ABSTRACT
Betanin, a natural food colorant with powerful antioxidative properties, has not been studied in terms of neurodegenerative disease intervention. Therefore, the present study aimed to investigate the neuroprotective effects of betanin against trimethyltin chloride (TMT) -induced neurodegeneration in mice. Forty male ICR mice were randomly divided into four groups: Sham-veh, TMT-veh, TMT-Bet50 and TMT-Bet100. In the TMT groups, neurodegeneration was induced with a one-time intraperitoneal injection of 2.6 mg/kg TMT. Betanin-treated groups (Bet) were given oral doses of 50 or 100 mg/kg dissolved in normal saline solution. Administrations were started 24 h prior to TMT injection and continued for 2 weeks. Anxious behavior and spatial cognition were evaluated, respectively. After behavioral tests, brain oxidative status, hippocampal histology and choline acetyltransferase (ChAT) activity were evaluated. Results showed that TMT significant induce anxious behavior and spatial learning and memory deficits (p < 0.05). These were found concurrently with significant decreases in CA1 ChAT activity, brain tissue catalase (CAT) and superoxide dismutase (SOD) activities with significant increase in hippocampal CA1 degeneration (p < 0.05). Betanin 100 mg/kg exhibited significant anxiolytic effect, preventive effect on CA1 degeneration and CA1 ChAT activity alteration as well as improvement of spatial learning and memory deficits (p < 0.05). These were found concurrently with significant increases of reduced glutathione, CAT and SOD activities as well as the decrease in malondialdehyde (p < 0.05). We conclude that betanin 100 mg/kg exhibits neuroprotective effects against TMT-induced neurodegeneration in mice via its anti-oxidative properties, protective against hippocampal CA1 degeneration and ChAT activity alteration. Therefore, betanin is interesting in further neurodegenerative therapeutic study and applications.
Subject(s)
Betacyanins/administration & dosage , Neurodegenerative Diseases/chemically induced , Neurodegenerative Diseases/prevention & control , Neuroprotective Agents/administration & dosage , Trimethyltin Compounds/toxicity , Administration, Oral , Animals , Brain/drug effects , Brain/metabolism , Injections, Intraperitoneal , Male , Mice , Mice, Inbred ICR , Neurodegenerative Diseases/metabolismABSTRACT
Intestinal ischemic-reperfusion (IR) injury has detrimental effects on both local and distant organs in the body. Betanin is known for its antioxidant properties, and it is found mostly in vegetables. Therefore, the aim of the present study was to test the hypothesis that betanin administration prior intestinal IR, may be beneficial in protecting jejunal mucosa and lung parenchyma against IR damage. Male specific pathogen-free Charles River Wistar rats were used (nâ¯=â¯42). Betanin (50â¯mg/kg) was administered intraperitoneally 30â¯min before ischemia of the superior mesenteric artery lasting 1â¯h, followed by 1, 4 and 24â¯h of reperfusion. Immunohistochemical as well as histomorphometrical analysis indicated a protective effect of betanin pretreatment on jejunal tissue. Regarding morphometrical analysis betanin significantly (pâ¯<â¯0.01) augments intestinal villus height after 24 of reperfusion comparing to early stages. Betanin application reduced number of mast cells population in early reperfusion periods (pâ¯<â¯0.05). The protective effect of betanin on lung parenchyma, was detected in late reperfusion period (24â¯h) with improvement of histopathological injury index and morphometric analysis (pâ¯<â¯0.001 for both). The improvement of histopathological injury index (pâ¯<â¯0.001) and morphometric analysis (pâ¯<â¯0.001) during the late reperfusion period, suggests a protective effect of betanin on lung parenchyma. Moreover, suppression of the inflammatory response was mirrored by the reduction of myeloperoxidase (MPO) positive cells within lung parenchyma after 1 and 4â¯h of reperfusion (pâ¯<â¯0.001). Especially, during the first 4â¯h of reperfusion after betanin administration, a reduction of 74% of the polymorphonuclear neutrophils infiltration (MPO positive cell population) and of a nearly 46% of active MCs was observed. Upon morphometric examination, the lung histological architecture after 24â¯h of reperfusion appeared to be almost 100% better following betanin treatment, with 25% thinner interalveolar septa and 20% larger alveolar surface for respiratory gas exchange. The results suggest that betanin pretreatment protects the jejunal mucosa and the lung parenchyma, as well as reduces the inflammatory cell density after intestinal IR injury.
Subject(s)
Betacyanins/pharmacology , Inflammation/drug therapy , Jejunum/drug effects , Lung/drug effects , Reperfusion Injury/complications , Animals , Betacyanins/administration & dosage , Inflammation/etiology , Jejunum/injuries , Jejunum/pathology , Lung/pathology , Male , Parenteral Nutrition , Rats , Rats, WistarABSTRACT
Oxidative stress is a common condition described in risk factors for cardiovascular disease. Betanin, a bioactive pigment from red beetroot demonstrates anti-inflammatory and antioxidant properties. The main aim of this study was to evaluate the short-term intake of betanin against oxidative stress in a rodent model, a common condition described in several risk factors for cardiovascular disease. Oxidative stress was induced in Wistar rats by a hyperlipidemic diet for 60 days, followed by betanin administration (20 mg·kg-1) through oral gavage for 20 days. Plasma biochemical parameters and antioxidant enzyme activities were evaluated. Lipid peroxidation and histopathological changes were determined in the liver. The hyperlipidemic diet caused hyperglycemia, hyperinsulinemia, insulin resistance, and increases in alanine transaminase and aspartate transaminase levels. Oxidative stress status was confirmed by reduction of antioxidant enzyme activities, increased lipid peroxidation, and liver damage. Purified betanin regulated glucose levels, insulin, and insulin resistance. Hepatic damage was reversed as evidenced by the reduction in alanine transaminase and aspartate transaminase levels and confirmed by histological analyses. Betanin reduced hepatic malondialdehyde and increased superoxide dismutase, catalase, and glutathione peroxidase activities. Short-term betanin intake modulated biochemical parameters, reversed hepatic tissue damage, and attenuated oxidative stress in Wistar rats.
Subject(s)
Antioxidants/administration & dosage , Betacyanins/administration & dosage , Hyperlipidemias/prevention & control , Liver/drug effects , Oxidative Stress/drug effects , Animals , Biomarkers/blood , Blood Glucose/drug effects , Blood Glucose/metabolism , Diet, High-Fat , Disease Models, Animal , Drug Administration Schedule , Hyperlipidemias/blood , Hyperlipidemias/pathology , Insulin/blood , Insulin Resistance , Lipid Peroxidation/drug effects , Lipids/blood , Liver/metabolism , Liver/pathology , Male , Rats, Wistar , Time FactorsABSTRACT
This study aims to investigate the thermoprotective properties of Opuntia ficus-indica f. inermis. Extracts were prepared from cladodes (CE) and mesocarps (ME), then subjected to a spectrophotometric and LC-MS analyses. Lymphocytes were isolated from peripheral blood of non-stressed sheep, supplemented with CE, ME, betanin or α-tocopherol, and subjected to two thermal treatments: 40 and 41⯰C, for 6â¯h. Viable lymphocytes and H2O2 production were evaluated. The antioxidant activity of ME was 3.43 folds higher than CE. The LC-MS analysis of CE and ME allowed identifying 11 phenolic acids, 2 flavanones, 6 flavones, 3 flavonols and 1 betanin type betacyanin. Lymphocytes mortality increased linearly as function of the severity and the duration of heat stress. This mortality was correlated with H2O2 production. At 41⯰C, only ME allowed maintaining lymphocytes viability. Moreover, ME was more efficient than CE in reducing H2O2 production. This thermoprotection was ensured by betaxanthin and betacyanin pigments. Interestingly, betanin was more efficient than α-tocopherol in preventing hyperthermia-induced lymphocytes' mortality. We report here for the first time the thermoprotective properties of cladodes and mesocarps of Opuntia ficus-indica f. inermis. Betanin was able to maintain lymphocyte viability through reducing H2O2 production, and therefore the oxidative-induced heat stress.
Subject(s)
Antioxidants/administration & dosage , Heat-Shock Response , Lymphocytes/physiology , Opuntia/chemistry , Plant Extracts/administration & dosage , Protective Agents/administration & dosage , Animal Nutritional Physiological Phenomena , Animals , Antioxidants/chemistry , Betacyanins/administration & dosage , Betacyanins/isolation & purification , Betacyanins/metabolism , Cell Survival/drug effects , Dietary Supplements , Hydrogen Peroxide/metabolism , Plant Extracts/chemistry , Plant Extracts/isolation & purification , Sheep , alpha-Tocopherol/administration & dosage , alpha-Tocopherol/isolation & purificationABSTRACT
The influence of the matrix of red beetroot products and interindividual variability on betacyanins bioavailability in humans was studied. In a randomized crossover study 12 volunteers consumed red beet juice and crunchy slices containing betanin and isobetanin. Betalains were analyzed by the HPLC-DAD-MS. Urine samples examined after the consumption of both products contained not only native betacyanins but also their aglycones. In case of juice, the highest betacyanins urine excretion rate was observed within the first 2â¯h (64â¯nmol/h), while in case of crunchy slices within the period of 2-4â¯h (66â¯nmol/h). Among volunteers, the average total betacyanins excretion rate ranged from 18.54 to 67.96â¯nmol/h and, 13.15 to 63.58â¯nmol/h for red beet juice and crunchy slices, respectively. In total, approximately 0.3% of betacyanins (ranging from 0.12 to 0.58%) ingested from both products was excreted. The study showed that betacyanins bioavailability from juice and crunchy slices is similar, with the matrix of products consumed having an impact on betacyanins excretion profile, and the phenotype of volunteers affecting betacyanins excretion rate.
Subject(s)
Beta vulgaris/metabolism , Betacyanins/pharmacokinetics , Fruit and Vegetable Juices , Plant Roots/metabolism , Administration, Oral , Adult , Betacyanins/administration & dosage , Betacyanins/urine , Biological Availability , Chromatography, High Pressure Liquid , Cross-Over Studies , Female , Food Handling/methods , Humans , Male , Poland , Renal Elimination , Spectrometry, Mass, Electrospray Ionization , Young AdultABSTRACT
BACKGROUND AND PURPOSE: Defective autophagy contributes to the pathogenesis of inflammatory disorders such as inflammatory bowel disease and there are interactions between autophagy and inflammation. Here we have analysed the effects of autophagy stimulators on murine colitis. EXPERIMENTAL APPROACH: Mice were treated with intrarectal administration of 2,4,6-trinitrobenzenesulfonic acid (TNBS) (3.5 mg·20 g-1 ) and body weight was measured daily. Histological damage was scored 2 or 4 days after treatment. Some mice received trehalose (3% in drinking water 3 weeks before TNBS administration) or a daily administration of rapamycin (1.25 mg·kg-1 , i.p.), betanin (1 g·kg-1 , i.p.) or betanin + 3-methyladenine (3MA) (10 mg·kg-1 , i.p.). Protein levels of p-mTOR, p62, LC3, BCL10, NFκB, IκBα and p-IκBα in mucosa were determined by Western blots and mRNA expression of TNFα, IL1ß, IL6, IL10, COX2, CCR7, CD11c, inducible NOS and CD86 by qRT-PCR. KEY RESULTS: Impaired autophagy associated with body weight loss and intestinal damage was detected in the mucosa of TNBS-treated mice. Administration of trehalose, rapamycin or betanin prevented the impaired autophagic flux induced by TNBS and decreased mucosal protein levels of BCL10, p-IκBα and NFκB-p65 and the expression of pro-inflammatory cytokines and M1 macrophage markers. Blockade of autophagosome formation by treatment with 3MA, prevented the reduction in protein levels of p62, BCL10, p-IκBα and NFκB-p65 induced by betanin in TNBS-treated mice and weakened the protective effects of betanin on murine colitis. CONCLUSIONS AND IMPLICATIONS: Pharmacological stimulation of mucosal autophagy reduced intestinal inflammation and improved murine colitis.
Subject(s)
Autophagy/drug effects , Betacyanins/pharmacology , Colitis/drug therapy , Inflammation/drug therapy , Intestinal Mucosa/drug effects , Sirolimus/pharmacology , Trehalose/pharmacology , Administration, Rectal , Animals , Betacyanins/administration & dosage , Colitis/chemically induced , Colitis/pathology , Female , Inflammation/metabolism , Injections, Intraperitoneal , Intestinal Mucosa/metabolism , Male , Mice , Mice, Inbred BALB C , Sirolimus/administration & dosage , Trehalose/administration & dosage , Trinitrobenzenesulfonic Acid/administration & dosageABSTRACT
ETHNOPHARMACOLOGICAL RELEVANCE: The fruits of Opuntia elatior Mill are being used traditionally in different disease condition like diabetes, obesity, asthma, inflammatory disorders, and anemia. Betanin, a compound isolated from fruits of Opuntia elatior Mill has potent anti-oxidative and anti-inflammatory activity. Recent study from our lab indicated the protective effect of betanin against high glucose induced rat renal epithelial cell fibrosis and matrix accumulation, major features of diabetic nephropathy (DN). However the molecular mechanism of betanin in DN has not yet been fully elucidated. AIM OF THE STUDY: The aim of the present study was to further investigate the anti-fibrotic mechanisms of betanin against streptozotocin (STZ) induced DN. MATERIALS AND METHODS: Betanin was isolated from fruits of Opuntia elatior Mill (Cactaceae) and structure was elucidated using spectroscopy (UV, IR, 1H-NMR and mass). STZ was injected intraperitoneally with single dose of 50mg/kg for diabetes induction. In order to develop DN the animals were left in diabetes condition without any treatment during the following 4 weeks. Betanin (25, 50 and 100mg/kg/day) and lisinopril (5mg/kg/day, reference compound) were orally administered for 8 weeks after the induction of DN. Renal function, blood glucose, serum creatinine, blood urea nitrogen (BUN) and antioxidant enzyme activities in the kidney tissue were measured. Kidney tissue samples were used for glomerulosclerosis, tubulointerstitial fibrosis and morphometric studies. The expression of transforming growth factor-beta (TGF-ß), type IV collagen, alpha-smooth muscle actin (α-SMA) and E-cadherin in kidney tissue were evaluated using reverse transcription-polymerase chain reaction, and immunohistochemistry. RESULTS: Betanin was successfully isolated from fruits of Opuntia elatior Mill (Cactaceae) and purified by column chromatography. The results showed that betanin attenuated diabetic kidney injury by significantly inhibiting proteinuria, blood glucose, serum creatinine and BUN levels and restored antioxidant enzyme activities in kidney tissue. Histological studies exhibited that betanin treatment reduced the glomerular surface area, glomerulosclerosis and tubulointerstitial fibrosis. Furthermore, betanin modulated mRNA and protein expression of TGF-ß, type IV collagen, α-SMA and E-cadherin in kidney. CONCLUSIONS: The results conclude that betanin can effectively suppress renal fibrosis in DN, and may slow down the progression to end-stage renal disease by regulating TGF-ß signal pathway.
Subject(s)
Betacyanins/pharmacology , Diabetes Mellitus, Experimental/drug therapy , Diabetic Nephropathies/prevention & control , Opuntia/chemistry , Animals , Betacyanins/administration & dosage , Betacyanins/isolation & purification , Blood Glucose/drug effects , Blood Urea Nitrogen , Creatinine/blood , Diabetes Mellitus, Experimental/complications , Dose-Response Relationship, Drug , Female , Fibrosis/prevention & control , Fruit , Lisinopril/pharmacology , Oxidative Stress/drug effects , Rats , Rats, Sprague-Dawley , Signal Transduction/drug effects , Streptozocin , Transforming Growth Factor beta/metabolismABSTRACT
PURPOSE: To evaluate the plasma bioavailability of betanin and nitric oxide (NOx) after consuming beetroot juice (BTJ) and whole beetroot (BF). BTJ and BF were also analysed for antioxidant capacity, polyphenol content (TPC) and betalain content. METHODS: Ten healthy males consumed either 250 ml of BTJ, 300 g of BF or a placebo drink, in a randomised, crossover design. Venous plasma samples were collected pre (baseline), 1, 2, 3, 5 and 8 h post-ingestion. Betanin content in BTJ, BF and plasma was analysed with reverse-phase high-performance liquid chromatography (HPLC) and mass spectrometry detection (LCMS). Antioxidant capacity was estimated using the Trolox equivalent antioxidant capacity (TEAC) and polyphenol content using Folin-Ciocalteu colorimetric methods [gallic acid equivalents (GAE)] and betalain content spectrophotometrically. RESULTS: TEAC was 11.4 ± 0.2 mmol/L for BTJ and 3.4 ± 0.4 µmol/g for BF. Both BTJ and BF contained a number of polyphenols (1606.9 ± 151 mg/GAE/L and 1.67 ± 0.1 mg/GAE/g, respectively), betacyanins (68.2 ± 0.4 mg/betanin equivalents/L and 19.6 ± 0.6 mg/betanin equivalents/100 g, respectively) and betaxanthins (41.7 ± 0.7 mg/indicaxanthin equivalents/L and 7.5 ± 0.2 mg/indicaxanthin equivalents/100 g, respectively). Despite high betanin contents in both BTJ (~194 mg) and BF (~66 mg), betanin could not be detected in the plasma at any time point post-ingestion. Plasma NOx was elevated above baseline for 8 h after consuming BTJ and 5 h after BF (P < 0.05). CONCLUSIONS: These data reveal that BTJ and BF are rich in phytonutrients and may provide a useful means of increasing plasma NOx bioavailability. However, betanin, the major betalain in beetroot, showed poor bioavailability in plasma.
Subject(s)
Beta vulgaris/chemistry , Betalains/pharmacokinetics , Nitrates/pharmacokinetics , Adult , Antioxidants/administration & dosage , Antioxidants/pharmacokinetics , Betacyanins/administration & dosage , Betacyanins/blood , Betacyanins/pharmacokinetics , Betalains/administration & dosage , Betalains/blood , Betaxanthins/administration & dosage , Betaxanthins/blood , Betaxanthins/pharmacokinetics , Biological Availability , Chromatography, High Pressure Liquid , Cross-Over Studies , Fruit and Vegetable Juices , Humans , Male , Nitrates/administration & dosage , Nitrates/blood , Nitric Oxide/administration & dosage , Nitric Oxide/blood , Nitric Oxide/pharmacokinetics , Plant Roots/chemistry , Polyphenols/administration & dosage , Polyphenols/blood , Polyphenols/pharmacokinetics , Pyridines/administration & dosage , Pyridines/blood , Pyridines/pharmacokinetics , Young AdultABSTRACT
Betacyanins (BC) were purified from beetroot (Beta vulgaris var. rubra L.) and tested, alone or in combination with vitexin-2-O-xyloside (XVX) from Beta vulgaris var. cicla L., for their ability to reduce the proliferation rate in T24 bladder cancer cells. Combination of BC and XVX exhibited a synergistic effect concerning the inhibition of proliferation in T24 cancer cells at 24 and 48 h but not after 72 h of incubation. The induction of apoptosis was evidenced by means of fluorescence activated cell sorting (FACS) analysis, as well as through the increase in caspase 3 and 8 activities. Using RTqPCR experiments, it was shown that the combination of XVX + BC was able to enhance the expression levels of pro-apoptotic BAX and downregulate anti-apoptotic BIRC5 (survivin), as well as pro-survival CTNNB1 (ß-catenin). The most evident effect of BC was the increase of the activity of caspase 8, leading to induction of extrinsic apoptosis. Moreover, XVX, BC and their combination showed no cytotoxic effect on normal human skin NCTC 2544 keratinocytes. These results demonstrated the efficacy and the mechanisms of the action of BC and XVX, extracted from edible plants, and suggested that a diet or a nutrition supplement, enriched with these bioactive molecules, could be used in the prevention of human bladder cancer.
Subject(s)
Anticarcinogenic Agents/pharmacology , Betacyanins/pharmacology , Cell Proliferation/drug effects , Flavonoids/pharmacology , Glycosides/pharmacology , Anticarcinogenic Agents/administration & dosage , Apoptosis , Beta vulgaris/chemistry , Betacyanins/administration & dosage , Betacyanins/chemistry , Cell Line, Tumor , Down-Regulation , Flavonoids/administration & dosage , Glycosides/administration & dosage , Humans , Molecular StructureABSTRACT
Natural bioactive compounds in food have been shown to be beneficial in preventing the development of obesity, diabetes, and other metabolic diseases. Increasing evidence indicates that betacyanins possess free-radical-scavenging and antioxidant activities, suggesting their beneficial effects on metabolic disorders. The main objective of this study was to isolate and identify the betaycanins from Hylocereus undatus (white-fleshed pitaya) peel and evaluate their ability to ameliorate obesity, insulin resistance, and hepatic steatosis in high-fat-diet (HFD)-induced obese mice. The purified pitaya peel betacyanins (PPBNs) were identified by liquid chromatography/tandem mass spectrometry (LC/MS/MS), and the male C57BL/6 mice were fed a low-fat diet, HFD, or HFD supplemented with PPBNs for 14 weeks. Our results showed that the white-fleshed pitaya peel contains 14 kinds of betacyanins and dietary PPBNs reduced HFD-induced body weight gain and ameliorated adipose tissue hypertrophy, hepatosteatosis, glucose intolerance, and insulin resistance. Moreover, the hepatic gene expression analysis indicated that PPBN supplementation increased the expression levels of lipid-metabolism-related genes (AdipoR2, Cpt1a, Cpt1b, Acox1, PPARγ, Insig1, and Insig2) and FGF21-related genes (ß-Klotho and FGFR1/2) but decreased the expression level of Fads2, Fas, and FGF21, suggesting that the protective effect of PPBNs might be associated with the induced fatty acid oxidation, decreased fatty acid biosynthesis, and alleviated FGF21 resistance.
Subject(s)
Betacyanins/administration & dosage , Cactaceae/chemistry , Insulin Resistance , Obesity/drug therapy , Plant Extracts/administration & dosage , Animals , Betacyanins/chemistry , Blood Glucose/metabolism , Diet, High-Fat/adverse effects , Fruit/chemistry , Humans , Insulin/metabolism , Liver/drug effects , Liver/metabolism , Male , Mice , Mice, Inbred C57BL , Obesity/genetics , Obesity/metabolism , Plant Extracts/chemistry , Triglycerides/metabolismABSTRACT
A number of vegetables have a high nitrate content which after ingestion can be reduced to nitrite by oral bacteria, and further to vasoprotective NO endogenously. In the present study, two separate randomly controlled, single-blind, cross-over, postprandial studies were performed in normotensive volunteers. Ambulatory blood pressure (BP) was measured over a 24 h period following consumption of either four doses of beetroot juice (BJ), 0, 100, 250 and 500 g (n 18), or three bread products, control bread (0 g beetroot), red beetroot- and white beetroot-enriched breads (n 14). Total urinary nitrate/nitrite (NO(x)) was measured at baseline, and at 2, 4 and 24 h post-ingestion. BJ consumption significantly, and in a near dose-dependent manner, lowered systolic BP (SBP, P < 0·01) and diastolic BP (DBP, P < 0·001) over a period of 24 h, compared with water control. Furthermore, bread products enriched with 100 g red or white beetroot lowered SBP and DBP over a period of 24 h (red beetroot-enriched bread, P <0·05), with no statistical differences between the varieties. Total urinary NO(x) significantly increased following the consumption of 100 g (P < 0·01), 250 g (P <0·001) and 500 g BJ (P <0·001) and after red beetroot-enriched bread ingestion (P <0·05), but did not reach significance for white beetroot-enriched bread compared with the no-beetroot condition. These studies demonstrated significant hypotensive effects of a low dose (100 g) of beetroot which was unaffected by processing or the presence of betacyanins. These data strengthen the evidence for cardioprotective BP-lowering effects of dietary nitrate-rich vegetables.
Subject(s)
Antihypertensive Agents/therapeutic use , Beta vulgaris/chemistry , Beverages , Bread , Cardiotonic Agents/therapeutic use , Plant Roots/chemistry , Prehypertension/diet therapy , Adult , Antihypertensive Agents/administration & dosage , Antihypertensive Agents/chemistry , Betacyanins/administration & dosage , Betacyanins/analysis , Beverages/analysis , Bread/analysis , Cardiotonic Agents/administration & dosage , Cardiotonic Agents/chemistry , Cross-Over Studies , England , Humans , Male , Nitrates/administration & dosage , Nitrates/analysis , Nitrates/urine , Nitrites/analysis , Nitrites/urine , Pigmentation , Pilot Projects , Prehypertension/prevention & control , Prehypertension/urine , Single-Blind Method , Time Factors , Young AdultABSTRACT
Reaction kinetics of betanin and its aglycone betanidin towards peroxyl radicals generated from the azo-initiated oxidation of methyl linoleate in methanol and of a heterogeneous aqueous/soybean phosphatidylcholine liposomal system were studied by monitoring formation of linoleic acid hydroperoxides and consumption of the pigments. Betanin was a weak retarder in methanol and an effective chain breaking antioxidant in the liposomal model, indicating that kinetic solvent effects and partition in lipid bilayers may affect its activity. Betanidin behaved as a chain terminating antioxidant in both models. Kinetic parameters characterizing peroxyl radical-scavenging activity showed that betanidin was more effective than betanin, in terms of both radical-scavenging rate constant and stoichiometric factor, with effectiveness of the same order as vitamin E under comparable conditions. Products identified by spectrophotometric and HPLC techniques indicated reaction of the glucose-substituted monophenol and ortho-diphenol moieties of betanin and betanidin, respectively, and suggested mechanisms of the antioxidant activity. Either betanin or betanidin incorporated in liposomes with alpha-tocopherol had additive effects, supporting partition of the pigments in the bilayer and lipoperoxyl radical reduction.
Subject(s)
Betacyanins/pharmacology , Free Radical Scavengers/pharmacology , Lipid Peroxidation/drug effects , Betacyanins/administration & dosage , Betacyanins/chemistry , Chromatography, High Pressure Liquid , Drug Synergism , Free Radical Scavengers/administration & dosage , Free Radical Scavengers/chemistry , Linoleic Acid/metabolism , Linoleic Acids/metabolism , Lipid Bilayers , Liposomes/administration & dosage , Methanol , Molecular Structure , Oxidation-Reduction , Phosphatidylcholines/chemistry , Solutions , Solvents , Spectrophotometry , Structure-Activity Relationship , Water , alpha-Tocopherol/pharmacologyABSTRACT
Betalains are water-soluble nitrogenous vacuolar pigments present in flowers and fruits of many caryophyllales with potent antioxidant properties. In the present study the antiproliferative effects of betanin, a principle betacyanin pigment, isolated from the fruits of Opuntia ficus-indica, was evaluated on human chronic myeloid leukemia cell line (K562). The results show dose and time dependent decrease in the proliferation of K562 cells treated with betanin with an IC(50) of 40 microM. Further studies involving scanning and transmission electron microscopy revealed the apoptotic characteristics such as chromatin condensation, cell shrinkage and membrane blebbing. Agarose electrophoresis of genomic DNA of cells treated with betanin showed fragmentation pattern typical for apoptotic cells. Flow cytometric analysis of cells treated with 40 microM betanin showed 28.4% of cells in sub G0/G1 phase. Betanin treatment to the cells also induced the release of cytochrome c into the cytosol, poly (ADP) ribose polymerase (PARP) cleavage, down regulation Bcl-2, and reduction in the membrane potentials. Confocal microscopic studies on the cells treated with betanin suggest the entry of betanin into the cells. These studies thus demonstrate that betanin induces apoptosis in K562 cells through the intrinsic pathway and is mediated by the release of cytochrome c from mitochondria into the cytosol, and PARP cleavage. The antiproliferative effects of betanin add further value to the nutritional characteristics of the fruits of O. ficus-indica.