Analgesic activity of methanolic extract of Heliotropium indicum Linn leaves in mice

Heliotropium indicum (Family: Boraginaceae) locally known as ‘Hatishur’, is a small annual or perennial herb distributed throughout Bangladesh, India, Srilanka, Nepal, Thailand, Tropical Asia, Africa and Philippines. The plant is used in different traditional and folklore systems of medicine for curing various diseases. This study was undertaken to evaluate the analgesic activity of methanolic extract of Heliotropium indicum (MEHI) in animal models with an aim to justify its traditional use. Five groups of five mice each were created out of the animals. Before the tests, the control group was given 0.1 mL/mouse of deionized water orally. The positive control group received intraperitoneally diclofenac sodium at the dose of 10 mg/kg 15 minutes prior to the experiments in hot plate, tail immersion, and acetic acid-induced writhing tests. Thirty minutes before to the trials, MEHI was given orally at dosages of 100, 200, and 400 mg/kg. Deionized water was used to make each medication dosage and MEHI dose. The hot plate and tail immersion tests are distinguished by their tendency to respond to the pain stimuli conducting through neuronal pathways. As our extract of Heliotropium indicum showed significant analgesic activity in thermal heat method, it can be assumed that the extract could act by a central antinociceptive mode like that of diclofenac. On the other hand, Acetic acid-induced writhing test represents pain sensation by triggering localized inflammatory response. Inhibition levels in the acetic acid-induced writhing test were 55.82%, 69.01% and 78.68%, respectively. Based on this result, the methanolic extract of Heliotropium indicum might possess analgesic activity in mice. Additional studies are necessary to further investigate and validate the safe traditional uses of Heliotropium indicum, facilitating its integration into broader research initiatives. Overall, the results give scientific support for the use of the plant in the management of pain.