Effect of Intrathecal Epigallocatechin-3-gallate on Formalin-induced Pain Rat Model

Green tea is being widely consumed as a health beverage. Recently, green tea polyphenols have been shown to possess potent anti-inflammatory property by inhibiting the production of prostaglandins; in particular, systemic green tea is shown to produce an antinociceptive effect. We examined the effect of epigallocatechin-3-gallate (EGCG), one of green tea catechins, administered at the spinal level, on the nociception. Male Sprague-Dwaley rats were used. Nociception was induced by subcutaneous injection of formalin solution (5%, 50μl) into the paw of the rat. For EGCG administration, intrathecal catheter was inserted into the subarachnoid space of the spine. Formalin-induced pain behavior (flinching response) was observed for 60 min and divided into the two phases, Intrathecal EGCG did not affect the flinching responses during both phase 1 and phase 2. These findings suggest that intrathecal EGCG may b