Evaluation of the Methanolic Rhizome Extract of Anchomanes difformis for Analgesic and Antipyretic Activities

Abstract

Objectives: To evaluate rhizomes extract of Anchomanes difformis (extract) for analgesic, antipyretic and local anesthetic activities.

Methods: Extract was prepared by cold maceration in 70% methanol. Oral acute toxicity was evaluated and LC50 determined. Extract at 100, 250, 500 and 1000 mg/kg was tested against Sodium pentobarbital (SPB)-induced narcosis, acetic acid (AC)–induced abdominal constrictions, formalin-induced paw-licking (FIPL) and brewer’s yeast-induced pyrexia. Local anesthetic effect tested using twitch response test in guinea pig at 0.33, 0.66 and 1% extract.

Results: Mice tolerated extract up to 4000 mg/kg. LC50 was 589.13 ppm. Induction and sleeping times of SPB were significantly (p<0.05) decreased at 500 and 1000 mg/kg and 250, 500 and 1000 mg/kg respectively compared with SPB. Abdominal constriction significantly (p<0.05) decreased at 500 mg/kg compared with negative control. There was significant (p<0.05) decrease in paw licking in both 1st and 2nd phases of FIPL at 250 and 500 mg/kg and 500 and 1000 mg/kg respectively compared with negative control. Rectal temperature significantly (p<0.05) decreased at 1000 mg/kg 1 h post-administration compared with aspirin (100 mg/kg) and at 2 – 4 h compared with negative control. Local anesthetic effect was concentration-dependent.

Conclusion: The extract showed promising analgesic, antipyretic and local anesthetic effects.