Guggulipid of Commiphora mukul, with antiallodynic and antihyperalgesic activities in both sciatic nerve and spinal nerve ligation models of neuropathic pain.

CONTEXT: Guggulipid is a neutral fraction of ethyl acetate extract of gum resin of the tree Commiphora mukul Engl. (Burseraceae) and used in Ayurvedic medicine for treatment of neurological disorders.

OBJECTIVES: The present study was undertaken to assess the antiallodynic and antihyperalgesic activities of guggulipid in rats.

MATERIALS AND METHODS: The screening study included the CCI and L5-L6 SNL models of neuropathic pain. Guggulipid (100 and 50 mg/kg) or saline was administered intraperitoneally in a blinded, randomized manner from postoperative day (POD) 7 to 13. Paw withdrawal duration (PWD) to spontaneous pain, chemical allodynia and mechanical hyperalgesia and paw withdrawal latency (PWL) to mechanical allodynia and thermal hyperalgesia were tested before surgery, before and after guggulipid or saline administration (from POD7 to 13) and after the withdrawal of treatment (from POD14 to 20).

RESULTS: The activity profiles of the different doses of guggulipid were found to vary with time. In CCI rats, guggulipid (100 and 50 mg/kg) significantly (p < 0.05) reduced the spontaneous pain, mechanical allodynia and mechanical and thermal hyperalgesia responses and the LD50 of guggulipid was 1600 mg/kg. In SNL rats, both doses of guggulipid were found to be ineffective in reversing the spontaneous pain but showing antiallodynic and antihyperalgesic activity.

DISCUSSION AND CONCLUSION: The results demonstrated that guggulipid produce antinociception in the peripheral nerve injury (CCI and SNL) models of neuropathic pain. The underlying mechanisms are expected to be modulating microglial activation occurring due to peripheral nerve injury.