## 1 Introduction  
Nowadays, the consumption of natural extracts from plants and seeds present in nature and the discovery of the many benefits connected to their intake, have favoured and promoted research in the field of extraction and use. For this purpose, in recent years, extract of plant parts (seeds, cladodes, stem, fruits, etc.) of the family _Opuntiaceae_ have been investigated, as for instance: _Opuntia joconstle_ seeds for cholesterol-lowering properties [1]; _Opuntia humifusa_ cladodes, for cytotoxic activity against the human breast cancer cell lines MCF-7 and human colon SW-480 cells, and stem and fruits able to inhibit the growth of U87 MG glioblastoma cells [2]; _Opuntiastricta_ for antioxidant, anti-inflammatory and cytotoxic activities [3,4]. Instead, our attention was focused on the cladodes of the cactus pear (_Opuntia ficus-indica_ ([PERSON] [PERSON], a tropical or subtropical invasive plant, widespread and well adapted to Mediterranean area due to the climate. _Opuntia_ was an important source of the agricultural economy and diet of the ancient Mexicans of the Aztec empire [5] and it was also traditionally used to differentiate the properties of the peasants and to curb fires; the cladodes have high water content, 95% in mass [6]. In some countries, like Mexico, Italy and South Africa, the most commercial variety _Opuntia ficus-indica_ ([PERSON] [PERSON] is cultivated on the considerable surface for industrial purposes; in Mexico, its culture stretches on a surface of 300,000 ha [7]. The immature cladodes of Opuntia ficus indica are a part of the edible plant and also used in Mexican cuisine for many traditional dishes and in folk medicine for certain diseases, such as obesity, gastrointestinal disorders [8], ulcers and healing of wounds [8]. _Opuntia ficus indica_ fruits are used as a laxative in Turkey, to reduce kidney stones, rheumatism pains, and as a sedative [9]. It was also been reported that the extracts of fruits and stems exhibit hypoglycemic, anti-ulcer [10], anti-allergic, analgesic and antioxidant activity [11]. From the fruits and the stem extracts was isolated the \(\beta\)-sitosterol, an active anti-inflammatory principle [12], whereas the fruit and flower infusions significantly increase diuresis [13]. Several researches show that the prickly pear is a plant very rich in vitamins, minerals, amino acids and sugars [14]. In particular, its fruit, with a pleasant flavor, has a high content of potassium, phosphorus, magnesium, sodium, calcium, vitamins C and E, dietary fibers, pigments betalains (betacyanins and betaxanthins), polyphenols and their glycosides, glutamine, proline and taurine; the cladodes, consumed as vegetables and used also as animal feed too [15], are rich of mucilages, pectins, sterols, vitamins and polyphenols. The blades of the prickly pear are however very perishable and can be stored for about 5 days at room temperature or up to 10 days in refrigerated environments [16]. They contain high quantities of pectins and fibers that are capable of increasing fecal mass and intestinal motility, which therefore improve plasma levels of cholesterol and glucose. [17]. The young cladodes of OFI, also known as nopalitos, contain functional polyphenols (Figure 1), like Ruthin, Iso-querctrin, Narcissin and Nicotiflorin [18] and a series of polysaccharides with high molecular weight and important functional properties, as rheological [19], medicinal and nutritional [20]. Rutin is found in many fruits and vegetables and has been used in over 130 therapeutic medicinal preparations that have been registered as drugs worldwide [21]. In literature, it has been found that Rutin improves the memory of mice in Alzheimer's as it reduces the levels of A\(\beta\)-oligomer and attenuates oxidative stress and neuroinflammatory. [22]. Isoquerctrin, as glycosylated flavonoid, is rapidly absorbed and transformed, in the gastro-intestinal tract, in glucuronidated Querctin [23,24] that was found to be the major form in plasma after oral administration of Isoquerctrin in rats [25].