International Journal for Pharmaceutical Research Scholars (IJPRS) V-3, I-1, 2014 ISSN No: 2277 - 7873 RESEARCH ARTICLE © Copyright reserved by IJPRS Impact Factor = 1.0285 227 Comparative Evaluation of Analgesic Activities of Aniseed Essential and Fixed Oils Jamshidzadeh A, Hamedi A*, Altalqi A, Najibi A School of Pharmacy, Shiraz University of Medical Sciences, Shiraz, Iran. Manuscript No: IJPRS/V3/I1/00025, Received On: 23/01/2014, Accepted On: 01/02/2014 ABSTRACT Different dosage forms of Aniseed oil have been used in Persian traditional medicine for their pain killer and analgesic properties but their effects have not been compared scientifically. Aniseed essential oil was extracted using hydro-steam distillation method. Fixed oil was extracted with petroleum ether and oils composition was analyzed by GC-MS. Phenolic content of fixed oil was determines spectrophotometrically. Different concentrations of essential and fixed oil were injected i.p. to the rats and animals were evaluated for analgesic effect at three times (30, 60 and 120 min) after injection by tail-flick and formalin tests. Major constituents of essential and fixed oil were anethole (87.58%) and 9- octadecenoic acid (74.55%). All doses of fixed and essential oil after 60 min had the highest significant analgesic effect compared to the control group (P < 0.01). The analgesic effect of the essential oil (500 mg/kg) was higher than paracetamol (100 mg/kg) in chronic phase of pain in formalin test (P < 0.05). Also, in both tests analgesic effects of essential oil was higher than fixed oil in all doses but it was significant just at 500 mg/kg (P < 0.05). Analgesic effects of essential and fixed oils of P. anisum are comparable with paracetamol but essential oil in higher doses was significantly more effective than fixed oil. KEYWORDS Aniseed, Analgesia, Essential oil, Fixed oil, Pain, Pimpinella anisum, Rat INTRODUCTION Pain is an unpleasant feeling often caused by intense or damaging stimuli. The management of pain is considered as a major clinical problem. 1 Acute pain indicates injury and has essential biological value as an alert of imminent or ongoing tissue lesion, leading the individual to fight, flee, or attempt to remove the causal agent. 2 Chronic pain is considered a disease that results from extensive inflammatory reactions that usually results in tissue damage and a loss of function. 3 Medicinal plants and their active components have been increasingly explored to find promising alternatives to treat pain and inflammation processes. Pimpinella anisum L. (Anise), member of Apiaceae family, is an annual herb with white flowers and small green-yellow seeds, which grow in warm regions of the world. 4 Whole aniseed, its extracts or volatile oils are used as a food spice in many countries. 5 The aniseed also has a long list of traditional medicinal uses such as carminative, diuretic, diaphoretic, expectorant antiseptic and antispasmodic. 6 Both the extracts and essential oil of Pimpinella are known to be rich in pseudoisoeugenol type phenylpropanoids which is unique to the genus. Aniseed oil has been used in Persian traditional *Address for Correspondence: Azadeh Hamedi Medicinal Plants Processing Research Center, School of Pharmacy, Shiraz University of Medical Sciences, Shiraz, Iran. E-Mail Id: Hamediaz@sums.ac.ir