Antipyretic effect of methanolic extracts of Limnophila repens and Argyreia cymosa whole plant on albino rats

Abstract

Objective: The aim of the study was to evaluate the antipyretic activity of methanolic whole plant extracts of Limnophila repens (L. repens) and Argyreia cymosa (A. cymosa) using Brewer’s yeast-induced pyrexia model. Materials and methods: It was a randomized controlled experimental study. A total of 60 rats were taken, dividing them into six groups, each containing ten rats. Methanolic extract of L. repens (MELR) and A. cymosa (MEAC) was administered at 200, and 400mg/kg doses orally to the respective four groups. The control group was fed with normal saline at 2ml/kg. A 20% suspension of Brewer's yeast in normal saline was injected subcutaneously at a dose of 10ml/kg body weight under the nape of the throat of rodents in all groups. Pyrexia produced following ten h of Brewer's yeast injection, and the temperature was recorded. Drugs received soon after the development of pyrexia and temperatures were recorded. Paracetamol at 150ml/kg orally was taken as the conventional medication. Results: The MELR and MEAC were showed significant (P<0.05) antipyretic activity at 400mg/kg. Paracetamol showed substantial antipyretic activity from 30min of drug administration to 180min. At 400mg/kg dosage the extracts (MELR and MEAC) revealed a considerable decrease in yeast evoked raised temperature when compared with that of standard drug paracetamol where by the extract dose 200mg/kg had been less effective as compared to the higher dose (p<0.05). Conclusion: This research confirmed that MELR and MEAC at a dose of 200 and 400mg/kg own considerable antipyretic outcome against the yeast-induced raised temperature. However, the active chemical constituents responsible for the antipyretic action need to be investigated further.