Evaluation of Cardiovascular Effects of the Hydroalcoholic Fruit Extract of Berberis vulgaris in Acute L-NAME Hypertensive Rats

Introduction: Due to the lack of sufficient studies on the mechanisms of the cardiovascular effects of Berberis vulgaris (B. vulgaris), this study aimed to evaluate the cardiovascular effects of the hydroalcoholic extract of B. vulgaris fruit on nitric oxide (NO) and acute hypertension caused by NG-nitro-L-arginine methyl ester (L-NAME; a NOS inhibitor). Methods: In total, 48 male rats were assigned to six groups (n = 8): the control group, which received saline intraperitoneally (i.p), the L-NAME group, which received L-NAME intravenously (10 mg/kg. i.v), the L-NAME + SNP group, which received sodium nitroprusside (SNP, 50 μg/kg, i.p), followed by L-NAME after 30 min, and three treatment groups, which received the B. vulgaris extract at concentrations of 100, 200, and 400 mg/kg, followed by L-NAME. The heart rate (HR), mean arterial pressure (MAP), and systolic blood pressure (SBP) were measured up to 30 min after L-NAME injection. Afterward, changes (Δ) in SBP, MAP, and HR were calculated and analyzed. Results: All doses of the extract attenuated ΔSBP, ΔMAP, and ΔHR; however, these changes in the groups receiving the extract at the doses of 200 and 400 mg/kg were significantly lower than in the group receiving saline (P < 0.05-P < 0.01, respectively). In the L-NAME group, ΔSBP, ΔMAP, and ΔHR were significantly increased (P < 0.01-P < 0.001). In the L-NAME + SNP group, all responses were significantly lower than in the L-NAME group (P < 0.01-P < 0.001). The extract at the doses of 200 and 400 mg/kg significantly reduced ΔHR, ΔMAP, and ΔSBP induced by L-NAME (P < 0.05-P < 0.001). Moreover, these changes at the doses of 100 and 200 were significantly higher than in the L-NAME + SNP group. Discussion: In the present study, it was demonstrated that the dose of the B. vulgaris extract dependently decreased cardiovascular parameters in basal and L-NAME-induced hypertensive conditions. This response suggests that the cardiovascular effect of the hydroalcoholic extract of B. vulgaris is partly mediated by an increase in NO production. Given the vasodilatory effect of NO, it seems that NO reduces vascular resistance and causes a decrease in blood pressure. Conclusion: NO has a beneficial effect on the cardiovascular system, and the hypotensive effect of B. vulgaris extract is partly mediated by increased NO production.