S. Zeghichi*, S. Kallithraka**, A. P. Simopoulos***, M. Chibane*

Biophysics, Biomathematics, Biochemistry and Scientometry Laboratory. Faculty of Nature and life Siences. Bejaia University. Algeria

MEDITERRANEANAGRONOMIC INSTITUTEOF CHANIA. Crete. Greece.

* Faculty of Nature and Life Siences. Bejaia University. Algeria.**Mediterranean Agronomic Institute of Chania, Crete, Greece.

***The Center for Genetics, Nutrition and Health, Washington, D.C.

This study was carried out to analyze the nutritional composition of tender leaves of twenty24 wild leafy plants widely eaten in Crete. Their contents of alpha-tocopherol, total phenols,nitrates and minerals (K, Na, Ca, Mg, Fe, Cu, Mn, Zn, and P) as well as their antioxidant activitywere determined. The plants were harvested from the wild from Heraklio North of Crete, Greece.

The results showed that all the plants contained considerable amounts of antioxidants andmineral elements. Tordylium apulum contained the higher amount of α-tocopherol, 2.426 mg/100gwet weight. Rumex ssp. contained the highest amount of total phenols, 102.56±3.13 mg/100g wetweight followed by Cichorium pumilum 93.643±0.28 mg/100g. Whereas Oenotherapimpineloides was more efficient antioxidant than the rest of the plants (EC50 = 0.222±0.018). Another specie has shown a great antioxidant activity is Ranunculus ficarioides (EC50 = 0.28±0.08).

All analyzed wild plants contained small amounts of nitrates (8±0.002-203±0.016 mg/100gwet weight), whereas, they contained considerable amounts of minerals. Tragopogon sinuatus andScandix pecten-veneris had the highest quantity of calcium comparing to the rest of the plants,3120±1.2 and 2790±1.43 mg/100g dry weight respectively. Ranunculus ficarioides presented themaximum quantity of zinc, 7.01±0.82 mg/100g dry weight, while Rumex ssp. has shown themaximum level of phosphorus equal to 804±1.11 mg/100g dry weight.

Key-Words: Wild plants, Cretan diet, human nutrition, alpha-tocopherol, total phenols, antioxidant activity, minerals, nitrates.

ABSTRACT

The Mediterranean basin contains approximately 25000 species, about halfof which are endemic to the region and is one of the world’s major centers ofplant diversity2. Recent evidence has underlined the importance of plant foodsrich in antioxidants and omega-3 fatty acids to health.

INTRODUCTION

Wild plants have contributed to the diet of both humans and animalssince their first appearance on planet earth. Humans used to eat a variety of wildplants, whereas today the diet of developed societies is limited to a few cultivatedvegetables1.

Wild plants have always been significant in all cultures of theMediterranean region, being used for food, medicine, fuel, and many otherpurposes2. Greeks, Egyptians, and Romans were familiar with many wild plantsand were aware of their usefulness in nutrition and treatment of various diseases.

Edible wild plants are wild plants with one or more parts that can beused for food if gathered at the appropriate stage of growth, andproperly prepared.

WHAT ARE USEFUL WILD PLANTS3?

Portulaca oleracea

Cichorium spinosum They're the trees, the flowers and the grasses, the vines, thebushes and even the weeds in your lawn.

They're what our ancestors ate before we had supermarkets.

They're what our great grandparents used to doctor the family, put foodon the table, and make their tools.

They are our vital link to life and they are our most important resourcefor our future.

Green leafy wild plants could be one of the ways to delay the onset of chronic diseases due to their considerable content of:

Antioxidant vitamins Phytochemicals Minerals

Phytochemicals are substances that plants naturally produce to protect themselves against viruses, bacteria and fungi and may play an important nutritional role in human health. Polyphenols have three major physiological effects4-9 :

antioxidant effects anticarcinogenic effects antimutagenic effects

Many of these phenols have been found to be more powerful antioxidants than vitamins C, E and β-carotene using an in vitro model for heart disease, namely the oxidation of low density lipoproteins (LDL)5.

Table 1. The roles of vitamins10

Vitamins Function Deficiency symptoms Food sources

A The beauty vitamin. Needed to maintain healthy skin, hair, eyes, etc. Improves resistance to infections. Helps break down fats.

Rough, dry skin, low resistance to infections, night blindness, keratomalacia.

Whole milk, liver, butter, carrots, eggs, green and yellow vegetables.

D Needed for calcium and phosphorus absorption to produce good bones and teeth.

Rickets, softening of bones in adults, osteoporosis, and poor teeth.

Fish liver oil. Sardines, salmon, liver. Some made by the skin in sunlight.

E Helps in the formation of red blood cells, muscle, and other tissues. Prevents abnormal break down of fat.

Circulation problems, loss of sexual and body vigor, muscular and heart problems.

Vegetable oils, whole grain cereals, green leafy vegetables.

K Aids in blood clotting. Rare , generalized bleeding Green vegetables.

Thiamin B1 Needed for oxidation of carbohydrates. Insures proper use of sugars.

Loss of energy, depression, poor appetite, skin problems (edema).

Whole grain cereals, dry yeast, pork, fish, lean meat.

Riboflavin B2 Needed for energy metabolism in cells. Helps synthesize fats.

Tissue damage, eye strain, fatigue, itching, sensitivity to light.

Liver, milk, cheese, green leafy vegetables, beans.

Niacin B3 Involved in energy metabolism in cells. Lack of concentration, headaches, insomnia, backache, poor memory.

Meat, poultry, fish, whole wheat and enriched grains.

Vitamin B12 Builds genetic molecules. Essential for proper functioning of the nervous system.

Anemia, bowel disorders, poor appetite, and poor growth, neurological symptoms.

Liver, kidney, fish.

C Helps to maintain normal development of bones, teeth, gums, and cartilage.

Scurvy, bleeding gums, easy bruising, low resistance to infections

Citrus fruits, green vegetables, potatoes.

Folate Red blood cell formation, cell division, protein metabolism

Anemia, diarrhea, smooth tongue, depression Green leafy vegetables, liver, legumes, seeds, enriched breads, cereals, rice

Table 2. The roles of minerals11

Mineral Function Deficiencies Sources

Calcium Forms bones and teeth, aids blood clotting, and nerve impulse conduction.

Poor calcification of teeth and bones, Rickets.

Green leafy vegetable(purslane, molokhia, stamnagathi), milk, cheese, cereals, beans, and hard water.

Phosphorus Also required for teeth and bones, some cell reactions.

Poor development in teeth and bones.

Meat, fish, dairy products, grains; common in many foods, soft drinks.

Iron Needed for hemoglobin. Helps cells obtain energy from foods.

Anemia, lack of energy, especially needed in young children, girls and women.

Liver, heart, meat, green leafy vegetables, whole wheat bread, cereals, and nuts.

Iodine Formation of hormones in thyroid gland. Goiter, swollen thyroid gland, mental retardation. Seafood, iodized table salt.

Sodium Regulates water between cells and blood, blood pressure. Dehydration. Table salt, bread, canned meats, and

vegetables.

Potassium Needed for synthesis of proteins in cells. Weakness in muscles. Meat, cereals, milk, fruits, green vegetables.

Magnesium Enzyme co-factor, skeletal development, muscles and nerves membranes Weakness in muscles. Green leafy vegetables, nuts, cereal

grains, beans, peas.

Manganese Enzyme co-factor. Growth and health. Weakness in muscles. Whole grains, cereal products, green leafy vegetables, dry beans and peas.

Copper Enzyme co-factor. Skeletal fragility. Green leafy vegetables, cereals, and nuts.

Fluoride Strengthens teeth during development. More rapid tooth decay. Drinking water by natural or artificial addition.

Phytochemical Source Function

Terpenes Green foods, soy products, grains Antioxidant, protect lipids, blood and other fluids from free radicals, and the plant from reactive oxygen

Carotenoids Yellow, orange and green vegetables and fruits Antioxidant include the carotenes and xanthophylls, protect from sunlight, and protect other vitamins from oxidation

Limonoids Citrus fruits peels, lemon and other citrus fruits Protection of lung tissue

Phytosterols Green and yellow vegetables and fruits and their seeds, beans, peanuts,

Compete with dietary cholesterol for uptake in the intestines and facilitate its excretion from the body

Phenols Fruits, vegetables, soybeans, cereals, tea, Block specific enzymes that cause inflammation, modify the prostaglandin pathway and thereby protect platelets from clumping

Flavonoids Fruits, vegetables, Herbs, spices (mint,rosemary, thyme, oregano,sage, basil)

Subclass of phenols include; flavones, flavonols and flavonones. Enhance the effect of vitamin C, and protect the body against allergies, inflammation, free radicals, hepatotoxins, platelets aggregation, bacteria, ulcers, viruses and tumors

Anthocyanidins Fruits, vegetables, red wine, grapes Known as flavonals, they reinforce the strength of collagen protein, and scavenge free radicals

Isoflavones Flax seed, lentils, soybeans Subclass of phenols, block enzymes that promote tumor growth

Thiols Garlic, cruciferous vegetables (cabbage, turnips, members of mustard family)

antimutagenic and anticarcinogenic properties, immune and cardiovascular protection

Glucosinolates Cruciferous vegetables(broccoli, cauliflower,cabbage, Brussels sprouts, kale, turnips, bok choy)

Activation of liver detoxification enzymes, regulate white blood cells and cytokines, block enzymes that promote tumour growth (breast, liver, lung, stomach, oesophagus)

Allylic sulfides Allium foods (garlic, onion, leeks) Thiol subclass, released when the plant is cut or smashed, antimutagenic and anticarcinogenic properties, immune and cardiovascular protection, antigrowth activity for tumours, fungi, parasites, cholesterol and platelets/leucocytes adhesion factors, activate liver detoxification enzyme system.

Indoles Cruciferous vegetables Bind chemical carcinogens and activate detoxification enzymes mostly in the gastrointestinal tract.

Isoprenoids Citrus fruits Neutralize free radicals, and protect membranes from oxidation

Lipoic acid and Ubiquinone (Coenzyme Q)

Potatoes, Peanuts, Spinach. Important antioxidant that works to extent the effect of other antioxidants, efficient hydroxyl radical quencher. Lipoic acid protect also superoxide dismutase, catalase and glutathione peroxidase which are important endogenous enzymes in liver detoxification activities.

Catechins, Gallic acid Green and black tea, fruits, vegetables antimutagenic and anticarcinogenic properties, immune and cardiovascular protection

Table 3. Selected phytochemicals in edible plants11

POLYPHENOLS

Simple phenols & phenolic acids Flavonoids Stilbenes

Ex : Vanillin ex. Resveratrol Gallic acid so: red graps, berries, peanuts

Chlorogenic acidso: Tea, coffee, vanilla,Cherries, Citrus fruits

Isoflavones Anthocynins Flavonols Flavones Flavanols Flava nones

Ex: daidzein Ex: cyanidin Ex: quercitin Ex: apigenin Ex: catechins, Ex: naringin,Genistein delphinidin myricetin luteolin gallocatechins hespe ridinBiochanin A pe largonidin so: onion, red wine, so: red pepper, so: tea, red wine, grapes, so: citrusso: soy beans, so: berries, wine, grapes green tea, tomatoes celery, citrus fruits cocoa, chocolate, apples fruits+ peels,red clover leaf brightly colored vegetables, citrus fruits, onionbarley, brown tearice, whole wheat,flax seed

The major classes of Polyphenols

THE CRETAN DIET = HEALTH & LONGIVITY

The diet of Crete continues to gain enormous popularity. There was something unique about the diet of Crete, the missing clues were identified by Dr. Artemis Simopoulos from the center for Genetics, Nutrition and Health, Washington DC12,13:

Consumption of red wine with every meal (about 2 glasses per day).

The ideal ratio of essential fatty acids ω6: ω3;

The high antioxidant content of this diet due to the high intake ofvegetables, fruits and wild plants, such as purslane (Portulaca oleracea)

A good source of α-linolenic acid in the diet of Crete is walnuts;

Consumption of moderate amounts of fish and poultry weekly;

The use of olive oil as the principal fat, replacing other fats and oils;

In view of the importance of the wild plants in human diet, it was of interestto examine the antioxidant and mineral contents of 24 widely eaten Cretan wildleafy plants.

These plants were chosen because of their large contribution to the dietof Crete, since they are eaten throughout the year, especially during periods ofLent when they become a major component of the diet. There is a total of about120 days when people abstain from meat and dairy products.

The Cretan table is garnished from 2 to 5 times per week with salads,vegetable pies, or meals based on wild plants12.

Nutritional Composition of Selected Wild Plants in the Diet of Crete

MATERIALS &

METHODS

This study was carried out during the academic year 2000–2001 at the Mediterranean Agronomic Institute of Chania, Crete, Greece. 24 selected commonly eaten Cretan wild plants were assayed for antioxidant activity, total phenols, mineral and nitrate contents. Only edible parts of the plants were used. Samples were gathered from Heraklio in Northern Crete.

MATERIAL & METHODS

Figure 1. CRETE MAP

Plant material

Photographs of the assayed 24 Cretan wild plants

(a) Papaver rhoeas, (b) Sonchus oleraceus, (c)Pimpinela peregrina, (d) Centaurea idaea, (e)Tragopogon sinuatus, (f) Crepiscommutata, (g)Helmintotheca echioides, (h) Tordylium apulum,(i) Scandix pecten-veneris, (j) Pontikes, (k)Alliumsubhirstum, (l) Rumex ssp., (m) Silenevulgaris, (n) Crepisvesicaria, (o) Uropermumpicroides, (p) Tolpis virgata, (q) Hypochoerisradicata, (r) Cichorium pumilum, (s) Oenotherapimpineloides, (t) Leontodon tuberosus, (u)Cichorium spinosum, (v) Ranunculusficarioides, (w) Prasium majus, (x) Foeniculumvulgare ssp. Piperitum.

N° PLANT NAMES USES1 Papaver rhoeas Cooked with olive oil , vegetable pie2 Sonchus oleraceus Boiled salad, Cooked with olive oil , vegetable pie, raw salad3 Pimpinela peregrina Cooked with oil , vegetable pie4 Centaurea idaea Boiled salad5 Tragopogon Sinuatus Cooked with olive oil , vegetable pie6 Crepis Commutata Boiled salad7 Helmintotheca echioides Boiled salad8 Tordylium apulum Cooked with oil , vegetable pie9 Scandix pecten-veneris Cooked with olive oil , vegetable pie

10 Pontikes Cooked with olive oil , vegetable pie, raw salad11 Allium subhirstum Cooked with olive oil , vegetable pie12 Rumex ssp. Cooked with olive oil , vegetable pie13 Silene Vulgaris Cooked with olive oil , vegetable pie14 Crepis vesicaria Boiled salad15 Uropermum picroides Boiled salad16 Tolpis virgata Cooked with olive oil , vegetable pie, Boiled salad17 Hypochoeris radicata Boiled salad18 Cichorium pumilum Boiled salad19 Oenothera pimpineloides Cooked with olive oil , vegetable pie20 Leontodon tuberosus Cooked with olive oil , vegetable pie21 Cichorium spinosum Boiled salad, raw salad22 Ranunculus ficarioides Cooked with olive oil , vegetable pie, Boiled salad, raw salad23 Prasium majus Cooked with olive oil , vegetable pie24 Foeniculum vulgare ssp.piperitum Cooked with olive oil , vegetable pie

Table 4. Scientific names and uses of the Cretan edible wild plants

Both raw and boiled salads are dressed with olive oil and lemon or vinegar

The extraction of tocopherols was performed by percolation using n-hexane14,15.Tocopherols were determined by reverse phase-High Performance LiquidChromatography analysis14.

Total phenols were first extracted with methanol16, and determined using Folin-Ciocalteu reagent17.

The antioxidant activity was determined using DPPH method (2,2-diphenyl-1-pycrylhydrazyl)18. Antiradical activity was defined as the amount of antioxidantnecessary to decrease the initial DPPH• concentration by 50% (Efficient concentration=EC50 (mg antioxidant/ mg DPPH•).

Minerals were determined according to the method of Bhattacharjee et al.19 by theInductively Coupled Plasma technique.

Nitrates were determined using the salicylic acid method20.

MATERIAL & METHODS

RESULTS &

DISCUSSION

Table 5. α-Tocopherol content of Cretan edible wild plants (mg/100 g wet weight)

N° Plant Names α-tocopherol (mg/100g wet weight)1 Papaver rhoeas 0.5242 Sonchus oleraceus 0.2943 Pimpinela peregrina 0.4904 Centaurea idaea 0.1085 Tragopogon Sinuatus 0.2066 Crepis Commutata 0.3607 Helmintotheca echioides 0.0298 Tordylium apulum 2.4269 Scandix pecten-veneris 1.133

10 Pontikes 0.36011 Allium subhirstum 1.21512 Rumex ssp. 0.50913 Silene Vulgaris 0.35414 Crepis vesicaria 0.40115 Uropermum picroides 0.48216 Tolpis virgata 0.04317 Hypochoeris radicata 0.19318 Cichorium pumilum 0.42019 Oenothera pimpineloides 0.23220 Leontodon tuberosus 0.09921 Cichorium spinosum 0.39822 Ranunculus ficarioides 0.44323 Prasium majus 1.28724 Foeniculum vulgare ssp.piperitum 1.117

Table 6. Total phenols content of Cretan edible wild plants (mg/100 g wet weight)

N° Plant Names Total phenols (mg/100gwet weight)

1 Papaver rhoeas 33.5±0.812 Sonchus oleraceus 48.04±0.793 Pimpinela peregrina 47.65±0.334 Centaurea idaea 61.55±1.455 Tragopogon Sinuatus 20.82±0.146 Crepis Commutata 49.08±2.327 Helmintotheca echioides 44.86±1.088 Tordylium apulum 46.87±1.259 Scandix pecten-veneris 46.51±1.1310 Pontikes 59.27±1.1011 Allium subhirstum 14.54±0.6512 Rumex ssp. 102.56±3.1313 Silene Vulgaris 40.18±1.2014 Crepis vesicaria 49.42±2.8715 Uropermum picroides 35.76±0.5416 Tolpis virgata 21.46±0.4717 Hypochoeris radicata 57.03±0.3218 Cichorium pumilum 93.64±0.2819 Oenothera pimpineloides 55.05±1.3120 Leontodon tuberosus 48.06±0.3921 Cichorium spinosum 72.63±0.3722 Ranunculus ficarioides 32.99±0.6023 Prasium majus 78.72±0.4424 Foeniculum vulgare ssp.piperitum 82.521±0.60

Table 7. Antioxidant activity and antiradical power of Cretan edible wild plants

N° Plant Names Antioxidant Activity(EC50)(mg dry extract/mg DPPH)

ARP(1/EC50)

1 Papaver rhoeas 0,995±0.14 1,005±0.152 Sonchus oleraceus 3,664±0.05 0,273±0.0043 Pimpinela peregrina 2,909±0.29 0,346±0.0364 Centaurea idaea 1,400±0.011 0,714±0.0055 Tragopogon Sinuatus 3,679±0.16 0,272±0.0126 Crepis Commutata 3,169±0.14 0,316±0.0147 Helmintotheca echioides 2,344±0.17 0,428±0.0318 Tordylium apulum 2,852±0.13 0,351±0.0179 Scandix pecten-veneris 2,477±0.11 0,404±0.018

10 Pontikes 7,261±0.25 0,138±0.00511 Allium subhirstum 2,697±0.08 0,371±0.0112 Rumex ssp. 2,344±0.17 0,428±0.0313 Silene Vulgaris 2,852±0.13 0,351±0.0214 Crepis vesicaria 2,284±0.42 0,438±0.0915 Uropermum picroides 0,830±0.20 1,205±0.3716 Tolpis virgata 1,350±0.12 0,741±0.0617 Hypochoeris radicata 0,761±0.22 1,390±0.4518 Cichorium pumilum 0,696±0.55 2,039±1.1819 Oenothera pimpineloides 0,222±0.018 4,520±0.3520 Leontodon tuberosus 1,194±0.047 0,838±0.0321 Cichorium spinosum 1,115±0.28 0,944±0.2822 Ranunculus ficarioides 0,280±0.08 3,812±1.2723 Prasium majus 0,818±0.27 1,321±0.4624 Foeniculum vulgare ssp.piperitum 1,041±0.15 0,974±0.14

Table 8. Mineral content of Cretan edible wild plants (mg/100g dry weight)

Plant Names K Na Ca Mg Fe Cu Mn Zn PP. rhoeas 3880±0.31 960±0.67 2110±1.49 511±1.54 51.7±1.63 2.13±0.32 7.13±0.53 5.81±0.15 729±0.98S. oleraceus 4300±0.33 579±0.95 1960±0.48 448±2.35 45.4±1.67 2.58±2.14 8.76±1.48 6.63±0.53 692±1.38P. peregrina 4210±0.14 903±0.46 1990±0.43 318±0.45 82.2±0.82 1.95±1.33 5.58±0.60 5.23±0.84 480±0.81C. idaea 2860±0.36 1640±0.41 1750±0.54 347±0.74 103±0.8 2.54±2.41 11.8±0.48 3.84±1.31 667±2.26T. Sinuatus 3020±0.26 955±0.72 3120±1.2 319±0.99 176±0.34 2.11±0.8 13.4±1.12 2.48±1.38 344±1.25C. Commutata 4370±0.64 537±0.42 310±0.13 427±1.19 46.5±0.35 3.29±0.41 5.76±0.74 5.34±1.25 651±1.43H. echioides 3840±0.25 937±1.09 2110±1.26 314±1.36 29.9±1.66 1.93±2.06 5.75±0.79 2.05±0.36 574±1.22T. apulum 3790±0.58 545±2.25 1550±1.04 254±1.22 28.4±1.44 1.53±0.43 6.69±1.0 4.27±0.33 728±2.5S. pecten-veneris 4450±0.73 662±0.66 2790±1.43 228±0.81 44.3±0.23 1.71±0.53 5.67±0.48 2.15±0.23 518±1.07Pontikes 4270±0.17 402±0.46 1310±0.77 317±0.62 53.5±0.34 9.33±0.99 8.76±1.39 4.74±0.97 605±0.19A. subhirstum 2520±0.83 98.9±1.66 1380±1.24 166±1.43 53.2±0.85 1.12±0.57 3.69±0.98 1.81±1.84 391±2.21Rumex ssp. 3680±0.12 338±0.49 595±1.71 354±0.89 39.9±0.73 10.2±1.29 4.51±0.57 5.0±1.57 804±1.11S. Vulgaris 5140±0.64 362±0.93 1990±0.37 517±0.06 18.5±0.99 2.87±0.82 7.96±0.68 3.40±1.72 429±1.09C. vesicaria 3540±0.43 1150±0.27 2030±1.16 438±2.18 108±0.38 2.47±2.86 12.5±0.40 5.44±1.07 512±0.71U. picroides 4210±0.39 1070±1.38 1850±1.36 310±0.47 23.4±0.18 2.94±1.05 8.49±1.30 6.60±1.26 801±0.75T. virgata 5040±0.19 1130±0.97 1550±0.22 350±0.08 31.3±0.29 26.6±0.25 7.8±1.22 6.76±1.58 742±0.71H. radicata 1360±0.59 1700±0.42 1790±0.89 353±0.23 136±0.86 2.05±1.4 10.2±1.3 1.57±0.80 374±0.16C. pumilum 1940±0.65 1370±1.68 1840±1.35 452±0.79 172±1.12 2.87±2.18 14.7±1.04 4.15±0.89 455±0.47O.pimpineloides 4270±0.53 1180±0.22 1350±0.38 347±0.61 18.2±1.0 3.17±0.58 8.93±0.44 3.84±0.93 629±1.3L. tuberosus 2590±0.34 2370±0.54 1980±0.34 494±1.48 37.0±1.42 2.69±0.41 12.4±0.67 2.12±1.16 331±0.53C. spinosum 2030±3.6 1260±0.75 1400±0.61 279±0.11 65.1±0.17 1.72±0.33 11.3±0.94 3.01±0.62 287±0.86R. ficarioides 3820±1.08 448±0.52 1550±0.76 454±1.75 41.7±1.35 3.63±2.48 9.98±0.53 7.01±0.82 422±1.71P. majus 1630±0.38 144±0.34 1720±1.38 148±0.17 9.98±0.13 0.49±0.54 2.39±0.21 1.25±0.81 378±0.52F. vulgare ssp. piperitum 1440±0.18 839±0.47 1190±0.25 235±0.31 8.25±0.48 2.85±0.44 3.32±0.29 1.65±0.22 274±0.33

Table 9. Nitrates contents of Cretan edible wild plants

N° Plant Names Nitrates (g/100g wet weight)1 Papaver rhoeas 0.203±0.0162 Sonchus oleraceus 0.100±0.0063 Pimpinela peregrina 0.015±0.0024 Centaurea idaea 0.097±0.0025 Tragopogon Sinuatus 0.148±0.0096 Crepis Commutata 0.037±0.0127 Helmintotheca echioides 0.034±0.0048 Tordylium apulum 0.044±0.0089 Scandix pecten-veneris 0.076±0.003

10 Pontikes 0.032±0.00311 Allium subhirstum 0.133±0.00512 Rumex ssp. 0.043±0.00113 Silene Vulgaris 0.090±0.00614 Crepis vesicaria 0.028±0.00115 Uropermum picroides 0.008±0.00216 Tolpis virgata 0.008±0.00317 Hypochoeris radicata 0.054±0.00218 Cichorium pumilum 0.057±0.00719 Oenothera pimpineloides 0.055±0.00220 Leontodon tuberosus 0.101±0.00221 Cichorium spinosum 0.056±0.0122 Ranunculus ficarioides 0.064±0.0023 Prasium majus 0.189±0.00524 Foeniculum vulgare ssp.piperitum 0.024±0.001

Unlike other nutrients, such as amino acids and fatty acids, vitamins, minerals and polyphenols must be supplied from the diet, since the body cannot produce them.

For this reason, this study was focused on the determination of the nutritional values of some wild plants. The results have shown that the investigated plants contained considerable amounts of antioxidants and mineral elements:

Tordylium apulum contained a higher amount of alpha-tocopherol of 2.426 mg/100 g wet weight than other plants.

Rumex ssp. contained the highest amount of total phenols, 102.56± 3.13 mg/100 g wet weight followed by Cichorium pumilum 93.643 ± 0.28 mg/100 g.

Oenothera pimpineloides was more efficient antioxidant than the rest of the plants (EC50=0.222±0.018), another species, Ranunculus ficarioides, also showed significant antioxidant activity (EC50=0.28±0.08).

RESULTS & Discussion

CONCLUSION From this study we conclude that the 24 commonly eaten wild plants in Crete contained considerable amounts of antioxidants and appreciable amounts of calcium, iron, zinc, magnesium and potassium in addition to their low content of nitrates and sodium.

Taking into consideration the current recommended dietary allowances (RDAs), these wild plants could contribute largely to the human diet, especially in terms of essential fatty acids, antioxidants and minerals. Thus, the diet of Crete may be a reference standard for modern human nutrition and a model for defense against diseases of affluence.

It should be emphasized that more studies are required on biochemical and molecular, ethno-botanic and phytogenetic aspects of the wild plants, and more research is needed on their special potential regarding the prevention and treatment of chronic degenerative diseases by increasing the dietary intake of wild plants in both developed and developing countries.

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JUST TRY THEM !!!