title: Salivary amylase - The enzyme of unspecialized euryphagous animals.
abstract: BACKGROUND
  Alpha-amylase (EC 3.2.1.1) is the most abundant enzyme in the saliva of man and of several vertebrates. In humans, salivary amylase is mainly formed in the parotid gland; its activity is of high inter-individual and intra-individual variability. The physiological functions of α-amylase have not yet been explored completely. It is well known that the enzyme cleaves the α-(1,4)-glycosidic bonds of polysaccharides. Furthermore it plays an important role in initial bioadhesion in man, facilitating carbohydrate metabolism and bacterial adherence at the tooth surface and therewith caries initiation. Nevertheless, it is still a matter of interest why humans have such high amounts of salivary amylase.
  
  
  OBJECTIVE
  The review presents an evolutionary approach by considering salivary amylase in the animal kingdom with special focus on mammalians divided into the three main nutritional types carnivores, herbivores, and omnivores; it was postulated that for most mammalian animals salivary α-amylase is essential.
  
  
  RESULTS
  The enzyme has been detected in saliva of some herbivores and many omnivorous animals, but not in pure carnivores. Focusing on ruminants, negligible levels or an absence of α-amylase was determined. Presence and activity probably differ depending on the species-specific diet. Animals feeding on unripe fruits, seeds, roots and bulbs exhibit higher activity of salivary α-amylase than species consuming ripe fruits, insects, and vertebrates.
  
  
  CONCLUSIONS
  In contrast to carnivores and most herbivores, omnivores have considerable amounts of amylase in their saliva. Though, the starch-digesting enzyme has been investigated well, the physiological function of amylase in saliva has not yet been explored completely. It can be hypothesized that nutritional habits affect expression of enzymes in the saliva of animals. It has to be verified, whether α-amylase is genetically or epigenetically determined. As a consequence of the development of agriculture, and following dietary changes, amylase can be recognized as a nutritional and evolutionary marker. Interdisciplinary evolutionary research might offer new perspectives for preventive dentistry.
authors.affiliation: Clinic of Operative and Pediatric Dentistry, Faculty of Medicine Carl Gustav Carus, TU Dresden, Fetscherstraße 74, 01307 Dresden, Germany; Institute of Zoology, Molecular Cell Physiology and Endocrinology, TU Dresden, 01062 Dresden, Germany.
authors.forename: Carolin
authors.initials: C
authors.lastname: Boehlke
authors.affiliation: Institute of Zoology, Molecular Cell Physiology and Endocrinology, TU Dresden, 01062 Dresden, Germany.
authors.forename: Oliver
authors.initials: O
authors.lastname: Zierau
authors.affiliation: Clinic of Operative and Pediatric Dentistry, Faculty of Medicine Carl Gustav Carus, TU Dresden, Fetscherstraße 74, 01307 Dresden, Germany. Electronic address: Christian.Hannig@uniklinikum-dresden.de.
authors.forename: Christian
authors.initials: C
authors.lastname: Hannig
mesh_terms: D000818:Animals; D018407:Bacterial Physiological Phenomena; D003731:Dental Caries / Q000209:etiology* / Q000382:microbiology; D044622:Dental Pellicle; D003773:Dental Plaque / Q000209:etiology* / Q000382:microbiology; D004032:Diet; D012463:Saliva / Q000201:enzymology*; D000516:alpha-Amylases / Q000502:physiology*
chemical_list: D000516:alpha-Amylases
keywords: Amylase; Caries; Dietary shifts; Enzyme; Pellicle; Saliva