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.

Antimycobacterial activity of Indigofera suffruticosa with activation potential of the innate immune system.

Mycobacterium tuberculosis is responsible for over 8 million cases of tuberculosis (TB) annually. Natural products may play important roles in the chemotherapy of TB. The antimycobacterial activity and the innate immune response of methanol (METH) and dichloromethane (DCM) extracts of Indigofera suffruticosa Miller (Fabaceae) were evaluated. We observed that the minimum inhibitory concentrations (MICs) for METH and DCM extracts were 125 and 1000 microg/mL, respectively. However, they were able to induce the innate immune response through the production of high levels of NO and TNF-alpha (p < 0.001) by peritoneal exudate cells (PECs). These results suggest that I. suffruticosa extracts may have an important immunological role in the control of TB once macrophage activity is induced by them.

Isolated flavonoids against mammary tumour cells LM2.

The purpose of the present study was to investigate antitumour and anti-inflammatory activities of flavonoids isolated from Byrsonima crassa, Davilla elliptica and Mouriri pusa. The antitumour activity was measured by the MTT assay in murine mammary tumour cells (LM2) and the IC50 values of the flavonoids tested ranged from (31.5 +/- 2.97) to (203.1 +/- 5.9) microg/ml. The flavonoids 1 (myricetin-3-O-alpha-L-rhamnopyranoside) and 3 (quercetin-3-O-galactopyranoside) from D. elliptica were the most active ones against the tumour cells. The same samples were tested to determine the inhibition of the release of nitric oxide (NO) and of the tumour necrosis factor-alpha (TNF-alpha) in murine macrophages by the Griess and ELISA sandwich assay, respectively. Almost all the samples showed inhibitory activity to the release of NO but not of TNF-alpha. Of all substances tested, flavonoids 2 (quercetin) and 6 (myricetin) may show promising activity in the treatment of murine breast cancer by immunomodulatory and antiproliferative activities.

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.

Byrsonima fagifolia: an integrative study to validate the gastroprotective, healing, antidiarrheal, antimicrobial and mutagenic action.

ETHNOPHARMACOLOGICAL RELEVANCE: Ethnopharmacological survey indicated leaves of Byrsonima fagifolia Nied. (Malpighiaceae) against gastrointestinal disorders. AIM OF THE STUDY: The methanolic extract from the leaves of Byrsonima fagifolia (denominated BF) was evaluated for toxic, mutagenic, gastroprotective, antidiarrheal, antibacterial and immunomodulatory activities. MATERIALS AND METHODS: The preventive and healing action of BF against gastric ulcer was evaluated in experimental models in rodents. We evaluated immunomodulatory (by murine peritoneal macrophages), antidiarrheal (by induced diarrhea with castor oil and intestinal motility) and antibacterial action of BF against standard strain of Escherichia coli, Staphylococcus aureus and Helicobacter pylori. The safety of use of BF was also evaluated by mutagenic (Ames assay) and by analyses of toxicity parameters. RESULTS: Phytochemical BF profile indicated the presence of phenolic compounds with antioxidant and radical-scavenging properties. BF significantly inhibited gastric lesions induced by ethanol and HCl/ethanol and endogenous mucosal sulphydryl groups (SHs) participated efficaciously in BF gastroprotection. BF blocked development of inflammation process and also has antidiarrheal actions. This extract accelerated the healing of the gastric ulcerated mucosa by stimulating proliferative factors and by increasing production of gastric mucus with no toxic action. The substances responsible for the protective action are concentrated in the ethyl acetate fraction that demonstrated no mutagenic action in vitro. CONCLUSIONS: Byrsonima fagifolia presents gastroprotective, healing and antidiarrheal activities supporting previous claims that its traditional use by Brazilians can treat these gastrointestinal ailments.

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.

Mouririelliptica: validation of gastroprotective, healing and anti-Helicobacter pylori effects.

ETHNOPHARMACOLOGICAL RELEVANCE: Mouriri elliptica Martius (Melastomataceae) is species reputed in folk medicine to heal gastric ulcer and gastritis. AIM OF THE STUDY: Methanolic extract (ME) and ethyl acetate fraction (EAF) from leaves of Mouriri elliptica were evaluated for their gastroprotective, healing, immunological, toxicological and anti-Helicobacter pylori activities. MATERIAL AND METHODS: The gastroprotective action of ME and EAF was evaluated in rodent experimental models and to elucidate mechanisms of action, the antisecretory action, involvements of NO, SH, PGE(2), anti-Helicobacter pylori action of ME was evaluated. We also used immunohistochemical (PCNA and COX-2) and immunomodulatory (murine peritoneal macrophages) assays to evaluate Mouriri elliptica effects. RESULTS: ME present gastroprotective action without antisecretory effect. Otherwise, ME showed anti-Helicobacter pylori action (MIC=0.025mug/mL) and was able to inhibit NO production by macrophages. This species also accelerate the healing of ulcerated gastric mucosa by stimulating proliferation factors (PCNA), COX-2 and maintained basal PGE(2) level independent action of NSAID in gastric mucosa. The phytochemical investigation showed that this species possesses phenolic acid derivatives, acylglycoflavonoids and condensed tannins which probably influenced their pharmacological action. CONCLUSION: All these results suggest the efficacy and safety of Mouriri elliptica in combating and healing gastric ulcer.

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.