RESUMO
The purpose of this study was to investigate the therapeutic effects and underlying mechanism of alpha-linolenic acid based intra-mammary nano-suspension (ALA-NS) on both in vitro antimicrobial and in vivo activity. The ALA-NS formulated and optimized for parameters like particle size, zeta potential, polydispersity index, sedimentation volume, and stability studies. In vitro, our results showed that ALA-NS (F1 and F2) have the higher zone of inhibition and lower minimum inhibitory concentration (MIC) value than ALA and cefotaxime alone against mastitis-causing pathogens. In vivo, our results showed that ALA-NS (F1 and F2) restored the altered oxidative biomarkers (superoxide dismutase, catalase, glutathione, TBARs, and protein carbonyl) along with histopathological changes in lipopolysaccharides (LPS) treated rats. Western blot results indicated that ALA-NS (F1 and F2) inhibited LPS induced inflammatory proteins (NFκBp65, COX, LOX, and IFN-γ) in rat mammary epithelial cells. ALA-NS (F1 and F2) also suppressed the hypoxia inducible factor-1α (HIF-1α) and upregulated prolyl-hydroxylase (PHD-2), sterol regulatory element binding protein (SREBP-1c), and fatty acid synthase (FASN) protein expression. In addition, ALA-NS upregulated the pro-apoptotic (BAX and BAD) and downregulated anti-apoptotic (BCL-2 and BCL-XL) proteins expression in rat mammary epithelial tissue. In conclusion, we found that ALA-NS (F1 and F2) have in vitro antimicrobial activity and protective effects on LPS-induced mastitis in rats.