Planta Med 2006; 72 - P_078
DOI: 10.1055/s-2006-949878

Antinociceptive profile of ethyl acetate extract of Hyptis fruticosa Salzm. ex Benth. (Labiatae)

RM Marçal 1, DM Ptak 1, RR Krempser 1, MR Krempser 1, SV Floresta 1, MPN Moreno 2, SCH Cavalcanti 1, JB Fernandes 2
  • 1Physiology Department, Federal University of Sergipe, Av. Marechal Rondon, s/n; CEP 49.100–000, São Cristóvão, SE, Brazil
  • 2Chemistry Department; Federal University of São Carlos, Rodovia Washington Luis, KM 235, CEP 13.0565–905, São Carlos, SP, Brazil

Hyptis fruticosa, an aromatic medicinal shrub, is commonly used in Brazilian folk medicine to soothe pain. In this work, the antinociceptive profile of the ethyl acetate extract of H. fruticosa (EA) was investigated on three different pain models: the acetic acid-induced writhing reaction [1], the hot-plate test [2], and the formalin test [3]. H. fruticosa leaves, collected in São Cristóvão (Brazil), were dried, pulverized and macerated (r.t.) in ethyl acetate (17.8% yield). The exploratory HPLC show compounds at A (236; 276 nm), B (242nm; 275 nm), C (196; 202; 236; 276 nm), D (198; 214; 229; 262; 273 nm) and E (198; 214; 229; 262; 273 nm). Indomethacine (7.5mg/kg; p<0.001) and morphine (2.5mg/kg; p<0.001) were used as positive control in the writhing and the hot-plate tests, respectively. The EA (25–400mg/kg) dose-dependently reduced writhing induced by acetic acid (p>0.05– p<0.001) and increased the latency time in the hot-plate test (p>0.05– p<0.001). The analgesic effect of EA was reversed by naloxone (3mg/kg) in the hot-plate model. Naloxone (3.0mg/kg) was ineffective in the hot-plate method. Morphine (7.5mg/kg) reduced the pain reaction in both the early (p<0.001) and the late (p<0.001) phases of the formalin model. Ethyl acetate extract (100mg/kg, p<0.05 and 200mg/kg; p<0.05), like morphine, showed analgesic effects in both phases of the formalin test. In conclusion, the ethyl acetate extract of Hyptis fruticosa showed an opioid-like antinociceptive effect.

Acknowledgments: CNPq.

References: 1. Koster, R. et al (1959), Fed. Proc. 18: 412–418. 2. Ankier, S.I. (1974), Eur. J. Pharmacol. 27:1–4. 3. Hunskaar, S., Hole, K. (1987), Pain 30:103–114.