Major essential oil components, antinociceptive and anti-inflammatory effects of hexane extract of Vitexagnus- castus L. fruits and possible mechanism in male mice

Vitexagnus- castus L. [Vac.] has been used in the Iranian traditional medicine for the treatment of pain and swelling of uterus. In this study, GC and GC/MS analyses were carried out for the identification of essential oil chemical components. Formalin and Xylene-induced ear-edema were used in order to nociception and inflammation activity. Then, the possible interaction between 3drugs including Naloxone (2mg/kg), Dextrometorphane(20mg/kg), and L-NAME (10mg/kg) have been used and Vitexagnus-castus hexane extract was examined. 1,8-Cineole (23 %), alpha-Pinene (16 %), beta- Pinene (13 %),, Z- Caryophylene (11 %), alpha- Terpinyl acetate (9 %), E- caryophylene (9 %) and Linalool (6.5 %) were the major identified components of the essential oil of Vitexagnus- castus L. Hexane extract was reduced licking time as compared to the control group in the first and second phase of formalin test. In Xylene-induced ear-edema, the hexane extract of Vitexagnus- castus fruits was strongly inhibited inflammation as compared to the positive control group. Interaction between L-NAME and Vitexagnus-castus hexane extract showed significant effect. It was concluded that the anti-inflammatory and antinociceptive effects of the fruit of Vitexagnus- castus L. may be due to its very pharmacological effective essential oil components. Interaction between L-NAME and Vitexagnus-castus hexane extract showed that one of the possible pathways is NO pathway, but Vitexagnus-castus hexane extract probably acts via other pathways that need more research.