Influence of particle size on the in vitro and in vivo anti-inflammatory and anti-allergic activities of a curcumin lipid nanoemulsion

Abstract

The polyphenolic compound, curcumin, is a natural yellow pigment component of turmeric. It exerts various biological effects, such as anti-inflammatory effects, and we have previously demonstrated that curcumin is a specific inhibitor of DNA polymerase λ. Curcumin is characterized by poor bioavailability as it is water-insoluble, is poorly absorbed and is systemically eliminated. In order to increase the bioavailability of curcumin, in this study, we produced a curcumin-loaded lipid nanoemulsion of various particle sizes (50, 100 and 200 nm). The curcumin lipid nanoemulsion was prepared by a modified thin-film hydration method followed by sonication. To identify the optimal particle size which exhibits the strongest physiological activity, we investigated the inhibitory effects of the obtained nanoemulsions against inflammatory and allergic activities. In in vitro cell culture experiments, the 100-nm curcumin lipid nanoemulsion showed the most prominent inhibitory effect on the production of tumor necrosis factor-α (TNF-α) induced by lipopolysaccharide (LPS) in RAW264.7 murine macrophages, and on the release of β-hexosaminidase induced by the calcium ionophore, A23187, in rat basophilic leukemia RBL-2H3 cells. In an in vivo experiment, in which mice were administered the curcumin-loaded lipid nanoemulsion of various particle sizes, the 100-nm curcumin lipid nanoemulsion showed the most prominent anti-inflammatory and anti-allergic effects, inhibiting 12-O-tetradecanoylphorbol-13-acetate-induced inflammatory ear edema and immunoglobulin E (IgE)-induced passive cutaneous anaphylactic (PCA) reaction. The effects of particle size on serum curcumin absorption were also assessed in mice, and the 100-nm lipid nanoemulsion showed the greatest absorption. The results from our study suggest that the physiological activities of curcumin lipid nanoemulsions differ depending on particle size. Our data indicate that the curcumin lipid nanoemulsion with a particle size of 100 nm has potential for use in enhancing the bioavailability and medical value of curcumin.

Curcumin alleviates IL‐17A‐mediated p53‐PAI‐1 expression in bleomycin‐induced alveolar basal epithelial cells

“…Curcumin modulates the expression of DNA repair genes Downregulation of pro‐inflammatory cytokines such as IL‐6 and TNF‐α, resulting in suppression of cell proliferation is reported in curcumin treatment . Curcumin acts as a key regulator of IL‐17A and inhibits progression of lung injury . Curcumin also is known for its efficacy as an epigenetic modulator of genes involved in DNA methylation and histone modification by targeting miRNAs…”

Formulation of More Efficacious Curcumin Delivery Systems Using Colloid Science: Enhanced Solubility, Stability, and Bioavailability

“…The physical and chemical stability of curcumin-loaded oil droplets has been shown to depend on their mean diameter (0.17, 0.52, or 14 µm) [ 138 ]. As expected, the rate of droplet creaming increased with increasing droplet size because of the increase in gravitational forces.…”

Self-nanoemulsifying system improves oral absorption and enhances anti-acute myeloid leukemia activity of berberine

“…Self-nanoemulsifying systems serve as a means to improve the bio-safety of lipophilic compounds and to improve their solubility, membrane transport, and absorption via the lymphatic system by bypassing first-pass metabolism [ 30 ]. A higher solubilization capacity, rapid onset of action, and reduced inter-subject differences are the advantages of self-nanoemulsifying system over with conventional systems [ 31 ]. In recent years, this system has emerged as a promising new technique to increase solubility, reduce side effects and enhance anti-tumor capacity [ 32 ].…”