Antibacterial, anti-invasive, and anti-inflammatory activity of bovine lactoferrin extracted from milk or colostrum versus whole colostrum

Lactoferrin (Lf), a multifunctional cationic glycoprotein extracted from milk or colostrum, is able to chelate two ferric ions per molecule, inhibit the formation of reactive oxygen species, interact with the anionic components of bacteria or host cells, and enter inside host cell nucleus, thereby exerting antibacterial, anti-invasive, and anti-inflammatory activities. By virtue of Lf presence, bovine colostrum is expected to perform analogous functions to pure Lf, along with additional activities attributable to other bioactive constituents. The present research aims to compare the antibacterial, anti-invasive, and antiinflammatory activities of bovine Lf purified from milk (mbLf) and colostrum (cbLf) in comparison to those exhibited by whole bovine colostrum (wbc). The results demonstrated a major efficacy of mbLf in inhibiting pathogenic bacteria and in exerting anti-invasive and anti-survival activities with respect to cbLf and wbc. Furthermore, mbLf lowered IL-6 levels to those of uninfected cells, while a less evident decrease was observed upon cbLf treatment. Conversely, wbc managed to slightly lower IL-6 levels compared to those synthesized by infected cells. These data demonstrate that, to obtain maximum effectiveness in such activities, Lf should be formulated/used without addition of other substances and should be sourced from bovine milk rather than colostrum.