Dhrubjyoti Sharma

Chronic ethanol exposure activates inflammatory signaling pathways and inflicts hepatocellular damage, leading to alcohol‐associated liver diseases (ALDs). ALD is one of the major causes of global burden, yet there are no FDA‐approved treatment options available. This study evaluates the hepatoprotective effects of short‐chain fatty acids (SCFAs), mainly sodium acetate (NaA) and sodium butyrate (NaB), against ethanol‐induced inflammation and oxidative stress in both in vitro (Buffalo Rat Liver‐3A [BRL3A]) and in vivo (male Wistar rats) models. The treatment of NaA and NaB and their combination was given to the cell lines where maximum viability was observed at concentrations of 1.5 mM, 5 mM, and 0.1 mM + 1 mM, respectively. Additionally, reactive oxygen species (ROS) and nuclear morphology were assessed by fluorescent staining. For in vivo samples, the hepatic injury was analyzed by serum biochemical markers. Furthermore, hematoxylin and eosin (H&E) staining and immunohistochemistry (IHC) staining were employed, which provided structural and immunological alterations in hepatic tissue. RT‐qPCR profiled the expression levels of various pro‐inflammatory and anti‐inflammatory cytokines, as well as cytochrome P450 E1 (CYP2E1) and antioxidative stress markers. Moreover, enzyme‐linked immunosorbent assay (ELISA) quantified the essential protein targets such as TNF‐α, MCP‐1, IL‐1β, IL‐6, HO‐1, and Nrf2. The administration of NaA, NaB, and their combination resulted in reduced ROS levels and expression of pro‐inflammatory cytokines, preserved nuclear integrity, and neutrophil infiltration. These findings were further confirmed by in silico analysis and conserved amino acid interactions, and the affinities of NaA and NaB for TNF‐α and MCP‐1 were observed as compared to established inhibitors or activators. This study is the first demonstration to report the synergistic effects of NaA and NaB on the feedback loop of the nuclear factor kappa B (NF‐κB) signaling pathway, suggesting their potential as promising therapeutic candidates for alleviating alcohol‐induced hepatic damage.

The human gut consists of > 1000 different bacterial species for the smooth functioning of the gut. In normal conditions, the antioxidant system present in cells minimize the effects of reactive oxygen species. Upon exposure to antibiotics, there is a rise in ROS level which induces oxidative stress to the cells, ultimately killing the cells. Two broad-spectrum antibiotics, streptomycin and gentamicin at a concentration of 50 µM and 25 µM, were treated with Bacillus subtilis SRMIST201901 (MN726522) and B. cereus SRMIST201902 (MN726923); the treatment reduced the cell counts. Considering the bacterial defense property which relies on the antioxidant mechanism, in this study, we have reported an antioxidant peptide (GM15) derived from glutathione oxidoreductase of spirulina (or called cyanobacteria) Arthrospira platensis (Ap) which reduced the intracellular oxidative stress. Cellular ROS detection was confirmed by fluorescent-associated cell sorting (FACS) using the DCFDA dye. Resazurin dye test also confirmed the activity of peptide on the growth of the Bacillus sp. Based on the results obtained, it was concluded that there was a significant (P < 0.05) reduction in the intracellular oxidative stress on treating with GM15 peptide. Overall, the study indicates the influence of antioxidant peptide on the intracellular oxidative stress, leading to the development of an antioxidant drug from glutathione oxidoreductase of A. platensis against oxidative-related stresses.