[Lycopene protects against hypoxia/reoxygenation-injury by preventing calpain activation].
OBJECTIVE
To investigate the possible mechanism of lycopene on protecting against hypoxia/reoxygenation (H/R)-injury.


METHODS
Primary cultured cardiomyocytes, isolated from neonatal mouse, were divided into three groups randomly: control group (C) ; H/R group(4 h H followed by 8 h R); lycopene+H/R group(L+H/R), in which the cardiomyocytes were pretreated with lycopene for 4 h before H/R. The survival of cardiomyocytes was counted. Apoptotic cells were detected by TUNEL assays. The release of cytochrome c from mitochondrial matrix into the cytosol, the activity of caspase-3, intracellular ROS levels and the activity of calpain were also determined in these groups respectively at the same time.


RESULTS
The pretreatment of cardiomyocytes with lycopene significantly improved the survival of cardiomyocytes [C: (89.84 ± 5.15)%, H/R: (63.59 ± 5.11)%, L+H/R: (79.25 ± 1.48)%, P < 0.05] and reduced the extent of apoptosis [C: ( 10.37 ± 1.25)%, H/R: (32.03 ± 4.79)%, L+H/R: (22.57 ± 3.22)%, P < 0.05], significantly reduced caspase-3 activation [C: (2.61 ± 0.19), H/R: (5.82 ± 0.92), L+H/R: (3.74 ± 0.64) pNA pmol/µg protein, P < 0.05]. To further study the mechanism underlying the benefits of lycopene, interactions between lycopene and calpain activation were examined. Lycopene pretreatment of cardiomyocytes suppressed the activation of calpain(C:272.33 ± 300.46, H/R: 1156.00 ± 212.02, L+H/R: 607.33 ± 166.23, P < 0.05) by reducing the H/R induced increased intracellular ROS levels [C: 100%, H/R: (239.79 ± 27.27)%, L+H/R: (188.19 ± 17.63)%, P < 0.05].


CONCLUSIONS
Lycopene may protect against hypoxia/reoxygenation-induced injury by preventing calpain activation.
Department of Cardiology,Affiliated Hospital of North Sichuan Medical College,Nanchong 637000, China.
Rong-chuan
RC
Yue
Hou-xiang
HX
Hu
Tao
T
Luo
Ke
K
Li
Shuang
S
Zhang
Lei
L
Xu
D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D002154:Calpain / Q000378:metabolism*; D002338:Carotenoids / Q000494:pharmacology*; D053148:Caspase 3 / Q000378:metabolism; D015687:Cell Hypoxia; D002478:Cells, Cultured; D045304:Cytochromes c / Q000378:metabolism; D000077276:Lycopene; D051379:Mice; D008810:Mice, Inbred C57BL; D032383:Myocytes, Cardiac / Q000187:drug effects / Q000378:metabolism / Q000473:pathology*
D002338:Carotenoids; D045304:Cytochromes c; D002154:Calpain; C505409:Casp3 protein, mouse; D053148:Caspase 3; D000077276:Lycopene