This article has Open Peer Review reports available.
Antioxidant and antiproliferative activities of Abrus precatorius leaf extracts - an in vitro study
© Gul et al; licensee BioMed Central Ltd. 2013
Received: 2 November 2012
Accepted: 21 February 2013
Published: 2 March 2013
The use of traditional medicine at the primary health care level is widespread and plant-based treatments are being recommended for curing various diseases by traditional medical practitioners all over the world. The phytochemicals present in the fruits, vegetables and medicinal plants are getting attention day-by-day for their active role in the prevention of several human diseases. Abrus precatorius is a widely distributed tropical medicinal plant with several therapeutic properties. Therefore in the present study, A. precatorius leaf extracts were examined for their antioxidant and cytotoxic properties in vitro in order to discover resources for new lead structures or to improve the traditional medicine.
In this study, antioxidant and antiproliferative properties of the different leaf extracts (hexane, ethyl acetate, ethanol and water) from A. precatorius were investigated along with the quantification of the polyphenol and flavonoid contents. The ability of deactivating free radicals was extensively investigated with in vitro biochemical methods like DPPH•, •OH, NO, SO2- scavenging assays and inhibition capability of Fe(II)-induced lipid peroxidation. Furthermore, antiproliferative activities using different human cancer cell lines and primary cell line was carried out by MTT method.
Total phenolic content and total flavonoid content of the extracts were found in the range of 1.65 ± 0.22 to 25.48 ± 0.62 GAE mg/g dw and 6.20 ± 0.41 to 17.16 ± 1.04 QE mg/g dw respectively. The experimental results further revealed that A. precatorius extracts showed strong antiradical properties, capable to chelate Fe2+ and possess good inhibition ability of lipid peroxidation. In addition, as a first step towards the identification of phytoconstituents endowed with potent chemopreventive activities, we evaluated the inhibitory effects of A. precatorius extracts on the proliferation of four different human tumour cell lines such as human colon adenocarcinoma cells (Colo-205), human retinoblastoma cancer cells (Y79), human hepatocellular carcinoma cells (HepG2) and Leukemia cells (SupT1). Ethanol extract (APA) and ethyl acetate extract (APE) of A. precatorius had apparent capabilities of inhibiting the survival of tested human cancer cell lines. Moreover, it was observed that the A. precatorius extracts did not inhibit the growth of mice peritoneal macrophages, thus confirming that plants extracts are selective against the cancer cell lines.
This work provides a scientific support for the high antioxidant and antiproliferative activity of this plant and thus it may find potential applications in the treatment of the diseases caused by ROS. Further studies are needed to confirm in vivo anti-tumorgenicity and subsequent chemical characterization of the active molecule(s).
The human body possesses numerous antioxidant defences and repair mechanisms against oxidative stress. However, these mechanisms are insufficient to prevent the damage entirely as production of reactive oxygen species (ROS) is certain to play multiple important roles in tissue damage and loss of function in a number of tissues and organs . Free radicals and ROS have been implicated as endogenous initiators in the etiology of cancer and several other degenerative or pathologic processes of various serious diseases, as well as in aging processes . Oxidative damage to DNA is considered a critical step in cancer development . Over the past decade or so, numerous experimental and epidemiological studies have shown that a wide variety of phytochemicals such as phenolics, flavonoids, isoflavone, flavones, anthocyanins, catechin, isocatechin and carotenoids are able to prevent or slow down oxidative stress-induced damage leading to carcinogenesis by upsetting the molecular events in the initiation, promotion or progression conditions. Recent studies demonstrated that the high dietary intake of fruits and vegetables could be associated with lower cancer prevalence in humans [4–7]. Natural products mainly from plant kingdom offer a wide range of biologically active compounds that act as natural antioxidants with recognized potential in drug discovery and development . Great interest is currently being paid to natural products for their interesting anticancer activities. High percentages (~ 60%) of all the drugs applied in the treatment and/or prevention of cancer are from natural products and their derivatives, of which higher plants contribute around 25%. Approximately 60% of drugs approved for cancer treatment are of natural origin [9, 10]. This has elicited the pursuit of effective antioxidant and anticancer agents from various sources particularly medicinal and edible plants . Investigations on natural products have regained prominence in the recent past with increasing understanding of their biological significance such as antioxidant, radical scavenging, antiproliferative activities and increasing recognition of the origin and function of their structural diversity [12–15].
Abrus precatorius L. (Fabaceae) is a vine originally native to India that is now commonly found throughout the tropical and subtropical parts of the world . It grows best in fairly dry regions at low elevations. Leaves, roots and seeds are used as a medicament in traditional system of Indian medicine for antihelminthic, antidiarrhoeal, antiemetic and inhibits intestinal motility. Researchers have reported that seeds are used for the treatment of diabetes and chronic nephritis . The leaves of A. precatorius are sweeter [18, 19] and as equivalent in sweetness potency to sucrose . In West Tropical Africa, A. precatorius leaves have been employed to sweeten foods and certain medicines used for stomach complaints, to treat fevers, cough and cold (used as decoction). The leaves are casually chewed and the vine sometimes sold as a masticatory in Curacao [21, 22]. The plant is also traditionally used to treat tetanus, and to prevent rabies. Though considerable work has been done on the seeds for different activities, however, scientific information on antioxidant and antiproliferative properties of leaves of this plant is still not available or rather scarce. Thus, we evaluated the abilities of leaf extracts of A. precatorius to function as an antioxidant agent using in vitro assays. Additionally, the ability of the leaf extracts to inhibit proliferation of various cancer cell lines was investigated. Since elimination of cancer in early stages is an integral part of chemoprevention, measuring antiproliferative properties against cancer cells provide useful insight on the chemo-protective potential of natural extracts. Thus, the objective of this study was to examine the efficacy of A. precatorius as an antioxidant as well as its inhibitory effect on human cancer cell proliferation.
The analytical grade chemicals were purchased from Hi-Media and Merck, India. Standard drugs were purchased from Sigma-Aldrich chemicals co. (Germany); RPMI-1640, DMEM and foetal bovine serum (FBS) from Gibco (USA).
Abrus precatorius leaves were kindly provided by Central Research Institute of Unani Medicine, Hyderabad. A voucher specimen (UoH/VS/AP-2) has been preserved in our laboratory for future reference.
Preparation of extracts
The air-dried leaves of the plant were powdered with a mechanical grinder to obtain a coarse powder, which was then subjected to successive extraction in a soxhlet apparatus using hexane, ethyl acetate, ethanol and water. Each time before extracting with the next solvent, the material was dried in hot air oven at 40°C. Extracts were then filtered through a Whatman No.1 paper filter and concentrated to the dry mass with the aid of rotary evaporator. The extraction process was repeated three times at different time periods. It was observed that there was no significant difference in the percentage yield and content of phyto-constituents that are believed to play an important role in biological activities. The yield of each extract was measured and residues were stored in dark glass tubes for further analysis. The different extracts were designated as APH (for hexane extract), APE (for ethyl acetate extract), APA (for ethanol extract) and APW (for water extract). The dried extracts were dissolved in dimethyl sulfoxide (DMSO) as 20 mg/mL and diluted with phosphate-buffered saline (PBS, pH 7.4) to give final concentrations.
Determination of phytoconstituents
Determination of total phenols
Total phenolics were determined using Folin-Ciocalteu reagent as described by Yang et al. with minor modifications. Total phenolic assay was conducted by mixing 2.7 mL of deionised water, 0.01 mL of extracts, 0.3 mL 20% Na2CO3 and 0.10 mL Folin-Ciocalteu reagent. Absorbance of mixture was measured at 725 nm. A standard curve was prepared with gallic acid (r2 = 0.9454) and final results were given as mg gallic acid equivalents (GAE) g dw.
Determination of total flavonoids
The total flavonoids was measured by addition of aluminium chloride reagent to the solution containing the extract using the method of Barrera et al. . Briefly, 10 μL of plant extracts of known concentrations (20 mg/mL) were diluted with 0.5 mL of double distilled water. To this mixture, 30 μL of 5% sodium nitrite (NaNO2) and 60 μL of 10% aluminium chloride were added and incubated at room temperature for 10 min. After incubation, 350 μL of 1 M NaOH was added and total volume was made up to 1 mL with distilled water. Finally, absorbance was measured against the prepared blank at 510 nm and results were given as quercetin equivalents (mg QE)/g of dw. Standard curve was prepared with known concentrations of quercetin (r2 = 0.955).
Antioxidant ability assays
The total antioxidant activity of extracts was evaluated by green phosphomolybdenum complex according to the method of Prieto et al.. An aliquot of 10 μL of sample solution was mixed with 1 mL of reagent solution (0.6 M sulphuric acid, 28 mM sodium phosphate and 4 mM ammonium molybdate) in micro centrifuge tube. Tubes were incubated in a dry thermal bath at 95°C for 90 min. After cooling, the absorbance of the mixture was measured at 695 nm against a blank. Ascorbic acid have been used (r2 = 0.964) for reference and the reducing capacities of the analyzed extracts were expressed as mg of ascorbic acid equivalents (mg AAE)/g of dw.
Ferric-reducing/antioxidant power (FRAP) assay
The Fe3+ reducing power of the extracts was determined by the method of Oyaizu  with slight modifications. Briefly, extracts and standard (ascorbic acid) in 1 mL of appropriate solvents were mixed with 2.5 mL of phosphate buffer (0.2 M, pH 6.6) and 2.5 mL of potassium ferricyanide (1%), and then mixture was incubated at 50°C for 30 min. Afterwards, 2.5 mL of trichloroacetic acid (10%) was added to the mixture, which was then centrifuged at 5000 rpm for 10 min. Finally, 2.5 mL of the upper layer solution was mixed with 2.5 mL of distilled water and 0.1 mL of FeCl3 (0.1%). The absorbance was measured at 700 nm and the reducing power of the extracts was presented as mg AAE/g of dw.
DPPH• radical scavenging activity
The DPPH free radical scavenging activity of leaf extracts of A. precatorius was measured in term of hydrogen donating or radical scavenging ability using the stable radical DPPH . Briefly, 0.004% w/v of DPPH radical solution was prepared in methanol and then 900 μL of this solution was mixed with 100 μL of extract solution containing 40–400 μg/mL of dried extract. The absorbance was measured at 517 nm after 30 min of incubation. Methanol (95%), DPPH solution and ascorbic acid were used as blank, control and reference respectively.
Hydroxyl radical scavenging activity
The ability of the extracts to inhibit site-specific hydroxyl radical-mediated peroxidation was carried out according to the method given by Hinneburg et al.  with some modifications. Briefly, the mixture containing FeCl3 (10 mM), ascorbic acid (1 mM), H2O2 (10 mM), deoxyribose (28 mM) and different concentrations of test samples (40–400 μg/mL) in 500 μL phosphate buffered saline (PBS, 20 mM, pH 7.4) was incubated for 30 min at 37°C. After adding 1 mL of trichloroacetic acid (10%, w/v) and 1 mL thiobarbituric acid (2.8% w/v; in 25 mM NaOH), the reaction mixture was boiled for 15 min. The extent of oxidation was estimated at 532 nm and the scavenging activity of test sample was expressed as the percentage inhibition of the deoxyribose degradation to malondialdehyde. Ascorbic acid was used as the positive control.
Hydrogen peroxide scavenging assay
The ability of plant extracts to scavenge hydrogen peroxide was determined according to Long et al. . A 40 mM of H2O2 solution was mixed with different concentrations of plant extracts (20–200 μg/mL) and incubated for 3.5 h at room temperature. After incubation, 90 μL of the H2O2-sample solution was mixed with 10 μL of HPLC-grade methanol and 0.9 mL of FOX reagent was added (prepared by mixing 9 volumes of 4.4 mM BHT in HPLC-grade methanol with 1 volume of 1 mM xylenol orange and 2.56 mM ammonium ferrous sulfate in 0.25 M H2SO4). The reaction mixture was vortexed and then incubated at room temperature for 30 min. The absorbance of ferric-xylenol orange complex was measured at 560 nm. Ascorbic acid was used as the reference compound.
Nitric oxide scavenging activity
The free radical scavenging potential of A. precatorius was further substantiated by scavenging of nitric oxide radical assayed by sodium nitroprusside method . The reaction solution (50 μL) containing 10 mM sodium nitroprusside in PBS (pH 7.0) was mixed with different concentration (40–400 μg/mL) of sample extracts, followed by incubation at 37°C for 20 min under light. After incubation, the samples were mixed with 300 μL of Griess reagent (1% sulfanilamide, 2% H3PO4). The samples were again incubated for 30 min at room temperature under light conditions followed by the addition of 0.1% N-(1-naphthyl) ethylenediamine dihydrochloride. The absorbance was recorded at 546 nm and the results were expressed as per cent of scavenged nitric oxide with respect to the negative control without addition of any antioxidant. Ascorbic acid was used as a positive control.
Superoxide radicals scavenging activity
The scavenging activity of the plant extracts towards superoxide anion radicals was measured by the nitro-blue tetrazolium (NBT) reduction method  with minor modifications. Superoxide anions were generated in a non-enzymatic phenazine methosulfate nicotinamide adenine dinucleotide (PMS-NADH) system through the reaction of PMS, NADH and oxygen. It was assayed by the reduction of nitroblue tetrazolium. In the experiment, the superoxide anion was generated in 2 mL of phosphate buffer (100 mM, pH 7.4) containing 500 μL of 156 μM nitroblue tetrazolium (NBT solution), 500 μL of 468 μM nicotinamide adenine dinucleotide (NADH) solution and 300 μL of different concentrations (40–400 μg/mL) of extracts. DMSO and L-ascorbic acid were used as solvent and positive control respectively. The reaction was initiated by adding 100 μL of 60 μM phenazine methosulfate (PMS) to the mixture. After 5 min of incubation at room temperature, the absorbance was measured at 560 nm against blank. Decreased absorbance of the reaction mixture indicated increased superoxide anion scavenging activity.
Inhibition of lipid peroxidation assay
Fe2+ induced lipid peroxidation is one of the established system for assessing antioxidant action of different plant extracts. A modified thiobarbituric acid-reactive species (TBARS) assay  was used to measure the lipid peroxide formed using rat liver homogenate as lipid rich media. Malondialdehyde (MDA), a secondary end product of the oxidation of polyunsaturated fatty acids, reacts with two molecules of TBA yielding a pinkish red chromogen. Healthy albino rats of the wister strain (250 grams) were sacrificed (procedure described was reviewed and approved by the University of Hyderabad, School of Life Sciences’ animal ethics committee) and liver was perfused with 0.15 M KCl, homogenate was centrifuged at 800 g for 15 min at 4°C and the supernatant was used for thiobarbituric acid assay. The extracts of A. precatorius at different concentrations (40–400 μg/mL) were mixed with the liver microsome preparation and incubated at room temperature for 10 min. Then, 50 μL Fenton’s reagent (10 mM FeCl3; 10 μL of 2.5 mM H2O2; 0.1 M L-ascorbic acid) in phosphate buffer (0.2 M, pH 7.4) were added, and the volume was made to 1 mL. The tubes were then incubated for 30–45 min at 37°C to induce lipid peroxidation. Thereafter, 2 mL of ice-cold HCl (0.25 N) containing 15% trichloroacetic acid, 0.5% thiobarbituric acid and 0.5% butylated hydroxytoluene (BHT) were added in each sample followed by heating at 100°C for 15 min. The reaction mixture was put in an ice bath for 10 min. The mixture was centrifuged at 1000 rpm for 10 min and the extent of lipid peroxidation was subsequently monitored by formation of thiobarbituric acid reactive substances (TBARS) as pink chromogen in presence or absence of extracts and standard (L-ascorbic acid). The absorbance of the supernatant was measured spectrophotometrically at 532 nm and decline in formation of pink chromogen in pre-treated reactions was considered as inhibition of lipid peroxidation.
A panel of four human cell lines namely, (a): human colon adenocarcinoma cells - Colo-205, (b): human retinoblastoma cancer cells - Y79, (c): human hepatocellular carcinoma cells - HepG2 and (d): Leukaemia cells - SupT1 were used to study antiproliferative activity. The cell lines were obtained from National Centre for Cell Sciences (NCCS), Pune, India. The cell lines HepG2 & Colo-205 were cultured in Dulbecco’s modified Eagle’s medium (DMEM) and Y79 & SupT1 in RPMI 1640 containing 10% (v/v) FBS, 100 units/mL penicillin and 100 μg/mL streptomycin. Cells were maintained in a humidified incubator with 5% CO2 for 24 h at 37°C and seeded onto 75 cm2 culture flasks. In vitro response to extracts and standard drug was evaluated by means of a growth inhibition using the MTT assay . The cells were seeded at a density of ~5 × 103 per well using a brief trypsinization. Furthermore, Doxorubicin and sample extracts (25–200 μg/mL) dissolved in dimethylsulfoxide (DMSO; not exceeding the concentration of 2%), and further diluted in cell culture medium were added into a 96-well plate. After 48 h of incubation, 20 μL of MTT reagent (5 mg/mL) were added and mixtures were reincubated for 4 h. Finally the absorbance of formazan was measured at 550 nm. Doxorubicin was also assayed as a positive control at the concentration of 0.5–10 μg/mL. The resulting growth data represents the net outcome of cell proliferation and cell death. The cell viability (%) was obtained by comparing the absorbance between the samples and a negative control.
Assessment of extract toxicity in normal cells
To assess the toxicity of the plant extracts on primary cells (peritoneal murine macrophages), the MTT toxicity assay was used. Thioglycollate-elicited mouse peritoneal macrophages were harvested from female BALB/C mice . Experimental protocol was again undertaken in accordance with the ethical guidelines and the permission of the University of Hyderabad, School of Life Sciences’ animal ethics committee was obtained. Toxicity toward mouse peritoneal macrophages was assessed with cells plated in 96-well plates at a density of 2 × 106 cells per well (in 200 μL volume). After adherence, the medium was removed and replaced by one of the media containing the plant extracts. The plates were incubated for 72 hrs at 37°C in a humidified 5% CO2 incubator. Control cells were incubated with culture medium alone. Cell viability was determined by a colorimetric assay with the tetrazolium salt MTT . Absorbance of the formed formazan product was measured at a test wavelength of 540 nm. Results were expressed as percentage cellular viability of the extracts.
Calculations and statistical analysis
All results are expressed as mean ± standard deviation (SD) values average from 3 to 4 independent experiments performed in duplicate. IC 50 value (the concentration of the extracts required to scavenge 50% of radicals) was calculated for different extracts of A. precatorius.
Statistical differences between correlated samples were evaluated using Student’s t-test and composite treatments were compared using one-way analysis of variances (ANOVA) and considered significantly different where probability values were found to be equal to or less than 0.05. Statistical tests as well as mean and SD calculations and graphical representation of the results were performed using GraphPad Prism v5 and Sigmaplot v11.0 software’s.
Results and discussion
Determination of phyto-constituents
Quantitative estimation of phytochemicals and antioxidant activities of different extracts of A. precatorius
Type of Extract
Total antioxidant capacityc
Ferric reducing antioxidant powerc
1.65 ± 0.22
6.20 ± 0.41
7.16 ± 0.43
2.67 ± 0.40
23.57 ± 0.31
17.16 ± 1.04
17.92 ± 0.38
8.45 ± 0.65
7.44 ± 0.10
7.23 ± 0.68
24.73 ± 0.72
10.28 ± 0.47
25.48 ± 0.62
10.70 ± 0.56
16.66 ± 0.68
13.34 ± 0.35
Antioxidant ability assays
In phosphomolybdenum assay, which is a quantitative method to evaluate the antioxidant capacity, all the extracts exhibited different degrees of activity as shown in Table 1. The reducing power of a compound is associated with electron donating capacity and serves as an indicator of antioxidant activity [42, 43]. Results indicated that APA has higher antioxidant capacity (24.73 ± 0.72 mg ascorbic acid equivalent/g dw) than other three extracts which showed antioxidant capacity in the order: APE (17.92 ± 0.38 mg AAE/g dw) > APW (16.66 ± 0.68 mg AAE/g dw) > APH (7.16 ± 0.43 mg AAE/g dw).
Ferric-reducing/antioxidant power (FRAP) assay
In reducing power assay, the presence of reductants (antioxidants) in samples would result in the reduction of Fe3+ to Fe2+ by donating an electron which serves as a significant reflection of antioxidant activity . The amount of Fe2+ complex can be monitored by measuring the formation of Perl’s Prussian blue at 700 nm. Increasing absorbance at 700 nm indicates an increase in reductive ability . Earlier reports suggest that some phenolic compounds such as flavonoids and phenolic acids exhibited antioxidant activity through their reductive capacity in a Fe3+- Fe2+ system . All the four extracts showed some degree of electron donating capacity and reduced Fe3+ to Fe2+. The reducing ability of the extracts was in range of 13.34 ± 0.35 to 2.67 ± 0.40 AAE mg/g dw (Table 1). The FRAP values for APW was found to be higher than other three extracts. This suggests that APW has a significant ability to react with free radicals to alter them into more stable non-reactive species and to terminate radical chain reaction.
DPPH• radical scavenging activity
Hydroxyl radical scavenging activity
IC 50 values obtained in the antioxidant activity assays
IC 50 μg/mL
196.70 ± 2.06
464.25 ± 4.43
112.59 ± 3.24
192.45 ± 3.76
427.26 ± 5.72
377.07 ± 5.23
57.66 ± 1.32
205.51 ± 3.08
121.02 ± 3.14
107.58 ± 2.12
143.44 ± 3.28
45.46 ± 3.71
60.67 ± 1.03
209.33 ± 4.13
92.83 ± 3.23
145.96 ± 2.17
157.07 ± 2.56
285.22 ± 4.63
79.97 ± 1.84
309.90 ± 5.21
152.35 ± 1.06
264.95 ± 4.24
201.45 ± 6.23
302.02 ± 4.11
6.86 ± 0.92
62.40 ± 3.72
19.90 ± 2.30
32.86 ± 3.78
48.72 ± 3.20
14.34 ± 1.64
245.30 ± 4.60
21.09 ± 2.16
Hydrogen peroxide scavenging assay
Nitric oxide scavenging activity
Superoxide radicals scavenging activity
Inhibition of lipid peroxidation assay
Percentage inhibition of cancer cell proliferation and IC 50 values
Type of cell line
Colo – 205
IC 50 Value
% age Inhibition
IC 50 Value
% age Inhibition
IC 50 Value
% age Inhibition
IC 50 Value
APE (200 μg/mL)
68.33 ± 1.41*
29.57 ± 2.02
66.40 ± 5.44*
35.94 ± 2.10
53.33 ± 1.21*
44.31 ± 3.07
61.34 ± 1.32*
37.00 ± 2.38
APA (200 μg/mL)
92.25 ± 2.05***
18.91 ± 1.06
92.80 ± 6.34*
26.74 ± 1.34
88.52 ± 3.04**
27.03 ± 1.03
94.12 ± 3.34**
26.89 ± 3.24
Doxorubicin (Standard) 10 μg/mL
94.81 ± 3.42
0.41 ± 0.08
94.20 ± 4.11
0.39 ± 0.10
89.18 ± 3.42
0.47 ± 0.08
95.20 ± 3.11
0.39 ± 0.11
DMSO 2% (Solvent control)
6.67 ± 1.67
3.33 ± 0.78
3.13 ± 1.01
4.33 ± 0.78
The criterion for cytotoxicity for the crude extracts, as established by the National Cancer Institute (NCI), is an IC 50 value lower than 30 μg/mL . In this study, the APA crude extract displays an IC 50 values less than 30 μg/mL in all the four tested cell lines, which established APA as more active extract than APE. Comparatively, Doxorubicin, an anticancer drug used in this study as a positive control, demonstrated IC 50 values in the tumor cell lines ranging from 0.39-0.47 μg/mL. Although, the activity of APA and APE are weak in comparison to the standard drug, which could be due to the crude nature of the extracts and can be further enhanced by the purification.
Assessment of drug toxicity
During the past decade, both in vivo and in vitro studies have suggested that natural antioxidants such as phenolics, carotenoids, tocotrienols exhibit antitumor activities by inhibiting the growth and proliferation of many cancer cells such as breast, lung and liver cancer cells [68–71]. These observations and reports (with regard to the cytotoxicity of the plant extracts) indicate that there are great differences among the antiproliferative activity of the same plant species, depending on plant parts and extraction solvents used. Furthermore, the different cell lines vary in their sensitivity to the same plant extract.
This work has gathered experimental evidence that A. precatorius leaf extracts contained substantial amount of polyphenols and flavonoids and exhibited significant antioxidant activity by effectively scavenging various free radicals. Additionally, it has been demonstrated that the A. precatorius leaf extracts (APA and APE) are potential antiproliferative agents without any toxic effect on normal cells. The antioxidant and antiproliferative activities might be due to the synergistic actions of bioactive compounds present in them. Therefore, the plant has promising compounds to be tested as potential antioxidant drugs for treatment of diseases resulting from oxidative stress. However, these findings warrant extensive studies on chemical profiles and mechanistic action of antiproliferative and antioxidant activities. The study will be helpful to understand this important herbal medicine and further studies are underway in our laboratory.
The authors would like to thank Central Research Institute of Unani Medicine, Hyderabad Andhra Pradesh for providing the plant material. Authors gratefully acknowledge the help of S. Chandrasekaran, Research Scholar, Dept. of Animal Sciences, UoH in animal studies. The authors; MZG and FA acknowledge the financial support in the form of Senior Research Fellowship (SRF) from Council of Scientific and Industrial Research (CSIR) and University Grants Commission (UGC), New Delhi, India respectively. Authors are also thankful to DBT-CREBB, DBT-FIST and UGC-SAP - CAS, UGC- XI plan seed money for supporting infra structural facilities of Department of Plant Sciences and School of Life Sciences.
- Verma AR, Vijayakumar M, Mathela CS, Rao CV: In vitro and in vivo antioxidant properties of different fractions of Moring oleifera leaves. Food Chem Toxicol. 2009, 47: 2196-2201. 10.1016/j.fct.2009.06.005.View ArticlePubMedGoogle Scholar
- Devasagayam TPA, Tilak JC, Boloor KK, Sane KS, Ghaskadbi S, Lele RD: Free radicals and antioxidants in human health: current status and future prospects. J Assoc Physicians India. 2004, 52: 794-804.PubMedGoogle Scholar
- Guyton KZ, Kensler TW: Oxidative mechanisms in carcinogenesis. Brit Med Bull. 1993, 49: 523-544.PubMedGoogle Scholar
- Sun J, Chu YF, Wu X, Liu RH: Antioxidant and antiproliferative activities of common fruits. J Agric Food Chem. 2002, 50: 7449-7454. 10.1021/jf0207530.View ArticlePubMedGoogle Scholar
- Matito C, Mastorakou F, Centelles JJ, Torres JL, Cascante M: Antiproliferative effect of antioxidant polyphenols from grape in murine Hepa-1c1c7. Eur J Nutr. 2003, 42: 43-49. 10.1007/s00394-003-0398-2.View ArticlePubMedGoogle Scholar
- Halliwell B: Dietary polyphenols: good, bad, or indifferent for your health?. Cardiovas Res. 2007, 73 (2): 341-347. 10.1016/j.cardiores.2006.10.004.View ArticleGoogle Scholar
- Liu H, Qiu N, Ding HH, Yao RQ: Polyphenols contents and antioxidant capacity of 68 Chinese herbals suitable for medical or food uses. Food Res Int. 2008, 41: 363-370. 10.1016/j.foodres.2007.12.012.View ArticleGoogle Scholar
- Mishra KP, Ganju L, Sairam M, Banerjee PK, Sawhney RC: A review of high throughput technology for the screening of natural products. Biomed Pharmacother. 2008, 62: 94-98. 10.1016/j.biopha.2007.06.012.View ArticlePubMedGoogle Scholar
- Balunas MJ, Kinghorn AD: Drug discovery from medicinal plants. Life Sci. 2005, 78: 431-441. 10.1016/j.lfs.2005.09.012.View ArticlePubMedGoogle Scholar
- Boopathy NS, Kathiresan K: Anticancer drugs from marine flora: an overview. J Oncol. 2010, 214186: 18-Google Scholar
- Srinivasan P, Vadhanam MV, Arif JM, Gupta C: A rapid screening assay for antioxidant potential of natural and synthetic agents in vitro. Int J Oncol. 2002, 20: 983-986.PubMedGoogle Scholar
- Gul MZ, Bakhshu LM, Ahmed F, Kondapi AK, Qureshi IA, Ghazi IA: Evaluation of Abelmoschus moschatus extracts for antioxidant, free radical scavenging, antimicrobial and antiproliferative activities using in vitro assays. BMC Complement Altern Med. 2011, 11: 64-10.1186/1472-6882-11-64.View ArticlePubMedPubMed CentralGoogle Scholar
- Hogan S, Chung H, Zhang L, Li J, Lee Y, Dai Y, Zhou K: Antiproliferative and antioxidant properties of anthocyanin-rich extract from acai. Food Chem. 2010, 118: 208-214. 10.1016/j.foodchem.2009.04.099.View ArticleGoogle Scholar
- Zhang DM, Wang Y, Tang MQ, Chan YW, Lam HM, Ye WC, Fung KP: Saxifragifolin B from Androsace umbellata induced apoptosis on human hepatoma cells. Biochem Biophys Res Commun. 2007, 362: 759-765. 10.1016/j.bbrc.2007.08.068.View ArticlePubMedGoogle Scholar
- Deng XK, Yin W, Li WD, Yin FZ, Lu XY, Zang XC, Hua ZC, Cai BC: The anti-tumor effects of alkaloids from the seeds of Strychnos nux-vomica on HepG2 cells and its possible mechanism. J Ethnopharmacol. 2006, 106: 179-186. 10.1016/j.jep.2005.12.021.View ArticlePubMedGoogle Scholar
- Morton JF: Plants Poisonous to People in Florida and Other Warm Areas. 1982, Miami, Florida: Hallmark Press, 45-Google Scholar
- Manago CC, Alumanah EO: Antidiabetic effect chloroform-methanol extracts of Abrus precatorius seed. J Appl Sci Environ Mgt. 2005, 9: 85-88.Google Scholar
- Dymock W, Warden CJH, Hooper D: Pharmacographia Indica. 1890, London: Kegan, Paul, Trench, Triibner & Co, 1:430Google Scholar
- Anonymous: The Wealth of India. Raw Materials. 1985, New Delhi, India: Council of Scientific and Industrial Research, I: A (revised) 1985, 18Google Scholar
- Inglett GE, May JF: Econ Bot. 1968, 22: 326-10.1007/BF02908127.View ArticleGoogle Scholar
- Morton JF: Atlas of Medicinal Plants of Middle America: Bahamas to Yucatan. 1981, Springfield, Illinois: Charles C Thomas, 267-Google Scholar
- Irvine FR: Woody Plants of Ghana. 1961, London: Oxford University Press, 358-Google Scholar
- Yang J, Paulino R, Janke-Stedronsky S, Abawi F: Free radical scavenging activity and total phenols of noni (Morinda citrifolia L.) juice and powder in processing and storage. Food Chem. 2007, 102: 302-308. 10.1016/j.foodchem.2006.05.020.View ArticleGoogle Scholar
- Barreira JCM, Ferreira ICFR, Oliveira MBPP, Pereira JA: Antioxidant activities of the extracts from chestnut flower, leaf, skins and fruit. Food Chem. 2008, 107: 1106-1113. 10.1016/j.foodchem.2007.09.030.View ArticleGoogle Scholar
- Prieto P, Pineda M, Aguilar M: Spectophotometric quantitative of antioxidant capacity through the formation of a phosphomolybdenum complex: specific application to the determination of vitamin E. Anal Biochem. 1999, 269: 337-341. 10.1006/abio.1999.4019.View ArticlePubMedGoogle Scholar
- Oyaizu M: Studies on products of browning reaction prepared from glucoseamine. Jpn J Nutri. 1986, 44: 307-315. 10.5264/eiyogakuzashi.44.307.View ArticleGoogle Scholar
- Braca A, Sortino C, Politi M: Antioxidant activity of flavonoids from Licania licaniae flora. J Ethnopharmacol. 2002, 79: 379-381. 10.1016/S0378-8741(01)00413-5.View ArticlePubMedGoogle Scholar
- Hinneburg I, Dorman HJD, Hiltunen R: Antioxidant activities of extracts from selected culinary herbs and spices. Food Chem. 2006, 97: 122-129. 10.1016/j.foodchem.2005.03.028.View ArticleGoogle Scholar
- Long LH, Evans PJ, Halliwell B: Hydrogen peroxide in human urine: implications for antioxidant defense and redox regulation. Biochem Biophys Res Commun. 1999, 262: 605-609. 10.1006/bbrc.1999.1263.View ArticlePubMedGoogle Scholar
- Sreejayan N, Rao MNA: Nitric oxide scavenging by curcuminoids. J Pharm Pharmacol. 1997, 49: 105-107. 10.1111/j.2042-7158.1997.tb06761.x.View ArticlePubMedGoogle Scholar
- Nishikimi M, Rae NA, Tagi K: The occurrence of superoxide anion in the reaction of reduced phenazine methosulphate and molecular oxygen. Biochem Biophys Res Commun. 1972, 461: 489-494.Google Scholar
- Ohakawa H, Ohishi N, Yagi K: Assay for lipid peroxides in animal tissues by thiobarbituric acid reaction. Anal Biochem. 1979, 95: 351-358. 10.1016/0003-2697(79)90738-3.View ArticleGoogle Scholar
- Mosmann T: Rapid colorimetric assay for cellular growth and survival: application to proliferation and cytotoxicity assays. J Immunol Methods. 1983, 65: 55-63. 10.1016/0022-1759(83)90303-4.View ArticlePubMedGoogle Scholar
- Bhattacharjee S, Gupta G, Bhattacharya P, Mukherjee A, Mujumdar SB, Pal A, Majumdar S: Quassin alters the immunological patterns of murine macrophages through generation of nitric oxide to exert antileishmanial activity. J Antimicrob Chemoth. 2009, 63: 317-324.View ArticleGoogle Scholar
- Rice-Evans C: Flavonoids and isoflavones: absorption, metabolism and bioactivity. Free Radic Biol Med. 2004, 36: 827-828. 10.1016/j.freeradbiomed.2003.12.012.View ArticlePubMedGoogle Scholar
- Dixon RA, Xie DY, Sharma SB: Proanthocyanidins-a final frontier in flavonoid research?. New Phytol. 2005, 165: 9-28.View ArticlePubMedGoogle Scholar
- Manian R, Anusuya N, Siddhuraju P, Manian S: The antioxidant activity and free radical scavenging potential of two different solvent extracts of Camellia sinensis (L.) O. Kuntz, Ficus bengalensis L. and Ficus racemosa L. Food Chem. 2008, 107: 1000-1007. 10.1016/j.foodchem.2007.09.008.View ArticleGoogle Scholar
- Kahkonen MP, Hopia AI, Vuorela HJ, Rauha JP, Pihlaja K, Kujala TS, Heinonen M: Antioxidant activity of plant extracts containing phenolic compounds. J Agr Food Chem. 1999, 48: 1485-1490.Google Scholar
- Zheng W, Wang SY: Antioxidant activity and phenolic compounds in selected herbs. J Agr Food Chem. 2001, 49: 5165-5170. 10.1021/jf010697n.View ArticleGoogle Scholar
- Heck CI, Mejia EG: Yerba mate tea (Ilex paraguariensis): a comprehensive review on chemistry, health implication, and technological consideration. J Food Sci. 2007, 72: 138-151.View ArticleGoogle Scholar
- Hakkim FL, Shankar CG, Girija S: Chemical composition and antioxidant property of holy basil (Ocimum sanctum L.) leaves, stems and inflorescence and their in vitro callus cultures. J Agr Food Chem. 2007, 55: 9109-9117. 10.1021/jf071509h.View ArticleGoogle Scholar
- Yen GC, Duh PD, Tsai CL: Relationship between antioxidant activity and maturity of peanut hulls. J Agric Food Chem. 1993, 41: 67-70. 10.1021/jf00025a015.View ArticleGoogle Scholar
- Siddhuraju P, Mohan PS, Becker K: Studies on the antioxidant activity of Indian laburnum (Cassia fistula L.): a preliminary assessment of crude extracts from stem bark, leaves, flowers and fruit pulp. Food Chem. 2002, 79: 61-67. 10.1016/S0308-8146(02)00179-6.View ArticleGoogle Scholar
- Bhandari MR, Kawabata M: Organic acid, phenolic content and antioxidant activity of wild yam (Dioscorea spp.) tubers of Nepal. Food Chem. 2004, 88: 163-168. 10.1016/j.foodchem.2003.12.027.View ArticleGoogle Scholar
- Yang QM, Pan XH, Kong WB, Yang H, Su YD, Zhang L, Zhang Y, Yang Y, Ding L, Liu G: Antioxidant activities of malt extract from barley (Hordeum vulgare L.) toward various oxidative stress in vitro and in vivo. Food Chem. 2010, 118: 84-89. 10.1016/j.foodchem.2009.04.094.View ArticleGoogle Scholar
- Zhao HF, Dong JJ, Lu J, Chen J, Li Y, Shan LJ, Lin Y, Fan W, Gu G: Effects of extraction solvent mixtures on antioxidant activity evaluation and their extraction capacity and selectivity for free phenolic compounds in barley (Hordeum vulgare L.). J Agric Food Chem. 2006, 54: 7277-7286. 10.1021/jf061087w.View ArticlePubMedGoogle Scholar
- Rice-Evans CA, Miller NJ, Paganga G: Structure-antioxidant activity relationships of flavonoids and phenolic acids. Free Rad Biol Med. 1996, 20: 933-956. 10.1016/0891-5849(95)02227-9.View ArticlePubMedGoogle Scholar
- Schubert A, Pereira DF, Zanin FF, Alves SH, Beck RCR, Athayde ML: Comparison of antioxidant activities and total polyphenolic and methylxanthine contents between the unripe fruit and leaves of Ilex paraguariensis A. St Hil Pharmazie. 2007, 62: 876-880.PubMedGoogle Scholar
- Tung YT, Wu JH, Huang CY, Kuo YH, Chang ST: Antioxidant activities and phytochemical characteristics of extracts from Acacia confuse bark. Bioresour Technol. 2009, 100: 509-514. 10.1016/j.biortech.2008.01.001.View ArticlePubMedGoogle Scholar
- Chandra S, Mejia EG: Polyphenolic compounds, antioxidant capacity, and quinone reductase activity of an aqueous extract of Ardisia compressa in comparison to mate (Ilex paraguariensis) and green (Camellia sinensis) teas. J Agric Food Chem. 2004, 52: 3583-3589. 10.1021/jf0352632.View ArticlePubMedGoogle Scholar
- Shyamala BN, Gupta S, Lakshmi A, Prakash J: Leafy vegetable extracts antioxidant activity and effect on storage stability of heated oils. Innovative Food Sci Emerging Technol. 2005, 6: 239-245. 10.1016/j.ifset.2004.12.002.View ArticleGoogle Scholar
- Adedapo AA, Jimoh FO, Afolayan AJ, Masika PJ: Antioxidant activities and phenolic contents of the methanol extracts of the stems of Acokanthera oppositifolia and Adenia gummifera. BMC Complement Altern Med. 2008, 8: 54-10.1186/1472-6882-8-54.View ArticlePubMedPubMed CentralGoogle Scholar
- Tsimogiannis DI, Oreopoulou V:Free radical scavenging and antioxidant activity of 5, 7, 3′4′hydroxy-substituted flavonoids.Innovative Food Sci Emerging Technol. 2004, 5: 523-528. 10.1016/j.ifset.2004.05.006.View ArticleGoogle Scholar
- Moncada S, Palmer RMJ, Higgs EA: Nitric oxide: physiology, pathophysiology, and pharmacology. Pharmacol Rev. 1991, 43: 109-142.PubMedGoogle Scholar
- Tsai CH, Stern A, Chiou JF, Chern CL, Liu TZ: Rapid and specific detection of hydroxyl radical using an ultraweak chemiluminescence analyser and a low-level chemiluminescence emitter: application to hydroxyl radical scavenging ability of aqueous extracts of food constituents. J Agric Food Chem. 2001, 49: 2137-2141. 10.1021/jf001071k.View ArticlePubMedGoogle Scholar
- Gülçin I, Elmastaş M, Aboul-Enein HY: Determination of antioxidant and radical scavenging activity of basil (Ocimum basilicum) assayed by different methodologies. Phytother Res. 2007, 21: 354-361. 10.1002/ptr.2069.View ArticlePubMedGoogle Scholar
- Sacan O, Yanardag R: Antioxidant and antiacetylcholinesterase activities of chard (Beta vulgaris L. var. cicla). Food Chem Toxicol. 2010, 48: 1275-1280. 10.1016/j.fct.2010.02.022.View ArticlePubMedGoogle Scholar
- Sroka Z, Cisowski W: Hydrogen peroxide scavenging, antioxidant and antiradical activity of some phenolic acids. Food Chem Toxicol. 2003, 41: 753-758. 10.1016/S0278-6915(02)00329-0.View ArticlePubMedGoogle Scholar
- Nakayama T: Suppression of hydroxyperoxide-induced cytotoxicity by polyphenols. Cancer Res. 1994, 54: 1991-1993.Google Scholar
- Bourgou S, Ksouri R, Bellila A, Skandrani I, Falleh H, Marzouk B: Phenolic composition and biological activities of Tunisian Nigella sativa L. shoots and roots. Compte Rendu de Biologies. 2008, 331: 48-55. 10.1016/j.crvi.2007.11.001.View ArticleGoogle Scholar
- Ksouri R, Falleh H, Megdiche W, Trabelsi N, Mhamdi B, Chaieb K, Bakrouf A, Magné C, Abdelly C: Antioxidant and antimicrobial activities of the edible medicinal halophyte Tamarix gallica L. and related polyphenolic constituents. Food Chem Toxicol. 2009, 47: 2083-2091. 10.1016/j.fct.2009.05.040.View ArticlePubMedGoogle Scholar
- Szekanecz Z, Koch AE: Mechanisms of disease: angiogenesis in inflammatory diseases. Nat Clin Pract Rheum. 2007, 3: 635-643. 10.1038/ncprheum0647.View ArticleGoogle Scholar
- Dahl MK, Richardson T: Photogeneration of superoxide anion in serum of bovine milk and in model systems containing riboflavin and amino acids. J Dairy Sci. 1978, 61: 400-407. 10.3168/jds.S0022-0302(78)83613-3.View ArticleGoogle Scholar
- Aruoma O: Assessment of potential pro-oxidant and antioxidant actions. J Am Oil Chem Soc. 1996, 73: 1617-1625. 10.1007/BF02517962.View ArticleGoogle Scholar
- Pulido R, Bravo L, Saura-Calixto F: Antioxidant activity of dietary polyphenols as determined by a modified ferric reducing/antioxidant power assay. J Agric Food Chem. 2000, 48: 3396-3402. 10.1021/jf9913458.View ArticlePubMedGoogle Scholar
- Evan GI, Vousden KH: Proliferation, cell cycle and apoptosis in cancer. Nature. 2001, 411: 342-348. 10.1038/35077213.View ArticlePubMedGoogle Scholar
- Suffness M, Pezzuto JM: Assays related to cancer drug discovery. Methods in Plant Biochemistry: Assays for Bioactivity. Edited by: Hostettmann K. 1990, London: Academic, 71-133. 6Google Scholar
- Van PG: Carotenoids and cancer: an update with emphasis on human intervention studies. Eur J Cancer. 1993, 29 ((A)): 1335-1344.Google Scholar
- Eberhardt MV, Lee CY, Liu RH: Antioxidant activity of fresh apples. Nature. 2000, 405: 903-904.PubMedGoogle Scholar
- Wada S, Satomi Y, Murakoshi M, Noguchi N, Yoshikawa T, Nishino H: Tumor suppressive effects of tocotrienol in vivo and in vitro. Cancer Lett. 2005, 229: 181-191. 10.1016/j.canlet.2005.06.036.View ArticlePubMedGoogle Scholar
- Nesaretnam K, Stephen R, Dils R, Darbre P: Tocotrienols inhibit the growth of human breast cancer cells irrespective of estrogen receptor status. Lipids. 1998, 33: 461-469. 10.1007/s11745-998-0229-3.View ArticlePubMedGoogle Scholar
- The pre-publication history for this paper can be accessed here:http://www.biomedcentral.com/1472-6882/13/53/prepub
This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.