In vitro studies on the antioxidant and growth stimulatory activities of a polyphenolic extract from Cudrania cochinchinensis used in the treatment of wounds in Vietnam.

The leaves of Cudrania cochinchinensis, a Vietnamese folk remedy, have been suggested as a beneficial agent for wound healing. Animal studies and clinical observations in Vietnam have shown positive wound healing activity. We studied the effects of a polyphenolic extract from the plant on the proliferation of cells in culture and their response to oxidative damage by hydrogen peroxide. Fibroblasts were incubated with different concentrations of the extract in 0.4% fetal calf serum, and proliferation was monitored by a colorimetric assay. Cell damage was induced by exposure to hydrogen peroxide 7 x 10(-5) mol/L for 3 hours. The same colorimetric assay was used to assess cell damage and the protective effect of the extract against oxidative damage. The extract at low concentrations (0.1 to 5 microg/ml) had a stimulatory effect on fibroblast growth. The effect was significant by 7 days after the addition of the extract and was strongest at a concentration of 1 microg/ml of extract (p< or = 0.01). The extract at concentrations of 5 or 50 microg/ml protected fibroblasts and endothelial cells against hydrogen peroxide-induced damage. Pretreatment with the extract or exposure to extract simultaneously with hydrogen peroxide gave only partial protection against oxidative damage, whereas a combination of the two treatments gave complete protection (p< or = 0.005). Stimulation of fibroblast proliferation and protection of cells against destruction by inflammatory mediators may be ways in which the polyphenolic substances from the plant, Cudrania cochinchinensis, contribute to wound healing.