Growth factors are biologically-active mediators that bind to specific receptors on target cells and regulate genes involved in cell growth, wound healing and regeneration. In the case of wound healing, a proper wound dressing is needed to cover the wound area, protect the damaged tissue, and if possible to activate cell proliferation and stimulate the healing process. In this study we examined the efficacy of a glycolipoprotein tissue homogenate extract from Eisenia foetida (G-90) to activate signal transduction pathways, leading to wound healing. We measured the activation of EGF and FGF in healthy skin, in wounds with physiological healing and in wounds treated with G-90. The activation of EGF and FGF was measured during the first 24 h of wound healing under both physiological conditions and treatment with G-90. In both cases an increased concentration of EGF and FGF was observed 6 h after wounding. In comparison with healthy skin, the concentration of EGF increased 10-fold and FGF five-fold in wounds treated with G-90 (10 ng ml(-1)). Healing in physiological conditions resulted in a two-fold increase of EGF and 1.5-fold of FGF.

u-PA is secreted by the most malignant tumors. As a response to u-PA synthesis surrounding cells synthetize inhibitors of plasminogen activators for tissue protection. Plasminogen activators were found also in earthworm tissue. From the tissue homogenate of earthworm Eisenia foetida the glycolipoprotein mixture named G-90 was isolated. It contains two serine proteases (P I, P II) with fibrinolytic and anticoagulative activities. The fibrinolytic activity of G-90, P I and P II was tested in an in vitro euglobulinic test applied to fibrin clot from blood plasma of patients suffered from malignant tumors. G-90 and above-mentioned proteases applied in this study showed euglobulinic time proportionally with the concentrations of added substances. The influence of G-90 on the fibrinolysis rate does not depend only on its concentration, but depends too on histological type of tissue (organ) where the malignant tumors are located. Enzyme P I and P II do not show this activity.

Searching for bioactive molecules from natural source represents an attractive strategy. Natural bioactive molecules form the backbone of modern therapeutics. For that reason the glycolipoprotein extract (G-90) from tissue homogenate of earthworm Eisenia foetida represents a valuable source of bioactive molecules. The molecules in this preparation exhibit many biological characteristics, useful in different biological processes. This extract showed interaction with biological materials from evolutionary more developed species, such as serums, erythrocytes, normal and transformed cells in culture from different origin. The numerous biological activities in vitro and in vivo, such as mitogenicity, anticoagulation, fibrinolysis, bacteriostasis, antioxidation, were detected in G-90. In therapeutic concentrations G-90 was not toxic, allergenic, mutagen or carcinogen. G-90 protected cells in culture from oxidative damage, caused by hydrogen peroxide. It is capable to stimulate the cellular immune system. As fibrinolytic and anticoagulative agent it can participate in active maintenance of homeostasis. G-90 has the ability to stimulate the synthesis of growth factors and helps in tissue regeneration. It stimulates proliferation of fibroblasts and epithelial cells, as well as their differentiation. Accordingly, G-90 is a valuable mixture of bioactive molecules from natural source, which could be very useful in human and veterinary medicine.