Food & Function PAPER Cite this: Food Funct., 2016, 7, 4675 Received 1st September 2016, Accepted 5th October 2016 DOI: 10.1039/c6fo01295g www.rsc.org/foodfunction Bioactive and functional properties of sour cherry juice (Prunus cerasus) Guillermo Cásedas, a Francisco Les, a Maria Pilar Gómez-Serranillos, b Carine Smith c and Víctor López* a Sour cherry juice (Prunus cerasus) is consumed as a nutritional supplement claiming health effects. The aim of the study was to evaluate the different properties of sour cherry juice in terms of antioxidant activity and inhibition of target enzymes in the central nervous system and diabetes. The content of poly- phenols and anthocyanins was quantified. Different experiments were carried out to determine the radical scavenging properties of the juice. The activity of sour cherry juice was also tested in physiological relevant enzymes of the central nervous system (acetylcholinesterase, monoamine oxidase A, tyrosinase) and others involved in type 2 diabetes (α-glucosidase, dipeptidyl peptidase-4). Sour cherry juice showed significant antioxidant effects but the activity of the lyophilized juice was not superior to compounds such as ascorbic, gallic or chlorogenic acid. Furthermore, sour cherry juice and one of its main polyphenols known as chlorogenic acid were also able to inhibit monoamine oxidase A and tyrosinase as well as enzymes involved in diabetes. This is the first time that sour cherry juice is reported to inhibit monoamine oxidase A, α-glucosidase and dipeptidyl peptidase-4 in a dose dependent manner, which may be of interest for human health and the prevention of certain diseases. 1. Introduction Cherry belongs to the Rosaceae family, and specifically to the genus Prunus. The most common types of Prunus are Prunus cerasus and Prunus avium, the first one is known as sour cherry and the other is called sweet cherry. Both are considered nutri- ent dense food with a relatively low caloric content and a sig- nificant amount of important nutrients and bioactive food components. 1 Several studies have confirmed that eating a diet rich in fruit is related to a reduced risk of oxidative stress, cardiovascular disease, cancer, neurodegenerative disorders and diabetes. 2–6 This may be due to dietary polyphenols, which are formed by at least one aromatic ring with one or more hydroxyl groups attached. 7 Some of the most common dietary polyphenols present in fruits and berries are anthocyanidins, which generate several anthocyanins. These anthocyanins are responsible for the red colour of fruits and the potential antioxidant activity. Although cherry is botanically classified as a stone fruit (drupe) due to the pit in the centre, it has the appearance of a berry. Several studies in animal models and in human subjects have demon- strated that dietary polyphenols are bioavailable and exert a protective role against oxidative stress and free radical damage. 7 Antioxidants have the ability to scavenge or to neu- tralize free radicals, or are necessary to enable other molecules to perform such a function. 8 There is strong evidence demonstrating that several ROS- mediated pathways may be involved in the neurodegenerative diseases, like Alzheimer’s disease (AD) and Parkinson’s disease (PD). It has been described that the accumulation of iron ions in the brain leads to higher ROS generation, involve- ment of mitochondrial pathways and to a decrease of endo- genous antioxidants levels. Thus, natural antioxidants may prevent neurodegenerative disorders. 9 Although mechanisms remain unclear, a body of evidence links type-2 diabetes with dementia and neurodegenerative diseases. 10 One therapeutic approach to treat diabetes is to retard the absorption of glucose via inhibition of enzymes, such as α-glucosidase, in the digestive organs. It has been con- firmed that α-glucosidase activity in vitro can be inhibited by berry extracts, i.e. blueberry, blackcurrant, strawberry, and raspberry rich in polyphenols. 11 In recent years, there has also been an increasing interest in the ability of dietary factors to treat diabetes via modulating GLP-1 levels. GLP-1 is secreted from enteroendocrine L cells, which are present in the lower small intestine and large intestine, and stimulates insulin secretion in a blood glucose concentration dependent manner. a Department of Pharmacy, Faculty of Health Sciences, Universidad San Jorge, 50.830 Villanueva de Gállego, Zaragoza, Spain. E-mail: ilopez@usj.es b Department of Pharmacology, Faculty of Pharmacy, University Complutense of Madrid, Plaza Ramón y Cajal s/n, 28040 Madrid, Spain c Department of Physiological Sciences, Science Faculty, Stellenbosch University, Stellenbosch, South Africa This journal is © The Royal Society of Chemistry 2016 Food Funct. , 2016, 7, 4675–4682 | 4675 Open Access Article. Published on 06 October 2016. Downloaded on 6/28/2019 9:47:25 AM. This article is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported Licence. View Article Online View Journal | View Issue