| چکیده انگلیسی مقاله |
BACKGROUND AND OBJECTIVE: Chamomile has several analgesic properties, while the mechanism of these effects in interaction with male sex hormones compared tofemales are not well known. This study aimedto evaluate the analgesic effects of hydro-alcoholic extract of chamomile in male mice, and two phases of femalesexual cycle (diestrus and proestrus) in the presence or absence of estrogen receptors. METHODS: In this experimental study, adult mice of both genders(weight: 27±3 g) were divided into four groups of control, chamomile recipients (30 or 50 mg/kg), tamoxifen recipients (0.5 or 1 mg/kg), and recipients of combined tamoxifen (1 mg/kg) and chamomile (30 or 50 mg/kg). Drugs were administeredintraperitoneally in one milligram per a kilogram of the body weight, and formalin test was used to induce acute and chronic pain. In addition, cumulative length of foot licking was calculatedin seconds as theindicator of pain perception. FINDINGS: In male mice,chamomile extract (30mg/kg) reduced acute pain (53±2, p< 0.01)and chronic pain (71±2, p< 0.001), and dosage of 50 mg/kgcould reduce acutepain (41±1, p< 0.001) and chronic pain (73±2, p< 0.001). In diestrus and proestrusfemales, chamomile extract could relieve acute pain at 50 mg/kg (42±2, p< 0.05 and 39±1, p< 0.05, respectively). As for the chronicphase of pain, chamomile extract (30 mg/kg) was effective in diestrus (72±1, p< 0.01) and proestrus (80±2, p< 0.001) female mice, whileit could reduce chronic pain at 50 mg/kgindiestrus (59±1, p< 0.001) and proestrus (62±2, p< 0.001) females. In male mice, the analgesic effects of the extract were more significant.In addition, tamoxifen (1mg/kg)reduced chronic pain in diestrus (81±3, p< 0.05) and proestrus (92±2, p< 0.05) female mice. In male mice,combination of chamomile (30 mg/kg) and tamoxifen (1mg/kg) decreased acutepain(43±3, p< 0.05), andcombination of chamomile (50 mg/kg)and tamoxifen (1mg/kg) reduced acute pain (29±1, p< 0.05) and chronic pain (41±2, p< 0.01) in male mice. Moreover, the drug combination reduced acutepain (21±1, p< 0.001) and chronic pain (44±3, p< 0.01)in diestrus females, as well as proestrus ones(19±2, p< 0.001) (43±3, p< 0.001). CONCLUSION: According to the results of this study, analgesic effects of chamomile extract are gender-dependent,and these effects are more significant in male mice.Increased analgesic effectsof combinedchamomile and tamoxifen couldbe due to the interaction between estrogenreceptorsand analgesic agents of chamomil. |