Context: The health effects of Sambucus nigra L. (Caprifoliaceae) could be due to polyphenols whose modes of action differ from the traditional one proposed for exogenous antioxidants.
Objective: The study emphasizes the effects of the association between the renin inhibitor and the polyphenolic extract on biochemical parameters and systolic (TAS) and diastolic (TAD) blood pressure within an L NAME-induced experimental model of arterial hypertension (AHT).
Materials and methods: The polyphenols are extracted with ethanol from isolated and purified vegetable material represented by the mature fruit of the S. nigra with a dosage of 0.046 g/kg body weight (PS), every 2 days, for 8 weeks. The dose represents 1/20 of LD50. The Wistar white rat blood pressure values were recorded using a CODA™ system, which uses a non-invasive blood pressure measuring method.
Results and discussion: The total antioxidant capacity levels were significantly decreased (p < 0.001) in AHT group as compared to the rats in the AHT + PS group. A combination of a renin inhibitor (Aliskiren) and polyphenolic extract generated a superior antioxidant effect compared to administering the two separately. Both TAS and TAD in rats with drug-induced hypertension were reduced by polyphenolic extract. The homogeneous values of TAS record a significant decrease (p < 0.001) of the average values in AHT + PS group or AHT + Aliskiren group.
Conclusion: The combination of two different classes of substances, namely, renin inhibitors and natural polyphenol extracts, reduces arterial pressure and also might reduce the side effects of the major classes of antihypertensive agents and improve the quality of live.
Keywords: Blood pressure; aliskiren; oxidative stress; polyphenols.