Natural cordiaquinones as strategies to inhibit the growth and biofilm formation of methicillin-sensitive and methicillin-resistant Staphylococcus spp.

AIMS: The aim of this study was to investigate the antibacterial and antibiofilm potential of cordiaquinones B, E, L, N, and O against different Staphylococci strains, in addition to analyzing in silico the observed effect. METHODS AND RESULTS: The minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) were determined according to CLSI guidelines. The inhibition of biofilm formation was investigated at sub-MICs. Atomic force microscopy (AFM) and density functional theory method were performed. The tested strains of Staphylococcus spp. were susceptible to cordiaquinones B, E, and L, among which cordiaquinone B exerted a bactericidal effect, confirmed by a bacterial growth curve study, against Staphylococcus saprophyticus. Cordiaquinones B and E showed lowest MBC values against S. saprophyticus. AFM revealed that cordiaquinone L reduced the mean cell size of S. saprophyticus. Cordiaquinones B and E inhibited the biofilm formation ability of S. aureus by ∼90%. The in silico analysis suggested that the antimicrobial activity of cordiaquinones is driven by their electron donation capability. CONCLUSIONS: Cordiaquinones inhibit the growth and biofilm formation (virulence factor) of both methicillin-sensitive and methicillin-resistant Staphylococci strains, indicating their antimicrobial potential.

New Synthetic Sulfonamide Chalcone Induced Cell Cycle Arrest and Cell Death in Colorectal Adenocarcinoma Metastatic Cells (SW-620).

BACKGROUND: New chalcones have been developed from the insertion of organic groups, among them sulfonamides, presenting varied biological activity. OBJECTIVE: The aim of this work was to determine the antitumor potential of a new synthetic sulfonamide chalcone (SSC185) against a colorectal metastatic lymph node-derived colorectal cancer cell line (SW-620). METHODS: Synthesis and characterization, including crystallography, of SSC185 were performed. SSC185 showed a selective cytotoxic effect against colorectal cancer cell lines. Therefore, the cytotoxic effect of SSC185 against SW- 620 was further investigated. We used optical and fluorescence microscopy, flow cytometry and Western blot to determine the antitumor effects of SSC185. RESULTS: SSC185 induced cytotoxicity in SW-620 cells in a time and concentration-dependent manner. Cell cycle progression was disrupted, with increased G2/M cell number and consequent cell death, with morphological alterations associated with apoptosis and necrosis. Cell death was associated with the activation and cleavage of PARP, and with reduced expression of the pro-apoptotic Bax protein and caspase 8, depending on the SSC185 concentration tested. Expression of the necroptosis pathway proteins RIP and MLKL was also reduced. These proteins are phosphorylated during the process of necroptosis. CONCLUSION: We suggest that the mechanism involved in the cytotoxic effect of SSC185 against SW-620 in vitro may be related to the induction of cell cycle arrest in the G2/M phase and cell death by apoptosis or necroptosis, depending on the concentration used.

Cytotoxicity against tumor cell lines and anti-inflammatory properties of chitinases from Calotropis procera latex.

The role of chitinases from the latex of medicinal shrub Calotropis procera on viability of tumor cell lines and inflammation was investigated. Soluble latex proteins were fractionated in a CM Sepharose Fast-Flow Column and the major peak (LPp1) subjected to ion exchange chromatography using a Mono-Q column coupled to an FPLC system. In a first series of experiments, immortalized macrophages were cultured with LPp1 for 24 h. Then, cytotoxicity of chitinase isoforms (LPp1-P1 to P6) was evaluated against HCT-116 (colon carcinoma), OVCAR-8 (ovarian carcinoma), and SF-295 (glioblastoma) tumor cell lines in 96-well plates. Cytotoxic chitinases had its anti-inflammatory potential assessed through the mouse peritonitis model. We have shown that LPp1 was not toxic to macrophages at dosages lower than 125 µg/mL but induced high messenger RNA expression of IL-6, IL1-ß, TNF-α, and iNOs. On the other hand, chitinase isoform LPp1-P4 retained all LPp1 cytotoxic activities against the tumor cell lines with IC50 ranging from 1.2 to 2.9 µg/mL. The intravenous administration of LPp1-P4 to mouse impaired neutrophil infiltration into the peritoneal cavity induced by carrageenan. Although the contents of pro-inflammatory cytokines IL-6, TNF-α, and IL1-ß were high in the bloodstreams, such effect was reverted by administration of iNOs inhibitors NG-nitro-L-arginine methyl ester and aminoguanidine. We conclude that chitinase isoform LPp1-P4 was highly cytotoxic to tumor cell lines and capable to reduce inflammation by an iNOs-derived NO mechanism.