Effects of hydrogen peroxide on wound healing in mice in relation to oxidative damage.

It has been established that low concentrations of hydrogen peroxide (H(2)O(2)) are produced in wounds and is required for optimal healing. Yet at the same time, there is evidence that excessive oxidative damage is correlated with poor-healing wounds. In this paper, we seek to determine whether topical application of H(2)O(2) can modulate wound healing and if its effects are related to oxidative damage.

Effects of hydrogen peroxide in a keratinocyte-fibroblast co-culture model of wound healing.

Recently, there has been renewed interest in the role of reactive oxygen species (ROS), especially H(2)O(2), in wound healing. We previously showed that H(2)O(2) stimulates healing in a keratinocyte scratch wound model. In this paper, we used a more complex and physiologically relevant model that involves co-culturing primary keratinocytes and fibroblasts.

Mechanism of hydrogen peroxide-induced keratinocyte migration in a scratch-wound model.

Recent studies have shown that low concentrations of H(2)O(2) are produced endogenously by nonphagocytes after wounding. We observed that H(2)O(2) at such concentrations can stimulate proliferation as well as migration of keratinocytes in a scratch-wound assay. Both wounding and H(2)O(2) can induce phosphorylation of ERK1/2 via EGFR, but the activation of ERK1/2 by H(2)O(2) is more sustained and can last more than 8h.

Assay-guided fractionation study of alpha-amylase inhibitors from Garcinia mangostana pericarp.

Alpha-amylase inhibitor (alpha-AI) activity of Garcinia mangostana, commonly known as mangosteen, pericarp extracts was studied by assay guided fractionations from lipophilic to hydrophilic using combined solvent extraction and Amberlite XAD2 adsorption chromatography. Neither the lipophilic, xanthone containing fraction, nor the highly polar fraction, which has no affinity on Amberlite XAD2, showed any alpha-AI. The fraction that shows very high inhibitory activity contains primarily polyphenols and can be adsorbed on Amberlite XAD2.

Oligomeric proanthocyanidins from mangosteen pericarps.

Oligomeric proanthocyanidins were extracted from mangosteen pericarps and fractionated by a Sephadex LH-20 column to give 0.66% yield (dry matter). (13)C and (1)H NMR signals showed the presence of predominantly procyanidins together with a few prodelphinidin units along with small amounts of stereoisomers of afzelechin/epiafzelechin, catechin/epicatechin, and gallocatechin/epigallocatechin.