Sweet Sorghum (Sorghum bicolor) Stalk Extract, a Byproduct of Biofuel Production, Ameliorates Systemic Oxidative Stress in a Murine Model of High‐Caloric Diet‐Induced Obesity

Abstract

Humans are exposed to reactive oxygen species (ROS) through internal metabolic processes and environmental toxicants. An imbalance between oxidants and anti‐oxidants occur due to either an impaired anti‐oxidant system, or due to increased ROS production leading to oxidative stress. Dietary and lifestyle factors have been attributed as key causal agents in the onset and progression of chronic oxidative stress. Accumulating scientific evidence has implicated stress in the etiology of various chronic disorders, such as cancer, aging, metabolic syndrome and many others. 8‐isoprostane is a prostaglandin like compound that is considered as a sensitive marker to quantitate oxidative stress, with elevated levels associated with an increased oxidative stress response. A diet rich in fruits and vegetables has been considered as an effective strategy to both strengthen the antioxidant system of the body, and scavenge excess ROS. Sweet Sorghum (SS) possesses a unique array of phenolic compounds, including 3‐deoxyflavonoids. SS stalk, an inexpensive by‐product of the biofuels industry, can be used to develop science‐based standardized extracts with potential anti‐oxidant properties. We investigated the potential of phenolic rich extract of the dermal layer of SS stalk in alleviating oxidative stress in an animal model of diet‐induced obesity. A/J mice were fed a low‐caloric diet (LCD), high‐caloric diet (HCD) with 40% kcal from dietary fat and HCD supplemented with 1% w/w SS (HCD + SS) for 10 weeks. Our results show that SS was well tolerated by the mice consuming the experimental diets, as indicated by normal body weight, vital organ weights, feed intake and water intake. SS administration blunted systemic oxidative stress by suppressing plasma 8‐isoprostane levels. SS was also able to suppress the high‐calorie diet‐induced elevation of TNF‐α levels in the HFC + SS group. These results support the effectiveness of SS stalk as a potential source of bioactive compounds with potent in vivo anti‐oxidant and potential anti‐inflammatory activity.Support or Funding InformationNational Research Initiative Grant 2009‐55200‐05197 and fellowship grant 2011‐67012‐22951 from the USDA National Institute for Food and Agriculture (2009–2012).