Antitumour and anti-inflammatory effects of palladium(II) complexes on Ehrlich tumour.

Palladium(II) complexes are an important class of cyclopalladated compounds that play a pivotal role in various pharmaceutical applications. Here, we investigated the antitumour, anti-inflammatory, and mutagenic effects of two complexes: [Pd(dmba)(Cl)tu] (1) and [Pd(dmba)(N3)tu] (2) (dmba = N,N-dimethylbenzylamine and tu = thiourea), on Ehrlich ascites tumour (EAT) cells and peritoneal exudate cells (PECs) from mice bearing solid Ehrlich tumour. The cytotoxic effects of the complexes on EAT cells and PECs were assessed using the 3-(4,5-dimethylthiazol-3-yl)-2,5-diphenyl-tetrazolium bromide (MTT) assay. The effects of the complexes on the immune system were assessed based on the production of nitric oxide (NO) (Griess assay) and tumour necrosis factor-alpha (TNF-alpha), interleukin-12 (IL-12), and interleukin-10 (IL-10) (ELISA). Finally the mutagenic activity was assessed by the Ames test using the Salmonella typhimurium strain TA 98. Cisplatin was used as a standard. The IC50 ranges for the growth inhibition of EAT cells and PECs were found to be (72.8 +/- 3.23) microM and (137.65 +/- 0.22) microM for 1 and (39.7 +/- 0.30) microM and (146.51 +/- 2.67) microM for 2, respectively. The production of NO, IL-12, and TNF-alpha, but not IL-10, was induced by both complexes and cisplatin. The complexes showed no mutagenicity in vitro, unlike cisplatin, which was mutagenic in the strain. These results indicate that the complexes are not mutagenic and have potential immunological and antitumour activities. These properties make them promising alternatives to cisplatin.

Lichen metabolites modulate hydrogen peroxide and nitric oxide in mouse macrophages.

The activities of perlatolic acid (1), atranorin (2), and lecanoric acid (3) and their derivatives, such as orsellinates and beta-methyl orsellinates obtained by alcoholysis, were assessed for stimulation of the release of hydrogen peroxide and nitric oxide in cultures of peritoneal macrophage cells from mice. The hydrogen peroxide production was estimated by oxidation of phenol red, while the Griess reagent was used to determine the nitric oxide production. 1 and 4-methoxy-ethyl orsellinate (XVII) were the compounds that induced the greatest release of H2O2, whereas n-pentyl orsellinate (IV), iso-propyl orsellinate (V), sec-butyl orsellinate (VI), and XVII induced a small release of NO. These results indicate that lichen products and their derivatives have potential immune-modulating activities.

Immunostimulatory effects of the phenolic compounds from lichens on nitric oxide and hydrogen peroxide production / Efeito imunoestimulante de compostos fenólicos de líquens na produção de peróxido de hidrogênio e óxido nítrico

The effects of isolated compounds from Brazilian lichens and their derivatives on H2O2 and NO production were studied using murine macrophages as a part of an attempt to understand their possible immunomodulatory properties. The compound cytotoxicity was studied using MTT assay. Macrophage stimulation was evaluated by the determination of NO (Griess assay) and H2O2 (horseradish peroxidase/phenol red) in supernatants of peritoneal macrophage cultures of Swiss mice. This research demonstrated stimulatory activities of some phenolic compounds isolated from lichens and their derivatives on H2O2 and NO production. Structure-activity relationships suggest several synthetic directions for further improvement of immunological activity.

Os efeitos dos compostos isolados de líquens brasileiros e seus derivados na produção de NO e H2O2 foram estudados utilizando macrófagos murinos na tentativa de desvendar suas possíveis propriedades imunomodulatórias. A citotoxicidade dos compostos foi estudada utilizando o ensaio de MTT. A estimulação dos macrófagos foi avaliada através da determinação de NO (metodologia de Griess) e H2O2 (peroxidase de raíz forte/vermelho de fenol) no sobrenadante de culturas de macrófagos peritoneais de camundongos Swiss. Este estudo demonstrou atividade estimulante de alguns compostos fenólicos e seus derivados na produção de NO e H2O2. A relação estrutura atividade sugere inúmeras direções sintéticas para futuros melhoramentos da atividade imunológica.

Identification of ellagic acid derivatives in methanolic extracts from Qualea species.

The methanolic extract from the barks of the medicinal plant Qualea parviflora (Vochysiaceae) was fractionated by column chromatography over silica gel followed by gel permeation over Sephadex LH-20 to give 3,3'-di-O-methylellagic acid-4-O-beta-D-glucopyranoside (1), 3-O-methylellagic acid-4'-O-alpha-L-rhamnopyranoside (2), 3,3',4-tri-O-methylellagic acid-4'-O-beta-D-glucopyranoside (3), and 3,3'-di-O-methylellagic acid (4), together with triterpenes and saponins. We also performed comparative analyses among this species and Q. grandiflora and Q. multiflora using high-pressure liquid chromatography. The biological assays showed that, when compared to the standard ellagic acid, compounds 1-4 are less cytotoxic but have a lower capacity of stimulating murine peritoneal macrophages to release nitric oxide and tumoural-alpha necrose factor.