The essential oil of Hyptis crenata Pohl ex Benth. presents an antiedematogenic effect in mice

Hyptis crenata, commonly known as "salva-do-Marajó", "hortelã-do-campo", and "hortelãzinha", is used in folk medicine in Northeast Brazil as tea or infusion to treat inflammatory diseases. Due to the pharmacological efficacy and the low toxicity of the essential oil of Hyptis crenata (EOHc), we decided to investigate the EOHc antiedematogenic effect in experimental models of inflammation. EOHc was administrated orally at doses of 10-300 mg/kg to male Swiss albino mice. Paw edema was induced by subcutaneous injection in the right hind paw of inflammatory stimuli (carrageenan, dextran, histamine, serotonin, and bradykinin) 60 min after administration of EOHc. EOHc significantly inhibited the induced edema. The inhibitory effect of EOHc on dextran-induced edema extended throughout the experimental time. For the 30, 100, and 300 mg/kg doses of EOHc, the inhibition was of 40.28±1.70, 51.18±2.69, and 59.24±2.13%, respectively. The EOHc inhibitory effect on carrageenan-induced edema started at 10 mg/kg at the second hour (h) and was maintained throughout the observation period. At 30, 100, and 300 mg/kg doses the inhibition started earlier, from 30 min. At the edema peak of 180 min, 56, 76, and 82% inhibition was observed for 30, 100, and 300 mg/kg doses, respectively. Additionally, the effect of EOHc on carrageenan-induced paw edema was influenced by the time of administration. The EOHc also inhibited myeloperoxidase activity. In conclusion, the EOHc showed a potent effect, both preventing and reversing the edema, consistent with its anti-inflammatory use in folk medicine.