Original Paper

Human Gastric Juice Contains Chitinase That Can Degrade Chitin
Maurizio G. Paoletti^a, Lorenzo Norberto^b, Roberta Damini^a, Salvatore Musumeci<sup>c

a</sup>Department of Biology, Laboratory Agroecology and Ethnobiology, and
^bDepartment of Surgical and Gastroenterological Science, Section of 1st General Surgery, Surgical Endoscopy Unit, University of Padova, Padova,
^cDepartment of Pharmacology, Gynecology and Obstetrics, Pediatrics, University of Sassari and Institute of Biomolecular Chemistry, CNR, Li Punti (SS), Italy

Address of Corresponding Author

Ann Nutr Metab 2007;51:244-251 (DOI: 10.1159/000104144)

  Key Words

• Acidic mammalian chitinase
• Gastric juice
• Chitin digestion
• Entomophagy

  Abstract

Chitin digestion by humans has generally been questioned or denied. Only recently chitinases have been found in several human tissues and their role has been associated with defense against parasite infections and to some allergic conditions. In this pilot study we tested the gastric juices of 25 Italian subjects on the artificial substrates 4-methylumbelliferyl--D-N,N',diacetylchitobiose or/and fluorescein isothiocyanate (FITC) chitin to demonstrate the presence of a chitinase activity. Since this chitinase activity was demonstrated at acidic pH, it is currently referred to acidic mammalian chitinase (AMCase). AMCase activity was present in gastric juices of twenty of 25 Italian patients in a range of activity from 0.21 to 36.27 nmol/ml/h and from 8,881 to 1,254,782 fluorescence emission (CPS), according to the used methods. In the remaining five of 25 gastric juices, AMCase activity was almost absent in both assay methods. An allosamidine inhibition test and the measurement at different pH values confirmed that this activity was characteristic of AMCase. The absence of activity in 20% of the gastric juices may be a consequence of virtual absence of chitinous food in the Western diet.

Copyright © 2007 S. Karger AG, Basel

  Author Contacts

Prof. Salvatore Musumeci
Department of Pharmacology, Gynecology and Obstetrics, Pediatrics
University of Sassari, Viale San Pietro n. 43b
IT-07100 Sassari (Italy)
Tel. +39 360 285 505, Fax +39 95 717 9690, E-Mail smusumeci@tiscalinet.it

  Article Information

Received: November 7, 2006
Accepted: March 9, 2007
Published online: June 18, 2007
Number of Print Pages : 8
Number of Figures : 3, Number of Tables : 2, Number of References : 36