The effect of Hypericum perforatum on isolated rat aorta

Investigation of the embryotoxic and teratogenic effect of Hypericum perforatum in pregnant rats

Objective:

Hypericum perforatum (HP) is a herbal product used in the treatment of depression, but its harm on the fetus has not been established. This study investigated the effects of HP according to fetal clinical, morphologic, and histologic findings. Study design is an animal study.

Materials and Methods:

Fifty-four 4-5-month-old female Wistar rats were divided into three groups: control, 100 mg/kg HP, and 300 mg/kg HP. HP treatment using drinking water was started one week before mating and ended with the delivery of pups.

Results:

HP exposure before conception diminished the pregnancy rate and decreased the fetal number; during pregnancy it tended to increase the duration of gestation, and deteriorated the fetal development as determined using body weight. It also damaged liver and kidney tissues, most probably due to oxidative stress, as supported through inducible nitric oxide synthase antibody staining findings at both doses.

Conclusion:

HP should not be recommended to women who would like to be pregnant or are pregnant because it can be harmful for both fetal and maternal health.

Treated effect of silymarin on vascular function of aged rats: Dependant on nitric oxide pathway

Abstract Context: Aging leads to endothelial dysfunction and vascular stiffness which are the main causes of many cardiovascular diseases. Previous reports have shown that the cell protective effect of silymarin (SM) is dependent on its antioxidant properties. Objectives: We investigated the effect of SM on vascular functions of aged rats and the involvement of nitric oxide or cyclooxygenase (COX) activity in this effect. Materials and methods: Isolated rat aortas were obtained from 22-month old rats. Each ring was incubated with SM (50 mg/L), SM/l-nitro-arginine methyl ester (100 μM, l-NAME) or SM/indomethacin (10 μM, INDO) in tissue bath. Three- to four-month-old rats were used as young controls. Endothelium-intact rings were precontracted with α-receptor agonist phenylephrine (0.001-30 µM) or voltage-dependent high potassium (40 mM), endothelium dependent/independent relaxant responses were obtained using acetylcholine (0.001-30 µM) and sodium nitroprusside (0.0001-3 µM), respectively. Results: Aging increased phenylephrine sensitivity (6.45 ± 0.08; 6.88 ± 0.09) and decreased KCl contraction (882 ± 118.4; 499 ± 80.4). SM treatment decreased the Emax of both agents (548 ± 109; 223 ± 48.9). Aging deteriorated acetylcholine relaxation (93.9 ± 2.09; 72.0 ± 2.56) and SM improved the response (86.3 ± 1.90). l-NAME prevented the SM effect whereas INDO was ineffective. Discussion and Conclusion: Immediate SM treatment partially restored endothelial dysfunction and vascular tone in aging. The possible mechanism might not be mediated by prostacyclin or the COX pathway in acute administration; the nitric oxide pathway and calcium antagonistic features of SM relate to its action on the vessel.