Evaluation of the Analgesic Properties of Aqueous Extract of Piper guineense Seeds in Albino Rats: A Study Contextualised in South South Nigeria

Piper guineense, commonly known as West African pepper or Uziza, is widely consumed in South South Nigeria as a culinary spice and traditional remedy for pain, rheumatism, and inflammatory conditions. Despite its widespread use, systematic pharmacological evaluations of its analgesic properties remain limited. This study investigates the analgesic activity of aqueous extract of Piper guineense seeds using established animal models. Wistar albino rats were grouped into five cohorts receiving varying doses of the extract (100, 200, and 400 mg/kg body weight), a standard analgesic control (morphine, 10 mg/kg), and a negative control (normal saline). Analgesic activity was assessed using the acetic acid-induced writhing test and hot plate method. Phytochemical analysis confirmed the presence of alkaloids, piperine derivatives, flavonoids, and tannins. Results showed a dose-dependent reduction in writhing frequency, with the 400 mg/kg dose producing effects comparable to the morphine control in the writhing test. Significant increases in pain latency were also observed on the hot plate at higher doses. Acute toxicity evaluation using the Lorke method indicated an LD50 greater than 5000 mg/kg, suggesting a favourable safety profile. These findings provide scientific validation for the traditional use of Piper guineense as an analgesic agent in the Niger Delta region. Keywords: Piper guineense, analgesic, Wistar rats, aqueous extract, South South Nigeria