Baicalein attenuates neuropathic pain and improves sciatic nerve function recovery in rats with partial sciatic nerve transection.

BACKGROUND: Modulating the inflammatory response to nerve injury may provide therapeutic opportunities by aborting the neurobiological alterations that support the development of persistent pain. Baicalein, a 12-lipoxygenase inhibitor, has anti-inflammation properties. It also demonstrates anti-inflammatory functions by inhibiting lipopolysaccharide-induced barrier disruption, expression of cell adhesion molecules, and adhesion and migration of leukocytes. The aim of the present study was to assess the possibility of early treatment of neuropathic pain via the systemic injection of baicalein in rats with left partial sciatic nerve transection (PST).

METHODS: Wistar rats were divided into Sham, Vehicle, and Baicalein groups. The Vehicle and Baicalein rats underwent PST, whereas the Sham rats were not transected. Baicalein was administered 20 mg/kg/day intraperitoneally for 7 days after PST and after behaviour tests. After PST, rats developed mechanical and cold allodynia, and impaired sciatic nerve function.

RESULTS: Baicalein attenuated mechanical and cold allodynia and improved sciatic nerve function after PST. Baicalein significantly inhibited the expression of tumour necrosis factor α (TNF-α), interleukin 6 (IL-6), and IL-1β on days 14 and 28, and attenuated the activation of astrocytes in the L4-5 spinal cord less than day 28 after PST.

CONCLUSION: Our study revealed that early and multiple doses of systemic baicalein attenuated neuropathic pain and improved sciatic nerve function by inhibiting pro-inflammatory cytokine expression and attenuating the activation of astrocytes in the spinal cord.