A prophylactic study of curcumin nanoparticle-induced bacterial ghosts against Helicobacter pylori in a C57BL/6 mouse model.

Gastro-duodenal diseases are becoming a chronic health burden worldwide. Helicobacter pylori plays a key role in developing gastro-duodenal disorders including dyspepsia, peptic ulcers, gastritis and MALT lymphoma. It is the major cause of stomach cancer due to infectious agents (IARC, 2020). Inefficiency of proper diagnostic approaches and reduced efficacy of existing treatments are leading to an increase in antimicrobial resistance (AMR) sharply. The development of a vaccine calls for the isolation of a potent immunogen sufficient to induce a robust immune response by activating both humoral and cellular arms of immunity. Bacterial ghost is a membrane-bound empty capsule embedded with various antigens and is an emerging next generation vaccine candidate. Curcumin, the major bioactive component of the herb turmeric, is known to have an anti-Helicobacter pylori effect, indicating its therapeutic potential as an alternative treatment. Formulation of curcumin nanoparticles alters its biophysical properties without affecting its chemical integrity, allowing the preparation of a suspension with a heterogeneous particle population. In vitro, curcumin nanoparticle-induced bacterial ghost cells (CurBGs) showed considerably reduced cytotoxicity. Serum IgG as well as its subtypes IgG1 and IgG2c were significantly evoked by three consecutive oral immunizations. Furthermore, a strong immunogen-specific response was produced in immunized animals, which may provide cross-protection regardless of the circulating H. pylori strains' cag (cytotoxin-associated gene) status. Therefore, curcumin nanoparticles treated bacterial ghosts can be an excellent novel ghost-based vaccine candidate, potentially reducing the H. pylori-mediated clinical health burden worldwide in the near future.