Analgesic activity and safety assessment of heliotropium indicum Linn. (Boraginaceae) in rodents

This study presented the analgesic and safety assessment of Heliotropium indicum, a plant traditionally used for the management of abdominal pains, dysmenorrhoea and post-labour inflammatory conditions in Ghana using formalin-induced pain model in mice. For comparison of analgesic effect, morphine (1 -10 mg kg ^-1) and diclofenac sodium (1 -10 mg kg ^-1) were used as a reference opioid and NSAID, respectively. The aqueous and ethanolic extracts (30-300 mg kg ^-1) dose-dependently inhibited both the first and second phases of the formalin-induced nociception. Oral doses of the aqueous extract (1 -5 g kg ^-1) in imprint control region mice were well tolerated in acute toxicity studies; however a 14-day oral administration of 1-2 g kg ^-1 of the extracts in sprague-Dawley rats produced pathologic effects on the heart, kidney, liver and lungs. Therefore, although the aqueous and ethanolic extracts of H, indicum have analgesic activity, it could have a cumulative toxic effects hence prolonged and continuous use is not advised.