Phytochemical Screening and Analgesic Effect of Methanol Root Extract of Datura Metel in Experimental Animals

Owing to the fact that plants have been used from ancient times in almost all cultures as a source of medicine; they are considered to be the backbone of traditional medicine and are widely used to treat acute and chronic diseases. Hence, the approval by WHO in the use of natural products for national policies and drug regulatory measures in order to strengthen research and evaluation of the safety and efficacy of herbal products. It is reported that of the 119-plant derived drug listed by WHO study, 74% were discovered as a result of chemical studies to isolate the active compounds responsible for the medicinal properties. Datura metel is a bitter narcotic plant that relieves pain and inflammation when taken as concoctions. It has a long history of use as native medicine, commonly used for management and treatment of chest complaints, including asthma, cough, tuberculosis and bronchitis etc. Phytochemical results revealed the presence of alkaloids, tannins etc. that might be responsible to the analgesic activity of the plant parts. Lorke’s method was used to establish the dose of the plant extract as well as determine the safety margin (LD50) of the root extract as greater 5,000 mg/kg. Twenty-five healthy albino miceof both sexes were randomly assigned into five groups of five each. The mice in group 1 served as the control, which were given Normal saline, group 2 were administered with standard drug (ibuprofen 400 mg/kg), while groups 3, to group 5 served with 218, 436, 654 mg/kg of the methanol root extracts respectively; which is 5%, 10% and 15% of the extracts LD50.The result of the work shows that analgesic activity of methanol root extract of D. metel is dose dependently effective. Hence, the need to isolate and characterize the lead compound in order to produce new drugs.