Antihypertensive Effect of Pomegranate Polyphenols in Spontaneously Hypertensive Rats / 中国药师

Objective: To observe the anti-hypertensive effect of pomegranate polyphenols in spontaneously hypertensive rats ( SHR) and explore the underlying mechanism. Methods:Totally 40 male SHR rats at the age of 12 weeks were randomly divided into five groups:SHR control group, pomegranate polyphenols groups respectively at the dose of 120 mg·kg-1 , 240 mg·kg-1 and 480 mg ·kg-1 , and captopril group at the dose of 15 mg·kg-1 . The age-matched Wistar-Kyoto ( WKY) rats were randomly divided into two groups:WKY control group and pomegranate polyphenols group at the dose of 480 mg·kg-1 . All the rats were given corresponding drug or water by intragastric administration for four weeks. The systolic blood pressure ( SBP) and diastolic blood pressure ( DBP) were measured weekly. After the 4-week administration, the rats were fasted 12 hours and anaesthetized with 25% urethane solution. The blood samples were collected from abdominal aorta. The serum concentrations of angiotensin II ( Ang II) and endothelin ( ET) were de-termined by euzymelinked immunosorbent assay. The concentration of nitric oxide ( NO) in serum was determined by nitrate reduction test. Results:Pomegranate polyphenols could significantly lower the SBP and DBP, decrease the serum concentrations of Ang II and ET, and increase the serum concentration of NO(P<0.05 or P<0.01). In addition, pomegranate polyphenols had no effects on blood pressure and vasoactive substances in WKY rats. Conclusion: Pomegranate polyphenols has anti-hypertensive effect in SHR rats. The mechanism may be related to regulating the expression of vasoactive substances, such as Ang II, ET and NO.

Alginate-pomegranate peels' polyphenols beads: effects of formulation parameters on loading efficiency

Calcium alginate beads containing pomegranate peels' polyphenol extract were encapsulated by ionic gelation method. The effects of various formulation factors (sodium alginate concentration, calcium chloride concentration, calcium chloride exposure time, gelling bath time maintaining, and extract concentration) on the efficiency of extract loading were investigated. The formulation containing an extract of 1 g pomegranate peels in 100 mL distilled water encapsulated with 3 % of sodium alginate cured in 0.05 M calcium chloride for 20 minutes and kept in a gelling bath for 15 minutes was chosen as the best formula regarding the loading efficiency. These optimized conditions allowed the encapsulation of 43.90% of total extracted polyphenols and 46.34 % of total extracted proanthocyanidins. Microencapsulation of pomegranate peels' extract in calcium alginate beads is a promising technique for pharmaceutical and food supplementation with natural antioxidants.

Pérolas de alginato de cálcio, contendo polifenóis de extrato de casca de romã, foram encapsuladas pelo método de gelificação iônica. Os efeitos de vários fatores de formulação (concentração de alginato de sódio, concentração de cloreto de cálcio, cloreto de cálcio, o tempo de exposição, o tempo de manutenção do banho de gelificação e a concentração do extrato) sobre a eficiência de carga do extrato foram investigados. A formulação que contém 1 g extrato de casca de romã em 100 mL de água destilada, encapsulado com 3% de alginato de sódio curada em 0,05 M de cloreto de cálcio durante 20 minutos e mantido em banho de gelificação por 15 min foi escolhida como a melhor em relação à eficiência de carga. Estas condições otimizadas permitem o encapsulamento de 43,90% do total de polifenóis extraídos e de 46,34% do total de proantocianidinas extraídas. A microencapsulação de extrato de cascas de romã em esferas de alginato de cálcio é uma técnica promissora para a suplementação farmacêutica e de alimentos com antioxidantes naturais.