Water extract of gromwell (Lithospermum erythrorhizon) enhances migration of human keratinocytes and dermal fibroblasts with increased lipid synthesis in an in vitro wound scratch model.

ABSTRACT

BACKGROUND: Although organic extracts of gromwell (Lithospermum erythrorhizon) have been shown to promote wound healing, the wound healing effects of water extracts of gromwell (WG) that are commonly used in traditional remedies have not been elucidated. OBJECTIVE: We investigated whether WG promotes the migration and/or proliferation of cultured human keratinocytes (CHK) or dermal fibroblasts in parallel with increases in lipid synthesis during in vitro wound healing. METHODS: CHK or fibroblasts were treated with 1-1,000 µg/ml WG for up to 48 h following scratch wound formation. Cell migration was assessed by measuring coverage (in percent) from the wound margin, while cell proliferation and lipid synthesis were determined by [(3)H]thymidine incorporation into DNA fractions, and [(3)H]palmitate or [(3)H]serine incorporation into lipid fractions, respectively. RESULTS: Low-dose WG (1 µg/ml) enhanced the wound coverage for both CHK and fibroblasts at 24 h, while cell proliferation was not altered in either cell types. Synthesis of both total lipids and individual lipid classes, including phospholipids, sphingolipids and neutral lipids, were found to be increased at 24 h in CHK treated with 1 µg/ml WG; in similarly treated fibroblasts, only the syntheses of sphingolipids (such as ceramides and glucosylceramides), but not other lipid species, were significantly increased. In contrast, a higher dose of WG (10-1,000 µg/ml) did not enhance wound coverage, and 100 µg/ml WG neither altered cell proliferation nor lipid synthesis in both CHK and fibroblasts. CONCLUSION: Low-dose WG (1 µg/ml) enhances the migration of both CHK and fibroblasts with increased lipid synthesis in an in vitro wound scratch model.