Ameliorative effect of nanocurcumin on Staphylococcus aureus-induced mouse mastitis by oxidative stress suppression

Mammary pathogenic Staphylococcus aureus is related to a mastitis and its treatment is still based on the use of antibiotics. In the era of antimicrobial resistance, natural plant based product (curcumin) as an efficient treatment or prophylactic option. Since curcumin is rapidly eliminated from the body, its oral bioavailability is low. However, nanoformulation of curcumin significantly enhances its therapeutic efficiency by improving its oral bioavailability. The present study synthesized a novel, anti-mastitis agent, the nanocurcumin and analyzed its activity against bovine S. aureus mastitis in mouse model. Curcumin-loaded PLGA nanoparticles (CUR-NP) were prepared by solid-in-oil-in-water emulsion method. The mouse model of mastitis was induced by inoculation of a field strain of S. aureus on the 9th day of parturition through the duct of the mammary gland. CUR-NP and curcumin were given orally for 7 days (day 2 to day 8 of parturition) prior to S. aureus inoculation. In infected mice, CUR-NP elicited a time dependent decrease in mammary gland pathology that included inflammatory cell infiltration, cellular exudates in the alveolar lumen and mammary cell necrosis. Furthermore, CUR-NP inhibits inflammatory response in mammary tissues from S. aureus-infected mice by inhibiting super oxide anion radical and increased antioxidants activities. Together, nanocurcumin administration in Staphylococcus aureus mastitis reduced markers of oxidative stress, reversed antioxidant depletion and restored the histology structure of mammary gland.