Βeta-glucans promote wound healing in common carp (Cyprinus carpio L.)

β-glucans are well known for their ability to modulate the immune system. These polysaccharides, derived from fungi, plants and bacteria cell wall [1] potently trigger inflammatory response in infected host [2]. The effects of β-glucans depend on the origins, route of administration, molecular weight, water solubility, degree of branching and polymer length [3]. In vitro studies in mammals have shown that β-glucans directly activate leukocytes by increasing phagocytosis, cytotoxicity, antimicrobial and antiviral activity and reactive oxygen production. In addition, β-glucans affect the wound healing process [1, 4]. Previous studies have shown that β-glucans stimulate production of pro-inflammatory mediators, cytokines and chemokines like e.g. IL-8, IL-1b, or IL-6 [5]. Studies in higher vertebrates clearly show that both PAMPs (pathogen associated molecular pattern) and DAMPs (danger-associated molecular pattern) cause inflammation. The aim of this study was to investigate capability to modulate immune parameters during the wound healing processes of two commercially available β–glucans. In in vivo study, carps of ~50g were anaesthetised and wounded with 5mm biopsy punches. During the extent of the experiment the fish were kept in ordinary tap water or in tap water supplemented with two different β–glucans to a final concentration of 0.1µg/ml. Skin and muscle tissue from wounded and unwounded areas were collected at 24 hours, 3 days and 2 weeks post injury and subjected to real-time RT-PCR for measuring the expression of immune and wound healing related genes (e.g. IL-1β, IL-6, IL-8). The visual healing of the wounds was registered using a multispectral imaging device called a VideometerLab (Hørsholm, Denmark). Our results clearly show that both types of β–glucans promoted faster wound healing.