Liriodendrin, ameliorates hypertension by calcium channel blockade and enhancing enos expression in wistar rats

Introduction: Hypertension is found to be the prime cause of death worldwide in spite of a number of available treatments which suggests that there is a need of discovering new lead molecules that would be more effective to treat cardiovascular disease (CVD). Liriodendrin, the lignan phytoconstituent possesses potential pharmacological effects. Literature survey suggests that liriodendrin could be effective in mitigating hypertension considering its structural similarity with reported cardiovascular protective drugs. Hence liriodendrin is investigated to reveal its mechanism of actions to support its antihypertensive property. Methods: Hypertension was induced in male wistar rats with DOCA salt. Hypertensive rats were treated with liriodendrin for 4 weeks. Blood pressure, heart rate, body weight, lipid profile, serum nitrite levels, vascular reactivity to various catecholamines, in-vitro calcium channel blocking assays, antioxidant assay, determination of aortic calcium level, endothelial function, expression of eNOS analysis were studied. Result: Liriodendrin was found safe orally up to 2000 mg/kg. It showed a significant decrease in heart rate, blood pressure and mean arterial pressure. In-vitro study on the isolated rat aorta revealed the calcium channel blocking potential of liriodendrin. Vascular reactivity to various catecholamines was normalized. Vascular endothelium was significantly protected by the enhanced release of nitric oxide and eNOS expression by the western blot technique. Oxidative stress was also significantly reduced. Conclusion: Liriodendrin was found to be beneficial in hypertension as it produced vasorelaxation by blocking calcium channels, enhancing nitric oxide release, and reducing oxidative stress. Thus, liriodendrin may be useful to relieve hypertension and cardiovascular complications.