ABSTRACT
Background: Pain is defined as an unpleasant feeling caused by intense or damaging stimuli. Amorphophallus paeoniifolius known as “Elephant foot yam” is a highly potential tropical tuber crop of Araceae family. The tubers are used as antihaemorrhoidal, haemostatic, expectorant, appetizer, anthelmintic, aphrodisiac and rejuvenating agent. Diclofenac, a COX inhibitor is used as analgesic widely. Analgesic activity of alcoholic extract of Amorphophallus paeoniifolius has been proved in previous animal studies.Methods: Swiss Albino mice of either sex (20-30g) were procured from the central animal house of KFMS&R, Coimbatore. Animals were maintained under controlled temperature and light conditions with food and water ad libitum. Mice were kept in the department to get acclimatized. 24 mice were divided into 4 groups (n=6). Drugs were given orally after 12 hours of fasting. Group I was the control received normal saline, Group II received standard-diclofenac (25mg/kg). Group III and Group IV received aqueous extract of Amorphophallus paeoniifolius 200mg/kg and 400mg/kg respectively.Results: The latency period of Group IV (aqueous extract of Amorphophallus paeoniifolius 400mg/kg) was significant (p<0.01) compared to Group I (controls) and Group II (standard) was significant (p<0.001) when compared to Group IV (aqueous extract of Amorphophallus paeoniifolius 400mg/kg) by hot plate method. In acetic acid induced writhing when compared to control, the percentage inhibition of aqueous extract of Amorphophallus paeoniifolius was 43.65% at 200mg/kg, 46.09% at 400mg/kg and that of the standard was 54.39%.Conclusions: It was concluded that aqueous extract of Amorphophallus paeoniifolius has analgesic activity due to peripheral and central inhibition of prostaglandins synthesis. The extract may have phytoconstituents which inhibit COX enzyme peripherally or act on central opioid receptors(µreceptors) for producing analgesia. It can be used as an add-on drug there by reducing side effects by conventional analgesics.