Antioxidant Activities of Muntingia calabura, Syzygium cumini, Ocimum basilicum, and Eleutherine bulbosa using DPPH Method

Antioxidants are substances that can provide endogenous protection and exogenous oxidative stress by capturing free radicals. Many plants are efficacious as antioxidants, namely plants that contain polyphenols, especially flavonoids, so many are formulated as natural antioxidants. Plants such as Muntingia calabura, Syzygium cumini, Ocimum basilicum and Eleutherine bulbosa contain polyphenol compounds, especially flavonoids which are efficacious as natural antioxidants.This research aimed to study antioxidant activity derived from some potential plants using the DPPH method by calculating the IC50 value of each plant extract. This research method starts from the determination process to prove the validity of the plants used, the extraction process using the maceration method with 70% ethanol solvent, then the antioxidant activity of extracts from each plant was carried out using the DPPH method. This research starts from the determination process to ensure the correctness of the plants used, then the extraction process is carried out using the maceration method with 70% ethanol solvent. After that the antioxidant activity was determined from the four plants using the DPPH method to see the strongest IC50 value among the four plants. IC50 is the concentration of the sample to inhibit 50% of free radicals. The results of IC50 values fromethanol extract of Muntingia calabura leaves, Syzygium cumini leaves, Ocimum basilicum leaves and Eleutherine bulbosa bulbs, were 18.72; 63,84; 141.59 and 173.15 ppm. Ethanol extract of Muntingia Calabura has a smaller IC50 value of 18.72 ppm which has a very strong and most powerful antioxidant from the ethanol extract of Syzygium cumini, Ocimum basilicum and Eleutherine bulbosa.


Introduction
Antioxidants defined as molecules having ability to inhibit the oxidation of other molecules mostly caused by free radicals, therefore can reduces the damages due to oxygen [1,2,3]. Antioxidants can be catagorized as either synthetic or natural and both are included in formulations. Synthetic antioxidants (e.g. butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), and propyl gallate) has been largely used for many purposes since the ease of production leading to lower prices. However, high potential health risks following a high consumption of synthetic antioxidants has been reported by some studies. Despite the high demand for synthetic antioxidants by market, concerns on natural antioxidants have been increased in the last few years and it is expected to continue and growing. There are some reasons to explain this trend. Mostly, the consumer prefer organic and natural products, since they use less additives thus it is hoped to have less side effects than synthetic ingredients [4].
Natural antioxidants has been used in the cosmetic industries including a great number of substances and extracts obtained from a variety of plants, grains and fruits, either by reducing the skin oxidative stress or protecting the skin from oxidative degradation [4].
Plants that are efficacious as antioxidants are plants that contain carotenoids and polyphenols, especially flavonoids which can be formulated as natural antioxidants in oral dosage forms such as vitamins and topicals for skin care products.
Determination of antioxidant activity in this study

Material collection and plant determination.
Plant material used was obtained from the Manoko plantation, Lembang, West Java. Plants were determined at the Taxonomy Laboratory, Biology Department, Faculty of Mathematics and Natural Sciences, Padjadjaran University.

Extraction
The extraction of Muntingia calabura leaf, Syzygium cumini leaf, Ocimum basilicum leaf and Eleutherine bulbosa bulbs plant were conducted using maceration with 70% ethanol solvent for 3 times 24 hours. Liquid extract concentrated with a rotary evaporator then steamed above a water bath until constant weight of the extract. The yield of the extract can be calculated by the formula :

Determination
The

Antioxidant Activity
In this study, antioxidant activity was tested for all four plants, using the DPPH method. The principle of the DPPH method is based on measurements of capture of antioxidant capacity. DPPH is a free radical is stable in purple, can be reduced by the presence of antioxidant molecules resulting in changes in color from purple to yellow.The results of testing the antioxidant activity indicate IC50 values can be seen in table 6.        antioxidant activity. Based on the compound content in it, the four plants have positive antioxidant activity [13].
The anti oxidant activity test was carried out using a UV-Viss pectrophotometer. This test was conducted to determine thea bsorbance of the remaining DPPH after adding the sample. If the DPPH solution is dissolved with a compound that has antioxidant activity, there will be a decrease in the value of DPPH absorbance which is characterized by a change in color from purple to yellow after incubation for 30 minutes.
This study uses the DPPH method to obtain IC 50 values from a plant extract. IC 50 is the concentration of the sample to inhibit 50% of free radicals. A compound is said to have very strong antioxidant activity if the IC 50 value is less than 50 ppm, strong if the IC 50 value is 50-100 ppm, moderate if it is 100-150 ppm and weak if the IC 50 value is 150-200 ppm (Zuhra et al., 2008). Based on the results of the study of IC 50 Muntingia calabura leaf ethanol extract of 18.72 ppm including very strong, the IC 50 Syzygium cumini leaf value of 63.84 ppm was strong, IC 50 Ocimum basilicum leaf value was 141.59 ppm including moderate and IC 50 Eleutherine bulbosa leaf value ie 173.15 ppm including weak. Based on IC 50 values produced from the four plants, it can be seen that the ethanol extract of Muntingia calabura has the strongest antioxidant activity because it has a very high content of phenolic compounds, especially flavonoids.

Conclusion
The result showed that ethanol extract of Muntingia calabura produced an IC 50 value of 18.72 ppm so it can be concluded that ethanol extract of Muntingia calabura leaf has the strongest and most powerful antioxidant activity between Syzygium cumini, Ocimum basilicum and Eleutherine bulbosa.