Lumbricus rubellus Protein Fraction DLBS1033N Increases Nerve Growth Factor Expression via Tyrosine Kinase Activation

Nerve injury occurred due to mechanical, thermal, chemical, or ischemic factors. Nerve regeneration is needed for recovery. Schwann cell proliferation and differentiation are important factors in the nerve regeneration process. Schwann cells release neurotrophins in the nerve regeneration process. In this study, Lumbricus rubellus protein fraction DLBS1033N was used as therapeutic protein candidate for nerve regeneration treatments. DLBS1033N treatments promoted the growth and survival of Schwann cell in free serum and free serum plus minimum O₂ conditions. Real-time PCR and ELISA methods revealed that DLBS1033N induced NGF expressions. The growth and survival of Schwann cells were related to NGF expressions in a specific inhibitor TrkA study. Furthermore, in real-time PCR study, DLBS1033N was able to activate phosphatidylinositol-3-kinase (PI3K) pathway. This study showed that L. rubellus protein fraction DLS1033N can promote the growth and survival of Schwann cells by inducing NGF expressions. Cells growth and survival activities are likely achieved via PI3K pathway.