Acute toxicity, anti-inflammatory, analgesic and antipyretic effects of aqueous and hydroethanolic extracts of Brenania brieyi (Rubiaceae)

Abstract

Brenania brieyi (Rubiaceae) is widely used in traditional Congolese medicine in the treatment of many pathologies that are manifested by inflammation, pain and fever. The objective of this study was to study the acute toxicity as well as to evaluate the antipyretic, analgesic and anti-inflammatory effects of the aqueous and hydro-ethanolic extracts of Brenania brieyibark on models of pyrexia, algesia and inflammation induced in rodents. The aqueous extract of Brenania brieyidoes not cause any mortality up to the dose of 4000 mg/kg, but promotes a slight increase in body weight. From 2000 mg/kg, the signs of toxicity observed were the significant decrease in mobility as well as the loss of alertness. At doses of 100 and 200 mg/kg, aqueous and hydro-ethanolic Brenania brieyiextracts showed a very significant anti-inflammatory effect (***p< 0.001) on edemas induced by carrageenin (1%), formaldehyde (2.5%) and histamine (1 mg/mL), greater than that of diclofenac at 10 mg/kg. At 200 mg/kg, both extracts showed a very significant analgesic effect (***p< 0.001), greater than that of paracetamol 100 mg/kg against pain induced by acetic acid 0.6% and formaldehyde 2.5%. Brenania brieyiwas slightly effective in the tail flick test. Brewer's yeast-induced hyperthermia was reduced by both extracts. However, the hydro-ethanolic extract proves to be more effective than the aqueous extract in all the tests carried out. These pharmacological effects would be related to the presence of alkaloids, tannins, flavonoids, anthraquinones, oses and saponosides.