Beta-glucan and pectin derivatives stimulate prolactin secretion from hypophysis in vitro

At low serum glucan concentrations there is an inverse correlation between serum glucan and serum cytokine levels in ICU patients with infections

Glucans are fungal cell wall glucose polymers that are released into the blood of infected patients. The role of glucans in infection is unknown. We examined serum glucan and cytokine levels in intensive care unit (ICU) patients with infections. There was an inverse correlation (p<0.001) between serum glucan levels and interleukin (IL)-2), IL-4, tumor necrosis factoralpha (TNFalpha) and granulocyte macrophage-colony stimulating factor (GM-CSF) levels in infected ICU patients. The correlation between serum cytokines and serum glucan was only observed at glucan concentrations <40 pg/ml. No change was observed at serum glucan levels of >40 pg/ml. There was no correlation between serum glucan levels and systemic levels of IL-1beta, IL-5, IL-6, IL-8, IL-10 or IFNgamma. Interestingly, blood borne glucans did not suppress systemic cytokine levels in infected ICU patients, instead they were maintained at control levels. We conclude that circulating glucans may prevent cytokine upregulation in response to infection. This may represent an adaptive response to septic injury.

Carbohydrates--the renewable raw materials of high biotechnological value

Carbohydrates are the potential biomolecules derived from nature. Their molecular diversity has led to a bewildering variety of species, structures and characteristics all performing a large array of functions of great significance. Biologically they are vital as message (immunological) carriers, physiologically they are useful as energy (nutritional) reserves, and technologically they are needed for altering the texture and consistency (functional) of foods. Recent advances in glycobiology have opened up a new understanding of the role of sugars in biology and medicine. Noncellulosic beta-(1-3)-linked D-glucans, a group of polysaccharides found as constituents of fungi, algae, and higher plants, exhibit many interesting properties, depending on their molecular conformation. They are excellent 'biological response modifiers' and show significant immunomodulatory activities. They elicit a variety of host defense biological responses, for example, potent antitumor activity. On the other hand, the mixed-linkage ((1-3/1-4)-beta-linked) glucans are important constituents of cereal cell walls, where they perform properties of physiological importance, such as water holding capacity, porosity, and plasticity, which are useful at different stages of growth/development of plants. Of late, carbohydrate-based therapeutics are becoming the promise against many chronic diseases of today and tomorrow. Some of the characteristic features, structural attributes, functional significance, and applications of a selected few carbohydrate species are the subject matter of this review.