Analgesic, Anti-Inflammatory and Antipyretic Effect of Mentha spicata (Spearmint)

Aim: Mentha spicata (L.) is popularly used as herbal remedy for various ailments. But the scientific basis for its medicinal use especially in pain and inflammation remains unknown. Therefore, the present study was aimed to investigate the analgesic, anti-inflammatory and antipyretic effects of whole plant of Mentha spicata in laboratory animals. Materials and Method: The methanol extract of Mentha spicata (MEMS) was used to investigate the acute effect on analgesia by Hot-plate test and acetic acid induced writhing method (By acetic acid) in mice and on inflammation in rats by carrageen induced paw edema method. Subcutaneous injection of 20% aqueous suspension of Brewer's yeast in wistar rats leads to pyrexia. Results: The extract showed a significant (p<0.001) dose dependent increase in reaction time in mice in the hot-plate test at the doses of 250 mg/kg and 500 mg/kg body weight. The extract showed a significant (p<0.05) dose dependent increase in reaction time in mice in writhing method at the doses of 250 and 500 mg/kg body weight. The extract also exhibited promising anti-inflammatory effect as demonstrated by statistically significant (p<0.05) inhibition of paw volume by 42.58% at the dose of 250 mg/kg body weight and 45.10% at the dose of 500 mg/kg body weight at the sixth hour of study. Intraperitoneal administration of MEMS showed dose dependent decrease in body temperature in brewer's yeast induced hyperthermia in rats at both doses. However, MEMS significantly decreased body temperature (p<0.05) at 500mg/kg compared to control. Conclusion: This study suggests that the methanol extract of Mentha spicata have analgesic, anti-inflammatory and antipyretic activity in a dose dependent manner which supports its use as an analgesic, anti-inflammatory and antipyretic drug in folk medicine.