BetalainsA New Class of Dietary Cationized Antioxidants

Abstract

Antioxidant nutrients from fruits and vegetables are believed to be a class of compounds that exert their effects in humans by preventing oxidative processes which contribute to the onset of several degenerative diseases. This study found a new class of dietary cationized antioxidants in red beets (Beta vulgaris L.). These antioxidants are betalains, and the major one, betanin, is a betanidin 5-O-beta-glucoside. Linoleate peroxidation by cytochrome c was inhibited by betanin, betanidin, catechin, and alpha-tocopherol with IC(50) values of 0.4, 0.8, 1.2, and 5 microM, respectively. In addition, a relatively low concentration of betanin was found to inhibit lipid peroxidation of membranes or linoleate emulsion catalyzed by the "free iron" redox cycle, H(2)O(2)-activated metmyoglobin, or lipoxygenase. The IC(50) inhibition of H(2)O(2)-activated metmyoglobin catalysis of low-density lipoprotein oxidation by betanin was <2.5 microM and better than that of catechin. Betanin and betanidin at very small concentrations were found to inhibit lipid peroxidation and heme decomposition. During this reaction, betanidin was bleached completely, but betanin remained unchanged in its absorption. This difference seems to derive from differing mechanisms of protection by these two compounds. The high affinity of betanin and betanidin for membranes was demonstrated by determining the rate of migration of the compounds through a dialysis tube. Betanin bioavailability in humans was demonstrated with four volunteers who consumed 300 mL of red beet juice, containing 120 mg of the antioxidant. The betacyanins were absorbed from the gut and identified in urine after 2-4 h. The calculated amount of betacyanins found in the urine was 0.5-0.9% of that ingested. Red beet products used regularly in the diet may provide protection against certain oxidative stress-related disorders in humans.

Betanidin significantly reduces blood glucose levels in BALB/c mice fed with an atherogenic diet

“…We did not quantify the hypoglycemic effect with different doses of betanidin nor the presence of this effect in other betalains. In respect to the latter, since the antioxidant capacity and the other effects mentioned before are considered to be present in all betalains 3,4,[6][7][8][10][11][12]14,15 , it may be possible that the hypoglycemic effect is present in all this group of molecules; further studies will determine if this is the case.…”

“…There are also not reports of any effect of betalains in the insulin or glucose tolerance. As with other betalains 3,[6][7][8][9] , the main biological action of betanidin known to date in animal biomolecules is its antioxidant capacity 10 . Betalains have also been shown to induce the expression of quinone reductases 11 , to inhibit the expression of ICAM-1 12 and to decrease the DNA methyl transferase activity 13 .…”

Effect of storage time on physicochemical and textural properties of sausages covered with oxidized banana starch film with and without betalains

“…This lower value could be due to the following: (1) the betalains reacted with the sausages' free radicals produced by lipid oxidation, (2) the betalains migrated from the film to the sausage and/or (3) betalains were exposed to light and air (Azeredo, 2009). In order for betalains to have a beneficial effect on the human body, it is recommended that the food contain ≈39 µg/g (Kanner, Harel, & Granit, 2001). Even after 10 days of storage, the starch films still have roughly that amount of betalain and can benefit humans if the film is eaten with the sausage.…”

Antioxidant properties of polyphenolic rich HPLC standardized extract of Beta vulgaris L. roots

“…This vegetable is a well-known plant for its high nutritive and therapeutic value since ancient times [1][2]. Betalains (anthocyanins) and carotenoids are the major active constituents of beetroot and generally recommended as safe natural preservative [3][4]. Dietary polyphenols and nitrate has been demonstrated to have a range of beneficial vascular effects, including reducing blood pressure, inhibiting platelet aggregation, preserving or improving endothelial dysfunction, enhancing exercise performance [5][6][7].…”