Analgesic activity of aqueous and methanol fruit pulp extracts of Hyphaene thebaica (Arecaceae) (Linn) mart in mice.

Objectives: Pain affects about one in every five persons and is considered a major global health burden. Hyphaene thebaica (Arecaceae), is a medicinal plant used in Cameroon, fruit pulp are macerated and orally administered in traditional medicine to treat various ailments, including hypertension, pain, and inflammation. This study aimed to evaluate the pain-killing effect of fruit pulp extracts of H. thebaica in mice.

Methods: Aqueous (AEHT) and methanol (MEHT) extracts were prepared from fruit pulp of H. thebaica, followed by a qualitative phytochemical analysis. The extracts were given orally at doses of 100, 200, and 400 mg/kg in acute pain models such as acetic acid, formalin, hotplate, and capsaicin. Control groups included distilled water (negative), and diclofenac, morphine, ruthenium red, diazepam (positive). Naloxone pretreatment was used to assess opioid pathway involvement. Locomotor and sedative effects were evaluated using rota-rod and open-field tests. Acute toxicity was assessed at 2,000 mg/kg.

Results: Phytochemical tests revealed saponins, flavonoids, tannins, and phenols. Both extracts greatly decreased the writhing induced by acetic acid. MEHT inhibited both phases of formalin-induced pain (p<0.01). Both extracts significantly inhibited hotplate-induced nociception (p<0.001), partially reversed by naloxone, except for MEHT. In the capsaicin test, extracts produced a remarkable reduction of paw licking time (p<0.01). No motor coordination alteration or acute toxicity effects were observed.

Conclusions: The findings demonstrated the analgesic activity of AEHT and MEHT, mediated by the stimulation of opioids and blockage of vanilloid receptors pathways.