Streptomyces hygroscopicus UFPEDA 3370: A valuable source of the potent cytotoxic agent nigericin and its evaluation against human colorectal cancer cells.

Streptomyces hygroscopicus UFPEDA 3370 was fermented in submerged cultivation and the biomass extract was partitioned, obtaining a fraction purified named EB1. After purification of EB1 fraction, nigericin free acid was obtained and identified. Nigericin presented cytotoxic activity against several cancer cell lines, being most active against HL-60 (human leukemia) and HCT-116 (human colon carcinoma) cell lines, presenting IC and (IS) values: 0.

Thiazolidinedione and thiazole derivatives potentiate norfloxacin activity against NorA efflux pump over expression in Staphylococcus aureus 1199B strains.

Thiazol and thiazolidinedione derivatives are known in the literature for presenting several biological activities, such as anti-diabetic, anti-inflammatory, antiparasitic, antifungal and antimicrobial activity. With this in mind, this study reports on the synthesis and antibacterial activity of thiazole (NJ) and thiazolidinedione (NW) derivatives, as well as their effects in association with norfloxacin, against NorA efflux pumps in the Staphylococcus aureus 1199B (SA-1199B) strain. Among the 14 compounds evaluated, 9 were found to potentiate norfloxacin activity, with 4 compounds from the NJ series promoting a threefold norfloxacin MIC reduction.

Antimicrobial, antiproliferative and proapoptotic activities of extract, fractions and isolated compounds from the stem of Erythroxylum caatingae plowman.

In the study, we have examined the antitumor and antimicrobial activities of the methanol extract, the fractions, a fraction of total alkaloids and two alkaloids isolated from the stem of Erythroxylum caatingae Plowman. All test fractions, except the hexane fractions, showed antimicrobial activity on gram-positive bacteria and fungi. The acetate: methanol (95:5), acetate, chloroform and hexane fractions show the highest cytotoxicity activity against the NCI-H292, HEp-2 and K562 cell lines using MTT.

Antiproliferative activity, antioxidant capacity and tannin content in plants of semi-arid northeastern Brazil.

The objective of this study was to evaluate antiproliferative activity, antioxidant capacity and tannin content in plants from semi-arid northeastern Brazil (Caatinga). For this study, we selected 14 species and we assayed the methanol extracts for antiproliferative activity against the HEp-2 (laryngeal cancer) and NCI-H292 (lung cancer) cell lines using the (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazole) (MTT) method. In addition, the antioxidant activity was evaluated with the DPPH (2,2-diphenyl-2-picrylhydrazyl) assay, and the tannin content was determined by the radial diffusion method.