Chronic oral pelargonidin alleviates streptozotocin-induced diabetic neuropathic hyperalgesia in rat: involvement of oxidative stress.
BACKGROUND
Diabetes mellitus in some clinical cases is accompanied with hyperalgesia. In this study, we evaluated the possible beneficial effect of chronic pelargonidin (PG) treatment on hyperalgesia in streptozotocin (STZ)-diabetic neuropathic rat.


METHODS
Male Wistar rats (n = 56) were divided into seven groups, i.e. control, diabetic, PG-treated control, PG (single- and multiple-dose)-treated diabetic, and sodium salicylate-treated control and diabetics. For induction of diabetes, STZ was injected i.p. at a single dose of 60 mg/kg. PG was orally administered at a dose of 10 mg/kg once and/or on alternate days for 8 weeks; 1 week after diabetes induction. After two months, hyperalgesia was assessed using standard formalin and hot tail immersion tests. Meanwhile, markers of oxidative stress in brain were measured. One-way analysis of variance was used for statistical analysis of the data.


RESULTS
Diabetic rats showed a marked chemical and thermal hyperalgesia, indicating that development of diabetic neuropathy and PG treatment (especially multiple-doses) significantly ameliorated the alteration in hyperalgesia (P less than 0.05-0.01) in diabetic rats as compared to untreated diabetics. PG (multiple doses) also significantly decreased diabetes-induced thiobarbituric acid reactive substances formation and non-significantly reversed elevation of nitrite level and reduction of antioxidant defensive enzyme superoxide dismutase.


CONCLUSIONS
These results clearly suggest that PG prevents diabetic neuropathic hyperalgesia through attenuation of oxidative stress.
Mirshekar
Mohammadali
M
Dept. of Physiology, Shahed University, Tehran, Iran.
Roghani
Mehrdad
M
Khalili
Mohsen
M
Baluchnejadmojarad
Tourandokht
T
Arab Moazzen
Saiedeh
S
D000284:Administration, Oral; D000818:Animals; D000872:Anthocyanins / Q000494:pharmacology*; D003921:Diabetes Mellitus, Experimental / Q000188:drug therapy* / Q000378:metabolism; D003929:Diabetic Neuropathies / Q000188:drug therapy* / Q000378:metabolism; D016166:Free Radical Scavengers / Q000494:pharmacology*; D006930:Hyperalgesia / Q000188:drug therapy* / Q000378:metabolism; D008297:Male; D009573:Nitrites / Q000378:metabolism; D018384:Oxidative Stress / Q000187:drug effects; D010147:Pain Measurement; D051381:Rats; D017208:Rats, Wistar; D013482:Superoxide Dismutase / Q000378:metabolism; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism
D000872:Anthocyanins; D016166:Free Radical Scavengers; D009573:Nitrites; D017392:Thiobarbituric Acid Reactive Substances; C066957:pelargonidin; D013482:Superoxide Dismutase