The analgesic properties of azadirachta indica (NEEM) in mice

Abstract

Pain is among the most common symptoms leading patients to consult a physician in the USA.The National Centre for Health Statistics estimates that about 25% of the US population has chronic or recurrent pain, and 40 % state that the pain has a moderate or severe degrading impact on their lives. Pain is therefore a very common condition. The major strategies of pain management include pain relieving medications,physical or occupational therapy and complementary therapies (such as acupuncture and massage). However,there is need to come up with other means of managing pain. Herbal medicines are therefore becoming increasingly popular in the management of pain, although research on herbal medicines is still in the early phases. The main objective of this study was to investigate the analgesic and antinociceptive properties of extracts of Azadirachta indica inmice. Assessment of analgesic potency was done using the hot plate method.The purpose of the experiment was to demonstrate whether leaf and bark extracts of Azadirachta indica exhibited any analgesic effects on mice. The drug was administered intraperitoneally in three different concentrations to three groups of mice and observations made on the duration taken for the animals to respond to the heat stimulus.Positive and negative control groups of mice were also set up using morphine and saline respectively administered to the mice. The end point was be taken as the time taken for the mouse to stand on its hind legs and lick its front paws.Naloxone was then given to study the mechanism of analgesia,that is, to demonstrate central origin of analgesia,given that it is an opioid antagonist.This was used to demonstrate whether the extract acted through the opioid receptors if the effect is reversed hence analgesia is decreased.The reaction time was takenat intervals of 5 minutes for 1hour after administration of drug. Phytochemical tests were also carried out on both the bark and leaf extracts. Dose dependent analgesic activity was observed for the A. indica extracts. The Azadirachta indica extracts exhibited mild analgesic activity, with the leaf extract showing more activity than the bark extract. The extract worked through opioid receptors.