Lacistema pubescens Mart.: A species with antinociceptive activity

 

Lacistema pubescens MART. (Lacistemataceae) is a plant species originally from Brazil. The Lacistema genus is traditionally used to treat several diseases, including rheumatism, body aches and fever [1]. The objective of this study was to evaluate the antinociceptive activity of its dichloromethane extract (DE) in the writhing, formalin, and tail flick tests [2]. Those tests are behavioral, so to verify that DE did not have sedative action, the open-field test was performed [3]. Besides not affecting the animals locomotion, DE was effective in all doses, 100, 200 and 300 mg/kg, inhibiting abdominal contortions in 67, 71 and 83%, respectively, when compared to the negative control group, in a way statistically equal to indomethacin. This model is sensitive to centrally or peripherally acting analgesic compounds with several different mechanisms of action [3]. In the formalin test, DE (100, 200 and 300 mg/kg) reduced the paw licking time in the initial phase (0 – 5 min) in 56, 54 and 48%, and in the late phase in 29, 38 and 44%, respectively, when compared to the negative control group. The nociceptive effect triggered in this assay is biphasic, with the first phase showing neurogenic nociception, while the second phase shows inflammatory nociception [2]. No effect was observed using the tail flick test, suggesting that DE presented no effect on the opioid system. Thus, these findings reinforce the popular use of the genus and strongly suggest that L. pubescens presented antinociceptive potential acting in neurogenic and inflammatory nociception.

This work was supported by the grants from FAPEMIG, CAPES and CNPq.

[1] Silva JM, Conegundes JL, Mendes RF et al. J Pharm Pharmacol 2015; 67:1613 – 1622

[2] Pinto A, Duque AP, Pacheco NR, Scio E. Pharm Biol 2015; 53:1 – 6

[3] Yin Z, Li L, Chu S, MA Z, Gu X. Sci Rep 2016; 6:27129