Blood pressure lowering effects of Ranunculus scleratus Linn. in normal and fructose induced hypertensive rats and estimation of underlying mechanisms.

Ranunculus scleratus Linn. is used in folk medicine to treat hypertension. This study was aimed at providing validation to its traditional use and to explore underlying mechanisms of action. Effects of hydro-ethanolic crude extract of the plant and its fractions on blood pressure was evaluated using direct surgical method in normotensive and in fructose induced hypertensive rats. Various doses of crude extract, RSC, (5, 10, 20, 30mg/kg) and all fractions (3, 5, 10, 20mg/kg) were studied. Results suggested that aqueous fraction of R. scleratus (RSA) produced most pronounced effects at 10mg/kg in normotensive and at 20mg/kg in hypertensive animals. Underlying mechanisms, using various pharmacological antagonists were also elucidated. Results suggested the involvement of muscarinic receptor, angiotensin converting enzyme (ACE) inhibition, ganglionic block and nitric oxide (NO) release in presenting hypotensive response.