Saliva sialidase

Application of sialidase inhibitors for medical use is still in a premature state. It is imaginable that inhibitors would be useful drugs in infections, caused by micro-organisms, that lead to extensive production of sialidase, for example, in gas edema.371 In the oral cavity, plaque formation and dental caries may be influenced by desialylation of salivary glycoconjugates,399 and bacterial sialidases may play a role therein. This process may be retarded by secretion of the inhibitor Neu2en5Ac in saliva at concentrations which, in some cases, were found to be close to the K value for sialidases.34... 

This Neu5Ac derivative lacking a glycosidic hydroxyl group at C2 has been found as free sialic acid in small quantities in blood serum, saliva and urine of man [5,8,13] and in tissue extracts of starfish [36] (Table 1). It is unknown, whether this compound, which is a potent competitive inhibitor of sialidases (see below), has a biological function. Its formation under physiological conditions has been described in section 2. 

Inhibition of sialidase by Neu5Ac2en may be important in specialized tissue sites, e.g. saliva, where sialidase-producing bacteria may influence tooth decay and mouth hygiene (Haverkamp et al. 1976). 

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