Possible potentiation by certain antioxidants of the anti-inflammatory effects of diclofenac in rats.
In the present study, we investigated the potential beneficial impact of the addition of antioxidant supplements to diclofenac regimen in a model of carrageenan-induced paw. Rats were treated daily with antioxidants, that is, a-lipoic acid (50 mg/kg), selenium (2.5 mg/kg), vitamin C (1 g/kg), vitamin E (300 mg/kg), or zinc (25 mg/kg) on seven successive days and then received a single treatment with diclofenac or saline before carrageenan was injected to induce paw inflammation. The results indicated that these combinations did not significantly affect the percentage inhibition of paw edema caused by diclofenac alone; however, some combination treatments ameliorated signs of concomitant oxidative stress (such as alterations in plasma malondialdehyde (MDA) levels, hemolysate reduced glutathione levels, and erythrocytic superoxide dismutase enzyme activities) imparted by diclofenac alone. In some cases, few tested antioxidants in combination with diclofenac resulted in increased plasma levels of interleukin- (IL-) 6 and C-reactive protein (CRP). In conclusion, the results of these studies suggested to us that the added presence of natural antioxidants could be beneficial as standard anti-inflammatory therapeutics for a patient under diclofenac treatment, albeit that these effects do not appear to significantly build upon those that could be obtained from this common anti-inflammatory agent per se.
Department of Pharmacology and Toxicology, Misr International University (MIU), Km 28, Cairo-Ismailia Road, P.O. Box 1, Heliopolis, Cairo, Egypt.
Samah S
SS
Abbas
Department of Biochemistry, Faculty of Pharmacy, Misr International University (MIU), Km 28, Cairo-Ismailia Road, P.O. Box 1, Heliopolis, Cairo, Egypt.
Mona F
MF
Schaalan
Department of Pharmacology and Toxicology, Faculty of Pharmacy, Cairo University, Giza, Egypt.
Ashraf K
AK
Bahgat
Department of Pharmacology and Toxicology, Faculty of Pharmacy, Cairo University, Giza, Egypt.
Ezzeddin S
ES
El-Denshary
D000818:Animals; D000893:Anti-Inflammatory Agents / Q000494:pharmacology*; D000975:Antioxidants / Q000494:pharmacology*; D004008:Diclofenac / Q000494:pharmacology*; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley
D000893:Anti-Inflammatory Agents; D000975:Antioxidants; D004008:Diclofenac