cólon HT-29 na concentração de 100 µg/mL. O extrato orgânico foi, então, analisado em três linhagens celulares: adenocarcinoma de cólon, HT-29; carcinoma de pulmão de não-pequenas células, NCI-H460 e câncer renal, RXF-393, demonstrando valores de IC50 que variaram de 21 a 38 µg/mL. A linhagem celular RXF-393 apresentou maior sensibilidade ao extrato e foi usada nas análises seguintes. Nesta linhagem, o extrato orgânico induziu um significativo aumento dose-dependente na peroxidação lipídica. A maior concentração (IC80) do extrato reduziu em 50 % a atividade da isoforma mitocondrial da enzima superóxido dismutase (SOD2). Estes achados sugerem que o extrato orgânico de folhas da Artemisia verlotorum induz morte celular através de um aumento no dano oxidativo em linhagens celulares de câncer humano.In this study the cytotoxic and oxidative effects of organic and aqueous extracts from the leaves of Artemisia verlotorum in human cancer cell lines was evaluated. Only the organic extract demonstrated cytotoxic activity in HT-29 colon adenocarcinoma cell line at 100 µg/mL. The organic extract was then analyzed in three cell lines: HT-29 colon adenocarcinoma; NCI-H460 non-small-cell lung cancer cell line and RXF-393 renal cancer cell line, demonstrating values of IC50 ranging from 21 to 38 µg/mL. The RXF-393 cell line displayed higher sensibility to these extract and it was used in the following analyses. In these cells, the organic extract induced a significant dose-dependent increase in the lipid peroxidation. The highest concentration (IC80) of the extract reduced in 50 % the activity of the mitochondrial isoform of the enzyme superoxide dismutase (SOD2). These findings suggest that the organic extract from the leaves of Artemisia verlotorum induces cell death through an increase in the oxidative damage in human cancer cell linesColegio de Farmacéuticos de la Provincia de Buenos Aire

Radioresistance of human glioma spheroids and expression of HSP70, p53 and EGFr

Background: Radiation therapy is routinely prescribed for high-grade malignant gliomas. However, the efficacy of this therapeutic modality is often limited by the occurrence of radioresistance, reflected as a diminished susceptibility of the irradiated cells to undergo cell death. Thus, cells have evolved an elegant system in response to ionizing radiation induced DNA damage, where p53, Hsp70 and/or EGFr may play an important role in the process. In the present study, we investigated whether the content of p53, Hsp70 and EGFr are associated to glioblastoma (GBM) cell radioresistance. Methods: Spheroids from U-87MG and MO59J cell lines as well as spheroids derived from primary culture of tumor tissue of one GBM patient (UGBM1) were irradiated (5, 10 and 20 Gy), their relative radioresistance were established and the p53, Hsp70 and EGFr contents were immunohistochemically determined. Moreover, we investigated whether EGFr-phospho-Akt and EGFr-MEK-ERK pathways can induce GBM radioresistance using inhibitors of activation of ERK (PD098059) and Akt (wortmannin). Results: At 5 Gy irradiation UGBM1 and U-87MG spheroids showed growth inhibition whereas the MO59J spheroid was relatively radioresistant. Overall, no significant changes in p53 and Hsp70 expression were found following 5 Gy irradiation treatment in all spheroids studied. The only difference observed in Hsp70 content was the periphery distribution in MO59J spheroids. However, 5 Gy treatment induced a significant increase on the EGFr levels in MO59J spheroids. Furthermore, treatment with inhibitors of activation of ERK (PD098059) and Akt (wortmannin) leads to radiosensitization of MO59J spheroids. Conclusions: These results indicate that the PI3K-Akt and MEK-ERK pathways triggered by EGFr confer GBM radioresistance

Nicotinic acid induces antinociceptive and anti-inflammatory effects in different experimental models

AbstractAlthough in vitro studies have shown that nicotinic acid inhibits some aspects of the inflammatory response, a reduced number of in vivo studies have investigated this activity. To the best of our knowledge, the effects induced by nicotinic acid in models of nociceptive and inflammatory pain are not known. Per os (p.o.) administration of nicotinic acid (250, 500 or 1000mg/kg, −1h) inhibited the first and the second phases of the nociceptive response induced by formalin in mice. Nicotinic acid (250 or 500mg/kg, −1 and 3h) also inhibited the mechanical allodynia induced by carrageenan in rats, a model of inflammatory pain. However, in a model of nociceptive pain, exposure of mice to a hot-plate, nicotinic acid was devoid of activity. In addition to inhibiting the nociceptive response in models of inflammatory pain, nicotinic acid (250 or 500mg/kg, p.o., −1 and 3h) inhibited paw edema induced by carrageenan in mice and rats. Picolinic acid (62.5 or 125mg/kg, p.o., −1h), a nicotinic acid isomer, inhibited both phases of the nociceptive response induced by formalin, but not paw edema induced by carrageenan in mice. The other nicotinic acid isomer, isonicotinic acid, was devoid of activity in these two models. In conclusion, our results represent the first demonstration of the activity of nicotinic acid in experimental models of nociceptive and inflammatory pain and also provide further support to its anti-inflammatory activity. It is unlikely that conversion to nicotinamide represents an important mechanism to explain the antinociceptive and anti-inflammatory activities of nicotinic acid. The demonstration of new activities of nicotinic acid, a drug that has already been approved for clinical use and presents a positive safety record, may contribute to raise the interest in conducting clinical trials to investigate its usefulness in the treatment of painful and inflammatory diseases

THE SUSCEPTIBILITY OF RECENT ISOLATES OF Schistosoma mansoni TO PRAZIQUANTEL

Introduction: Schistosomiasis is a chronic disease caused by trematode flatworms of the genus Schistosoma and its control is dependent on a single drug, praziquantel (PZQ), but concerns over PZQ resistance have renewed interest in evaluating the in vitro susceptibility of recent isolates of Schistosoma mansoni to PZQ in comparison with well-established strains in the laboratory. Material and methods: The in vitro activity of PZQ (6.5-0.003 µg/mL) was evaluated in terms of mortality, reduced motor activity and ultrastructural alterations against S. mansoni. Results: After 3 h of incubation, PZQ, at 6.5 µg/mL, caused 100% mortality of all adult worms in the three types of recent isolates, while PZQ was inactive at concentrations of 0.08-0.003 µg/mL after 3 h of incubation. The results show that the SLM and Sotave isolates basically presented the same pattern of susceptibility, differing only in the concentration of 6.5 µg/mL, where deaths occurred from the range of 1.5 h in Sotave and just in the 3 h range of SLM. Additionally, this article presents ultrastructural evidence of rapid severe PZQ-induced surface membrane damage in S. mansoni after treatment with the drug, such as disintegration, sloughing, and erosion of the surface. Conclusion: According to these results, PZQ is very effective to induce tegument destruction of recent isolates of S. mansoni

Pluronic® F127 Thermoresponsive Viscum album Hydrogel: Physicochemical Features and Cellular In Vitro Evaluation

Viscum album L., popularly known as mistletoe, is well known for its anti-cancer properties, and the pharmaceutical application of hydroalcoholic dry extracts is still limited due to its low solubility in aqueous media, and physicochemical instability. The Pluronic® F127 is an amphiphilic polymer, which permits the solubilization of lipophilic and hydrophilic compounds. In this investigation, physicochemical features of hydrogel containing V. album dry extract (VADE-loaded-hydrogel) were performed by: dynamic light scattering (DLS), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and transmission electron microscopy (TEM). VADE-loaded-hydrogel presented nanometer-size micelles with volume distribution ranging from 10.58 nm to 246.7 nm, and a polydispersity index of 0.441. The sample thermal analyses (TG and DSC) showed similar decomposition curves; however, the thermal events indicated an increase in thermal stability in relation to the presence of the extract. In addition to these interesting pharmaceutical features, IC50 values of 333.40 µg/mL and >1000 µg/mL were obtained when tumor (SCC-25) and non-tumor (L929) cells were incubated with VADE-loaded-hydrogel, respectively. The optical and ultrastructural cellular analysis confirmed the tumor selectivity since the following alterations were detected only in SCC-25 cells: disorganization of plasmatic membrane; an increase of cytoplasmatic vacuole size; alteration in the cristae mitochondrial shape; and generation of amorphous cellular material. These results emphasize the promising antitumoral potential of VADE-loaded-hydrogel as an herbal drug delivery system via in vitro assays

Effects induced by Apis mellifera venom and its components in experimental models of nociceptive and inflammatory pain

AbstractThe effects induced by Apis mellifera venom (AMV), melittin-free AMV, fraction with molecular mass < 10 kDa (F<10) or melittin in nociceptive and inflammatory pain models in mice were investigated. Subcutaneous administration of AMV (2, 4 or 6 mg/kg) or melittin-free AMV (1, 2 or 4 mg/kg) into the dorsum of mice inhibited both phases of formaldehyde-induced nociception. However, F<10 (2, 4 or 6 mg/kg) or melittin (2 or 3 mg/kg) inhibited only the second phase. AMV (4 or 6 mg/kg), but not F<10, melittin-free AMV or melittin, induced antinociception in the hot-plate model. Paw injection of AMV (0.05 or 0.10 mg), F<10 (0.05 or 0.1 mg) or melittin (0.025 or 0.050 mg) induced a nociceptive response. In spite of inducing nociception after paw injection, scorpion (Tityus serrulatus) or snake (Bothrops jararaca) venom injected into the dorsum of mice did not inhibit formaldehyde-induced nociception. In addition, AMV (6 mg/kg), but not F<10 (6 mg/kg) or melittin (3 mg/kg), inhibited formaldehyde paw oedema. Concluding, AMV, F<10 and melittin induce two contrasting effects: nociception and antinociception. AMV antinociception involves the action of different components and does not result from non-specific activation of endogenous antinociceptive mechanisms activated by exposure to noxious stimuli

Imidazolium salt and dielectric barrier discharge plasma treatment to enhance the conductivity of fabrics impregnated with pedot:PSS

Conductive textiles are a class of materials with a growing interest due to their potential applications in medical, healthcare, comfort, protective clothing, and sportswear sectors. They can be used for the development of smart textiles able to answer to different external stimuli such as thermal, mechanical, chemical, electrical, magnetic, and optical. The complex poly (3,4-ethylene dioxythiophene):polystyrene sulfonate (PEDOT:PSS) is the most explored polymer to prepare conductive textiles. Dopants can be introduced to add or remove electrons from the backbone of PEDOT:PSS, resulting in increased conductivity. Salts such as 1-butyl-3-methylimidazolium octyl sulphate (IZ) may promote ionic interactions with PEDOT:PSS, stimulating a microstructure reorganization. Moreover, the dielectric barrier discharge (DBD) plasma treatment has been shown to improve the adhesion of coatings by modifying the surface roughness, surface chemistry, and hydrophilicity of the fabrics. In this work, untreated and DBD plasma-treated polyester (PES) fabrics were impregnated with PEDOT:PSS with and without the addition of imidazolium salt (0.2M) as a dopant. Using the IZ, it was possible to adapt the textile materials into resistors, where the applied current converted electrical energy into heat. The developed textiles can be used to produce heating garments