Oral and systemic administration of β-glucan protects against lipopolysaccharide-induced shock and organ injury in rats

Abstract

Summaryb-Glucans are glucose polymers with a variety of stimulatory effects on the immune system. The objective of this study was to determine the effect of prophylactic oral administration of soluble Saccharomyces cerevisiae-derived b-1,3/1,6-glucan (SBG) on the outcome of experimental endotoxaemia and shock-associated organ injury. Male Wistar rats were pretreated with SBG orally (SBGpo, 20 mg/kg/day) for 14 days, subcutaneously (SBGsc, 2 mg/kg/ day) for 3 days, or vehicle (placebo). Rats were anaesthetized and subjected to endotoxaemia by intravenous infusion of Escherichia coli lipopolysaccharide (LPS) (6 mg/kg) or saline infusion (sham). We observed significant levels of plasma b-glucan in the SBGpo group (P < 0·5), although the SBGsc group had levels approximately 40-fold higher despite a 10-fold lower dose. SBG prophylaxis caused enhanced blood pressure recovery following LPS-induced blood pressure collapse. Oral treatment with SBG attenuated the LPS-induced rise in plasma creatinine levels (P < 0·05), indicating protection against renal injury. SBG also attenuated the plasma levels of aspartate aminotransferase and alanine aminotransferase (SBGpo, P < 0·01; SBGsc, P < 0·01), indicating protection against LPS-induced hepatic injury. A moderate increase in baseline interleukin (IL)-1b levels was observed in the SBGsc group (P < 0·05). In the LPS-challenged rats, plasma levels of proinflammatory cytokines was moderately reduced in both SBG-treated groups compared to placebo. SBG treatment, particularly oral administration, had a striking effect on the haemodynamics of LPS-treated rats, although only a minute fraction of the orally administered b-glucan translocated to the circulation. Enhanced organ perfusion may thus be responsible for the attenuated levels of indicators of kidney and liver injury seen in SBG-treated rats.

Protective effect of β-glucan and glutamine on intestinal and immunological damage in mice induced by cytarabine (Ara-C)

“…Several studies have shown that β-glucan is very good at improving immunity, and glutamine has an important role in cell-mediated immunity and the integrity of the intestinal mucosa (Sandvik et al 2007, Santos et al 2014, Wang & Ellis 2014, Chaudhry et al 2016, Li et al 2006 . In this report, we demonstrate for the first time the benefits of their association.…”

“…After oral administration of β-glucans, it comes in contact with the mucosa of gastrointestinal tract and it stimulates the intestinal immune cells, including Peyer's patches, promoting the increased number of intraepithelial lymphocytes (Sandvik et al 2007, Volman et al 2008). …”

Protective effect of beta-glucan on contrast induced-nephropathy and a comparison of beta-glucan with nebivolol and N-acetylcysteine in rats

“…While some studies have demonstrated that oral BG administration decreased TNF-a level [28], others reported that the level did not change significantly [29,30]. BG also increased the levels of IL-1 [29]. However, there are also studies which indicate no significant difference in the production of inflammatory cytokines [30].…”

“…BG administration is thought to blunt the host inflammatory response to the damage by inhibiting cytokine activity [27]. While some studies have demonstrated that oral BG administration decreased TNF-a level [28], others reported that the level did not change significantly [29,30]. BG also increased the levels of IL-1 [29].…”

Promising Effects of Beta-Glucans on Metabolism and on the Immune Responses: Review Article

“…The immunological potency of beta-glucans also can be associated with their ability to activate leukocytes (Sandvik et al, 2007). It is assigned and dependent on the molecular mass, conformation, solubility and also the degree and position of its ramifications.…”