Assessment of Analgesic and Anti-Inflammatory Properties of Piper nigrum Leaf Extract in Wistar Rat Models

Abstract

Piper nigrum L. (black pepper), a commonly utilized traditional herbal medicine, possesses possible anti-inflammatory and analgesic properties attributed to its alkaloids, especially piperine. This study assessed the effectiveness of a 70% ethanolic extract of dried leaves of Piper nigrum in male Wistar rats. The anti-inflammatory effect was evaluated using carrageenan-induced paw edema. In contrast, the analgesic function was examined by acetic acid-induced writhes and tail-flick tests at dosages of 250, 500, 750, and 1000 mg/kg. The 750 mg/kg doses showed statistically significant inhibition of edema (p < 0.05) at 3 and 4 hours following carrageenan injection, demonstrating effects equivalent to ibuprofen. Only the maximum 1000 mg/kg test dose exhibited statistically significant analgesia (p < 0.05) in the writhing test. However, the tail-flick test demonstrated dose-dependent efficacy, with the 750 mg/kg dose being statistically significant (p < 0.05) at 2 and 4 hours. Phytochemical research revealed the presence of piperine and chabamide, which are likely to suppress the release of prostaglandins, mainly through piperine. Consequently, the findings reinforced the ethnopharmacological assertion regarding Piper nigrum, suggesting that its leaf extract may be a viable natural alternative to synthetic analgesics with reduced side effects. It warrants further investigation to contextualize chabamide's efficacy in optimizing therapeutic applications.