The anti-inflammatory effects of venlafaxine in the rat model of carrageenan-induced paw edema.
OBJECTIVE
Recently anti-inflammatory effects of antidepressants have been demonstrated. Venlafaxine belongs to newer antidepressants with serotonin norepinephrine reuptake inhibition property. The pain alleviating properties of venlafaxine in different pain models such as neurogenic pain, diabetic neuropathy, and fibromyalgia have been demonstrated. Anti-inflammatory effects of venlafaxine and also its underlying mechanisms remain unclear. The present study was designed to evaluate the anti-inflammatory effects of venlafaxine and determine possible underlying mechanisms.


METHODS
We examined the anti-inflammatory effects of intraperitoneal (IP) and intracerebroventricular (ICV) administration of venlafaxine in the rat model of carrageenan-induced paw edema.


RESULTS
Our results showed that both IP (50 and 100 mg/kg) and ICV (50 and 100 μg/rat) injection of venlafaxine inhibited carrageenan-induced paw edema. Also IP and ICV administration of venlafaxine significantly decreased myeloperoxidase (MPO) activity and interleukin (IL)-1β and tumor necrosis factor (TNF)-α production. Finally, we tried to reverse the anti-inflammatory effect of venlafaxine by yohimbine (5 mg/kg, IP), an alpha2-adrenergic antagonist. Our results showed that applied antagonist failed to change the anti-inflammatory effect of venlafaxine.


CONCLUSIONS
These results demonstrated that venlafaxine has potent anti-inflammatory effect which is related to the peripheral and central effects of this drug. Also we have shown that anti-inflammatory effect of venlafaxine is mediated mostly through the inhibition of IL-1β and TNF-α production and decreases MPO activity in the site of inflammation.
Department of Pharmacology and Toxicology and Isfahan Pharmaceutical Research Center, School of Pharmacy and Pharmaceutical Sciences, Isfahan University of Medical Sciences, Isfahan, Iran.
Valiollah
V
Hajhashemi
Department of Pharmacology and Toxicology and Isfahan Pharmaceutical Research Center, School of Pharmacy and Pharmaceutical Sciences, Isfahan University of Medical Sciences, Isfahan, Iran.
Mohsen
M
Minaiyan
Physiology Research Center, Kashan University of Medical Sciences, Kashan, Iran ; Department of Pharmacology, School of Medicine, Kashan University of Medical Sciences, Kashan, Iran.
Hamid Reza
HR
Banafshe
Physiology Research Center, Kashan University of Medical Sciences, Kashan, Iran ; Department of Pharmacology, School of Medicine, Kashan University of Medical Sciences, Kashan, Iran.
Azam
A
Mesdaghinia
Department of Pharmacology, School of Medicine, Kashan University of Medical Sciences, Kashan, Iran.
Alireza
A
Abed
Carrageenan Inflammation; Rat; Venlafaxine