Rosmarinic and chlorogenic acid, isolated from ferns, suppress stem cell damage induced by hydrogen peroxide.

OBJECTIVES: Evaluating the effects of rosmarinic (RA) and cryptochlorogenic (CGA) acids isolated from Blechnum binervatum extract on stem cell viability, toxicity and the protective effect on oxidative cell damage. METHODS: MTT and LDH methods were employed, using stem cells from teeth. RA and CGA were evaluated at 100, 250 and 500 µM. The negative effect of hydrogen peroxide (H2O2) (200-2200 µM) and the capacity of RA and CGA (10-100 µM) as protective agents were also evaluated. DAPI followed by fluorescent microscopy was employed to photograph the treated and untreated cells. KEY FINDINGS: At all tested concentrations, RA and CGA demonstrated the ability to maintain cell viability, and with no cytotoxic effects on the treated stem cells. RA also induced an increase of the cell viability and a reduction in cytotoxicity. H2O2 (1400 µM) induced >50% of cytotoxicity, and both compounds were capable of suppressing H2O2 damage, even at the lowest concentration. At 100 µM, in H2O2 presence, total cell viability was observed through microscope imaging. CONCLUSIONS: These findings contribute to the continued research into natural substances with the potential for protecting cells against oxidative injury, with the consideration that RA and CGA are useful in the regeneration of damaged stem cells.

KDP:Mn piezoelectric coefficients obtained by X-ray diffraction.

Crystals of pure potassium dihydrogen phosphate KH(2)PO(4) (KDP) and Mn-doped KDP (KDP:Mn) were grown from a water solution by the slow evaporation method and their piezoelectric properties were studied by X-ray diffraction methods. The results have shown an increase in the piezoelectric coefficients with the doping.

[Acute psychotic disorder associated with vigabatrin]. / Perturbação psicótica aguda associada à vigabatrina.

Vigabatrin, a drug mainly used in the treatment of therapy-resistant epilepsy, has been associated to a large range of adverse effects, including acute psychotic disorders. The authors report the case of a 44-year-old patient with drug-resistant temporal lobe epilepsy that developed an acute psychotic episode about three weeks after initiating medication with vigabatrin. After the withdrawal of vigabatrin and the addition of an antipsychotic drug, the clinical picture improved promptly and the patient was discharged within a short period of time. The authors discuss the patient's diagnosis, the possible mechanisms of vigabatrin-associated psychosis and the therapeutic approach, stressing the questions that concern vigabatrin prescription and withdrawal.