Abstract

In this study acetic acid and formalin methods were used to assess analgesic activity in one insect and five plant crude extracts. Aspirin was used as a standard drug in both methods. In acetic acid method, significant inhibitory results were obtained on comparison with control as follows: A. mellifica (300 mg) revealed 21.42% inhibition in 3^rd phase. A. mellifica (500 mg) showed significant activity in all the three phases: 60% in phase 1, 37.5% in phase 2 and 57.14% in phase 3. D. purpurea (1 mg) exhibited 75% inhibition in first phase, 50% in second phase and 35.71% in third phase. D. purpurea (10 mg) presented inhibitory effect as follows; 55% (1^st phase), 56.25% (2^nd phase) and 85.71% (3^rd phase). S. nigra (10 mg) revealed 65% inhibition in first phase and 50% in third phase. S. nigra (50 mg) showed 55% inhibition of writhes in first phase. T. occidentalis (50mg) exhibited 60% inhibition in 1^st phase and 37.5% in 2^nd phase. T. occidentalis (100 mg) presented 50% inhibition in 2^nd phase and 21.42% in 3^rd phase. U. urens (500 mg) revealed significant inhibition in the three phases of activity, 75% (1^st phase), 56.25% (2^nd phase) and 21.42% (3^rd phase). U. ursi (500 mg) showed significant inhibition in 1^st phase 75% and 2^nd phase 56.25%. In formalin analgesic activity in comparison with control, the following results were obtained: A.mellifica (300 mg) showed inhibition of licking and biting response in first phase 28.57%, 41.17% in second phase and 53.33% in third phase. A. mellifica (500 mg) revealed 52.38% inhibition in 1^st phase and 60% in 3^rd phase. D. purpurea (10 mg) exhibited 42.85% inhibition in 1^st phase, 17.64% in second phase and 33.33%. S. nigra (50 mg) caused 28.57% inhibition in 1^st phase, 17.64% in 2^nd phase and 26.67% in 3^rd phase. T. occidentalis (50 mg) showed 33.33% inhibition in 1^st phase, 29.41% in 2^nd phase and 33.33% in 3^rd phase. T. occidentalis (100 mg) revealed inhibition in three phases as follows: 47.61% (1^st phase), 52.94% (2^nd phase) and 40% (3^rd phase). The above mentioned drugs show prominent analgesic activity in mice in comparison to control and standard drug.

Key words: Analgesic, Aspirin, Formalin, acetic acid, medicinal plants, insect drug.