The Effect of a Mixed Extract of Peppermint, Mentha, Evening Primrose, and Eucalyptus on Lowering Body Temperature in Rats

Background and aim: increased body temperature (fever) is a common clinical indicator of disease and can lead to altered metabolism and subsequently threaten life. studies have shown antimicrobial, analgesic/antipyretic effect for some eucalyptus and mentha species. therefore, in the present study we assessed the effect of the combination of mint (mentha), eucalyptus, evening primrose, and basil on lowering body temperature. methods: this experimental study was performed on 30 rats in five groups. a hydroalcoholic extract was prepared from each plants using ethanol as solvent and concentrated with a rotary apparatus. then the extracts were combined in equal proportions. to induce fever, the brewer's yeast fever induction method was used by intraperitoneal injection of a 20% aqueous suspension. the febrile rats were then divided into groups receiving different doses of the mixed extract (200, 500, 750 mg/kg); normal saline and paracetamol were used in control groups. rectal temperature was measured with a digital thermometer before injection and 6, 8, 12, and 16 hours after extract injection. the analysis of variance with repeated measurements was used to evaluate the effect of hydroalcoholic plant extracts on fever changes. results: the mean fever in the intervention groups with all effective doses decreased over the hours, and the mean fever with a dose of 750 mg decreased more than in the other groups (p-value < 0.05). we had the lowest fever at a dose of 750 mg and a time of 16 hours (p-value < 0.05).conclusion: the results show that the combined extract can reduce body temperature in rats, and by increasing the effective dose, the recovery rate and temperature reduction are faster and more effective.