This book was written to study the antihyperglycaemic activity of the RFN01 extract in mice. In vivo tests were performed in mice made hyperglycaemic after glucose overload (2 g/kg, per os) and by alloxane injection (150 mg/kg, i.p.). RNF01 reduced the transient hyperglycaemia induced by glucose overload to 6.85 ± 0.24 mmol/l and 5.95 ± 0.62 mmol/l at 400 mg/kg and 500 mg/kg compared to the control which was 8.85 ± 0.62 mmol/l (p<0.05) Two days after the alloxane injection, the blood glucose level of the mice increased to 12.26 ± 0.26 mmol/l, but the RNF01 extract administered orally at a dose of 500 mg/kg reduced the blood glucose level to 8.42 ± 0.36 mmol/l. The presence of flavonoids and alkaloids in RNF01 extract could be responsible for its hypoglycaemic effect.