IOSR Journal of Pharmacy and Biological Sciences (IOSR-JPBS) e-ISSN: 2278-3008, p-ISSN:2319-7676. Volume 11, Issue 1 Ver. I (Jan. - Feb. 2016), PP 45-51 www.iosrjournals.org DOI: 10.9790/3008-11114551 www.iosrjournals.org 45 | Page Bioactive potential of plants and spices extracts against human bacterial pathogens Dinesh Kumar Subbaraj, Athmanathan Baskaran, Indrajith Sureka, Meganathan Velmurugan, Edward Arockiaraj Jennifer Emelda and Karuppannan Sathiyamurthy* Molecular Microbial Pathogenesis Lab, Department of Biomedical Science, School of Basic Medical Sciences, Bharathidasan University, Tiruchirappalli 620 024, Tamil Nadu, India Abstract: The aim of this study was to screen antibacterial and antioxidant activity of four different plants and six spices extracts along with phytochemical constituents. Antibacterial activity of the crude extracts of four plants revealed that, plant Vitex negundo had high activity against all the pathogens tested followed by garlic and ginger in spices. It was found that presence of different kinds of chemical groups such as flavonoids, phenolic compounds, saponins, tannins, alkaloids and glycosides in all the four plants. The aqueous extract of V.negundo exhibited DPPH free radical scavenging activity with highest IC 50 value with concentration of 100 μg/ml followed by methanol. In the case of garlic, methanol extract showed good antioxidant activity with highest IC 50 value with concentration of 100 μg/ml followed by aqueous extract. The crude extracts of V. negundo and garlic were partially purified using thin layer chromatography. The highest Rf value 0.75 and 0.69 were found in methanol solvent system of for V. negundo and garlic extracts respectively. The results obtained in the present investigation suggest that the extracts of V. negundo leaves and garlic had promising antibacterial and antioxidant activity against free radicals. This will be of more useful in therapeutic of bacterial infections and possible replacement of synthetic antioxidants. Keywords: antibacterial, antioxidant, garlic, phytochemical, V. negundo I. Introduction Antibiotic therapy in recent years has faced difficulties due to the rapid emergence of multidrug resistance among bacteria causing several life threatening infectious diseases and this in turn, making the future management of infectious diseases uncertain. The increasing failure of chemotherapeutics and antibiotic resistance exhibited by pathogenic infectious agents has led the screening of several medicinal plants for potential antimicrobial activity and the plant extracts found to have promising activity against microorganisms (Mandel et al., 2007). According to a study conducted by the World Health Organization (WHO), more than 80% of the world population relies on traditional medicine for primary healthcare needs (WHO, 2013). Medicinal plants would be the best source to obtain a variety of drugs and active compounds. Therefore, such plants should be investigated to better understand about their properties, safety and efficiency (Gautam et al., 2012). There is no doubt that increasing our intake of these spices is one of the most effective, convenient and economical ways in which we can fortify ourselves against infectious diseases and related cancers (Gull et al., 2012). Many infectious diseases have been identified to be treated with herbal products right through the history of mankind (Wadud et al., 2007). Natural products provide huge opportunities for the development of new drugs, particularly antimicrobials, which can have therapeutic potential to treat infectious diseases. There is a continuous need to discover new antimicrobial compounds with suitable chemical structures and novel mode of actions against pathogens. Antimicrobial compounds of plant origin have an enormous therapeutic potential to treat many infectious diseases (Mukherjee and Wahile, 2006). In developing countries, due to the cost of efficient antimicrobials, a large proportion of the population utilizes medicinal plants and spices for the treatment of infectious diseases. It is estimated that about 80% of the world population relies on botanical preparations as medicines to meet their health needs (Melvin Joe et al., 2009) Many types of molecules with antibacterial activity have been isolated from plants (Boonnak et al., 2009 and Mahabusarakam et al., 2008). Medicinal plants contain active principles which can be used as an alternative to cheap and effective herbal drugs against common bacterial infections (Kareru et al., 2008). Spices occupy a prominent place in the traditional culinary practice and are essential part of daily diets of millions of people all over the world. They are basically flavoring agent used in small amounts and are reported to have both beneficial effect and antimicrobial properties (Papachan karur sofia et al., 2007). In the area of cancer prevention, plants consumption such as spices and their constituents as potential chemo preventive agents remains an extensive research topic. Numerous studies have been published in regards to the relation between plants utilization, antimicrobial effects, cancer prevention, and overall protection of human health (Bhattacharjee and Sengupta, 2009). In our