Bullfrog oil (Rana catesbeiana Shaw) induces apoptosis, in A2058 human melanoma cells by mitochondrial dysfunction triggered by oxidative stress.

Bullfrog oil, an animal oil extracted from the adipose tissue of Rana catesbeiana Shaw, showed promising cytotoxic activity against melanoma cells and, therefore, has the potential to become a pharmaceutical active compound. However, there is a lack of information regarding the pathways involved in its pharmacological activity. Thus, the aim of this study was to investigate and elucidate the cytotoxic effect of this oil against A2058 human melanoma cells. The cytotoxic potential was evaluated by the MTT assay, the cell cycle analysis and the cell death assay. In addition, the apoptotic potential was investigated by (i) the DNA fragmentation using propidium iodide staining analysis, (ii) the evaluation of mitochondrial membrane potential and (iii) the determination of intracellular Reactive Oxygen Species (ROS) level. The results showed that the bullfrog oil was able to promote a time-dependent cytotoxic effect, decreasing cell viability to 38% after 72 h of treatment without affecting the cell cycle. Additionally, the bullfrog oil induced the apoptosis in A2058 cells, increasing up to 50 ±â€¯13% of the intracellular ROS level, maintaining the DNA integrity and promoting an approximate decrease of 35 ±â€¯5% in the mitochondrial membrane potential. It can be concluded that the in vitro cytotoxic effect of the bullfrog oil in A2058 human melanoma cells is mediated by oxidative stress that induces mitochondrial dysfunction, triggering the apoptosis. These unprecedented results highlight the pharmacological potential of bullfrog oil and provide important information to support studies on the development of new pharmaceutical products for complementary and alternative treatments for melanoma.

Effect of plasma-nitrided titanium surfaces on the differentiation of pre-osteoblastic cells.

A titanium surface nitrided by plasma contains nitrogen ions that guarantee resistance to corrosion and biocompatibility. Despite this, no descriptions concerning the influence of the expression of cell adhesion proteins and their influence on osteogenic cell differentiation are available. Thus, the present study aimed to assess the response of murine pre-osteoblastic cells (MC3T3-E1) cultured on nitrided titanium surfaces. Pre-osteoblastic cells were grown on polished titanium discs, used as controls, and on previously characterized plasma-nitrided titanium discs. Cells from both groups were submitted to the MTT cell viability test. The expressions of α5, α2, and ß1 integrin were assessed by flow cytometry and immunofluorescence, while osteocalcin expression was assessed by flow cytometry. The nitrided surface presented higher α2 and ß1 integrin expressions, as well as osteocalcin expression, when compared to the polished surface, with no alterations in cell viability. These findings seem to suggest that the plasma nitriding treatment produces a titanium surface with the potential for effective in vitro osseointegration.

Stigmurin and TsAP-2 from Tityus stigmurus scorpion venom: Assessment of structure and therapeutic potential in experimental sepsis.

Microbial resistance to conventional antibiotics is a public health problem worldwide, motivating the search for new therapeutic alternatives in varied natural sources. Cationic peptides without disulfide bridges from scorpions have been targeted in this context, mainly due to their multifunctional action and the limited ability of microorganisms to develop resistance against them. The present study was focused on Stigmurin and TsAP-2, cationic peptides found in the transcriptome of the venom gland from the scorpion Tityus stigmurus. The aims were: to assess the secondary structure of TsAP-2 and the structural stability of both peptides by circular dichroism; to evaluate their antiproliferative effect, and antimicrobial activities in vitro, ex vivo and in vivo; and to investigate their therapeutic potential in a murine model of polymicrobial sepsis. Stigmurin and TsAP-2 secondary structures responded similarly to environment polarity changes, and were stable to temperature and pH variation. Both peptides showed antiproliferative effect on tumor cells. TsAP-2 showed lower cytotoxicity to normal cells, and had a mitogenic activity on murine macrophages. Stigmurin demonstrated bactericidal and bacteriostatic activity, depending on the microorganism, whereas TsAP-2 had bactericidal action upon different bacterial strains analyzed. Both peptides were able to reduce leukocyte migration, TNF-α levels and microorganism load in the peritoneal cavity after induction of experimental sepsis, decreasing inflammation in the lung and cecum of septic animals. TsAP-2 also reduced the release of nitric oxide in the peritoneal cavity. Taken together, these data suggest that Stigmurin and TsAP-2 are structurally stable molecules and are efficient in the control of the infectious focus in polymicrobial sepsis, with potential use as a prototype for the rational design of novel therapeutic agents.

A sulfated polysaccharide, fucans, isolated from brown algae Sargassum vulgare with anticoagulant, antithrombotic, antioxidant and anti-inflammatory effects.

Fucan (SV1) sulfated polysaccharides from the brown algae Sargassum vulgare were extracted, fractionated in acetone and examined with respect to chemical composition, anticoagulant, anti-inflammatory, antithrombotic effects and cellular proliferation. These polysaccharides contain low levels of protein, high level of carbohydrate and sulfate. Monosaccharides analysis revealed that SV1 was composed of fucose, galactose, xylose, glucuronic acid and mannose. SV1 polysaccharide prolonged activated partial thromboplastin time (aPTT) and exhibited high antithrombotic action in vivo, with a concentration ten times higher than heparin activity. PSV1, a purified form in gel filtration showed very low biological activities. SV1 stimulated the enzymatic activity of FXa. Its action on DPPH radical scavenging activity was 22%. This polymer has no cytotoxic action (hemolytic) on ABO and Rh blood types in different erythrocyte groups. It displays strong anti-inflammatory action at all concentrations tested in the carrageenan-induced paw edema model, demonstrated by reduced edema and cellular infiltration.