Ultrasound-treated apples reduce postprandial triglycerides in obese mice

[Speaker] Maria Del Carmen Naranjo Martin:1
[Co-author] Sergio Montserrat-de la Paz:2, Albert Ribas Agusti:1, Beatriz Bermudez Pulgarin:2, Maria Del Carmen Millan Linares:3, Olga Martin Belloso:1, Robert Soliva Fortuny:1, Pedro Elez Martinez:1
1:Universitat de Lleida, Spain, 2:Universidad de Sevilla, Spain, 3:Instituto de la Grasa, CSIC, Spain

Background: The health benefits of apple consumption are mainly related to their content in phenolic compounds, which possess anti-inflammatory and lipid-lowering properties. It is widely known lifestyle and dietary habits are crucial in the prevention of some human diseases such as hyperlipidemia. In this study, the biological activity of phenolic compounds from ultrasound-treated apples was investigated in obese-mice postprandial alterations.
 Methods: Golden Delicious apples were washed and immersed in tap water. Afterwards, they were treated in an ultrasonic processor (400 W, 24 kHz) for 1 min with 25% amplitude and stored during 48 h at 20 C. Phenolic compounds from treated and untreated apples were extracted with methanol, concentrated with rotary evaporator and resuspended in mineral water. Identification and quantification of phenolic compounds were performed using HPLC-DAD/MS-MS. Mice were orally fed with amounts of ultrasound-treated and untreated apple concentrate equivalent to one apple (human equivalent), using a dose scaling based on the body weight. Postprandial triglycerides, glucose and insulin were quantified spectrophotometrically in serum. Pro-inflammatory cytokines were analysed by ELISA. Flow cytometry was required to determine monocyte population.
Results: The data showed that apples contained phenolic compounds and they were especially rich in 5-caffeoylquinic acid (hydroxycinnamic acid). Phenolic contents in untreated apples were 255.94 mg/kg while ultrasound-treated apples exhibited a higher content (489.49 mg/kg). The oral administration of the phenolic concentrate from ultrasound-treated apples exerted a significant reduction of plasma postprandial triglycerides from 300 to 265 mg/dL respect to the control. Glucose was also reduced (p=0.0360) in serum while insulin was not affected. Classical monocyte population and pro-inflammatory cytokines were lower in mice fed with ultrasound-treated apples.
Conclusion: Ultrasound treatment increased apple phenolic compounds contents. Ultrasound-treated apples were able to reduce postprandial inflammatory response as well as plasma triglyceride levels.
Keywords: phenolic compounds; apples; ultrasound; triglycerides; postprandial

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