The authors report here the results of study on
Parkia biglobosa
seeds used in Burkina Faso for arterial
hypertension treatment. Investigations were done on acute toxicity and vascular properties of fermented and roasted seeds.
Acute toxicity test using mice, revealed by the intraperitoneal route a lethal dose 50 (LD
50) of 1800 mg/kg and 1600 mg/kg of
body weight for aqueous extract from roasted and fermented seeds respectively. According to the scale of Hodge and Sterner
and that of the World Health Organization, such drugs would be classified lightly toxic. Oral administration (up to 3000
mg/kg) did not induce any death of animal. For the vascular properties, the effects of these products were tested on the aorta
isolated from rats. The cumulative administration of extract from roasted and fermented seeds (0.1-10 mg/mL) in an organ
bath induced a concentration-dependent relaxation of the aorta pre contracted by phenylephrine, with or without functional
endothelium. The extracts (10 mg/mL) inhibited for 100% the contraction induced by phenylephrine. The EC
50 values in
presence and absence of endothelium were respectively of 5.37 ± 0.12 and 4.19 ± 1.02 mg/mL for fermented seeds; for
roasted seeds these values were respectively, 5.39 ± 1.12 and 5.93 ± 0.95 mg/mL. Nevertheless, low concentration of roasted
seeds (1-4 mg/mL) induced endothelium-dependent relaxation and this effect was inhibited by indomethacin (10
-5M), and not
by L-NAME (310
-4M). These experimental results revealed a vasorelaxant effect of
P. biglobosa seeds.
P. biglobosa seems
to act directly on the smooth muscle and via endothelium involving the generation of vasodilatating prostaglandins. This
vasodilator effect would be in favor of an anti hypertensive property of
P. biglobosa seeds.
