Short communication: Evaluation of α-linolenic acid-based intramammary nanosuspension for treatment of subclinical mastitis.

The current study investigates the therapeutic efficacy of an α-linolenic acid (ALA, 18:3n-3)-based intramammary nanosuspension (ALA-NS) for treatment of subclinical mastitis. After confirmation of mastitis with the help of field-based testing, a total of 9 mixed-breed cows (23 udder quarter samples) were divided into 3 groups and treated with ALA-NS and cefoperazone intramammary suspension for 10 d. Subclinical mastitis on d 1 was confirmed through field-based tests such as pH, California Mastitis Test (CMT), Whiteside test (WST), and bromothymol blue test (BBT) scores. Treatment with ALA-NS (F1 and F2) exhibited significant effects on field-based parameters, along with curtailment of total microbial count [28 ± 3.16 (mean ± standard deviation) and 25 ± 4.24 cfu/50 µL] and somatic cell count (SCC; 3.9 and 2.8 log SCC cells/mL), respectively for ALA-NS F1 and F2, after 10-d treatment. The efficacy of ALA-NS was further affirmed using more stringent markers for inflammation (nuclear factor kappa-light-chain-enhancer of activated B cells, NFκB-p65), milk quality (sterol response element-binding protein-1c, SREBP-1c), and bacterial resistance (ubiquitin carboxyl-terminal hydrolase-1, UCHL-1) in milk samples. Treatment with ALA-NS (at 2 concentrations of ALA, F1 and F2) significantly decreased expression of NFκB-p65, SREBP-1c, and UCHL-1 after d 10 of treatment. Apparently, anti-inflammatory, antibacterial, peripheral analgesic properties of ALA could account for the therapeutic efficacy of the proposed regimen.