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Reversal of LPS‐induced immobility in mice by green tea polyphenols: possible COX‐2 mechanism
Author(s) -
Singal Anjali,
Tirkey Naveen,
Chopra Kanwaljit
Publication year - 2004
Publication title -
phytotherapy research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.019
H-Index - 129
eISSN - 1099-1573
pISSN - 0951-418X
DOI - 10.1002/ptr.1520
Subject(s) - green tea extract , pharmacology , lipopolysaccharide , behavioural despair test , rofecoxib , mechanism of action , endocrinology , naproxen , medicine , chemistry , cyclooxygenase , green tea , biochemistry , antidepressant , food science , hippocampus , in vitro , enzyme , alternative medicine , pathology
An endotoxin (lipopolysaccharide, LPS) is known to activate the hypothalamo–pituitary adrenocortical axis, as well as norepinephrine and indolamine metabolism. Systemically administered LPS produces depression in the forced swimming‐induced despair behaviour model in mice. The present study was designed to investigate the effect of green tea extract (GTE) on LPS‐induced despair behaviour and to explore the mechanism involved in modulation of LPS‐induced immobility by GTE. GTE (10–100 mg/kg) pretreatment reversed LPS‐induced immobility in a dose‐dependent manner. Rofecoxib (2 mg/kg) and nimesulide (2 mg/kg), COX‐2 inhibitors, also reversed the LPS‐induced immobility, which was signicantly potentiated by concomitant administration of GTE. On the other hand, GTE did not show any potentiating effect on immobility with naproxen (10 mg/kg), which is a nonselective COX blocker. Interestingly the antioxidant, carvedilol (2 mg/kg) did not produce any effect on immobility either in normal or in LPS treated mice. The results of the study implicate the role of COX‐2 inhibition by GTE in the reversal of LPS‐induced immobility. Copyright © 2004 John Wiley & Sons, Ltd.