Investigating the Hydroalcoholic Extract of Cheese Plant on the Analgesic Effect of Morphine

Traditional medicine reported the appropriate analgesic and anti-inflammatory effects of Malva sylvestris, The anti-inflammatory effect, which was proved by literature, made it likely that the plant would be effective in pain modulation. Therefore, the effect of its hydro-alcoholic extract on the analgesic effect of morphine was assessed for reducing morphine dosage.

Pain intensity was assessed using Tail Flick test at spot heat of 55°C and cut off time of 10 seconds on adult male rats. An appropriate dose of morphine to cause analgesia was determined intraperitoneally using dose-response method. The analgesic effect of different doses 100,200,400 and 600 mg/kg of Malva sylvestris extract and the effect of the doses on the analgesic property of an appropriate dose of morphine (2.5mg/kg) were examined.

The best analgesic effect with the ability to increase the threshold for occurrence of tail painful reflex was related to dose 400 mg/kg of the extract, which its highest analgesic effect was observed in minute 45. Administration of the most effective dose of the extract with morphine significantly (pvalue<0.05) increased morphine’s analgesic effect. Naloxone administration, 15 minutes before administration of this dose, could significantly (pvalue<0.05) decrease its analgesic effect.

Hydroalcoholic extract of Malva sylvestris (HEMS) is capable of increasing morphine’s analgesic effect. Some of this effect is through its effect on opioid receptors, which are inhibited by Naloxone as an antagonist of morphine that is probably one of its analgesic mechanisms.