Abrine mitigates the effects of lipopolysaccharide on β-casein synthesis in buffalo mammary epithelial cells by modulating the P53/mTOR pathway

【Objective】The objective of this study was to investigate the mitigating effect of abrine on induced inhibition by lipopolysaccharide（LPS）of casein synthesis in buffalo mammary epithelial cells by modulating the P53/mTOR pathway，to provide a theoretical basis for mitigating the decline in milk quality in buffaloes caused by mastitis.【Method】 The LPS-induced inflammation model was established in buffalo mammary epithelial cells，co-incubated with abrine，P53 inhibitor（Pifithrin-μ），P53 activator（Kevetrin hydrochloride）and buffab mammary epithelial cells for 12 h；morphological observations of mammary tissues were conducted using HE staining；cell viability was assessed using the CCK-8 method，while the secretion levels of β-casein were determined using ELISA kits；real-time quantitative PCR was employed to measure the gene relative expression levels of NF-κB，IL-1β，TNFα，β-casein，mTOR，P53，JAK2，STAT5， and AKT1；additionally，Western blotting was used to assess the protein relative expression levels of NF-κB，β-casein， mTOR，and P53.【Result】Clinical mastitis（CMS）mammary tissues showed infiltration of neutrophils in the interstitium and alveolar cavities，accompanied by atrophy at certain degree in some alveolar structures. The buffalo mammary epithelial cell viability of the 1.0 μg/mL LPS treatment group was significant decreased（P<0.05，the same below），buffab mammary epithelial cell viability of 2.0，4.0，and 8.0 μg/mL LPS treatments extremely significantly（P<0.001）. Abrine at 25， 50，100，and 200 μmol/L alleviated the impact of LPS，resulting in obvious increase in cell viability. Compared to the blank control group，LPS treatment group significantly elevated relative expression NF-κB，IL-1β，TNFα and P53 genes and proteins in buffalo mammary epithlial cells，while extremely significantly reduced β-casein expression. Abrine cotreatment with LPS group resulted in significant increase in β-casein levels in buffalo mammary epithlial cells and significant decrease in NF-κB，IL-1β，TNFα and P53 genes and proteins relative expression compared to the LPS group. The LPS+Pifithrin-μ group showed significant increase in β-casein expression in buffalo mammary epithlial cells compared to the LPS group. Conversely，abrine+Kevetrin hydrochloride group exhibited significant decrease in β-casein expression in buffalo mammary epithlial cells compared to abrine group.【Conclusion】LPS decreases β-casein synthesis and expression levels of genes and their encoded proteins involved in β-casein synthesis；abrine alleviates LPS-induced mammary epithelial cells of buffalo by inhibiting NF-κB pathway，and alleviates LPS-induced reduction of β-casein synthesis in buffalo mammary epithelial cells by modulating P53/mTOR pathway.