Zinc -carnosine (beta-alanyl--histidinato zinc) (N-(3-aminopropionyl)--histidinato zinc), often simply called zinc carnosine, and also known as polaprezinc, is a mucosal protective chelate compound of zinc and -carnosine. It is a quadridentate 1:1 complex of a polymeric nature. It contains 23% zinc and 77% -carnosine by mass.
Contents
It is an approved drug in Japan where it is clinically used to treat gastric ulcers.
Gastrointestinal
Its mechanism of action is believed to oxygen radical scavenging, anti-oxidation, and acceleration of gastrointestinal wound healing. It exhibits ROS-quenching activities. It can remain in the stomach without rapid dissociation and adhere specifically to ulcerous lesions, after which L-carnosine and zinc are released to heal the ulcer. It has been shown to stimulate mucus production and to maintain the integrity of the gastric mucosal barrier. In summary, it maintains homeostasis of the gastric mucosa by prostaglandin-independent cytoprotective effects due to anti-oxidative membrane stabilizing actions, and it promotes the repair of damaged tissues by wound healing action.
It has a potential to stimulate Hsp70 expression, with overexpression of Hsp70 being found to prevent the development of inflammatory process in the large intestinal mucosa provoked by various damaging factors.
It possesses antioxidant, anti-inflammatory, and genomic stability enhancement effects, thereby having potential in preventing gastrointestinal cancer development.
It exhibits an inhibitory effect on H. pylori.
Comparisons
Its healing efficacy against ulceration is significantly greater than that of other zinc complexes, free L-carnosine, and zinc D-carnosine. Its pharmacological activity seems attributable mainly to zinc ion, presumably transported effectively into the ulcer by means of L-carnosine together with the action of L-carnosine itself. In contrast, a simple mixture of L-carnosine and zinc had a lesser effect, presumably due to rapid diffusion of L-carnosine and zinc ion in the entire stomach.
Other
It has a stimulatory effect on bone formation and a restorative effect on bone loss under various pathophysiologic conditions.
Safety
The typical clinical oral dose is 150 mg/day, containing 34 mg zinc and 116 mg L-carnosine. Good clinical compliance was observed at this dose, with no symptomatic side effect reported. Although zinc L-carnosine caused an increase in serum zinc level, the serum copper level and copper:zinc ratio decreased, and a case of preexisting copper deficiency deteriorated.
Note that the Tolerable Upper Intake Level (UL) for total zinc intake from all sources in adults is 40 mg/day.