Antihypertensive Activity of Aqueous-Methanol Extract of Berberis Orthobotrys Bien Ex Aitch in Rats

Purpose: To investigate the hypotensive potential of Berberis orthobotrys Bien Ex Aitch (Family: Berberidaceae) in both normotensive and hypertensive rats. Methods: Aqueous-methanol (70:30) extract of Berberis orthobotrys at doses of 25, 50, 75 and 100 mg/kg was evaluated for its effect on blood pressure and heart rate using non-invasive blood pressure measuring apparatus. After initial screening, 100 mg/kg dose that produced a maximum effect was selected for the antihypertensive study. Median lethal dose (LD50) and sub-chronic toxicity of the extract were also determined. Various biochemical parameters and organ weight were measured using standard procedures.Results: The extract produced a significant (p 0.01) decrease in systolic blood pressure (SBP), mean blood pressure (MBP), diastolic blood pressure (DBP) and heart rate of normotensive rats at all test doses with maximum effect at 100 mg/kg. Similarly, a significant antihypertensive and negative chronotropic effect was observed in both hypertensive models. LD50 of the extract was 200 mg/kg in mice. The extract also exhibited a reduction (p 0.05) in serum alanine transaminase (ALT), aspartate aminotransaminase (AST), alkaline phosphatase (ALP), triglycerides and low density lipoprotein (LDL) levels while a significant (p 0.05) increase in high density lipoproteins (HDL) level was observed. Conclusion: It seems that the aqueous-methanol extract of Berberis orthobotrys possesses active compounds which may be responsible for the antihypertensive and negative chronotropic effects in rats.