Antioxidant Activity of Extracts of Halodule pinifolia Seagrass from Solvents with Different Polarities

The purpose of this study was to analyze phytochemistry contents and antioxidant activity of extracts from seagrass of Halodule pinifolia from solvents with different polarities. Parameters of research were phytochemical content, DPPH scavenging activity and reducing power. The result showed content of phytochemical compounds of ethanol extract seagrass were flavonoids, tannins, saponins, steriods and triterpenoids. The use of ethyl acetate solvent showed phytochemical compounds were flavonoids, steroids and triterpenoids. For n-hexane solvent showed phytochemical compounds were steroids and triterpenoids. The highest of antioxidant activity with DPPH method (IC50) of H. pinifolia was 18.7 ppm with ethanol extract. The highest of reducing power of H. pinifolia was 1.749. keywords: Seagrass, Halodule pinifolia, antioxidant.


INTRODUCTION
S e a g r a s s e s a r e f l o w e r i n g p l a n t s (angiosperms) which grow in marine, fully saline environments.Seagrasses are a rich source of structurally novel and biologically active metabolites which they produce in order to sustain the extreme environmental conditions prevailing under sea 1 S e a g r a s s e s p r o d u c e a n t i ox i d a n t compounds that inhibits the oxidation of other molecules and there are many reports describing antioxidant activities [2][3][4][5] , antifungal 6 , antiviral 7 , antiinflammatory 8 , antidiabetic 9 and antibacterial [10][11][12] .
However reports on the phytochemical constituents of seagrasses and their bioactive activity of Indonesian sea are limited with the exception of few studies in this research 13,14 , we reported that antioxidant activity of extracts of Halodule pinifolia seagrass from solvents with different polarities.

Preparation of Seagrass extract
Extraction of Halodule pinifolia seagrass by stratified maceration method using n-hexane, ethyl acetate and ethanol .Sea grass powder were soaked in 2 L with solvent (1:4 w/v), and kept for 2 x 24 h in a shaker.The solution is filtered using the number 42 Whatman filter paper to obtain the filtrate.The filtrate is dried using a freeze dryer to remove the solvent that may remain in the extract

DPPH radical scavenging activity
DPPH radical scavenging activity was measured based on methods described in Hanani et al. 16 .

Reducing power
Reducing power was determined by Oyaiza method 17 .

The phytochemical screening
As seen as Table 1 showed content of phytochemical compounds of extract of seagrass were flavonoids, alkaloids, tannins, saponins, steroids and triterpenoids.
The result showed content of phytochemical compounds of ethanol extract seagrass were flavonoids, tannins, saponins, steriods and triterpenoids.The use of ethyl acetate solvent showed the phytochemical compounds were flavonoids, steroids and triterpenoids.For n-hexane solvent showed phytochemical compounds were steroids and triterpenoids.

DPPH radical scavenging activity
Method of DPPH radical scavenging activity is very popular for the research of natural antioxidants 18 .The extraction with solvents of increasing polarity involves of separating compounds of a plant according to their degree of solubility.DPPH radical scavenging activity of hexane, ethyl acetate and ethanol extracts obtained of the Halodule pinifolia were shown in Figure 1.The maximum DPPH radical scavenging activity was recorded in ethanol extracts followed by ethyl acetate and n-hexane.
The IC 50 of extract was 18.7 ppm for ethanol extract, 696.2 ppm for ethyl acetate extract and 2,378.2ppm for n-hexane extract.The IC 50 value for vitamin C was 7.7 ppm (Figure 2).The results

Reducing power
Reducing power of extract of H. pinifolia depicted in Figure 2. Increasing of concentration of H. pinifolia indicates an increase in reducing power The reducing power is considered as a significant indicator of potential antioxidant activity of compound or sample.A potential antioxidant will reduce the ferric ion to the ferrous ion.Reducing power of extract of H. pinifolia is probably due to the presence of phytochemical compounds that can serve as an electron donor.