The mode of antimicrobial action of curcumin depends on the delivery system: monolithic nanoparticles vs. supramolecular inclusion complex

Abstract

Curcumin has been known for a long time for its antimicrobial properties that are further increased by exposure to light. Due to the low aqueous solubility of curcumin, appropriate delivery systems are required to facilitate its implementation. In this work, we compared the antimicrobial activity toward Escherichia coli of two curcumin formulations: methyl-b-cyclodextrin supramolecular inclusion complex and polyelectrolyte-coated monolithic nanoparticles. The two formulations showed disparity both in the extent and in the mode of toxicity, highlighting the distinct properties of materials at the nanoscale. The tests showed that while curcumin-b-cyclodextrin complexes exhibited a potent bactericidal activity, the curcumin nanoparticles were bacteriostatic. Illumination with blue light significantly increased the bactericidal efficacy of curcumincyclodextrin complexes but had limited influence on the activity of nanoparticulate curcumin. While the antimicrobial effect of the supramolecular complex was predominantly characterized by the increase in ROS and inhibition of electron transport, the primary attributes of the nanoparticle action were membrane depolarization and reduced ATP concentrations. Interestingly, the treatment with curcumin nanoparticles induced a filamentous phenotype of the bacterium. Our results suggest that the antimicrobial properties of curcumin depend upon a delivery formulation, which may have both practical and regulatory implications on the applicability and safety of curcumin nanomaterials.

Obstacles against the Marketing of Curcumin as a Drug

“…There is evidence suggesting that mode of antimicrobial activity of curcumin depends on the properties of the delivery system [17]. For instance, in an attempt to compare the antimicrobial activity toward Escherichia coli of two curcumin formulations: methyl-β-cyclodextrin supramolecular inclusion complex and polyelectrolyte-coated monolithic nanoparticles, researchers showed that while curcumin-β-cyclodextrin complexes exhibited a potent bactericidal activity, the curcumin nanoparticles were bacteriostatic [17]. In Table 1, there is an overview of the multipotent antimicrobial character of curcumin that would be useful for investigators to additional studies on curcumin's antimicrobial role against new microorganisms.…”

“…Studies indicating antimicrobial effects of curcumin in the last decade focused on the pharmacokinetics of curcumin rather than pharmacodynamics, reflecting the concerns of researchers in this area. There is evidence suggesting that mode of antimicrobial activity of curcumin depends on the properties of the delivery system [ 17 ]. For instance, in an attempt to compare the antimicrobial activity toward Escherichia coli of two curcumin formulations: methyl-β-cyclodextrin supramolecular inclusion complex and polyelectrolyte-coated monolithic nanoparticles, researchers showed that while curcumin–β-cyclodextrin complexes exhibited a potent bactericidal activity, the curcumin nanoparticles were bacteriostatic [ 17 ].…”

Enhancing curcumin's solubility and antibiofilm activityviasilica surface modification

“…33,34 The delivery of curcumin in the form of nanocomposite, 35 nanoparticles, 34,36 inclusion complexes 37 and encapsulated in polymeric nanoparticles 38 has also been explored. Shlar et al 39 recently showed how the method for curcumin delivery affects the antibacterial mode of action of the compound. Curcumin has also been reported to downregulate quorum sensing (QS) genes related to the production of biolm virulence factors in P. aeruginosa, 40 reduce oxidative stress response, 41 and has been suggested as a modulin and curli protein (biolm matrix proteins) inhibitor in in silico studies performed with E. coli.…”

Nano-Based Drug Delivery or Targeting to Eradicate Bacteria for Infection Mitigation: A Review of Recent Advances

“…Curcumin as a natural compound is well-known for its antibacterial activity (Praditya et al, 2019). Shlar et al (2017) developed polyquaternium-10-based nanoparticles for curcumin to display anti-E. coli activity. Polyquaternium-10 is a cellulose ether with cationic nature.…”