Flavones are phenols that are widely present in the flowers, leaves and fruit tissues of living plants as flavonoid glycosides. The aglycones present in some flavones are poisonous to plants and can be separated only from dead timber. Deriving their name from their yellow color, and have dual roles. While sometimes they draw pollinating insects with their color, in other times their toxic property enable them act as repellents to insects that harm the plants. At the same time, tests have shown that flavonoids are also capable of regulating the growth of the plants. Flavonoids are either bitter or sweet in taste and recent chemical tests have proved that minor altercations in their cell structure can change their taste from bitter to sweet or the other way around. This is significant, as it shows that the bitter and sweet taste receptors in our tongue are situated close to each other and also analogous in structure.
Flavonoids may be found in almost all plants, but their concentration varies depending on the plant family. For example, citrus fruits, buckwheat (Fagopyrum esculentum) and all white and yellow flowers have very high concentration of flavonoids.
Flavonoid aglycones can be classified into five groups - flavones, isoflavone, flavonols, flavonones and xanthones. Flavones (apigenin) are found in celery seed and parsley, luteolin in Equisetum spp. (the horsetails), while isoflavones (genistein) are common in clover, gorse and other legumes, which is a pro-oestrogen with oestrogenic properties. Examples of flavonols (guercitol or glycoside rutin) are buckwheat, rue and over half of all plants tested kaempferol and in around half all plants tested myricetin in woody plants only. Similarly, flavonones (eridictyol / methyleriodictyol) jointly form the 'citrin' of citrus fruit glycoside and hesperidin liquiritigetol in licorice. Xanthones (gentisin) are normally found in gentian.
The pharmacological properties of different flavonoids include - diuretic, anti-inflammatory, antiseptic, antispasmodic and also anti-tumor. Flavonoids, however, are most useful in treating the vascular system and this has become evident from the research done on bio-flavonoids or 'vitamin P', especially hesperidin and rutin. During his research in 1939, scientist Albert von Szent-Gyorgyi found that ascorbic acid alone was not enough to cure scurvy (purpura haemorrhagica) caused by deficiency in the body and that when lemon juice and red pepper extracts were added to it, the amalgam proved to be more useful. He segregated a crystalline part of flavonoid having a specific result and called it 'citrin'. This later came to be known as 'hesperidin' and found to be an amalgamation of eriodictyol and methyleriodictyol glycosides.
While eriodictyol and methyleriodictyol glycosides help in reducing the feebleness and porous defects of the capillaries, a third element developed through chromatography contains the properties of quercitol and was ascertained to be rutin. Together these components increase the curative effect on the capillaries, but at the same time lower the blood pressure. Allopathically, rutin has multiple uses and is very effective for treating hypertension, diabetes, salicylate and arsenic poisoning and allergies. In the modern day of allopathic treatment, rutin is also used to treat hemorrhages due to radiation, while in herbal medicine buckwheat is used for the same purpose. In addition to these, there are many other medicinal values of flavonoids and yarrow (Achillea millefolium), elderflowers (Sambucus nigra), and lime or linden flowers (Tilia spp.) are especially useful in this regard.
Hence, it may be concluded that flavonoids present in major proportions in most plants are very useful in treating circulatory disorders. This is because flavonoids function as soothing and stabilizing components that help in normalizing the circulation system. In addition, these components have anti-inflammatory and diuretic qualities and they have a beneficial influence. One such plant that has all such properties is hawthorn (Crataegus oxyacantha).
Like other vitamins, ascorbic acid or vitamin C is an organic amalgam that is obtained from fruits and vegetables. Ascorbic acid, made up of carbon and oxygen and found in living organisms, is essential for our body to build and preserve our bones, skin and blood vessels. Ascorbic acid is also useful in producing collagen, a protein that is required to grow and maintain strong teeth, gums, cartilage, vertebrae discs, joint linings, skin and the blood vessels. It is soluble in water and cannot be stored in huge quantities in the body. Hence, it is necessary that the body restores this substance daily for wellness.
In addition, ascorbic acid has number other medicinal benefits. While it actively works to cure all external cuts, scratches and injuries, internally ascorbic acids is very useful to combat all kinds of infections. Significantly, it also restrains smog, tobacco smoke as well as specific foods from being converted to substances that might lead to cancer. Ascorbic acid is also useful in preventing high blood pressure and other heart diseases as it works to widen and enlarge the blood vessels and also helps in controlling the cholesterol levels in the blood. As ascorbic acid is particularly beneficial for maintaining a good circulation system, it helps the body to absorb iron as well as lower the lead content in the blood.
Ascorbic acid or vitamin C is also useful in preventing scurvy, an illness that is distinguished by weakness, exhaustion, anemia, swollen joints, bleeding gums and loose teeth. In early days, the disease was common among people traveling by ships because crews were bereft of eating fresh vegetables or fruit. Many sailors died of the disease for long periods, but today the disease is virtually unheard of. Ascorbic acid is also learnt to prevent the risk of being affected with cataracts, clouding of eye lenses that impairs vision and also protects diabetic patients from weakening of nerves, eyes and kidneys. Finally, although this issue is still controversial, vitamin C is also known to help people from catching colds and lower the power of cold symptoms in some cases.
Ascorbic acid is found in different fruits, vegetables, herbs and other organic substances too. While the fruits that contain ascorbic acid include lemons, oranges, limes, grapefruits, bananas, melons, papayas, strawberries, mangos, blackberries, blueberries, kiwi, pineapples, watermelons, cranberries, raspberries, cantaloupes, rose hips and acerola cherries, among vegetables asparagus, broccoli, green peppers, red peppers, cabbage, kale, cauliflower, potatoes, yams, squash, peas, turnips, onions, corns, pumpkins, carrots, parsley and sauerkraut have vitamin C or ascorbic acid. It is also found in major quantities in herbs like garlic and watercress and other sources like fishes and milk.
Here is a word of caution. Taken in adequate proportions, ascorbic acid is very beneficial, but consuming large amounts of ascorbic acid may turn out to be harmful and people may be susceptible to ailments like diarrhea, nausea, skin irritation, burning upon urination and reduction of the mineral copper from the body. There is enough evidence that shows that consuming large quantities of ascorbic acid may lead to formation of stones in the kidney. Again people suffering from excessive iron contents in the blood or glucose-6-phosphate dehydrogenase (G6PD) deficiency need to carefully watch their ascorbic acid consumption. At the same time, such people should strictly follow the physician's instructions in this regard.