A Detailed Review on Nociceptive Models for the Screening of Analgesic Activity in Experimental Animals

Pain is an unpleasant sensation, which informs about any abnormality in either body or part of it. Pain may be either physical or mental depending on its source of origin. Generally, mental or psychic pain is treated with antipsychotic agents, which include, antidepressant, anti-anxiety and anti manic drugs. However, the pain generated by physical stimuli may be treated with analgesic and anti-inflammatory medicine. Analgesic is those drugs or agent, which reduce or block the sensation of pain temporarily. Several synthetic and plant origin analgesic are being tested for their efficacy and potency on different animal model including hot plate, tail flick, tail clip, cold pain, filament pain, tail immersion technique, acetic acid induced writhing test, formalin induced writhing test. Many plant extract have been proved to be analgesic just by evaluating through any one of these model stated, but the present review is based on the detail working principle and constructional detail of all the possible models generally available in pharmacology laboratory. This review also provides the principles of several new models like, tooth pulp, formalin induced writhing, monkey shock test so that they should be used in future.