Vasodilator Effect of Ethanolic Extract of Mulberry Leaves (Morus alba L.) in Rat and Rabbit

The effects of ethanolic extracts of Mulberry Leaves (Morus alba L.) on nitric oxide (NO) serum level in rat and diameter of blood vessels in rabbit ear were investigated. NO level of ethanolic extract of mulberry leaves at dose of 100 mg/kg bw rats gave significant difference compared to negative control (P<0,05) at minute 30 after extract administration (4,51 ± 4,31 μM). Ethanolic extract of mulberry leaves at dose of 200 mg/kg bw had no significant difference in NO serum level. However, ethanolic extract of mulberry leaves at dose of 400 mg/kg bw rats increased NO serum level significantly compared to negative control (P<0,05) at minute 0, 10, 30, 60, and 90 after extract administration. The maximum serum level of NO of 400 mg/kg bw mulberry extract was 4,62 ± 3,05 μM, and it is the highest among other groups. Therefore this dose was choosen for vasodilatation assay in rabbit. Observation on blood vessels diameter in rabbit ears showed that ethanolic extract of mulberry leaves were able to dilatate the big vessels and small vessels of rabbit ears significantly compared to negative control (P<0,05) at minute 60 after extract administration. In conclusion, ethanolic extract of mulberry leaves at dose of 400 mg/kg bw rats or 202.67 mg/kg bw rabbits has a vasodilator effect, probably due to an increase of NO serum level.