Immunomodulatory activity of curcumin-entrapped poly d,l-lactic-co-glycolic acid nanoparticles in mice

Studies have shown that curcumin from Curcuma longa has a wide range of medicinal and immunomodulatory properties. These activities have, however, been hindered by its low bioavailability. Meanwhile, incorporation of nanoparticles has been shown to increase bioavailability of certain drugs. This study was, therefore, conducted to comparatively evaluate the immunomodulatory activity of free and nanoparticulate curcumin in mice.

Healthy albino mice were sensitized with sheep red blood cells (SRBCs) and thereafter free and nanoparticulate curcumin were administered orally at doses of 5 mg/kg/day and 10 mg/kg/day for 10 days to the mice. The assessment of the immunomodulatory activity was carried out by determining the humoral and cell-mediated immune responses using hemagglutination and delayed-type hypersensitivity assays, respectively. Hematological components and some lymphoid organs of treated mice were further evaluated.

The study showed that nanoparticulate curcumin stimulated higher early cell-mediated immune response at 5 mg/kg and 10 mg/kg when compared to control. While nanoparticulate curcumin significantly stimulated primary humoral immune response with 9.00 ± 1.00 antibody titre (p < 0.05), the free curcumin suppressed the immunity with 3.33 ± 0.67 antibody titre when compared to control. Similar result was observed with secondary humoral antibody titres. Production of white blood cells and weight of the lymphoid organs were also enhanced in the groups that received 10 mg/kg nanocurcumin.

This work showed that poly d,l-lactic-co-glycolic acid entrapped curcumin nanoparticle could increase bioavailability of curcumin for improved immunity.