Abstract
Hyaluronan (HA) has been utilized as a supplement. In a study that estimated the absorption of high molecular weight (MW) HA (900 kDa) from chicken comb cells labeled with 14C, over 88% of administered HA was absorbed and distributed throughout the body. However, the absorption mechanism of orally administrated HA has not been revealed. The degradation and absorption of HA in the intestine were investigated in this study. HA excretion into the feces, degradation in the intestinal tract, absorption through the large intestine, and translocation to the blood and skin were examined. HA administered orally was not detected in rat feces as intact HA. HA was degraded to oligosaccharides by cecal content, but not by artificial gastric and intestinal juice. Oligosaccharide HA passed through CaCo-2 cells and excised large intestine sacs. Furthermore, disaccharides and tetrasaccharides HA were distributed to the skin of rats following oral administration of high MW HA (300 kDa). The results of the study suggest that orally administered HA is degraded to oligosaccharides by intestine bacteria, and oligosaccharide HA is absorbed in the large intestine and is subsequently distributed throughout the tissues, including the skin.
