Effect of Different Solvents on Total Phenolic Contents and Antioxidant Activity of Zizyphus jujube Miller Fruits

Introduction: Phenolic compounds have an ability to scavenge free radicals and cause the balance of reactive oxygen species (ROS) in our body. This balance prevents atherosclerosis, coronary heart and cancer diseases. Butylated hydroxyl toluene (BHT) is a well-known synthetic antioxidant, which is restricted to be used due to its probable toxic effects. Therefore, replacement of synthetic antioxidants with plant materials with high amounts of antioxidant activity, which protect the body from free radicals and many diseases caused by lipid peroxidation, is an appropriate option. ZiziphusjujubaMiller is one of the forty species belonging to Rhamnaceae family, which produces a great deal of industrial raw materials for horticultural, ornamental, food, and pharmaceutical industries. Antioxidants can be extracted by various solvents and extraction methods. Solvent extraction is the most common method used for separating natural antioxidants. Solvent properties undoubtedly play a key role in the extraction of antioxidative compounds. The type and yield of antioxidant extracted have been found to vary as affected by the solvent properties such as polarity, viscosity and vapor pressure. Therefore, it is difficult to develop a unified standard method for the extraction of antioxidants from all plant materials. Materials and Methods: Plant materials Fresh fruits were collected from Birjand, Iran, in late summer 2014. The samples were air dried under the shade at room temperature. Dried fruits were ground by using a mortar and pestle and were separately extracted by distilled water and organic solvents such as methanol, ethanol and acetone (50%, 90% and100% (v/v)). After filtering through the Whatman paper #3 and removing the solvents (using a rotary evaporator (BUCHI V-850)) and water (using a freeze dryer, (OPERON, FDB-5503, Korea)), the dried extracts were stored in refrigerator for further analysis. Determination of Total Phenolic Content (TPC) Samples were measured for TPCs colorimetrically using the Folin-Ciocalteu method with modification. Absorbance was read at 725 nm against blank using UV-Visible spectrophotometer (Cecil. UK.). A calibration curve was prepared using a standard solution of Gallic acid (0.2-1mg/ml). Results were expressed as mg Gallic acid/g dry extract (mg GA/g DE). Determination of Total Flavonoid Content (TFC). TFC was determined using the method of Huang et al. (13) with minor modifications. Absorption was measured at 430 nm using UV-VIS spectrophotometer (Cecil. UK.). TFC was determined using a standard curve with quercetin as the standard, and expressed as mg of quercetin equivalents (CE)/g dry extract (mg QE/g DE). Determination of Total Anthocyanin Content (TAC). TAC was measured using a spectrophotometric differential pH method. Its absorbance was read at 510 and 700nm. Results were expressed as milligrams of cyanidin-3-glucoside (CY.) equivalents per g of dry extract. Determination of Total Tannin Content. For determination of tannins in the sample extracts, vanillin–HCl method was used. The absorbance was read at 500 nm using UV–vis spectrophotometer. The content of tannins in the sample was expressed as mgcatechine equivalent (CE)/100g sample. Determination of Antioxidant Activity. Antioxidant activity of the samples was determined using DPPH (2, 2-diphenyl-1-pic-rylhydrazyl) radical scavenging activity and ferric reducing antioxidant power (FRAP). In the presence of antioxidant, FRAP assay reduced Fe3+-TPTZ (2, 4, 6-tris (2-pyridyl)-5-triazine) complex to Fe2+ - TPTZ at low pH. The absorbance of the mixture was measured by using spectrophotometric ally at 595 nm. The effect of antioxidant on DPPH radical was thought to be due to their hydrogen donating ability or radical scavenging activity. DPPH assay expressed as IC50 and percentage inhibition. Lower IC50 value indicates higher antioxidant activity. Results and Discussion: Efficiency of different solvent extractions depends on the matrix of plant materials as well as the type of extractable compounds. The correct selection of solvent can improve the extraction yield of antioxidants from plants matrices considerably. For this reason, in the present study, some selected types of solvent showed different results. For extraction of total phenol and flavonoid compound, acetone 50% was the best yield. In methanolic extract (50, 100%), the highest amounts of anthocyanin and total tannin were reported. In all extracts, water had the least efficiency in comparison with other solvents. High correlation was observed in total phenolic content and antioxidant activity which was determined by DPPH and FRAP assay. Acetone 50% was the most potent for scavenging free radicals and reducing a ferric-tripyridyltriazine, Fe (III)-TPTZ, complex to ferrous, Fe (II) in all extracts. Conclusions: The results of the present study indicated that polarity, selectivity, viscosity, and vapor pressure are important physicochemical properties that should be considered when selecting a suitable solvent for the extraction of bioactive compounds from plant materials

Assessment of phenolic profile and antioxidant power of five pistachio (Pistacia vera) cultivars collected from four geographical regions of Iran

Objective: In this study, the levels and antioxidant activities of some secondary metabolites isolated from five pistachio (Pistacia vera)cultivars collected from four different geographical regions of Iran, were studied. Materials and Methods: Total phenolic compounds levels were determined by Folin-Ciocalteu method. Total flavonoid content was determined as AlCl3 complex and expressed as mg of quercetin equivalents (QE)/g dry extract and total proantocyanidins content was expressed as mg of catechin equivalents (CA)/g dry extract. In order to evaluated the antioxidant activity of the compounds, DPPH and FRAP assays were used. Results: The highest level of total phenols (156.42 mg GA/g DE), total flavonoids (130.94 mg QE/g DE) and total proantocyanidins (152.816 mg CA/g DE) were obtained in Akbari cultivar from Rafsanjan, followed by Badami-e-sefid and Ahmad aghaei. The lowest amount of total phenolic content (TPC), total flavonoid content (TFC) and total proanthocyanidin content (TPrAC) were found in Badami-e-sefid from Feizabad (128.140 mg GA/g DE, 93.176 mg QE/g DE and 118.870 mg CA/g DE, respectively). Also, a positive correlation (r2=0.9834) was found between antioxidant activity and total phenolic compounds. Conclusion: Pistachio increased their phytochemical compounds to contrast with abiotic stress. Our data could be useful for introducing special characteristics to the plants, and can be considered when planning a new breeding program or choosing a specific cultivar for a particular use

Therapeutic peptides of Mucuna pruriens L.: Anti‐genotoxic molecules against human hepatocellular carcinoma and hepatitis C virus

Abstract To assist the development of new therapeutic strategies for several disorders, biologically active peptides/proteins obtained from plant sources can be considered. Current study expected to determine the biological activities of peptide fractions of Mucuna pruriens against hepatocellular carcinoma cell lines (HepG2/ADM, HepG2, SMMC‐7721, and QGY‐7703), as well as normal cell line to prove their selectivity. Moreover, anti‐genotoxicity and antiviral activity against the hepatitis C virus (HCV) were assessed. The methods of this study were to isolate the peptides of M. pruriens and hydrolysate fractionation via fractionated pepsin‐pancreatin hydrolysates by ultrafiltration/high‐performance ultrafiltration cell, identify anti‐hepatoma activity of peptide fractions human liver cancer and normal cells by (3‐(4,5‐dimethylthiazole‐2‐yl)‐2,5‐biphenyl tetrazolium bromide) (MTT) assay, determine anti‐HCV, and assess anti‐genotoxic effect of peptide fractions against damage that induced via alkylating agent methyl methanesulphonate in human mononuclear cells. The results showed that the fraction 5–10 kDa has been reported to exhibit significant cytotoxic activity against HepG2 and QGY‐7703. It was proven that both of 5–10 and >10 kDa fractions are active against HCV. The cytotoxic concentration (CC50) of 5–10 kDa against the cell line was 703.04 ± 5.21 µg/ml. Anti‐genotoxic activities of the peptide fractions were evaluated as mean values for the analyzed comet images. In this regard, the highest activity of protecting DNA damages was observed by the peptide fraction of 5–10 kDa. This study revealed the potential ability of peptide fractions of M. pruriens for the treatment of liver cancer, HCV, and high activities of protecting DNA damages

LC-ESI/LTQOrbitrap/MS/MS and GC–MS profiling of Stachys parviflora L. and evaluation of its biological activities

The use of some Stachys genus as herbal remedies is known and the aerial parts have a pharmaceutical interest, being used in Anatolia and Iran as wild tea. In this study, chemical composition, antimicrobial, antioxidant, and antiproliferative activities of the methanolic extract and essential oil (EO) of Stachys parviflora L. (S. parviflora) were evaluated. Qualitative analysis of metabolites of S. parviflora methanolic extract was studied using liquid chromatography coupled to high resolution mass spectrometry (LC-ESI/LTQOrbitrap/MS), evidencing the presence of phenolic acids and flavonoids derivatives. The EO was analyzed using gas chromatography coupled to mass spectrometry (GC/MS). Eighty-seven compounds were characterized in the EO of S. parviflora, of which α-terpenyl acetate (23.6%), β-caryophyllene (16.8%), bicyclogermacrene (9.3%), spathulenol (4.9%) and α-pinene (4.2%) were found to be the major components. The highest antimicrobial effect of EO was found to S. aureus and B. cereus (MIC = 0.01 μg/ml), while the highest activity of extract was against B. cereus (MIC = 125 μg/ml). The methanolic extract exhibited strong antioxidant activity in DPPH (IC 50 = 76.87 μg/ml) and β-carotene/linoleic acid assay (BCB, IC 50 = 188.47 μg/ml) methods. Furthermore, in vitro cytotoxicity evaluation against three cell lines namely human ovarian carcinoma (A2780), human colon carcinoma (HCT), and mouse melanoma cell line (B16F10), showed an anti-proliferative activity of the EO ranging from IC 50 value 30.95 μg/ml to 16.55 μg/ml. The results from this study have demonstrated the promising cytotoxic, antibacterial, and antifungal properties of S. parviflora, which could have wide potential applications in food and pharmaceutical industries