Effect of cassia seed aqueous extract on blood pressure level in n-nitro-l-arginine-methyl ester induced hypertensive rats / 中国组织工程研究

ABSTRACT

BACKGROUND: The concept of modern diagnosis and treatment of hypertension is to protect target organs, improve clinical symptoms and minimize clinical events through antihypertensive treatment. Cassia seed has an antihypertensive effect that has been confirmed in animal experiment and clinical practice, but whether it can improve the vascular dysfunction, oxidative stress and end organ damage of hypertension remains to be further studied. OBJECTIVE: To evaluate the antihypertensive effect of cassia seed water extract on hypertensive rats induced by N-nitro-L-arginine methyl ester. METHODS: A rat model of hypertension was established by intragastric administration of N-nitro-L-arginine methyl ester to observe the changes of blood pressure and heart rate after the intervention of cassia seed aqueous extract (500 mg/kg per day), once a day, for 4 continuous weeks. Blood pressure and heart rate were measured once a week. At 24 hours after the final administration, serum levels of aspartate aminotransferase, alanine aminotransferase, urea and serum creatinine, and lipid mass spectrometry were detected by an automatic biochemical analyzer. Malondialdehyde, nitric oxide, reduced glutathione levels and angiotensin converting enzyme activity in rat liver and kidney were determined by corresponding assay kits. The expression levels of endothelial nitric oxide synthase and inducible nitric oxide synthase protein and gene in rat kidney tissues were examined by immunohistochemistry as well as real-time quantitative PCR. RESULTS AND CONCLUSION: Compared with the model group, cassia seed aqueous extract treatment significantly reduced mean arterial pressure, diastolic pressure and systolic pressure (P < 0.05) in hypertensive rats, and improved liver and renal markers, lipid distribution and oxidative status. In addition, cassia seed aqueous extract significantly reduced the activity of angiotensin-converting enzyme in the liver and kidney of hypertensive rats (P < 0.05). The protein and mRNA expression levels of endothelial nitric oxide synthase in the kidney of rats treated with cassia seed aqueous extract were significantly higher than those of the model group. In conclusion, cassia seed water extract has shown considerable potential for antihypertension, and its anti-hypertension mechanism includes up-regulation of endothelial nitric oxide synthase expression, antioxidants and inhibition of angiotensin-converting enzymes.