1.1 BACKGROUND OF RESEARCHPiper L. genus plants from Piperaceae family are well studied andeconomically important for human health. There are 1200 species of Piperdistributed in the pantropical and Neotropical region in the world with morethan 400 species have been recorded in Malaysia region alone (Rahman et al.,2016).
Piper sarmentosum and Piper nigrum are the plants which playan important role as the medicinal plant in Malaysia. P. sarmentosum is a wild growing plant in the tropical forests and mostly in Asiaregion. The leaves are simple, alternate and heart-shaped.
The young leavesconsist of waxy surface and light green in colour. On the other hand, P. nigrum is a woody perennial climbing vinethat grows in the tropical area which leaves and fruit producing fragrance andessential oil. The plant leaves are simple, alternate, oval-shaped and leatheryin texture. The upper leaves surface is dark green and whitish-green on theunderside. Both of the plant leaveshave medicinal values which are traditionally used to treat various diseases.
According to Rahman et al., (2016) and Nahak et al., (2011), these plants wereclaimed to possess anti-inflammatory, antioxidant, antimicrobial and anticancerproperties. Besides that, these species are also sharing similar values such asantioxidant properties that can reduce free radicals in human body.
Antioxidants or inhibitors of oxidation are the substances that are ableto reduce the free radicals chain reaction and oxidation process. Free radicalsor oxidants are the molecules which have high reactivity, short half-life anddamaging the macromolecule such as DNA, protein and lipids. The imbalanceamount of free radicals leads to various effect to human body such as cancer,aging, rheumatoid arthritis and ischemia (Patel et al.
, 2013). Plants are the primary natural sources ofantioxidants which beneficial to human health. Therefore, this research willfocus on the identification of antioxidant level in leave samples of P. sarmentosum and P. nigrum extracts of different solvents. 1.
2 RESEARCH OBJECTIVE1. To extract Piper sarmentosum and Pipernigrum by using ethanolic and aqueous extraction.2.
To analyze the antioxidantproperties of P. sarmentosum and P. nigrum by using DPPH assay. 1.3 RESEARCH HYPOTHESISThere are different level of antioxidant content in Piper sarmentosum and Pipernigrum by using different extraction solvents.