Antinociceptive effect of Allium schoenoprasum L. oral feeding in male diabetic rats

Hyperalgesia is considered as one of the marked signs of subchronic diabetes mellitus that could affect the life style of the patients. This study was designed to investigate the antinociceptive effect of chronic feeding of Allium schoenoprasum (AS) leaf in streptozotocin-diabetic rats using formalin and tail immersion tests. Rats were divided into control, AS leaf-treated control, diabetic, sodium salicylate (SS)-treated diabetic, and AS leaf-treated diabetic groups. The treatment groups received oral administration of AS leaf-mixed pelleted food (3%) for 8 weeks. Finally hyperalgesia were assessed using standard formalin and tail immersion tests. Averaged pain score for the first 0-10 min and the later 16-60 min after formalin injection was regarded as acute and chronic phases, respectively AS leaf treatment of diabetic rats reduced pain score in chronic phase of formalin test from 2.41±0.14 to 2.01±0.12 (P<0.05). Regarding hot tail immersion test, diabetic rats showed a significant reduction (5.9 s) in tail flick latency as compared to control ones (P<0.05). However, AS leaf treatment of diabetic rats did not significantly increase this latency relative to untreated diabetics. Taken together, 8-week administration of AS leaf could attenuate nociceptive score in chronic phase of formalin test in streptozotocin-induced experimental model of diabetes mellitus, but, had no effect on thermal pain. Perhaps, the anti-inflammatory property of the plant is responsible for its analgesic effect.