Studies on the analgesic, anti-inflammatory and antipyretic effects of Parquetina nigrescens leaf extract

Ethnopharmacological relevance: Parquetina nigrescens is a shrub that is commonly used in different parts of West Africa for the treatment of several ailments which includes pain, fever and inflammatory conditions. Aim of the study: The present study was designed to investigate the analgesic, anti-inflammatory and antipyretic effects of the aqueous extract of Parquetina nigrescens leaves in rats. Materials and methods: Five groups were used for each study, groups 1 and 5 served as control (saline) and reference (indomethacine) respectively, while groups 2-4 received the extract (50-200 mg/kg) orally. Formalin paw licking and hot plate latency tests were used for analgesic studies. Carrageenan oedema, cotton pellet granuloma and formaldehyde arthritis models were used to quantify the anti-inflammatory activities while the brewer's yeast was used for inducing pyrexia. Results: The results of the analgesic study show that the extract produced significant (p < 0.05) analgesia in the hot plate and in the formalin tests. In the anti-inflammatory study, Parquetina nigrescens produced significant (p < 0.05) inhibition of the various types of inflammation. The extract also inhibited the pyrexia induced by brewer's yeast. Conclusion: The result justifies the traditional uses of Parquetina nigrescens for the treatment of fever, inflammatory and painful conditions. (C) 2009 Elsevier Ireland Ltd. All rights reserved.