Rice hull smoke extract protects mice against a Salmonella lipopolysaccharide-induced endotoxemia

Endotoxemia (sepsis, septic shock) is an inflammatory, virulent disease that results mainly from infection by Gram-negative bacteria. The present study investigates the inhibitory effects of a rice hull smoke extract (RHSE) against murine endotoxemia induced by Salmonella lipopolysaccharide and d-galactosamine (LPS/GalN). Pretreatment of the mice with RHSE via dietary administration for 2 weeks resulted in the suppression (in %) of LPS/GalN-induced catalase by 70.7, superoxide dismutase (SOD) by 54.6, and transaminase (GOT/GPT) liver enzymes by 40.6/62.5, the amelioration of necrotic liver lesions, and the reduction of tumor necrosis factor-α (TNF-α) by 61.1 and nitrite serum level by 83.4, as well as myeloperoxidase (MPO) enzyme associated with necrotic injury of the lung and kidney by 65.7 and 63.3, respectively. The RHSE also extended the lifespan of the toxemic mice. The results using inflammation biomarkers and from the lifespan studies suggest that the RHSE can protect mice against LPS/GalN-induced liver, lung, and kidney injuries and inflammation by blocking oxidative stress and TNF-α production, thereby increasing the survival of the toxic-shock-induced mice. These beneficial effects and previous studies on the antimicrobial effects against Salmonella Typhimurium in culture and in mice suggest that the smoke extract also has the potential to serve as a new multifunctional resource in human food and animal feeds. Possible mechanisms of the beneficial effects at the cellular and molecular levels and suggested food uses are discussed.