Antinociceptive activity and acute toxicity profile of Leucus calostachys olive in animal models

Abstract

Pain remains a cardinal sign and symptom for most diseases and a major reason for patients visiting healthcare providers. Conventional treatment modalities do not adequately address pain, and as a result, most local communities globally resort to natural remedies, including medicinal plants. Leucus calostachys oliv is one of the many medicinal plants used by the many local communities in East Africa to treat various medical conditions, including pain however, there is limited scientific evidence for its efficacy and toxicity. An experimental study evaluated the antinociceptive and acute toxicity profile of Leucus calostachys oliv using the formalin-induced pain and the acetic acid-induced writhing models of antinociceptive activity and the up-and-down method for median lethal dose estimation (LD50) in Wistar albino rats. In the formalin-induced pain model, the total crude extract groups exhibited the greatest antinociceptive activity followed by aqueous and methanol extracts with mean time spent licking and biting of 5.2 ± 1.1, 3.2 ± 0.7, 8.6 ± 1.5, 3.8 ± 0.8, 19.7±1.4 and 10.8±1.1 seconds respectively at 500mg/kg and 1000mg/kg body weight doses. In the Acetic acid-induced writhing method, similar trends were observed and the total crude extracts showed the lowest mean number of writhes followed by aqueous and methanol extracts with the mean number of writhes of 8.4 ± 1.2, 3.8 ± 0.8, 8.6 ± 1.5 and 3.8 ± 0.8, 19.7 ± 1.4 and 10.8 ± 1.1 at same doses. The LD50 was estimated to be above 5000mg/kg the limit test dose as no death was recorded.