Leaf Extracts
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Bouyahya A et al. J Nutr Food Lipid Sci 2018(1): 06-14. https://doi.org/10.33513/NFLS/1801-02 Journal of Nutrition, Food and Lipid Science OCIMUM Review Article Correlation Between the Phenol Content and Antioxidant Efficacy ofMyrtus Communis (L.) Leaf Extracts Abstract In the present work, we have evaluated the antiradical efficacy of ethanol, 1* 2 Abdelhakim Bouyahya , Abdelaziz Benjouad , methanol and n-hexane extracts from leaves of Myrtus communis L. to find 1 1 Nadia Dakka and Youssef Bakri potential sources of natural antioxidants. Total phenolic content was assessed using the Folin-Ciocalteau assay and Total Flavonoid Content was assessed using 1Mohammed V University of Rabat, Faculty of Aluminum Chloride (AlCl ) colorimetric method with quercetin as standard Sciences, Department of Biology, Genomic Center 3 flavonoid. On the other hand, antioxidant activities of these extracts were of Human Pathologies, Laboratory of Human determined spectrophotometrically at ambient temperature and 517nm using Pathologies Biology, Rabat, Morocco 2,2-Diphenyl-1-Picrylhydrazyl (DPPH), and evaluated following the kinetics 2International University of Rabat (UIR), of the DPPH reduction. The Total Phenol Content of extracts ranged between Technopolis Rabat-Sale Shore, 11100 Sala Al 122.72 ± 1.16 to 137.46 ± 0.35 mg GAE/g extract, while the flavonoid content Jadida, Morocco ranged between 18.41 ± 0.43 and 31.24 ± 1.23mg QE/g extract. In addition, the n-hexane extract showed more activity than ethanol and methanol extracts. Received: 10 September 2018 The antiradical capacity (IC50) parameter and its TIC50 time equivalent have an Accepted: 08 October 2018 influence on the antiradical capacity of extracts. The antiradical efficiency is Version of Record Online: 26 October 2018 considered to be a stronger parameter to select antioxidants compared to IC50. The present study revealed that M. communis represents an important source of natural antioxidants to ensure food safety. Citation Bouyahya A, Benjouad A, Dakka N, Bakri Y Keywords (2018) Correlation Between the Phenol Content Antioxidant Capacity; Flavonoids; Myrtus communis; Polyphenol and Antioxidant Efficacy of Myrtus Communis (L.) Leaf Extracts. J Nutr Food Lipid Sci 2018(1): 06-14. Introduction Correspondence should be addressed to Oxidation reaction can be defined as the transfer of electrons from one Abdelhakim Bouyahya, Morocco atom to another. It is an important reaction in human living cells because E-mail: [email protected] it represents an essential reaction aerobic metabolism. During the aerobic oxidation process, Oxygen molecules are the key electron acceptor in the Copyright electron flow system for producing energy in the form of ATP. However, when the electron flow becomes uncoupled (transfer of unpaired single Copyright © 2018 Abdelhakim Bouyahya et al. electrons), some problems could arise generating so-called free radicals This is an open access article distributed under reactive [1]. On the other hand, an antioxidant is a compound that reacts the Creative Commons Attribution License to free radicals, neutralizing them and thereby preventing or reducing which permits unrestricted use, distribution, and their damaging effects on the human body [2]. The resulted oxidative reproduction in any medium, provided the original stress is involved in the pathogenesis of many related diseases such as author and work is properly cited. cancer and inflammation. In fact, the oxidation of lipids is responsible for the deterioration of fats and oils resulting in change in color, flavor and nutritive value [3]. Ocimum Scientific Publishers .01. Submit Manuscript Journal of Nutrition, Food and Lipid Science https://doi.org/10.33513/NFLS/1801-02 To prevent oxidation, particularly in food industry, the an electric grinder, then the investigated dried powdered addition of some synthetic molecules to fats, fatty food, and plant materials were extracted by maceration. The powder cosmetics is a common practice. These synthetic antioxidant (25g) of leaves was placed in an Erlenmeyer flask containing compounds were revealed to have several side effects including 100mL ethanol, methanol, and n-hexane for 72h. The plant carcinogenicity [4,5]. Consequently, synthetic antioxidants extracts were filtered with a filter paper (Whatman. No.1) used in products for human application are being restricted, and the combined filtrate was then steam-dried using a rotary considerably increasing interest in antioxidants of natural evaporator (Heidolph Collegiate, LV28798826, New Jersey, origin [6,7]. USA) at a temperature not exceeding 45°C. All extracts were stored in a dark bottle at 2 - 8°C until analysis. Medicinal plants have long been used for their pharmacological properties. Several extracts and essential oils are tested for their Determination of Total Phenolic Content (TPC) biological effects such as antibacterial, antioxidant, antitumor and antileishmanial activities [8-12]. Indeed, these plants The concentration of the phenolic compounds in the plants possess different secondary metabolites, some of which are extracts was determined using the Folin Ciocalteu assay [23], potent antioxidants, including polyphenols and flavonoids with some modifications. In brief, the extract was diluted to contents [1,6]. The antioxidant activity of phenolic compounds the concentration of 1mg /mL, and aliquots of 100μl or a is attributed to their redox properties which allow them to act as standard solution of gallic acid (20, 40, 60, 80 and 100mg/L) reducing agents, hydrogen donators, singlet oxygen quenchers were mixed with 500μl of Folin Ciocalteu reagent (previously and metal chelators [13]. Many in vitro studies confirm that diluted 10-fold with distilled water) and 400μl of Na2CO3 phenolic compounds such as flavonoids and phenolic acid can (7%). After 40 min of incubation at room temperature have a considerable antioxidant activity that depends on the (23 ± 2°C), the absorbance was measured at 760nm using a number and position of phenolic hydroxyls in the aromatic Spectro-photometer against a blank sample. The Total Phenolic ring moieties [14]. Generally, monophenols are less effective Content was calculated using a calibration curve for gallic than catecholic phenols and phenolic aglicons have higher acid (R2 = 0.998). The results were expressed as milligram of antioxidant activity than their respective glycosides [14]. gallic acid equivalent per gram of dry weight of extract (mg of GAE/g extract). All samples were analyzed in triplicate. Myrtle (Myrtus communis L.) is a medicinal plant endemic to the Mediterranean area and has been used local populations Determination of Total Flavonoid Content (TFC) for its culinary and medicinal properties since ancient times [15-18]. Its use is a well-established tradition in many countries, The Total Flavonoid Content of the extracts was determined using the Aluminum Chloride (AlCl ) colorimetric method including Morocco. Organic extracts and essential oils produced 3 by M. communis contain numerous bioactives compounds that described by Brighente et al., with minor modifications [24]. possess multiple biological properties, especially antioxidant In a nutshell, 1mL of the extract (1mg/mL in methanol) or a activity [2,19-22]. However, studies in the field have been standard solution of quercetin (20, 40, 60, 80 and 100mg/L) were mixed with 1mL of 2% AlCl in methanol. After 40 min of limited to the determination of the antioxidant capacity. 3 staying at room temperature (23 ± 2°C), the absorbance against The aim of the present study is to examine the in vitro blank was measured at 430nm using a Spectrophotometer. The antiradical activities of methanol, ethanol, and n-hexane of Total Flavonoid Content was calculated using a calibration Myrtus communis leaves extracts using DPPH (2,2-diphenyl- curve for quercetin (R2 = 0.985). The results were expressed 1-picrylhydrazyl) scavenging capacity and therefore determine as milligram of quercetin equivalent per gram of dry weight the antioxidant efficacy by studying the antiradical power of of extract (mg of QE/g extract). All samples were analyzed in M. communis extracts depending on kinetic reaction. triplicate. Materials and Methods Evaluation of the antioxidant activity Collection of plant material and preparation of The antioxidant activity of M. communis leaves extracts is extracts measured by using DPPH scavenging method. It is reduced to the form of hydrazine (no radicular) by accepting a hydrogen The leaves of Myrtus communis used in this research were atom. collected in July 2015 from the Ouezzane province. Samples were air dried in the shadows and milled into powder using DPPH radical scavenging capacity assay: The reduction Ocimum Scientific Publishers .02. Submit Manuscript https://doi.org/10.33513/NFLS/1801-02 Journal of Nutrition, Food and Lipid Science capability of DPPH radicals was determined by the antioxidant- Determination of antioxidant capacity (IC50) and induced decrease in its absorbance at 517nm, which is visually Equilibrium Time (TIC50): The antioxidant capacity (IC50) noticeable as a discoloration from purple to yellow [25]. This is defined as the concentration of a compound reducing the method has been widely used to evaluate the free-radical initial DPPH level by 50%. It was calculated from the graph of scavenging effects of various antioxidant substances [26]. This inhibition percentage plotted against the extract concentration average absorbance was used to calculate the DPPH scavenging