antioxidants are substances that may prevent or delay some types of cell damage.makopa andtambis are syzygium species that contains high number of antioxidants. the leaves of these two syzygium species were dried for one week. dried leaves were extracted through ethanol extraction. extracted essential oils were then subjected to dpph 2 2-diphenyl- 1 -pircyl-hydrazyl-hydrate radical scavenging assay in three concentrations: 20% 50% and 100% respectively. one way anova test was the statistical test used. findings showed that all set-ups with varying concentrations having scavenging activity of 36.700mcg/ml 38.954mcg/ml and 38.022mcg/ml for makopa and 37.075mcg/ml 35.618mcg/ml and 38.293mcg/ml for tambis showed no significant difference. also data showed no significant difference in the absorbance of the two syzygium species in three different concentrations having 1.404mcg/ml 1.354mcg/ml and 1.375mcg/ml for makopa and 1.396 mcg/ml 1.428mcg/ml and 1.369mcg/ml for tambis. results stated that with the values recorded of two properties combined there is a low potential that makopa and tambis leaves can function as antioxidants and no significant difference exist in their antioxidant property in three varying concentrations. keywords: antioxidant property makopa tambis scavenging activity dpph assayantioxidants are compounds that protect cells on the effects of free radicals- highly reactive unstable particles that are generated during normal cellular processes or when the body is exposed to radiation intense physical exertion or tobacco smoke zeratsky 2016 these powerful compounds keep errant oxidation under control by giving electrons to the free radicals thus neutralizing these particles. however free radicals in the human body outnumber the naturally occurring antioxidants which makes it necessary to have a continuous intake of external sources of antioxidants berkeley et al. 2014 fruits vegetables and whole grains are good external sources of antioxidants such as vitamins c and e and carotenoids. on the other hand naturally occurring antioxidants include phytochemicals such as lignans tannis phenols and flavonoids carlsen et al. 2013 these are substances that can be found in plant-based foods. moreover plant-based food like makopa and tambis are not known for its medicinal properties specially in the philippines because researches about these two syzygium species are uncommon stuart et al. 2017 these are syzygium species that are abundant in the philippines. in the present study essential oil yielded from fresh leaves of syzygium species like makopa and tambis showed monoterpenes characterized mainly by ?-pinene ?-pinene p-cymene and ?-terpineol stuart et al. 2017 these phytochemicals are classified as terpinolene- an organic compound present in the essential oils obtained from leaves. it has therapeutic attributes namely anticancer antibacterial antioxidant antibacterial and sedative properties lannigan 2016 also terpinolene exhibit high antibacterial activity against common bacteria like staphylococcus epidermidis bacillus subtilis escherichia coli staphylococcus aureus enterococcus faecalis and pseudomonas aeruginosa hodges 2017 despite having these therapeutic attributes makopa and tambis remain to be unfamiliar in the field of medicine cyweski et al. 2017 to maximize the benefits from these syzygium species the researchers aims to explore the possibilities of two syzygium species leaf extracts as a source of external antioxidants for the human body. makopa and tambisare easily obtainable thus making it affordable. furthermore this research would be a great help in the discovery of natural external sources of antioxidants and fresh perspective on the unpopular beneficial properties of makopa and tambis morton et al. 2017 the researchers pursued the following questions throughout the period of the study: 1. what is the antioxidant property of makopa and tambis leaf extracts in its varying amount of concentration 2. what is the significant difference in the absorbance property of makopa and tambis leaf extract in varying amounts of concentration specifically: 2.1. 20%; 2.2. 50%; and 2.3. 100% 3. what is the significant difference in the scavenging activity of makopa and tambis leaf extract in varying amounts of concentration specifically: 3.1. 20%; 3.2. 50%; and 3.3. 100% the researchers formulated hypotheses based on the stated problems above: 1. there is no significant difference between the antioxidant property of makopa leaf extract and tambis leaf extract in its varying amount of concentration. 2. there is significant difference between the antioxidant property of makopa leaf extract and tambis leaf extract in its varying amount of concentration. the research identified the certain phytochemicals of the makopa and tambis leaf extract are considered to have antioxidant properties. the study provided the leaves of the two syzygium species another use besides the utilization of the fruit itself in different areas of medicine. this study might also provide information to some people regarding the other uses of syzygium species in that their purpose is not solely for eating but the other parts can also be utilized in the field of medicine. it would be beneficial to pharmaceutical industries to use this research for the utilization of the two syzygium species for production of medicine derived from its properties. also it would be helpful to farmers of this plant species because this research would discover other uses for their plant. furthermore the research may be of service to future researchers because it would help them in learning about the properties of the syzygium species not only of the fruit but also of the other parts of the plant like the leaves. the main focus of this research was to determine the anti-oxidant properties of syzigiummalaccense leaf extract and syzigiumaqueum leaf extract through dpph radical scavenging assay. only one parameter was tested which was the amount of concentration of the leaf extracts. testing was done outside the school premises with the help experts because of the absence of facilities in the campus. definition of terms in this research study the following terms were operationally defined to improve the understanding of this work. dpph assay.a bioassay test offered in university of the philippines- manila that is used to evaluate the antioxidant property of makopa and tambisleaf extracts by recording the scavenging activity in different concentrations. essential oil.a substance extracted from makopaleaves that was evaluated through phytochemical analysis. free radicals.these are naturally occurring molecules and typically highly reactive that was used to test the antioxidant property of makopa and tambisleaf extracts through dpph assay. phytochemicals.in this study phytochemicals are the different medicinally active substances found in the extract of makopa and tambis leaves based on the analysis made by godofredo stuart last 2017. 2. methodology the researchers examined the antioxidant property of two syzygium species on different concentrations specifically 20% 50% and 100%. the samples of makopa leaves and tambisleaves were collected and extracted through ethanol extraction at the adamson university technology research and development center autrdc extract collected from both samples were subjected to dpph 2 2-diphenyl- 1 -pircyl-hydrazyl-hydrate radical scavenging assay analysis at the institute of pharmaceutical sciences at university of the philippines- manila. in accordance to the analysis performed this research resulted in statiscal data. the data collected from the dpph assay analysis was analyzed using the spss program and anova was the statiscal test used. the materials needed were 500 grams of makopaand tambis leaves. these leaves were extracted using the ethanol extraction method. the leaves were suspended beneath an inverted condenser that has multiple drip points across for even extraction. also ethanol extraction method has been proven in university experiments to be the most thorough extraction method available brittny 2018 the extracted sample of 10 ml makopa leaves and 10 ml tambis leaves were subjected to dpph assay analysis. dpph assay is the most commonly used antioxidant assay for plant extract. also scavenging activity of both samples were analyzed through the detected antioxidants that scavenged free radicals. the results from the dpph assay analysis were statistically analyzed using anova. with this the researchers were able to establish the antioxidant property of the two syzygium species. the procedure used in this research was based on the research study entitled antibacterial and antioxidant activities of three citrus leaves extracts r. dulay and m. de castro from department of biological sciences central luzon state university and department of biology college of science de la salle university taft avenue manila philippines published last august 13 2016. 2.1. design the researchers used the quantitative research method for this study investigated the antioxidant property of the tambis and makopa leaf extract. also this research should result in statistical data. in accordance the tambis and makopa leaf extracts were tested in varying concentrations of each extract. the processes of the research were reflected on the methodological framework on figure 1. figure 1. methodological framework 2.2. locale this research made use of two syzygium species namely syzygiummalaccense makopa and syzygiumaqueum tambis the two syzygium species were taken from las piñas city and quezon city. the extraction was done in adamson university technology research and development center autrdc after the extraction the dpph 2 2-diphenyl- 1 -pircyl-hydrazyl-hydrate radical scavenging assay analysis was done at the institute of pharmaceutical sciences at university of the philippines- manila to determine the anti-oxidant property of the species. 2.3. data gathering the tambis and makopa leaves were collected from las pinas city and quezon city. both of the samples were air-dried for a week and were then brought to the adamson university technology research and development center autrdc for extraction. 500 grams of each species were extracted using ethanol extraction. the extraction method used was distillation in which the leaves were placed in a vessel of boiling water or suspending the leaves above the boiling water so that the steam passes through the leaves. the steam strips the light oils from the plant material and carries it to a chilled condenser where the oil-entrained steam liquefies. the condensed fluid obtained from the previous process will separate into two layers. the lower part consists of the hydrosol which is made up of water soluble oil and water. the liquid forms a thin layer on top of the hydrosol will be the essential oil. the antioxidant property of the tambis and makopa leaves were measured through the varying concentration of each extract. in obtaining the antioxidant property in varying amounts of the tambis and makopa leaf extracts setups of 20% 50% and 100% concentrations of each extract underwent dpph assay. the stable 2 2-diphenyl-1-1picrylhydrazyl dpph radical was used to estimate the free radical scavenging activity of the samples following the standard method of dulay and de castro. a 100 µl of test sample in ethanol was added with 5 µl dpph solution 5 mg dpph powder in 2 ml of ethanol in 96-well microtitter plates. the mixture was shaken vigorously and left to stand for 30 min in the dark and the absorbance was then measured at 517 nm. the inhibition of dpph free radicals was calculated. table 1. setups of different concentrations of the makopa and tambis leaf extract concentration makopa 20% 50% 100% tambis 20% 50% 100% outcomes of the different setups were observed by the given time in the research design and the dpph assay test was done by institute of pharmaceutical science at the university of the philippines- manila. 2.4. statistical analysis the collected data were subjected to statistical treatment further understand the results of the experiment. it was also done to show if there was a significant difference between the antioxidant properties of the tambis and makopa leaf extract in varying concentrations. the anova test was used as a statistical tool through the spss version 20 for windows software for determining the significant differences of the antioxidant properties of the tambis and makopa leaf extract in varying concentrations. 3 results and discussions sample absorbance 20% 50% 100% ascorbic acid 0.273 0.037 0.047 syzygiummalaccense makopa 1.404 1.354 1.375 syzygiumaqueum tambis 1.396 1.428 1.639 the results from the dpph 2 2-diphenyl- 1 -pircyl-hydrazyl-hydrate radical scavenging assay analysis were given by the institute of pharmaceutical sciences at university of the philippines- manila. the results showed amounts of absorption and scavenging activity of the two syzygium species on three varying concentrations specifically 20% 50% and 100%. 3.1 findings table 2. the absorbance property of both the makopa and tambis leaf extracts obtained from different concentrations figure 7. graphical representation of the absorbance property of the three setups table 2 shows the absorption of makopa and tambisleaf extract under three concentrations namely 20% 50% and 100%. the said concentrations were based on a similar study entitled antibacterial and antioxidant activities of three citrus leaves extracts dulay et al. 2016 the positive control used for the dpph radical scavenging assay analysis was ascorbic acid which is known as an antioxidant. the ascorbic acid had an absorbance property of 0.273 for 20% concentration 0.037 for 50% concentration and 0.047 for 100% concentration. in relation to the antioxidant property absorbance is inversely proportional with the antioxidant property which is why the ascorbic acid is an efficient antioxidant since it has low absorbance. the makopaleaf extract had an absorbance property of 1.404 for 20% concentration 1.354 for 50% concentration and 1.375 for 100% concentration while the tambis leaf extract had an absorbance property of 1.396 for 20% concentration 1.428 for 50% concentration and 1.639 for 100% concentration. the absorbance properties of the two species were higher than the absorbance of ascorbic acid. table 3. the scavenging activity of both the makopa and tambis leaf extracts obtained from different concentrations sample scavenging activity 20% 50% 100% ascorbic acid 87.692 98.332 97.881 positive control syzygiummalaccense 36.7 38.954 38.022 makopa syzygiumaqueum 37.075 35.618 38.293 tambis figure 7. graphical representation of the scavenging activity of the three setups sources of variation sum of squares df mean squares p- value decision interpretation between groups 1.687 2 0.844 0.446 0.05 accept ho not significant within groups 5.671 3 1.89 table 3 shows the scavenging activity of the makopa and tambis leaf extracts under three concentrations namely 20% 50% and 100%. in relation to the antioxidant property the scavenging activity directly associates with the antioxidant property; the higher the value obtained under the scavenging activity the higher the species antioxidant property. the values obtained under the scavenging activity of the two species were far from the values obtained under the positive control which is the ascorbic acid. the ascorbic acid had a scavenging activity of 87.692 for 20% concentration 98.332 for 50% concentration and 97.881 for 100%. the makopa leaf extract had a scavenging activity of 36.7 for 20% concentration 38.954 for 50% concentration and 38.022 for 100% concentration. lastly the tambis leaf extract had a scavenging activity of 37.075 for 20% concentration 35.618 for 50% concentration and 38.293 for 100% concentration. it can be concluded that compared to the ascorbic acid the scavenging activity of both the makopa and tambis leaf extracts are lower. 3.2 analysis and discussion table 4. test of significant difference on the absorbance property of the two syzygiumspecies on three varying concentrations specifically 20% 50% and 100%. sources of variation sum of squares df mean squares p-value decision interpretation between groups 0.001 2 0 0.68 0.05 accept ho not significant within groups 0.003 3 0.001 table 5. test of significant difference on the scavenging property of the two syzygiumspecies on three varying concentrations specifically 20% 50% and 100%. the researchers determined that there is no significant difference in the antioxidant property of both syzygium species. the absorbance and scavenging activity determine the antioxidant property of both leaf extracts. based on the data showed on table 3 and 4 the mean difference of the absorbance and scavenging activity of the two syzygium species treated with three different concentrations is higher than the alpha value of 0.05 with the significance level of 95%. therefore the leaf extracts of makopa andtambishave no significant difference in its antioxidant property in varying concentrations specifically 20% 50% and 100%. 3.3 conclusion based on the data which had undergone statistical treatment it can be concluded that the null hypothesis is accepted. this states that there is no significant difference between the antioxidant property of the two syzygium species in three varying concentrations specifically 20% 50% and 100%. from the results presented the study suggested that the extracts from makopa and tambis leaves showed a low potential as an independent antioxidant. therefore its function as an antioxidant alone is not enough to protect the human body from free radical damage. it needs to be combined with other compounds with high rate of antioxidant property to effectively function as a natural antioxidant. after conducting the study the researchers recommend to use another type of extraction method to determine if it can affect the antioxidant property of the extracts.also the researchers recommend to broadenthe scope of the research by adding comparisons of other antioxidant-rich species endemic in the philippines. acknowledgement deep and sincere gratitude is given to everyone who helped and gave support in making this research successful. to dr. jonas feliciano domingo the researchers adviser in research in daily life ii for imparting invaluable knowledge and expertise that helped greatly in accomplishing the research and for his guidance and encouragement to the researchers. to the adamson university technology research and development center autrdc for extracting the leaf extracts and to the institute of pharmaceutical sciences at university of the philippines- manila for performing the dpph 2 2-diphenyl- 1 -pircyl-hydrazyl-hydrate radical scavenging assay analysis on the leaf extracts. to the parents of the researchers for their everlasting love and support.most importantly to god for blessing and guiding the researchers throughout their lives.