Biphasic effect of Solanum nigrum fruit aqueous extract on vascular mesenteric beds in non-diabetic and streptozotocin-induced diabetic rats.
BACKGROUND
In Asia, Solanum nigrum fruit is traditionally used to manage, control, and treat diabetes.


OBJECTIVE
This study was carried out to investigate the endothelium and nitric oxide roles in Solanum nigrum-induced vasorelaxation in non-diabetic and diabetic rat vessels.


METHODS
Diabetes was induced by a single i.p. injection of streptozotocin. Eight weeks later, superior mesenteric arteries of non-diabetic and diabetic groups were isolated and perfused according to the McGregor method. Solanum nigrum fruit extract (SNE) at concentrations of 0.00001 to 0.6 mg/ml was added to the medium and perfusion pressure was recorded.


RESULTS
Baseline perfusion pressure of diabetic group was significantly higher than non-diabetic rats in both intact and denuded endothelium. The low concentrations of SNE have vasodilatory effect in the diabetic and non-diabetic, but high concentrations of SNE produce initial significant contractions, followed by secondary relaxations in normal and diabetic rats. We observed vasorelaxation at low and high concentrations of SNE in both diabetic and non-diabetic groups after endothelium denudation. SNE-induced vasorelaxation in diabetic group is mediated by both endothelium and smooth muscle, but the relaxatory effect of SNE in non-diabetic group is not mediated by endothelium, and SNE has direct action on the smooth muscle.


CONCLUSIONS
Although the part of SNE-induced relaxation in diabetic vessel was mediated by endothelium, nitric oxide didn't play any role in this action, and maybe we can use SNE in the management of diabetes vessel complications in future.
Molecular Medicine Research Center, Hormozgan University of Medical Sciences, Bandar Abbas, Iran ; Department of Physiology, School of Medicine, Hormozgan University of Medical Sciences, Bandar Abbas, Iran.
Shahla
S
Sohrabipour
Department of Physiology, School of Medicine, Hormozgan University of Medical Sciences, Bandar Abbas, Iran.
Fatemah
F
Kharazmi
Molecular Medicine Research Center, Hormozgan University of Medical Sciences, Bandar Abbas, Iran ; Department of Physiology, School of Medicine, Hormozgan University of Medical Sciences, Bandar Abbas, Iran.
Nepton
N
Soltani
Department of Pharmacognosy, Faculty of Pharmacy, Shahid Bahashti University of Medical Sciences, Tehran, Iran.
Mohammad
M
Kamalinejad
Diabetes mellitus; Solanum nigrum fruit extract vasorelaxation; mesenteric bed; nitric oxide