Evaluation of chemical composition, anti-inflammatory and anti-nociceptive effects of Eugenia caryophyllata buds essential oil

Eugenia caryophyllata well known as Clove is a tree from Myrtaceae family that several parts of this plant traditionally used in dental care as an analgesic. This study aimed to assess the chemical composition, anti-inflammatory and anti-nociceptive activities of the essential oil extracted from Clove buds. The essential oil of Clove buds (EOC) was extracted by Clevenger type apparatus and its chemical composition determined by gas chromatography-mass spectrometry (GC-MS). Analgesic activities of EOC were measured by formalin-induced orofacial pain and tail immersion test in rat. Also anti-inflammatory effect of the EOC was evaluated by using xylene induced ear edema test in mice. EOC (100, 200 mg/kg, SC) and ketoprofen (80 and 160 mg/kg, IP) inhibit only the second phase of orofacial pain. Morphine (5 mg/kg) as a positive control significantly (p <0.05) reduced pain response in the both phases of pain. Pre-treatment of animals with naloxone did not prevent the EOC (200 mg/kg) analgesic activity. Co-administration of sub-analgesic doses of EOC (50 mg/kg) and ketoprofen (40 mg/kg) significantly (p <0.05) reduced nociceptive behavior in second phase. Also EOC (100 and 200 mg/kg) failed to increase nociceptive response latency in the tail immersion test. Meanwhile, EOC (100 and 200 mg/kg) and ketoprofen (80 mg/kg) significantly (p <0.001) attenuated xylene-induced ear edema in mice. Also according to GC-MS results the major components of the EOC were eugenol (54.86%), β-Caryophyllene (20.19%), α-Humulene (7.11%), eugenol acetat (4.85%) and Chavibetol (2.23%). These data showed that EOC possessed potent anti-inflammatory activity and produced non-opioid mediated analgesia in the second phase of orofacial pain without any effect on tail immersion response.