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.

Memory impairment induced by brain iron overload is accompanied by reduced H3K9 acetylation and ameliorated by sodium butyrate.

Iron accumulation in the brain has been associated to the pathogenesis of neurodegenerative disorders. We have previously demonstrated that iron overload in the neonatal period results in severe and persistent memory deficits in adult rats. Alterations in histone acetylation have been associated with memory deficits in models of neurological disorders. Here we examine histone acetylation in the brain and the effects of the histone deacetylase inhibitor (HDACi) sodium butyrate (NaB) on memory in the neonatal iron overload model in rats. Rats received vehicle or 30.0-mg/kg Fe⁺² orally at postnatal days 12-14. When animals reached adulthood, they were given training in either novel object recognition or inhibitory avoidance. Histone acetylation in the dorsal hippocampus and the effects of NaB were examined in separate sets of rats. Iron overload led to a reduction in H3 lysine 9 acetylation in the hippocampus, without affecting the acetylation of other H3 and H4 lysine residues. A single systemic injection of NaB (1.2 g/kg) immediately after training ameliorated iron-induced memory impairments. The results suggest that a reduction in H3K9 acetylation might play a role in iron-induced memory impairment and support the view that HDACis can rescue memory dysfunction in models of brain disorders.

Control of development and valepotriate production by auxins in micropropagated Valeriana glechomifolia.

Valeriana glechomifolia is a plant species endemic to southern Brazil that accumulates valepotriates, which are terpene derivatives, in all of its organs. Valepotriates are the presumed sedative generic components of the pharmaceutically used species of Valeriana. The influence of various concentrations of the auxins indole-3-acetic acid, indole-3-butyric acid and alpha-naphthaleneacetic acid on the growth of micropropagated V. glechomifolia was investigated under conditions of transient and continuous exposure. Changes in the development of roots and shoots as well as the production of the valepotriates acevaltrate, valtrate and didrovaltrate (analyzed by high-performance liquid chromatography) were evaluated. The best performance in valepotriate production, growth and survival under ex vitro conditions following plant acclimatization was achieved in the continuous presence of 5.71 microM IAA. When cultured in medium containing IAA plants produced stable levels of valepotriates throughout the entire cultivation period.