- Research Article
- Open Access
In vitro antioxidant properties of the biflavonoid agathisflavone
© The Author(s) 2018
Received: 2 March 2018
Accepted: 22 June 2018
Published: 29 June 2018
Free radicals are considered as the causative agents of a variety of acute and chronic pathologies. Natural antioxidants have drawn attention of the researchers in recent years for their ability to scavenge free radicals with minimal or even no side effects. This study evaluates the antioxidant capacity of agathisflavone, a naturally occurring biflavonoid by a number of in vitro methods.
Agathisflavone was subjected to DPPH, ABTS, OH and NO radical scavenging assay, reducing potential and inhibition of lipid peroxidation (TBARS) test using trolox as a standard.
Agathisflavone showed concentration-dependent antioxidant activity against all types of free radicals used in this study. The antioxidant capacity, reducing potential and inhibition of lipid peroxidation showed by agathisflavone were comparable to that of trolox.
Agathisflavone exhibited antioxidant capacity, which suggests considering this biflavonoid for the use in the prevention and/or treatment of diseases precipitated by oxidative stress.
Free radicals, both reactive oxygen and nitrogen species (ROS/RNS), produced by partial reduction of oxygen and nitrogen respectively, are inevitable processes of our body [1–3]. Some of these ROS and RNS are involved in various fundamental processes of cell survival, including mitochondrial respiration and regulation, signalization, cell proliferation and differentiation. However, any alteration in the cellular levels of the ROS/RNS can induce oxidative stress leading to cellular damages, hampering proper cellular functioning or even cell death [4, 5]. Prolonged exposure to ROS/RNS results in the damages to cell macromolecules such as carbohydrates, proteins, lipids as well as genetic materials (e.g., DNA, RNA) which eventually gives rise to the pathophysiology of a number of serious diseases including cancer, diabetes, atherosclerosis, immunosuppression, swelling, cardiovascular diseases and neurodegenerative disorders [6, 7]. Evidence suggests that certain neurological disorders such as, Alzheimer’s disease, Parkinson’s disease, schizophrenia, anxiety and depression have a direct link to long term exposure of the cells to excessive oxidative stresses . In this context, naturally occurring antioxidants have been studied extensively to find their possible role in the prevention and cure for such diseases [9, 10].
Flavonoids represent an important class of natural antioxidants with significant therapeutic potential. Biflavanoids, a type of flavonoids, comprehends a large group of compounds with promising effect against oxidative damage .
Thus the present study was designed to assess the antioxidant property of this biflavonoid by evaluating its ability to scavenge the free radicals, namely DPPH, ABTS, hydroxyl and nitric oxide (NO). It was also tested for its capacity to inhibit lipid peroxidation by TBARS method and the ability to transfer electron by ferric reducing assay.
Materials and methods
Trolox, 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,20-azinobis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS), thiobarbituric acid (TBA), trichloroacetic acid (TCA), sodium nitroprusside (SNP), 2,20-azobis-2-amidinopropane dihydrochloride (AAPH), 2-deoxyribose and potassium ferricyanide were purchased from Sigma-Aldrich Co. (St. Louis, MO, USA). All chemicals and solvents used were of analytical grade.
Fresh leaves of Caesalpinia pyramidalis Tull. (Family: Fabaceae) was collected from Valente, Brazil and identified by Prof. Dr. L. P. de Queiróz (State University of Feira de Santana) and Prof. Dr. M. de F. Agra (Laboratory of Pharmaceutical Technology UFPB). A voucher specimen was deposited at the herbarium of Alexandre Leal da Costa of Biology Institute of the Federal University of Bahia (accession number 240291).
Extraction, isolation and identification of agathisflavone
Fresh leaves of C. pyramidalis was extracted with methanol and chromatographed using silica gel to get pure agathiflavone. The structure was elucidated by spectroscopic data including 1D, 2D NMR and LS–MS carried out at the Department of Chemistry, Federal University of Bahia, Brazil (data not shown). Noteworthy to mention here that naturally occurring agathisflavone exhibits atropisomerism and thus was isolated as a mixture of the atropisomers.
In vitro antioxidant activity evaluation
DPPH radical scavenging test
ABTS radical scavenging test
The method described by Re et al.  with slight modifications was used for this test. The ABTS radical cation was initially formed by mixing 5 mL of 7 mM ABTS with 88 µL of 2.45 mM of potassium persulfate (K2S2O8) solution with further incubation at room temperature in the absence of light for 16 h. The resulting solution was diluted in ethanol in such a way to obtain an absorbance of 0.70 ± 0.05 at 734 nm. This test was done in the dark and at room temperature. An aliquot (0.5 mL) of agathisflavone/trolox (0.058–0.928 mM) solution was mixed with 1.96 mL of the ABTS solution and the absorbance was measured after 6 min. The results were expressed as percentage of inhibition of the ABTS in a similar fashion to that of DPPH radical scavenging assay.
OH radical scavenging assay
Reducing potential assay
The method described by Singhal et al.  with slight modifications was used to determine the reducing capacity of agathisflavone. Briefly, 1 mL of agathisflavone/trolox (0.058–0.928 mM) was added with 1 mL of 1% potassium ferricyanide and 0.5 mL of sodium phosphate buffer (0.2 M, pH 6.6). The reaction mixture was incubated at 50 °C for 20 min, followed by the addition of 0.5 mL of 10% TCA, 0.5 mL of distilled water and 0.25 mL of 0.1% ferric chloride. The absorbance of the reaction mixture was measured at 700 nm in a spectrophotometer against a blank solution. The EC50 of the sample and standard required for 50% reduction potential was determined.
NO scavenging test
Nitric oxide was produced from the spontaneous decomposition of sodium nitroprusside in 20 mM phosphate buffer (pH 7.4). Once generated, nitric oxide interacts with oxygen to produce nitrite ions, which was measured by the Griess reaction . The reaction mixture containing 1 mL of SNP in phosphate buffer (20 mM) and 0.5 mL of agathisflavone/trolox (0.058–0.928 mM) was incubated at 37 °C for 1 h. An aliquot (0.5 mL) of the reaction mixture was taken and homogenized with 0.5 mL of Griess reagent. Absorbance of chromophore was measured at 540 nm in a spectrophotometer and the results were expressed as percentage inhibition of nitrite ions.
Inhibition of lipid peroxidation (TBARS test)
All the experiments were done in triplicate and the results are expressed as mean ± standard error of mean (SEM). Statistical analysis was performed using the program GraphPad Prism® 6.02 (San Diego, CA, USA), one-way ANOVA, multiple comparisons following by t-Student–Newman–Keuls post hoc test. The results were considered statistically significant at p < 0.05.
DPPH radical scavenging
ABTS scavenging assay
OH radical scavenging assay
NO scavenging assay
Antioxidant activity of several flavonoids with mechanism similar to that of agathisflavone have been studied using methods as DPPH and/or ABTS, OH and NO scavenging assay, as well as their ability to inhibit lipid peroxidation by TBARS assay and reducing ability [35, 36].
When compared, agathisflavone was found to be a better scavenger of ABTS than that of DPPH. Although both ABTS and DPPH are free radicals, but the differ in the way that DPPH is a stable free radical itself but ABTS is formed instantly in the reaction solution. Thus both of the methods are used for antioxidant activity study but a difference in the EC50 of a compound can occur due to the difference in the mechanism of action of neutralizing free radicals. In relating the results of DPPH· (EC50 = 0.895 mM) and ABTS·+ (EC50 = 0.123 mM) tests, it is possible to say that agathisflavone showed a better scavenging capacity of ABTS·+. This may be due to effects of donation of electrons, leading to the reduction of ABTS·+ formation. On the other hand, transference of hydrogen atoms may occur to form of a DPPH stable molecule by the action of this biflavonoid [37, 38]. Our findings are similar to the results suggested by Ye et al. , who were isolated a biflavonoid from the methanolic extract of the Camellia oleifera Abel shells and with a chemical structure that of the agathisflavone.
Agathiflavone isolated from the leaf extract of Anacardium occidentale was subjected to DPPH radical scavenging assay by Ajileye et al. . The EC50 value calculated for agathisflavone was 366.37 μg/mL, which is equivalent to 0.679 mM, slightly lower that the value observed in the present work (0.474 mM). This slight change may happen due to the variation of the DPPH· concentration in the reaction mixture.
The compounds that have large quantities of ·OH (free) in their chemical structures have higher reducing potential . In a previous study the antioxidant activity of the natural biflavonoid (morelloflavone-4000-O-b-d-glicosil, fukugiside e morelloflavone) isolated from the ethyl acetate extract of the dried fruits of Garcinia brasiliensis was seen with the potential reduction capacity . Like the evaluated compound in this study, the biflavonoids isolated by Gontijo et al.  showed reducing capacities in a concentration-dependent manner.
The ·OH oxidizing radical and its presence in the reaction medium promotes degradation of 2-deoxyribose. In our study, agathisflavone at all concentration tested may react with ·OH, thus the inhibition of the degradation of the monosaccharide utilized [3, 40]. Based on the comparison between the EC50 values of the agathisflavone and the antioxidant standard (trolox) in inhibiting the 2-deoxyribose degradation, this biflavonoid can be considered as a potent scavenger of ·OH. This may be an indication of protecting important biomolecules, such as proteins, lipids and genetic materials (e.g.—DNA, RNA) .
Agathisflavone also significantly (p < 0.05) inhibited the levels of NO. An excessive generation of NO is related to a number of pathological conditions, including intracellular oxidative damages and cell death [13, 41]. Thus, the inhibitory effects of this damaging radicals may inhibit or protect cells and cellular organelles from the damaging effects of NO. Furthermore, peroxyl radicals generated by AAPH are evident to cause lipid peroxidation . In our study, we found that the agathisflavone significantly inhibited TBARS production in comparison to the NC and trolox, suggesting a prominent protective capacity of the lipid molecules from oxidative damage.
The biflavonoids procyanidin, fukugetin, amentoflavone and podocarpusflavone isolated from the ethyl acetate extract of the leaves of Garcinia brasiliensis have been found to exhibit antioxidant capacity at 10 µM (equivalent to 0.01 mM) with an average inhibition by 28, 42, 37 and 30%, respectively, those values are smaller than the activity observed in the quercetin group (100 µM; 47%) . In this study, we found an average inhibition for the agathisflavone at 0.928 mM by 88%. It seems, the biflavonoid agathisflavone may be a potent antioxidant.
The antioxidant capacity investigated of the agathisflavone applying in vitro test systems allows to conclude that the this biflavonoid delay or prevent significantly the lipid peroxidation and the other referred molecules induced by free radicals, since, the compound showed an antioxidant capacity in DPPH·, ABTS·+, OH·, NO and reduction potential tests. The oxidative damage is linked to inducing damages in the brain and other organs, leading to varieties of health effects in human and other animals. The agathisflavone may be a new hope in the context of drug discovery and development, especially with the importance of the prevention and treatment of diseases related to oxidative stress.
AWLA—Lab test, data collection & Writing of the draft; KCM—Data analysis & Writing of the draft; KCM—Lab test & Data collection; DDRF—Lab test & Data manipulation; JMD—Data manipulation & Data analysis; MTI—Data presentation, Writing & Revision; SJU—Writing & Revision; JAS—Writing & Revision; JPC—Work design, Writing final draft & Supervision. All authors read and approved the final manuscript.
The authors are grateful to the researchers of the Laboratory of Research in Experimental Neurochemistry (LAPNEX/UFPI), Fundação de Amparo à Pesquisa do Estado do Piauí (FAPEPI—Brazil) for materials, equipments, funds and collaborations.
The authors declare that they have no competing interests.
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- Barreiros ALBS, David JM, David JP (2006) Oxidative stress: relations between the formation of reactive species and the organism’s defense. Quim Nova 29(1):113–123View ArticleGoogle Scholar
- Adegoke O, Forbes PBC (2015) Challenges and advances in quantum dot fluorescent probes to detect reactive oxygen and nitrogen species: a review. Anal Chim Acta 862:1–13View ArticleGoogle Scholar
- Machado KC, Oliveira GLS, de Sousa ÉBV, Costa IHF, Machado KC, de Sousa DP, Satyald P, Freitaset RM (2015) Spectroscopic studies on the in vitro antioxidant capacity of isopentyl ferulate. Chem Biol Interact 225:47–53View ArticleGoogle Scholar
- Al-Gubory KH, Fowler PA, Garrel C (2010) The roles of cellular reactive oxygen species, oxidative stress and antioxidants in pregnancy outcomes. Int J Biochem Cell Biol 42(10):1634–1650View ArticleGoogle Scholar
- Arwa PS, Zeraik ML, Ximenes VF, da Fonseca LM, da Bolzani VS, Silva DHS (2015) Redox-active biflavonoids from Garcinia brasiliensis as inhibitors of neutrophil oxidative burst and human erythrocyte membrane damage. J Ethnopharmacol 174:410–418View ArticleGoogle Scholar
- Surveswaran S, Cai YZ, Corke H, Sun M (2007) Systematic evaluation of natural phenolic antioxidants from 133 Indian medicinal plants. Food Chem 102(3):938–953View ArticleGoogle Scholar
- Jabbari M, Jabbari A (2016) Antioxidant potential and DPPH radical scavenging kinetics of water-insoluble flavonoid naringenin in aqueous solution of micelles. Colloid Surf A Physicochem Eng Aspects 489:392–399View ArticleGoogle Scholar
- Shi Q, Chen J, Zhou Q, Lei H, Luan L, Liu X, Wu Y (2015) Indirect identification of antioxidants in Polygalae Radix through their reaction with 2,2-diphenyl-1-picrylhydrazyl and subsequent HPLC–ESI-Q-TOF-MS/MS. Talanta 144:830–835View ArticleGoogle Scholar
- Gontijo VS, Judice WAS, Codonho B, Pereira IO, Assis DM, Januário JP, Caroselli EE, Juliano MA, de Carvalho Dosatti A, Marques MJ, Viegas Junior C, Henrique dos Santos M (2012) Leishmanicidal, antiproteolytic and antioxidant evaluation of natural biflavonoids isolated from Garcinia brasiliensis and their semisynthetic derivatives. Eur J Med Chem 58:613–623View ArticleGoogle Scholar
- Barreca D, Gattuso G, Laganà G, Leuzzi U, Bellocco E (2016) C- and O-glycosyl flavonoids in Sanguinello and Tarocco blood orange (Citrus sinensis (L.) Osbeck) juice: identification and influence on antioxidant properties and acetylcholinesterase activity. Food Chem 196:619–627View ArticleGoogle Scholar
- de Freitas RL, Oliveira GL, de Freitas RM, Barreiros AL, David JP, Alves CQ, Pinto CR, David JM (2014) In vitro effects of arylhydrocoumarin on free radicals and oxidative stress in erythrocytes and Saccharomyces cerevisiae. Curr Pharm Biotechnol 15(11):1069–1082View ArticleGoogle Scholar
- Yeh PH, Shieh YD, Hsu LC, Kuo LMY, Lin JH, Liaw CC et al (2012) Naturally occurring cytotoxic [3′→8″]-biflavonoids from Podocarpus nakaii. J Tradit Complement Med 2(3):220–226View ArticleGoogle Scholar
- Kang SS, Lee JY, Choi YK, Song SS, Kim JS, Jeon SJ, Han YN, Sonc KH, Han BH (2005) Neuroprotective effects of naturally occurring biflavonoids. Bioorg Med Chem Lett 15(15):3588–3591View ArticleGoogle Scholar
- Castardo JC, Prudente AS, Ferreira J, Guimarães CL, Monache FD, Filho VC, Otuki MF, Cabrini DA (2008) Anti-inflammatory effects of hydroalcoholic extract and two biflavonoids from Garcinia gardneriana leaves in mouse paw oedema. J Ethnopharmacol 118(3):405–411View ArticleGoogle Scholar
- Jia BX, Zeng XL, Ren FX, Jia L, Chen XQ, Yang J, Liu HM, Wang Q (2014) Baeckeins F–I, four novel C-methylated biflavonoids from the roots of Baeckea frutescens and their anti-inflammatory activities. Food Chem 155:31–37View ArticleGoogle Scholar
- von Moltke LL, Weemhoff JL, Bedir E, Khan IA, Harmatz JS, Goldman P, Greenblatt DJ (2004) Inhibition of human cytochromes P450 by components of Ginkgo biloba. J Pharm Pharmacol 56(8):1039–1044View ArticleGoogle Scholar
- Lin YM, Flavin MT, Schure R, Zembower DE, Zhao GX (1999) Biflavanoids and derivatives there of as antiviral agents. US n. US5948918, 21 June 1996, 07 Sept 1999Google Scholar
- Freitas AM, Almeida MT, Andrighetti-Fröhner CR, Cardozo FT, Barardi CR, Farias MR, Simões CM (2009) Antiviral activity-guided fractionation from Araucaria angustifolia leaves extract. J Ethnopharmacol 126(3):512–517View ArticleGoogle Scholar
- Gomes NGM, Campos MG, Órfão JMC, Ribeiro CAF (2009) Plants with neurobiological activity as potential targets for drug discovery. Prog Neuro-Psychopharmacol Biol Psychiatry 33(8):1372–1389View ArticleGoogle Scholar
- Mbaveng AT, Hamm R (2014) Harmful and protective effects of terpenoids from African medicinal plants. In: Kuete V (ed) Toxicological survey of African medicinal plants, 1st edn. Toxicological survey of african medicinal plants. Elsevier, New York, pp 557–576View ArticleGoogle Scholar
- PubChem (2015). Pub Chem—open chemistry. Compound summary for CID 5281599—agathisflavone. www.pubchem.ncbi.nlm.nih.gov. Accessed 24 Aug 2015
- Shrestha S, Lee DY, Park JH, Cho JG, Lee DS, Li B, Kim YC, Jeon YJ, Yeon SW, Baek NI (2013) Flavonoids from the fruits of Nepalese sumac (Rhus parviflora) attenuate glutamate-induced neurotoxicity in HT22 cells. Food Sci Biotechnol 22(4):895–902View ArticleGoogle Scholar
- Shrestha S, Natarajan S, Park JH, Lee DY, Cho JG, Kim GS, Jeon YJ, Yeon SW, Yang DC, Baek NI (2013) Potential neuroprotective flavonoid-based inhibitors of CDK5/p25 from Rhus parviflora. Bioorg Med Chem Lett 23(18):5150–5154View ArticleGoogle Scholar
- Fidelis QC, Ribeiro TAN, Araújo MF, de Carvalho MG (2014) Ouratea genus: chemical and pharmacological aspects. Braz J Pharmacogn 24(1):1–19View ArticleGoogle Scholar
- Ajileye OO, Obuotor EM, Akinkunmi EO, Aderogba MA (2015) Isolation and characterization of antioxidant and antimicrobial compounds from Anacardium occidentale L. (Anacardiaceae) leaf extract. J King Saud Univ Sci 27(3):244–252View ArticleGoogle Scholar
- de Sousa LR, Wu H, Nebo L, Fernandes JB, da Silva MF, Kiefer W, Kanitz M, Bodem J, Diederich WE, Schirmeister T, Vieira PC (2015) Flavonoids as noncompetitive inhibitors of dengue virus NS2B-NS3 protease: inhibition kinetics and docking studies. Bioorg Med Chem 23(3):466–470View ArticleGoogle Scholar
- Pegnyemb DE, Mbing JN, Atchadé ADT, Tih RG, Sondengam BL, Blond A, Bodo B (2005) Antimicrobial biflavonoids from the aerial parts of Ouratea sulcata. Phytochemistry 66(16):1922–1926View ArticleGoogle Scholar
- Paulsen BS, Souza CS, Chicaybam L, Bonamino MH, Bahia M, Costa SL, Borges HL, Rehen SK (2011) Agathisflavone enhances retinoic acid-induced neurogenesis and its receptors α and β in pluripotent stem cells. Stem Cells Dev 20(10):1711–1721View ArticleGoogle Scholar
- Machado KC, Machado KC, Gomes Júnior AL, de Freitas RM (2014) Pharmaceutical application of protease inhibitors: an forecasting technology. Geintec 4(2):780–787View ArticleGoogle Scholar
- Re R, Pellegrini N, Proteggente A, Pannala A, Yang M, Rice-Evans C (1999) Antioxidant activity applying an improved ABTS radical cation decolorization assay. Free Radic Biol Med 26(9–10):1231–1237View ArticleGoogle Scholar
- Lopes GKB, Schulman HM, Hermes-Lima M (1999) Polyphenol tannic acid inhibits hydroxyl radical formation from Fenton reaction by complexing ferrous ions. Biochim Biophys ACTA 1479(1–2):142–152View ArticleGoogle Scholar
- Singhal M, Paul A, Singh HP (2014) Synthesis and reducing power assay of methyl semicarbazone derivatives. J Saudi Chem Soc 18(2):121–127View ArticleGoogle Scholar
- Basu S, Hazra B (2006) Review of pharmacological effects of Glycyrrhiza radix and its bioactive compounds. Phyther Res 34(21):2695–2700Google Scholar
- Guimarães AG, Oliveira GF, Melo MS, Cavalcanti SCH, Antoniolli AR, Bonjardim LR, Silva FA, Santos JPA, Rocha RF, Moreira JCF, Araffljo AAS, Gelain DP, Quintans-Júnior LJ (2010) Bioassay-guided evaluation of antioxidant and antinociceptive activities of carvacrol. Basic Clin Pharmacol Toxicol 107(6):949–957View ArticleGoogle Scholar
- Saxena A, Saxena AK, Singh J, Bhushan S (2010) Natural antioxidants synergistically enhance the anticancer potential of AP9-cd, a novel lignan composition from Cedrus deodara in human leukemia HL-60 cells. Chem Biol Interact 188(3):580–590View ArticleGoogle Scholar
- Zhang D, Tan LH, Wang G, Yua B, Zhao SP, Wang JW, Yao L, Cao WG (2016) Comparative analyses of flavonoids compositions and antioxidant activities of Hawk tea from six botanical origins. Ind Crops Prod 80:123–130View ArticleGoogle Scholar
- Gulcin I, Zubeyr H, Elmastas M, Aboul-Enein HY (2010) Radical scavenging and antioxidant activity of tannic acid. Arab J Chem 3(1):43–53View ArticleGoogle Scholar
- Musa KH, Abdullah A, Kuswandi B, Hidayat MA (2013) A novel high throughput method based on the DPPH dry reagent array for determination of antioxidant activity. Food Chem 141(4):4102–4106View ArticleGoogle Scholar
- Ye Y, Guo Y, Luo Y, Wang Y (2012) Isolation and free radical scavenging activities of a novel biflavonoid from the shells of Camellia oleifera Abel. Fitoterapia 83(8):1585–1589View ArticleGoogle Scholar
- Abad LV, Relleve LS, Racadio CDT, Aranilla CT, Rosa M (2013) Antioxidant activity potential of gamma irradiated carrageenan. Appl Radiat Isot 79:73–79View ArticleGoogle Scholar
- Wojtunik-kulesza KA, Oniszczuk A, Oniszczuk T, Waksmundzka-hajnos M (2016) The influence of common free radicals and antioxidants on development of Alzheimer’s disease. Biomed Pharmacother 78:39–49View ArticleGoogle Scholar
- Tsai M, Huang T (2015) Thiobarbituric acid reactive substances (TBARS) is a state biomarker of oxidative stress in bipolar patients in a manic phase. J Affect Disord 173:22–26View ArticleGoogle Scholar