A total of 9 plant extracts were tested, using two different kinds of extracting methods to evaluate the antioxidant and antimicrobial activities from Pilea microphylla (Urticaceae family) and including toxicity test. Antioxidant activity were tested by using DPPH free radical scavenging, also total phenolic contents and total flavonoid contents were determined. Toxicity assay carried out by using brine shrimps. Methanol extract of method I (ME I) showed the highest antioxidant activity at . Chloroform extract of method I (CE I) showed the highest total phenolic contents at and chloroform extract of method II (CE II) showed the highest total flavonoid contents at . The antimicrobial activity of Pilea microphylla extract was tested in vitro by using disc diffusion method and minimum inhibitory concentration (MIC). The Pilea microphylla extract showed antibacterial activity against some Gram negative and positive bacteria. The extracts did not exhibit antifungal and antiyeast activity. The hexane extract of method I (HE I) was not toxic against brine shrimp (LC50 value was 3880？ g/ml). Therefore, the extracts could be suitable as antimicrobial and antioxidative agents in food industry. 1. Introduction In recent decades, the essential oils and various extracts of plants have been of great interest as they have been the sources of natural products [1]. The most commonly used antioxidant at the present time are butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), propylgallate (PG), and tert-butyl hydroxyl toluene (TBHQ) [2]. However, they are suspected of being responsible for liver damage and carcinogenesis in laboratory animals [3, 4]. Therefore, the development and utilization of more effective antioxidant of natural origin are desired [5]. The antioxidant activity of phenolic compounds is mainly due to their redox properties, which can play an important role in absorbing and neutralizing free radicals, quenching singlet and triplet oxygen, or decomposing peroxidase [6]. Therefore, an investigation of such antioxidative phenolic compounds in edible plants has been conducted to improve our understanding of their dietary value and potential benefits [7]. Pilea microphylla (PM) (family: Urticaceae) is being used as folk medicine to treat several allergies/wounds in and around Malaysia peninsular especially Penang island. It is reported to possess antibacterial activity [8], moderate antioxidant activity, and total phenolic content [9] and PM is also used for infertility, inflammations, and womb cleanser [10]. There is no enough report about its
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