Location: Produce Safety and Microbiology ResearchTitle: Rice hull smoke extract protects mice against a salmonella lipopolysaccharide-induced endotoxemia Author
Submitted to: Journal of Agricultural and Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/19/2014
Publication Date: 7/28/2014
Citation: Kim, S.P., Nam, S.H., Friedman, M. 2014. Rice hull smoke extract protects mice against a salmonella lipopolysaccharide-induced endotoxemia. Journal of Agricultural and Food Chemistry. DOI:10.1021/jf501533s. Interpretive Summary: Endotoxemia (sepsis, septic shock) is a systemic infection caused by release into the bloodstream of endogenous mediators of inflammation and the response of the immune system to infections bacteria, fungi, viruses, and parasites in the blood, liver, kidney, lungs, and skin. Lipopolysaccharide (LPS), an outer membrane component of Gram-negative bacteria such as Salmonella, is a major virulence factor for the pathogenesis of endotoxemias The often fatal disease to which pregnant women and immunocompromised individuals are especially susceptible, is accompanied by failure of multiple organs, including liver, lungs, and kidneys. In the United States, about 750,000 individuals are afflicted with sepsis annually, with a 28-50% mortality rate . In a collaborative study, we evaluated the ability of a newly developed rice hull smoke extract to protect mice against Salmonella-LPS/D-galactosamine (GalN)- induced endotoxemia. The observed protective effect seems to involve amelioration of pathological effects in the liver, lung, and kidney tissues. These observed beneficial in vivo properties and our earlier report on the antimicrobial effectiveness of the extract against Salmonella Typhimurium in culture and in mice suggest that the extract has the potential to serve as multifunctional food preservative that might have advantages over widely used wood-derived liquid smoke.
Technical Abstract: Rice hulls accounting for 20% of the rice crop are a byproduct of post-harvest rice processing. Endotoxemia (sepsis, septic shock) is an inflammatory, virulent often fatal disease that results mainly from infection with Salmonella and other Gram-negative bacteria. The present study investigated the inhibitory effects of Rice Hull Smoke Extract (RHSE) against murine endotoxemia induced by the Salmonella lipopolysaccharide and D-galactosamine (LPS/GalN). Pretreatment of mice with RHSE via dietary administration for two weeks resulted in the suppression of LPS/GalN-induced catalase, superoxide dismutase (SOD), transaminases (GOT/GPT) liver enzymes, amelioration of necrotic liver lesions, and reduction of tumor necrosis factor-a (TNF-a) and nitrite serum levels as well as myeloperoxidase (MPO) activity, all indicators of necrotic injury. RHSE also extended the lifespan of the toxemic mice. These beneficial results with inflammation biomarkers and lifespan studies suggest that RHSE can protect mice against LPS/GalN-induced liver, lung, and kidney injuries and inflammation by blocking oxidative stress and TNF-a production, thereby increasing the survival of the toxic shock-induced mice. RHSE has the potential to serve as a new agriculture-based functional resource material for application to human foods and animal feeds by blocking oxidative stress and the tumor necrosis factor (TNF-a) production, thus reducing the toxic shock-induced symptoms. These positive results with inflammation biomarkers and lifespan studies and previously reported in vitro and in vivo antimicrobial effects suggest that the rice-derived smoke extract can protect against LPS/GalN-induced liver, lung, and kidney injuries and inflammation and serve as a new food preservative.