Abstract
Multiple sclerosis is an inflammatory disease of the central nervous system. Chronic pain is one
of the main symptoms, affecting many patients. Studies show that the lignans or the apolar
extracts of Phyllanthus amarus have antinociceptive effects in different animal models.
To evaluate the antihypernociceptive effect of a hexanic extract of P. amarus in
experimental autoimmune encephalomyelitis in mice, the chemical composition of the hexanic
extract was analyzed by gas chromatography mass spectrometry. After EAE induction, animals were
treated with the hexanic extract of P. amarus for 26 consecutive days. Motor coordination
and mechanical hypernociception were evaluated on alternate days. The principal lignans found
were phyllanthin, niranthin, and 5-demethoxyniranthin. The hexanic extract of P. amarus
at a dose of 100, 200, or 400 mg/kg did not affect the development of the disease. The motor
coordination and pain threshold of the treated animals were not altered in this experiment. In
conclusion, in this test, the hexanic extract of P. amarus did not show evidence of
antihypernociceptive activity in experimental autoimmune encephalomyelitis.
Key words
Phyllanthus amarus
- Euphorbiaceae - pain - hypernociception - experimental autoimmune encephalomyelitis - lignans
