Radical scavenging activity of orange and tangerine varieties cultivated in Brazil

Four citrus fruit varieties cultivated in Brazil (two kinds of sweet orange and two kinds of tangerine) were analyzed for physicochemical characteristics contents of total phenolics, total carotenoids and ascorbic acid, and antioxidant activities. The antioxidant activities of aqueous, methanolic, and acetone extracts of the citrus fruit juices were assessed on the basis of their ability to scavenge 1,1-diphenyl-2-picrylhydrazyl (DPPH(center dot)). The cravo tangerine has the highest content of citric acid, while the pera orange is richest in ascorbic acid. The lima orange has the highest total phenolic contents, and the ponkan the highest total carotenoids. The antioxidant activities, expressed as the concentration of antioxidant able to scavenge 50% of the initial DPPH(center dot) (EC(50)), ranged from 139.1+/-27.3 to 182.2+/-28.8 g extract/l for juice of orange varieties and 186.3+/-29.6 to 275.5+/-3.3g extract/l for juice of tangerine citrus varieties. In methanolic extracts the EC(50) ranged from 192.5+/-43.1 to 267.4+/-41.4 g extract/l for orange varieties and from 225.2+/-69.8 to 336.3+/-27.2 g extract/l for tangerine varieties. For EC(50) values of acetone fractions, there were no statistically significant differences between the different varieties. For every citrus fruit in the present study, the radical scavenging capacity was higher in the aqueous than in the methanolic or acetone fractions.

Antimicrobial and Cytotoxic Activity of Fruit Extract from Syzygium cumini (L.) Skeels

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Mutagenic Activity of Glycoallkaloids from Solanum palinacanthum Dunal (Solanaceae) in the Brazilian cerrado

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Anti-Mycobacterium tuberculosis activity of fungus Phomopsis stipata

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Assessment of estrogenic, mutagenic and antimutagenic activity of nemorosone

Currently, a wide range of research involving natural products is focused on the discovery of new drugs in many different therapeutic areas. A great number of the synthetic compounds on the market were derived from natural products, especially plants. Nemorosone is the major constituent of the floral resin of Clusia rosea Jacq., Clusiaceae, and in Cuban propolis. In vitro studies have shown cytotoxic activity in this substance against various tumor cell lines, including those resistant to various cytotoxic drugs, whereas it has low cytotoxicity to non-tumoral cells. Therefore, in order to characterize the biological activity of nemorosone, a substance with potential antitumor activity, and in view of preclinical testing of the toxicity of drug candidate compounds, the main aim of this study was to determine the mutagenic and antimutagenic activity of nemorosone by the Ames test, using the strains TA97a, TA98, TA100 and TA102 of Salmonella typhimurium. Secondly, to characterize the estrogenic activity in an experimental recombinant yeast model (Recombinant Yeast Assay) mutagenic activity was observed at in any of the concentrations in any of the test strains. To evaluate the antimutagenic potential, direct and indirect mutagenic agents were used: 4 nitro-o-phenylenediamine (NPD), mitomycin C (MMC) and aflatoxin B1 (AFL). Nemorosone showed moderate antimutagenic activity (inhibition level 31%), in strain TA100 in the presence of AFL, and strong antimutagenic activity in TA102 against MMC (inhibition level 53%). Estrogenic activity was observed, with an EEq of 0.41±0.16 nM at various tested concentrations.

Antimycobacterial activity of lichen substances

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Synthesis and in vitro anti Mycobacterium tuberculosis activity of a series of phthalimide derivatives

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Structure and antimycobacterial activity of the novel organometallic [Pd(C-bzan)(SCN)(dppp)] compound

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Mutagenic Activity of Indigofera truxillensis and I. suffruticosa Aerial Parts

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Melatonin and its kynurenin-like oxidation products affect the microbicidal activity of neutrophils

Activated phagocytes oxidize the hormone melatonin to N-1-acethyl-N-2-formyl-5-methoxykynuramine (AFMK) in a superoxide anion- and myeloperoxidase-dependent reaction. We examined the effect of melatonin, AFMK and its deformylated-product N-acetyl-5-methoxykynuramine (AMK) on the phagocytosis, the microbicidal activity and the production of hypochlorous acid by neutrophils. Neither neutrophil and bacteria viability nor phagocytosis were affected by melatonin, AFMK or AMK. However these compounds affected the killing of Staphylococcus aureus. After 60 min of incubation, the percentage of viable bacteria inside the neutrophil increased to 76% in the presence of 1 mM of melatonin, 34% in the presence of AFMK and 73% in the presence of AMK. The sole inhibition of HOCl formation, expected in the presence of myeloperoxidase substrates, was not sufficient to explain the inhibition of the killing activity. Melatonin caused an almost complete inhibition of HOCl formation at concentrations of up to 0.05 mM. Although less effective, AMK also inhibited the formation of HOCl However, AFMK had no effect on the production of HOCl These findings corroborate the present view that the killing activity of neutrophils is a complex phenomenon, which involves more than just the production of reactive oxygen species. Furthermore, the action of melatonin and its oxidation products include additional activities beyond their antioxidant property. The impairment of the neutrophils' microbicidal activity caused by melatonin and its oxidation products may have important clinical implications, especially in those cases in which melatonin is pharmacologically administered in patients with infections. (c) 2005 Elsevier SAS. All rights reserved.

Antioxidant activity of Agaricus blazei

The ethanolic extract of Agaricus blazei and ethyl acetate and hydroalcoholic fractions were evaluated for their antioxidant activity. (C) 2007 Elsevier B.V. All rights reserved.

Improvement of antischistosomal activity of praziquantel by incorporation into phosphatidylcholine-containing liposomes

Praziquantel (PZQ) is effective against all known species of Schistosomes that infect humans. The failure of mass treatment of schistosomiasis has been attributed to the fact that therapy is not sufficiently long-lasting. This effect may be due to the low bioavailability of PZQ that has a low hydrosolubility and fast metabolism. Liposomes have been used to prolong drug levels. reduce the side effects, direct drugs to specific sites and increase bioavailability after administration. The aim of this work was to study the effect of phosphatidylcholine (PC)-containing liposomes to vehiculate PZQ to improve the treatment of schistosomiasis. The in vitro Study was carried out using Schistosoma mansoni parasites recovered by perfusion from the hepatic portal system of infected mice. Suspensions of liposomes with PZQ and free PZQ were administered p.o. in mice after 14 days of infection. The effect of both preparations in vitro on S. mansoni culture was similar. In the in vivo test, PZQ-liposomes caused a decrease in amounts of eggs and parasites. Liposomes improve the antischistosomal activity of praziquantel. This can be used as a starting point to investigate alternative administration routes or dosage forms and to examine the mechanism of intestinal absorption of PRZ © 2005 Elsevier B.V. All rights reserved.