RESUMO
BACKGROUND: Aloe vera is being used since ages by human kind for treating various ailments including various inflammatory conditions, but scientific validation has not been done for analgesic activity against neuropathic pain. OBJECTIVE: The current study was designed to systematically evaluate the therapeutic potential of the ethanolic extract of A. vera (EEAV) against sciatic nerve ligation (SCNL) induced neuropathic pain. MATERIALS AND METHODS: Nociceptive threshold of EEAV against thermal hyperalgesia, chemical hyperalgesia and mechanical allodynia were performed on 0, 7, 14 and 21(st) day post-SCNL. Serum total protein, serum nitrite, in vivo anti-oxidant parameters and lipid peroxidation (LPO) were estimated. Sciatic nerve homogenate was used to estimate myeloperoxidase (MPO) and calcium levels. Histopathology of the sciatic nerve was done to confirm the biochemical findings. RESULTS: Treatment with ethanolic extract has increased the threshold for the nociception in thermal hyperalgesia, chemical hyperalgesia and mechanical allodynia models. A significant improvement of in vivo anti-oxidant parameters and decreased LPO levels were observed on treatment with A. vera. Significant decrease in serum nitrite, protein, calcium and MPO levels were observed, indicating protection against damage caused by SCNL. CONCLUSION: The results of the present study validate the use of EEAV to treat neuropathic pain. This effect may be attributed to the decreased migration of neutrophils and due to the anti-oxidant properties of A. vera. Further studies to confirm the mechanism of action will help develop suitable A. vera formulations for neuropathic pain therapy.
