Hajimahmoodi et al Tropical Journal of Pharmaceutical Research June 2014; 13 (6): 951-956 ISSN: 1596-5996 (print); 1596-9827 (electronic) © Pharmacotherapy Group, Faculty of Pharmacy, University of Benin, Benin City, 300001 Nigeria. All rights reserved. Available online at http://www.tjpr.org http://dx.doi.org/10.4314/tjpr.v13i6.18 Original Research Article Total Antioxidant Activity, and Hesperidin, Diosmin, Eriocitrin and Quercetin Contents of Various Lemon Juices Mannan Hajimahmoodi1*, Ghazaleh Moghaddam1, Seyed Mohsen Mousavi1, Naficeh Sadeghi1, Mohammad Reza Oveisi1 and Behrooz Jannat2 1Department of Drug and Food Control, Faculty of Pharmacy, Tehran University of Medical Sciences, 2Drug and Food Control Laboratory, Research Center, Ministry of Health and Medical Education, Tehran, Iran *For correspondence: Email: [email protected]; Tel/Fax: +98-21- 66954714 Received: 12 June 2013 Revised accepted: 27 March 2014 Abstract Purpose: To investigate 38 natural and 62 branded lemon juices for their total antioxidant activities and flavonoid content. Methods: The ferric reducing antioxidant power was applied to evaluation of antioxidant. Additionally quercetin, eriocitrin, diosmin and hesperidin contents were evaluated by high performance liquid chromatography (HPLC). Results: Total antioxidant activity of the juices ranged from 91.38 ± 0.01 to 526.93 ± 0.12 µg/ml. The maximum contents of quercetin, hesperidin and eriocitrin 14.83 ± 2.83, 104.84 ± 12.58 and 10.68 ± 2.41 µg/mL, respectively. The natural juices had diosmin levels as high as 236.18 mL. The limit of detection (LOD) ranged from 0.15 µg mg-1 for hesperidine to 0.53 µg ml-1 for diosmin while the limit of quantification (LOQ) ranged from 0.27 µg mg-1 for hesperidine to 0.93 µg ml-1 for quercetin. Conclusion: The developed method can also be applied to the determination of related extracts of orange cultivars as well as various extracts of medicinal plants. Keywords: Antioxidant, Flavonoid, Hesperidin, Diosmin, Eriocitrin, Quercetin, Lemon juice Tropical Journal of Pharmaceutical Research is indexed by Science Citation Index (SciSearch), Scopus, International Pharmaceutical Abstract, Chemical Abstracts, Embase, Index Copernicus, EBSCO, African Index Medicus, JournalSeek, Journal Citation Reports/Science Edition, Directory of Open Access Journals (DOAJ), African Journal Online, Bioline International, Open-J-Gate and Pharmacy Abstracts INTRODUCTION Recently, more attention had been paid to plant flavonoids and some publications have Lemon (Citrus limon L) is the third most suggested they might play important roles in important species of citrus fruit after orange and anticancer activity [5-7]. An imbalance between mandarin. The presence of bioactive antioxidants and free radicals results in oxidative compounds, such as hydrocinnamic acid, ferulic stress, will lead to cellular damage [8]. Quercetin, acid, cyaniding glucoside, flavonoid, vitamin C, as a flavonol, is used as a nutritional supplement carotenoid, hesperidin and naringin content found in fruits and vegetables. It is thought to contribute to the value of lemon in terms of it have potent antioxidant, ant diabetic and anti being associated with promoting good health [1]. tumor, and antiviral, anti inflammatory benefits Phenolic and flavonoids compounds are crucial [9,10]. Eriocitrin is an ingredient derived from for plants growth and reproduction, and are natural products, and it is contained in a juice of produced as a response to environmental factors citrus fruits. Another determined flavonoid is a and to defend injured plants [2-4]. synthetic antioxidant called diosmin. Recent clinical studies have demonstrated that the diosmin can be used to treat venous leg ulcers Trop J Pharm Res, June 2014; 13(6): 951 Hajimahmoodi et al and hemorrhoids. Diosmin drugs have been incubation at 37 ºC for 10 min. To construct successfully used as chemo-preventive agents in calibration curve, five concentrations of FeSO4 urinary-bladder 9 and colon carcinogenesis [11]. 7H2O (1000, 750, 500, 250, 125 µmol/lit) were Hesperidin is a flavanone glycoside found used and the absorbance were measured as abundantly in citrus fruits which is believed to sample solution. The values were expressed as play a role in plant defense and it acts as an the concentration of antioxidants having a ferric antioxidant according to in vitro studies [12]. reducing ability equivalent to that of 1 mmol/L FeSO4. All the measurements were taken in The purpose of this work was to determine the triplicate and the mean value ± standard total antioxidant activities of several lemon juices deviation (SD) were reported. by a spectrophotometric method as well as determine the flavonoid (quercetin, hesperidin, Chromatographic conditions diosmin, and eriocitrin) contents of the juices by HPLC for the purpose of developing a suitable These experiments were done using an quality control for levels of these compounds in analytical HPLC system consisting of a pump plant materials. (Maxi-Star K-1000, Knauer, Germany), a UV spectrophotometer detector (Knauer, Germany), EXPERIMENTAL controlled by software (EuroChrom 2000, Version 1.6, Knauer Co., Germany). Chemicals, reagents and materials Chromatographic analysis was carried out by Eurospher 100 C8 Column (4.6 mm × 25 cm, 5 All solvents/chemicals used were of analytical µm; Knauer, Germany) reversed phase column. grade and were purchased from Merck Company The mobile phase was water; acetonitrile: acetic (Darmstadt, Germany). Quercetin, eriocitrin, acid (77:21:2 v/v/v). The mobile phase was diosmin and hesperidin (Sigma, St. Louis) were filtered through a 0.45 μm membrane filter and used as standards. degassed ultrasonically prior to use. RP-HPLC separation of standard quercetin, eriocitrin, Sample preparation diosmin and hesperidin was set at 280 nm. Flow rate and injection volume were 1 ml /min and 10 The lemon juice samples were divided into two μl. The freshly squeezed juice was centrifuged at groups (38 natural lemon juices from local 3000 rpm for 10 min. The pH of juice was sources and 62 branded lemon juices from adjusted at 8.5 by NaOH (10 %) then it was supermarkets). Lemons in the first group were filtered through a specify membrane material of washed, peeled and squeezed to extract the the 0.45 μm filter to analyze by HPLC. The juice and then clarified with Whatman no. 4 filter chromatographic peaks of the analytes were paper. All samples were stored as recommended confirmed by comparing their retention time with on the labels and were analyzed before expiry those of the reference standards. All dates. This study was done during the fall and chromatographic operations were carried out at winter months of 2012. ambient temperature. Total antioxidant activity Method validation FRAP (ferric reducing antioxidant power) assay To check the accuracy of the method, natural is based on the reduction of a ferric-tripyridyl samples were spiked with the flavonoids of triazine complex to its ferrous blue colored form interest at intermediate concentrations of the in the presence of antioxidants. It is a relatively each calibration curves. The concentrations were simple method frequently used in the recalculated from the corresponding calibration assessment of antioxidant activity of various curve (experimental concentration) and fruits, vegetables and some biological samples compared with the theoretical concentrations. [13]. Recovery was determined as the relationship between the experimental and the theoretical Briefly, FRAP reagent contained 5 ml of 2, 4, 6- concentration expressed as a percentage (C tripyridyl-s-triazine (TPTZ, 10 mmol/L) solution in exptal/C theoretical) × 100. HCl (40 mmol/L) plus 5 mL of FeCl3 (20 mmol/l) and 50 mL of acetate buffer (0.3 mol/L, pH 3.6). Statistical analysis It was freshly prepared and warmed up to 37 ºC. A volume of 100 μL samples (filtered lemon All analyses were done in triplicate (n=3). The juice) was mixed with 3 ml of FRAP reagent and results are reported as mean ± standard the absorbance of the reaction mixture was deviation. Statistical analysis was carried out spectrophotometrically measured at 593 nm after using t SPSS 17.0 software (SPSS Inc, Chicago, Trop J Pharm Res, June 2014; 13(6): 952 Hajimahmoodi et al USA) and comparison of averages was based on Flavonoid analysis of the samples by HPLC the analysis of variance (one-way ANOVA) at a significance level of p < 0.05. The results obtained from the preliminary analysis of flavonoids are shown in Table 1. RESULTS Quercetin content in natural sample (4.04 ± 0.79 Ferric reducing antioxidant power (FRAP) µg/mL) was found to be highest compared to other samples. In contrast nos. 3 and 4 lacked Table 1 presents the validation data of four quercetin content. Quercetin belongs to the groups of samples. The recoveries (n=6) ranged flavonoid group with powerful antioxidant activity. from 89.6 ± 0.9 % in diosmin to 95.0 ± 0.7 % in It can be seen from the data in Table 1 that quercetin. Statistical analysis showed good hesperidin content in natural samples (67.11 standard deviations and recovery values. µg/mL) and no. 2 (49.06 µg/mL) are moderate, when compared with no. 1 (104.84 ± 12.58). The antioxidant activities were expressed as the Diosmin and eriocitrin were not detected in concentrations of antioxidant having a ferric sample nos. 3 and 4 and the maximum content reducing ability equivalent to that of 1 µM/L of diosmin that was detected was in natural 2 FeSO4 (Y = 0.01X-0.008, R = 0.997). Most of group with concentration