Role of K⁺ and Ca²⁺ Channels in the Vasodilator Effects of Plectranthus barbatus (Brazilian Boldo) in Hypertensive Rats

Figure 4

Role of Ca²⁺ channels in the relaxant effect induced by the hydroethanolic extract of P. barbatus (HEPB). Concentration-response curves to Phe in the presence or absence of HEPB: 100, 300, and 1000 μg/mL (a, b, and c, respectively). Concentration-response curves to CaCl₂ in the presence or absence of HEPB: 100, 300, and 1000 μg/mL (d, e, and f, respectively). Contraction induced by Phe (g), KCl (h), and caffeine (i) in the presence of HEPB in calcium-free PSS. Nifedipine (NIFE) was used as a positive control. when compared to the vehicle group.

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