Proanthocyanidins (PACs) are widely found in higher plants including teas, grapes, and cranberries. PACs have been associated with potential positive health benefits including antibacterial and cardio-protective properties. Only recently has the potent lipopolysaccharide (LPS)-binding activity of PACs been discovered, by scientists at the Naval Research Laboratory (NRL). The envisioned applications include LPS removal from contaminated solutions (e.g., pharmaceutical preparations) and in vivo removal and/or neutralization of LPS in septic patients.
The NRL team has identified PACs from multiple plant sources as a new class of LPS-binding substance. They have demonstrated that these PACs bind LPS with an affinity comparable to other well-known LPS-binding compounds such as polymyxin B (PMB). Further, PACs appear to preferentially recognize the conserved lipid A part of LPS, hence allowing the PACs to bind LPS from multiple gram-negative bacterial species.
- Specific – high removal rate of LPS with concomitant high recovery of proteins, even in complex samples
- User friendly – PACs are efficacious through a broad range of pHs: 5 through 9; and ionic strengths: 0.15 through 0.85; can be immobilized onto solid supports to run in either batch or column mode; ideal for both in vitro LPS purification and in vivo neutralization
- Readily available – no synthesis required; PACs are found in a variety of plant materials; purification method involves standard chemical procedures with relatively benign solvents
- Safe - PACs IC50 for toxicity is 700 nM; potential therapeutic candidate
- Regenerable – treatment with 1% sodium deoxycholate
- Inventors may be available for consultation and collaboration
- Two US Patents: 8,715,949; 9,040,250