Antinociceptive and anti-tussive activities of the ethanol extract of the flowers of Meconopsis punicea Maxim

BACKGROUND: As an important traditional Tibetan (veterinary) medicine, the flowers of Meconopsis punicea (family Papaveraceae) have been used to treat pain, fever, cough, inflammation, liver heat and lung heat of humans and animals by local people for thousands of years. In this paper, we aimed to investigate the antinociceptive and anti-tussive activities of the ethanol extract of M. punicea (EEM). METHODS: Firstly, HPLC was used to analyze the main constituents of the ethanol extract of M. punicea. In animal experiments, the acetic acid-induced writhing response test, hot plate test, barbiturate-induced sleeping time and formalin tests were used to evaluate the antinociceptive activity. Then, ammonia-induced coughing and sulfur dioxide-induced coughing tests in mice as well as the phenol red secretion in trachea test were used to investigate the anti-tussive activity of the extract. Finally, an acute toxicity study was carried out. RESULTS: The results showed that alkaloids and flavonoids were the main compounds in the ethanol extract of M. punicea flowers. The extract at 125, 250 and 500 mg/kg had good antinociceptive and anti-tussive activities in mice with a dose-dependent manner. CONCLUSIONS: These findings suggested that EEM has significant bioactivities, and the active components of M. punicea should be studied further.