Wound healing and angiogenic properties of supernatants from Lactobacillus cultures

Extracts or supernatants from cultures of Lactobacilli are used for their medicinal effects, including wound healing and immune system stimulating activity. We have studied the in vivo and in vitro effects of supernatants from bacterial cultures of two strains of Lactobacillus (LS) on tissue repair and angiogenesis. Subcutaneous injection of LS into rodent ears led to proliferation of blood vessels that also exhibited strong immunostaining for Flk-1 receptor. Some inflammatory cells were scattered among the blood vessels. The continuous influx of polymorphonuclear leukocytes (PMNs) and macrophages into transcutaneous wounds in mice treated with LS resulted in prolonged inflammatory phase of wound healing and delayed wound closure, including reepithelialization. Subcutaneous injection of Matrigel impregnated with LS into the abdominal wall led to rapid and transient influx of PMNs in the vicinity of the gel. LS stimulated the proliferation of murine macrophage J774.A1 cell line and porcine lymphocytes but not that of murine fibroblast AKR-2B cells. LS also induced production of TNF-alpha by J774.A1 cells and by porcine kidney epithelial LLC-PK1 cells. LS did not appear to have an effect on collagen production. In conclusion, our study demonstrates the potential of LS to function as a stimulator of the inflammatory stage of tissue repair, TNF-alpha production, and of angiogenesis.