American Journal of Plant Sciences, 2012, 3, 1127-1134 http://dx.doi.org/10.4236/ajps.2012.38136 Published Online August 2012 (http://www.SciRP.org/journal/ajps) 1127 Potentials of Melastoma malabathricum Linn. Flower and Fruit Extracts as Antimicrobial Infusions Siti Nurhadis Che Omar 1 , Janna Ong Abdullah 1* , Khairul Anuar Khairoji 1 , Sieo Chin Chin 2 , Muhajir Hamid 1 1 Department of Microbiology, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, Serdang, Malaysia; 2 Institute of Bioscience, Universiti Putra Malaysia, Serdang, Malaysia. Email: * janna@biotech.upm.edu.my Received June 21 st , 2012; revised July 18 th , 2012; accepted July 25 th , 2012 ABSTRACT Melastoma malabathricum Linn. is a shrub that belongs to the family Melastomataceae and a common herbal plant used in folk medicines to treat inflamed wounds. This study was carried out with the aim to evaluate the inhibitory ac- tivities of different concentrations of the M. malabathricum Linn. flower and fruit crude extracts against a variety of microorganisms. The inhibitory effects of both extracts were tested against the microorganisms using the disc diffusion method. The lowest concentrations of the extracts producing inhibition zones against the test microorganisms were used to determine their Minimum Inhibitory Concentrations (MICs) and Minimum Microbicidal Concentrations (MMCs). Both crude extracts showed strong inhibitory activities against Gram-positive bacteria. The range of MIC values for the crude flower and fruit extracts on all the bacteria tested were 12.5 to 100.0 mg/ml. Overall, Gram-positive bacteria were more susceptible to the crude extracts compared to Gram-negative species, potentiating a possible use of the extracts to inhibit or kill potential pathogens. Keywords: Melastoma malabathricum Linn.; Flower; Fruit; Disc Diffusion Method; Minimal Inhibitory Concentration; Minimal Microbicidal Concentration 1. Introduction In the present era, modern medicine develops very quickly and makes major contributions to worldwide diseases control. Despite the rapid growth in knowledge and techniques in modern medicine, the populations of developed and developing countries also show an in- crease interest in traditional medicines. According to the World Health Organization [1], the definition of tradi- tional medicine may be summarized as the sum total of all the knowledge and practices, whether explicable or not, used in the diagnosis, prevention and elimination of physical, mental or social imbalances, and relying exclu- sively on practical experiences and observations handed down from generation to generation, whether verbally or in writing. Today, almost 80% of the Asian population relies on traditional medicine as a part of their health care regime. Melastoma malabathricum Linn. is a shrub that be- longs to the family Melastomataceae. It can be found abundantly in Malaysia. It comes with beautiful pink or purple flowers. The flower consists of five narrow red- dish sepals and five purplish petals. The fruits are en- capsulated and contain many non-endospermous seeds [2] with small embryos inside purplish pulps. M. mala- bathricum Linn. is rich with flavonoid compounds [3,4]. In folklore remedies, different parts of the plants are used for the treatment of various human aliments. The leaf, root and flower crude extracts of M. malabathricum Linn. had been used to treat toothache, wounds, diarrhea, anti- infection, scar prevention, and post-partum recovery [5]. Numerous pharmacological studies and clinical prac- tices have reported that various parts of M. malabath- ricum Linn. plant possess biological functions such as antioxidant and anti-cancer [3], antiviral [6], anti-inflam- matory, antinociceptive and anti-pyretic [7], and anti- ulcerogenic [8]. In this study we employed thirty-two microbial species to test the possible antimicrobial activity of M. mala- bathricum Linn. crude fruit and flower extracts. These species include the Gram-positive and Gram-negative bacteria and fungi, which are food spoilers but normal human body flora. Most of these species cause serious cases of food poisoning and hence, there is a need for the development of preservatives to eliminate their growth. However, research on antibacterial properties of M. ma- labathricum Linn. is still scarce; only a few scientific * Corresponding author. Copyright © 2012 SciRes. AJPS