Benefits of oat β-glucan and sucrose feedings on infection and macrophage antiviral resistance following exercise stress

Abstract

Oat beta-glucan can counteract the exercise-induced increased risk for upper respiratory tract infection (URTI) in mice, which is at least partly mediated by its effects on lung macrophages. Substantial evidence in humans indicates that carbohydrate-containing sports drinks can offset the decreased immune function associated with stressful exercise. However, no studies in animals or humans have directly examined their effects on URTI using a controlled virus-challenge model. We examined the effects of sucrose feedings alone and in combination with oat beta-glucan on susceptibility to infection and on macrophage antiviral resistance in mice following stressful exercise. These effects were also examined in rested, nonimmunocompromised control mice. Mice were assigned to one of four groups: H(2)O (water), sucrose (S), oat beta-glucan (ObetaG), and sucrose + oat beta-glucan (S+ObetaG). ObetaG and S treatments consisted of a solution of 50% ObetaG and 6% sucrose, respectively, and were administered in drinking water for 10 consecutive days. Exercise consisted of a treadmill run to fatigue performed on three consecutive days. Mice were then intranasally inoculated with a standardized dose of herpes simplex virus 1 (HSV-1) and monitored for morbidity and mortality for 21 days. Additional mice were used to determine macrophage antiviral resistance. In the exercise experiment, S, ObetaG, and S+ObetaG all reduced morbidity (P < 0.05), while only S+ObetaG reduced mortality (P < 0.05). Macrophage antiviral resistance was also increased in S, ObetaG, and S+ObetaG treatments (P < 0.05). In resting controls, S and S+ObetaG reduced morbidity and mortality (P < 0.05) and showed a trend toward increased macrophage antiviral resistance. There was no significant additive effect of S and ObetaG in either control or exercised animals. These data extend our previous work on the benefits of oat beta-glucan to show that sucrose feedings have similar effects on susceptibility to respiratory infection and macrophage antiviral resistance in both resting controls and following exercise stress.

Pleuran (β-glucan from Pleurotus ostreatus) supplementation, cellular immune response and respiratory tract infections in athletes

“…Furthermore, there was no reduction of URTI incidence in athletes during 2-week period after intensive exercise. These data contrast with findings from studies investigating the effect of oat b-glucan on immunosuppression in exercised mice (Murphy et al 2004(Murphy et al , 2007(Murphy et al , 2009Davis et al 2004b). It may be related to differences in the ability of oat b-glucan to interact with immune cells through the proximal small intestine in humans.…”

“…The effects of b-glucan supplementation on exercise-induced changes in immune function and upper-respiratory tract symptoms have been investigated in several animal studies (Davis et al 2004a, b;Murphy et al 2004Murphy et al , 2007Murphy et al , 2008Murphy et al , 2009 and in three recent human studies of top-level athletes Talbott and Talbott 2009;Bobovcak et al 2010). In a very recent human study, Nieman et al (2008) investigated the effect of an oat b-glucan supplement on exercise-induced suppression of immune system in athletes.…”

“…A few human clinical studies demonstrated that b-glucan decreased infection incidence in surgical patients, need for antibiotics and it shortened intensive care unit length stay (Babineau et al 1994a, b;Dellinger et al 1999). Furthermore, rodent studies indicated that oat b-glucan supplements offset the increased risk of infection associated with exercise stress (Davis et al 2004a, b;Murphy et al 2007Murphy et al , 2008Murphy et al , 2009.…”

Evaluation of innate immune stimulating activity of polysaccharides using a silkworm (Bombyx mori) muscle contraction assay

“…Microarray analysis revealed that injection of PP alters gene expression patterns in the silkworm hemocytes and fat body cells, resulting in the induction of genes involved in innate immunity (10). Stimulants of innate immunity are therapeutically effective against viral infection (30)(31)(32)(33)(34). Thus, we hypothesized that activation of PP by GE-3 would contribute to the defense against viral infection in the silkworm.…”

“…Whereas several lines of evidence suggest the effectiveness of polysaccharides in the treatment for viral infectious diseases (30)(31)(32)41), evidence for a relationship between therapeutic effectiveness and stimulation of immunity by polysaccharides is limited. Our results provide new evidence for this relationship.…”