Antinociceptive effects of methanolic extracts of Pistacia aethiopica and Warbugia ugandensis in mice

Pistacia aethiopica and Warbugia ugandensis are medicinal plants used in folk medicine among the Embu, Kenya. Despite being in use since antiquity, no empirical data is available to validate their claimed use in pain management. This study evaluated the antinociceptive effects of methanolic extracts of these plants in mice. Qualitative phytochemical profile of the methanolic extracts was also established. The antinociceptive studies used formalin pain model. Harbone and Kotaki protocols for qualitative phytochemical screening were used. Stem bark extracts of P. aethiopica inhibited paw licking in mice by between 47.24% 55.13% in the early phase and by between 30.69%-52.12% in the late phase. W. ugandensis leaf extracts inhibited paw licking by between 38.45%- 51.85% in the early phase and by between 43.48%-65.61% in the late phase. Diclofenac sodium inhibited paw licking by between 30.33%- 30.36% in the early phase and by between 62.93% and 77.08% in the late phase. Phytochemical screening revealed presence of saponins, alkaloids, flavonoids, phenols and terpenoids. This study established existence of antinociceptive effects in the methanolic extracts of P. aethiopica and W. ugandensis in mice. The observed effects were ascribed to the presence of phytochemicals working individually or synergistically.