Márcia Aparecida Antônio

A novel sunscreen agent having antimelanoma activity.

A novel series of eight dibenzoylmethane derivatives having both sunscreen and cytotoxic activity has been obtained by derivatizing commercial dibenzoyl methanes. Four human cancer cell lines (MCF 7 (breast), NCI ADR (breast expressing the multidrug resistance phenotype), NCI 460 (lung) and UACC 62 (melanoma)) were used for the cytotoxic assay. Eight among the 19 dibenzoylmethane derivatives showed cytotoxicity against these four cell lines. Absorption spectroscopies revealed that these compounds can be used as sunscreens against UV radiation.

Efeito de um hidrolisado de proteínas de soro de leite e de seus peptídeos na proteção de lesões ulcerativas da mucosa gástrica de ratos

OBJECTIVE: To assess the ability of bovine whey protein hydrolysate and its low molecular weight fraction (molecular weight <1kDa) to protect the gastric mucosa of rats against ulcerative process induced by three different agents. METHODS: Adult Wistar rats were subjected to the indomethacin-induced ulcer (30mg/kg body weigh), absolute ethanol (1ml/animal) and immobilization and cold stress (40C/2h), models. RESULTS: Whey protein hydrolysate was obtained by treatment with pancreatin to a degree of hydrolysis of 20% and fractionated using a tangential flow membrane with a molecular weight cut-off of 1kDa to obtain the fraction containing low molecular weight peptides (<1kDa). In the ethanol-induced acute ulcer model (single dose), whey protein hydrolysate inhibited the gastric lesion index by 65.5% and the double dose resulted in a 77.4% inhibition. CONCLUSION: For the anti-inflammatory model, the cytoprotective effect of low molecular weight peptides was stronger than that of total hydrolysate (53.1 and 71.6%, ulcerative lesion index) for single and double dose, respectively. No mucosa cytoprotective activity was found for whey protein concentrate, whey protein hydrolysate or WPHP in the immobilization and cold stress model.

Photoinactivation of different human tumor cell lines and sheep red blood cells in vitro by liposome-bound Zn(II) Phthalocyanine: Effects of cholesterol.

The in vitro photoinactivation of human tumor cell lines and sheep red blood cells (SRBC) by Zinc (II) Phthalocyanine (ZnPc) was investigated using unilamellar liposome (LUV) as delivery system, in the presence and absence of cholesterol (CHOL) in the formulation. The presence of CHOL improves the stability of the system showing to be essential for the photodynamic action of ZnPc. LUVs prepared without CHOL did not present any antiproliferative effects neither induced significant photohaemolysis. The presence of ZnPc in the culture medium caused total cell growth inhibition (TGI) only at concentrations higher than 250 micromol dm(-3). For ZnPc in LUV/CHOL (mass ratio=3:1), the mean TGI values for almost all studied cells were around 80 micromol dm(-3), and 14 micromol dm(-3) for human ovarian carcinoma (NIH: OVCAR-3) cells. The cytoplasmic components of OVCAR-3 and SRBC when irradiated in presence of ZnPc in LUV/CHOL were completely destroyed, culminating in cell swelling, lysis and death by necrosis.

Antiproliferative activity, isolation and identification of active compound from Gaylussacia brasiliensis

Gaylussacia brasiliensis (Spreng.) Meissn., Ericaceae, is used in folk medicine for treatment of several inflammatory processes and as healing agent. The scope of this work was to evaluate the in vitro antiproliferative activity of crude dichloromethane extract (CHD) and to identify the compound(s) responsible for this activity. CHD was evaluated and showed a concentration dependent inhibition on all cells lines. Therefore CHD was submitted to several classical columns chromatography providing the most active fraction (FC), inhibiting all cells line at 25 µg/mL. FC was further fractionated affording isolated compound 2β, 3β-dihydroxy-urs-12-ene-28-oic acid , identified on basis of 2D-NMR experiments and showed concentration-dependent activity and selectivity for kidney and breast cell lines.