Vidya V. Gawande et al. / Journal of Pharmacy Research 2012,5(11),5099-5101 Review Article Available online through ISSN: 0974-6943 http://jprsolutions.info Flavonoids: An Overview

Vidya V. Gawande* and S. V. Kalikar Department of Pharmacy,Government Polytechnic, Gadgenagar, VMV Road, Amravati(MS), India 444603 Received on:14-07-2012; Revised on: 19-08-2012; Accepted on:23-09-2012

ABSTRACT Flavonoids belong to a group of polyphenolic compounds, which are classified as flavonols, flavonones, flavones, flavan-3-ols and isoflavones, anthocynidins according to the positions of the substitutes present on the parent molecule. Flavonoids occur as aglycones, glycosides and methylated derivatives in plants. Flavonoids occur naturally in fruit, vegetables, and beverages such as tea and wine and over 4000 structurally unique flavonoids have been identified in plant sources. These are primarily recognized as the pigments responsible for the many shades of yellow, orange, and red in flowers, fruits, and leaves. The major actions of flavonoids are those against cardiovascular diseases, ulcers, viruses, inflammation, osteoporosis, diarrhea and arthritis. Flavonoids have also been known to possess biochemical effects, which inhibit a number of enzymes such as aldosereductase, xanthine oxidase, phosphodiesterase, Ca+2-ATPase, lipoxygenase, cycloxygenase, etc. They also have a regulatory role on different hormones like estrogens, androgens and thyroid hormones. Flavonoids like quercetin are shown to produce anti-inflammatory effect. The flavonoids in tea are found to be responsible for the prevention of osteoporosis. Quercetin is now found to show inhibiting effects against herpes simplex virus. Antidiarrheal effect is found to be shown by the flavonoids present in cocoa.

Key words:Flavonoids, free radical, enzymes INTRODUCTION Flavonoids are the crystalline, organic compounds soluble in water, dilute · The flavonol quercetin and the flavone apigenin are found in many mineral acids, alkalies, alcohol etc and are nothing but pigments. They occur fruits and vegetables, including onions, apples, broccoli, and berries. either in free state or as glycosides associated with tannins. Flavonoids · Naringenin is a citrus flavanone. Catechin and other catechins are include flavones, flavonols, isoflavones, flavonones, anthoxanthines. abundant in green tea. · Cyanidin and other anthocyanidins are largely responsible for the Occurance of flavonoids deep colors of berries, grapes, and red wine. The flavonoids are widely distributed into plants, flowers, fruits, grasses. · Genistein is an isoflavone found predominantly in legumes. The flavonoid consumed most, in general, is quercetin, and the richest Food Type Food Item sources of flavonoids consumed in general are tea, onions, and Beverages apples. Tea, coffee, fruit and herbal drinks, Cocoa or drinking chocolate, Fruit juice concentrates, ready to drink fruit juices (still and carbonated), Beer, wine, Therapeutic Applications spirits, liqueurs. ØAntioxidant activity Fresh fruits Antioxidants are the substances which prevent oxidation. Antioxidants are Normally available Apples, bananas, oranges, grapefruit, pears, melons, ideal nutraceuticals for neutralizing stress induced free radicals. grapes, lemon, strawberries, peaches, pineapples, plums, raspberries, blueberries, blackcurrants, blackberries, rhubarbs. Exotic fruit section The flavones and catechins are the most powerful flavonoids for protecting Custard apple, passion fruit, pomegranate, sharon fruit, lychee, figs, the body against reactive oxygen species (ROS). gooseberry. Flavonoids can prevent injury caused by free radicals by direct scavenging Fresh vegetables of free radicals. Flavonoids are oxidized by radicals, resulting in a more Normally available Broccoli, carrots, onions, potatoes, courgette, stable, less-reactive radical. Thus shows antioxidant activity. mushrooms, Lettuce (different varieties), tomatoes (different types), celery, cucumber, sweet pepper, red and green), Seasonal Spinach, winter greens, ØAntiatherosceloratic activity leeks, suede, turnip, Brussels sprouts, red cabbage, parsnips,corn-on-cob, Atherosclerosis is a condition that results from the gradual deposition of red radish, mange tout, French beans, sweet potatoes, shallots, asparagus, fatty substances, including cholesterol, in the walls of the arteries. Flavonoids chives. Specialist Artichoke, squash, yam, celeric, fennel bulb, okra, oyster suppress LDL oxidation and inflammatory progression in the artery wall mushrooms. thus prevents atheroscelerosis.

A Japanese study reported an inverse correlation between flavonoid intake *Corresponding author. and total plasma cholesterol concentrations. Other clinical studies, stated Vidya V. Gawande that flavonoid intake protects against coronary heart diseases. Department of Pharmacy, Government Polytechnic, ØAntithrombotic activity Gadgenagar, VMV road, Thrombogenicity refers to the tendency of a material in contact with the Amravati(MS), India 444603

Journal of Pharmacy Research Vol.5 Issue 11.November 2012 5099-5101 Vidya V. Gawande et al. / Journal of Pharmacy Research 2012,5(11),5099-5101 blood to produce a thrombus (clot).The antithromobotic activity of apples, and quercetin from beans, onions and apples, may have reduced flavonoids is due to inhibition of thromboxane A 2 formation. In vitro studies risk of obtaining lung cancer. The polyhydroxylated flavonoid, quercetin showed that flavonoids bind to platelet membranes and are known to inhibit exerted potent growth inhibitory effects on several malignant tumor cell the interaction of platelets on collagen coated surfaces. lines in vitro, such as NK/LY ascites tumor cells, HeLa cells, gastric cancer cells (HGC-27, NUGC-2, MKN-7 and MKN-28), colon cancer cells (COLO ØAntiulcer activity 320 DM), human breast cancer cells, human squamous and gliosarcoma Flavonoids like Quercetin plays a very important role in the prevention cell, ovarian cancer cells, human epidermoidal cancer (A431), human liver and treatment of peptic ulcer. It acts by promoting mucus secretion, thereby cancer cells (HepG2) and human pancreatic cancer cells. Polyphenols were serves as gastroprotective agent, also quercetin has been shown to inhibit found to be strong topoisomerase inhibitors, similar to some the growth of helicobacter pylori bacterium in-vitro studies. chemotherapeutic anticancer drugs including etoposide and doxorubicin.

Among other flavonoids, methyl-3-(+)-catechin interferes with the ØAntinociceptive activity formation of histamine in gastric mucosa and hence produces the protective Flavonoids might account for the antinociceptive action reported for the effect against ulcer. hydroalcoholic extract of Phyllanthus caroliniensis such as protein kinase- C and the calcium influx. Quercetin and rutin have been used as effective constituents for treatment of gastric mucosa. Both meciadiol and sofalcone have been studied and ØCNS Activity proved to possess antiulcer effectiveness and found to be effective in clinical Synthetic flavonoids like 6-bromoflavone and 6-bromo-3'-nitro- flavones trials. were shown to displace[3H] flumazenil binding to membranes from rat cerebellum but not from spinal cord, indicating selectivity for the BZ- ØAntidiabetic effects Omega receptor subtype, but latter was very potent than 6-bromoflavone. Flavonoids, especially quercetin, has been reported to possess antidiabetic activity. ØAntimicrobial activity Flavonoids and esters of phenolic acids have also been investigated for their Vessal et al reported that quercetin brings about the regeneration of antibacterial, antifungal and antiviral activities. In vitro trypanocidal and pancreatic islets and probably increases insulin release in strptozotocin- leishmanicidal activities of the flavonoids hispidulin, from Ambrosia induced diabetic rats. Also in another study, Hif and Howell reported that tenuifolia and santin, from Eupatorium buniifolium, are reported. quercetin stimulate insulin release and enhanced Ca2+ uptake from isolated islets cell which shows antidiabetic activity of flavonoids. Antiviral All the other flavonoids except rutin too show anti viral effects against ØAntidiarrheal effects herpes simplex virus, respiratory syncytial virus, parainfluenza virus, Cocoa beans have historically been used as a treatment for diarrhea. The and adenovirus. Chlorflavonin Quercetin, morin, rutin, dihydroquercetin recent research attributes the antidiarrheal effect to the flavonoids present (taxifolin), apigenin, catechin, and hesperidine have been reported to possess in cocoa. antiviral activity against some of the viruses.

ØAntiinflammatory activity Antibacterial activity A number of reports have been published which demonstrate that flavonoids Antibacterial activity is shown by a number of flavonoids. Quercetin has can modulate arachidonic acid metabolism via the inhibition of cyclo- been reported to completely inhibit the growth of Staphylococcus aureus. oxygenase (COX) and lipooxygenase activity (LO). Quercetin has been shown to inhibit the growth of helicobacter pylori bacterium in in-vitro studies. Most of the flavonones having no sugar moiety Hesperidin, a citrus flavonoid possesses significant antiinflammatory and showed antimicrobial activities whereas none of the flavonols and analgesic effects. Recently, apigenin, luteolin and quercetin have been flavonolignans tested showed inhibitory activity on microorganisms. reported to exhibit anti-inflammatory activity. Flavonols like quercetin, myricetin and kaempferol inhibit the activity of the adenosine deaminase of Antifungal activity endothelial cells. A number of flavonoids isolated from the peelings of tangerine orange, when tested for fungistatic activity towards Deuterophomatracheiphila ØAntitumour activity were found to be active; nobiletin and langeritin exhibited strong and weak Many flavonoids are effective against tumour formation and metastasis. activities, respectively. Flavonoids might induce mechanisms that affect cancer cells and inhibit tumor invasion. ØHepatoprotective activity In view of the need for safe and effective treatment a study of the role of Luteolin and quercetin are responsible for inhibition of tyrosine kinase, silymarin in the management of non-B acute viral hepatitis was investigated, thereby show inhibitory effects on cell growth and metastasis. which showed significantly earlier recovery from hepatomegaly and enlarged spleen in patients receiving silymarin. Genistein is reported to inhibit in a dose dependent manner the growth of HGC-27 cells derived from human gastric cancer. The glycosides of luteolin, ØBiochemical effects apigenin and genistein exhibited their action through different mechanisms Flavonoids have also been known to possess biochemical effects, which by inhibition of the calcium release from sarcoplasmic reticulum. inhibit a number of enzymes such as aldosereductase, xanthine oxidase, +2 In preliminary studies, UCLA. cancer researchers proposed that smokers phosphodiesterase, Ca -ATPase, lipoxygenase, cycloxygenase, etc. They who ate foods containing certain flavonoids, such as catechins found in also have a regulatory role on different hormones like estrogens, androgens strawberries and green and black teas, kaempferol from brussel sprouts and and thyroid hormone.

Journal of Pharmacy Research Vol.5 Issue 11.November 2012 5099-5101 Vidya V. Gawande et al. / Journal of Pharmacy Research 2012,5(11),5099-5101

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Journal of Pharmacy Research Vol.5 Issue 11.November 2012 5099-5101