Radish sprouts, source of important nutraceuticals
Dr. Riccardo Matera
Raphanus sativus (L.) species comprises a large variety of dietary vegetables as radish and horseradish.
Among the wide Brassicaceae family, radish represents one of the most consumed vegetables in the world: easy to grow and with a good, sharp and spicy taste.
Features and benefits of radish
Mature radishes are rich of micro elements such as vitamins (A, B1, B2, B3 e C) and minerals (iron, potassium, calcium, magnesium, sodium, phosphorus) along with fiber.
Among the compounds of most interest there are a significant quantity of Glucosinolates, which originate isothiocyanates, with strong smell and spicy taste.
The isothiocyanates, diffused in several Brassica vegetables such as cabbage, radish, broccoli, mustard, rocket endowed with relevant antitumoral, antioxidant and detoxifying properties as shown by scientific in vitro and in vivo studies. Therefore, the intake of Brassica vegetables contributes to protect from several chronic degenerative disorders.
Contrary to other white Raphanus species, red radishes bear a lot of anthocyanins, the typical flavonoids, found in berries and red fruit as well. Natural occurrence of both groups of biocomponents (isothiocyanates and anthocyanins) with important antioxidant properties makes raphanus one of the most interesting health promoting food.
Raphanus Sango in laboratories of BeC
In particular, in the last few years, in R&D laboratories of BeC, we have recently studied juice of Sango sprouts.
It contains a high amount of isothiocyanates comparable to other Brassica sprouts (see our article Food Chemistry 2012), but it contain surprisingly a huge amount of anthocyanins, found only in blueberry and raspberry.
Moreover, sprouts offers a wide anthocyanins diversity in comparison to mature plant, where the differentiation produces only a few major components.
Anthocyanins, as shown by several epidemiologic studies, endowed with protective actions from risks related to cardiovascular pathologies, cancer and other chronic degenerative disorders. Such richness and structural diversity in Sango sprouts could strengthen the important dietary value.
During our Research project, we identified and characterized different unknown anthocyanins (see our article Food Chemistry 2015) which share cyanidin as structural motif making radish sprouts a unique food in vegetables.
Thanks to a proficient collaboration with University of Bologna it was possible to study antioxidant properties of isolated anthocyanins from Sango which were comparable to antioxidant profile of vitamin E, we highlighted the importance of structural diversity of Sango.
Anthocyanins, moreover, are responsible of red-violet colour of the sprouts and of the significant properties of sharp tasted isothiocyanates. Due to high content of dietary ingredients such as vitamins ad minerals, along with isothiocyanates and anthocyanins, Sango helps in strengthen muscular tissues and sight, it boasts antiseptic action and improves organism’s barriers, stimulates digestion and protect from action of free radicals.
We are proud to share with you our studies and we’ll let you know future developments!
Cyclooxygenase, lipoxygenase and the inflammatory process
Cyclooxygenase and lipooxygenase are the two families of enzymes that are commonly involved in the inflammatory process, through a complex of reactions which is called arachidonic acid cascade. This complex of reactions develops as follows: a first enzyme, a phospholipase cleaves the phospholipids of biological membranes, releasing arachidonic acid, a polyunsaturated fatty acid with 20 carbon atoms (eicosa-5Z,8Z,11Z,14Z-tetraenoic acid ; C20:4; ω-6). The arachidonic acid is then transformed by two parallel enzymatic pathways, that is, by two families of enzymes: the cyclooxygenase which transforms it into prostaglandins and thromboxanes and the lipooxygenase which transforms it into hydroperoxides which in turn transform into leukotrienes .
There are two cyclooxygenase isoforms indicated with type 1 and type 2, briefly COX-1 and COX-2. COX-1 is the enzyme present in most cells (except red blood cells), and is constitutive, that is, it is always present. COX-2 is an inducible cyclooxygenase isoform: it is constitutively present in some organs such as brain, liver, kidney, stomach, heart and vascular system, while it can be induced (i.e. developed if necessary) following inflammatory stimuli on the skin, white blood cells and muscles.
There are various types of lipooxygenase that lead to different products, the most important in the inflammatory process is 5-lipooxygenase, 5-LOX.
Prostaglandins, Thromboxanes, and Leukotrienes
Prostaglandins, Thromboxanes, and Leukotrienes are chemical messengers or mediators, that is, molecules that bring a message to specific cells and activate or deactivate metabolic responses in these cells. They, therefore, have a function similar to hormones, only that, unlike what hormones do, the chemical message is carried only at a short distance, that is, only to the cells that are in the vicinity of the place where the mediators were produced. There are different prostaglandins, different thromboxanes and different leukotrienes that carry specific messages. In many cases these act as mediators of the inflammatory process , therefore they trigger all the events that are involved in inflammation:
– vasodilation with consequent blood supply (redness),
– increased capillary permeability with consequent fluid exudation (swelling or edema),
– stimulation of nociceptive nerve signals (pain),
– on-site recall of immune system cells that attack a possible invader (chemotactic action)
– activation of the biosynthesis of fibrous tissue to strengthen or repair the affected part (even if there is no need)
– generations of free radicals that can chemically destroy an invader (but also damage our tissues, i.e. they just “shoot in the middle”).
Prostaglandins and thromboxanes, however, also play important physiological roles in normal conditions, i.e. in the absence of inflammation. For example, they regulate the secretion of mucus that protects the walls of the stomach, they regulate the biosynthesis of cartilages and synovial fluid in the joints, they regulate vasodilation, hence the correct flow of blood in the various local districts, and more.
Triglycerides are the main components of most oils and fats. These are heavy, non-volatile and little polar molecules, insoluble in water, made up of glycerol (or glycerin) esterified with three molecules of fatty acids: therefore, it is a tri-ester of glycerin, from which the name derives. Each fatty acid contains 8 to 22 carbon atoms (commonly 16 to 18) and can be saturated, mono-unsaturated or poly-unsaturated. The size of the fatty acids and their saturation determines the physical and sensorial properties of the triglycerides, which can appear as oils (liquids at room temperature) or fats (solid or semi-solid) and can have greater or less greasiness and smoothness on the skin. Unsaturated triglycerides or with shorter fatty acids are more fluid and have greater flowability.
Fatty acids (saturated, mono-unsaturated and poly-unsaturated)
The name fatty acids is commonly used to indicate those organic acids that are found in the composition of lipids, that is, in animal and vegetable oils and fats, both in the free form and in the form of esters with glycerol (e.g. in triglycerides), or they are esterified with “fatty” alcohols, that is, long chain alcohols, to form waxes. Fatty acids are carboxylic acids (formula R-COOH) which have a long carbon chain (R), unlike common organic acids such as acetic acid and propionic acid, which have 2 or 3 carbon atoms in total, respectively. Fatty acids are defined as saturatedif they do not have double carbon-carbon bonds, (called “unsaturations”), they are defined mono-unsaturated if they have only one, they are defined mono-unsaturatedpoly-unsaturated if they have two or more double bonds (see figure). The term omega-3 (ω-3) or omega-6 (ω-3), refers to the position of the first double bond starting from the bottom of the chain of carbon atoms: if the first double bond is encountered after 3 carbon atoms the fatty acid is classified as omega-3 , if after six carbon atoms omega-6 , as shown in the figure. The most common saturated fatty acids are palmitic acid (16 carbon atoms and no double bond, C16: 0) and stearic acid (18 carbon atoms, 18: 0), the most common mono-unsaturated is the oleic acid, typical of olive oil (18 carbon atoms and 1 double bond in position 9, C18: 1; ω-9), while the most common poly-unsaturated are linoleic acid and linolenic acid, progenitors respectively omega-6 and omega-3 (see figure).
Terpenes and terpenoids
Terpenes or terpenoids are a large family of natural molecules, typically containing 10 to 30 carbon atoms, which are biosynthesized from a common “brick”, isopentenyl pyrophosphate (IPP), containing 5 carbon atoms (see figure). The discovery that the repetitive brick consists of 5 carbon atoms is relatively recent, while it was once assumed that the entire family was created by repeating a brick of 10 carbon atoms, which was called “terpene”. Therefore, the molecules with 10 carbon atoms (such as limonene, see figure) were called mono-terpenes, i.e. composed of a single brick, diterpenes those with 20 carbon atoms (e.g. the cafestol that gives the aroma to the coffee), triterpenes those with 30 carbon atoms (e.g. beta-carotene). Since molecules made from 15 carbon atoms were also found (such as bisabolol), it was thought they contained a terpene and a half, and were called sesquiterpenes (from the Latin semis = half + atque = and). Today it is known that the repetitive unit is composed of 5 carbon atoms, therefore it is easy to understand how mono-terpenes contain two (see figure), sesquiterpenes three, diterpenes four, triterpenes six.