Figure 3
(A) Relaxant effects of various extracts (10-4 to 10-1g/l) of hibiscus sabdariffa calyx in aortic rings with endothelium precontracted with norepinephrine (10-8 to 10-6M) and (B) Comparative Emax (% values in terms of vasorelaxant effects of the various enriched extracts. Values are expressed as mean ± SEM of 6-8 experiments; ns: not significant; *: P < 0.05, ** P < 0.01, in comparison to crude extract as reference.