Journal of Pharmacy Research Vol.10 Issue 5 May 2016 Hemali Padalia et al. / Journal of Pharmacy Research 2016,10(5),211-220 211-220 Research Article ISSN: 0974-6943 Available online through http://jprsolutions.info * Corresponding author. Dr. Sumitra Chanda Phytochemical, Pharmacological and Microbiological laboratory, Department of Biosciences, Saurashtra University, Rajkot, India, 360005 Antimicrobial activity of some medicinal plant extracts and its synergistic interaction with some antibiotics Hemali Padalia, Anjali Trivedi, Sumitra Chanda* Phytochemical, Pharmacological and Microbiological laboratory, Department of Biosciences, Saurashtra University, Rajkot, India, 360005. Received on:14-02-2016; Revised on: 20-03-2016; Accepted on: 25-04-2016 ABSTRACT Background: The synergism is a new concept in developing agents for antimicrobial therapy. The new approach is combination therapy i. e. combination of different plant extracts with antibiotics against resistant microorganisms which may lead to new ways of treating infectious diseases. Synergistic interaction means when two agents are combined together and they exert an inhibitory effect that is greater than the sum of their individual effects. The present study focuses on the in vitro antimicrobial activity and synergistic activity of various parts of different plants such Aegle marmelos, Annona squamosa, Citrus limon, Piper betle, and Azadiracta indica. Material and Method: The synergistic antimicrobial activity was evaluated by the Agar disc diffusion method against Gram- positive, Gram -negative and Fungi. Result and Discussion: All the plant extracts with Gentamicin showed good synergistic antibacterial activity against Gram-positive and Gram- negative bacteria. All the plant extracts with Ketoconazol showed good synergistic antifungal activity against fungi. Conclusion: Hence, these plants extracts can be used as good medicinal sources in combination with antibiotics to treat infectious diseases. KEYWORD: Medicinal plants, Antibiotics, Antimicrobial activity, Synergistic activity INTRODUCTION Nature has been a valuable source of medicine and has helped human in the maintenance of his health since time immemorial. The world has rich wealth of medicinal plants. Without the plant kingdom humans cannot survive on this earth because the plant products and their active constituents play an important role in their survival. The plants and their parts are used in various systems of medicine like Chinese, Ayurveda, Siddha, Unani and Tibetan. Ancient literature such as Rigveda, Yajurveda, Atharvaveda, Charak Samhita and Sushrut Samhita also describes the use of plants for the treatment of various health problems 1 . Plants produce a diverse range of bioactive mol- ecules, making them a rich source of different types of medicines. The green medicines are healthier and safer than synthetic ones. A num- ber of herbal medicines are used for the management of various dis- eases. They have minimal toxicity, are cost effective and pharmaco- logically active and provide an easy remedy for many human ailments as compared to the synthetic drugs which are a subject of adultera- tion and side effects 2 . Medicinal plants are considered as an important source of new chemi- cal substances with potential therapeutic effects and that can be used to treat chronic and infectious diseases. Natural products from plants can be templates for new drug development and have many interest- ing biological activities like antidiabetic, antioxidant, antibacterial, anti- inflammatory, antipyretic, gastroprotective effects etc. All parts of plant can be used as herbal medicine like leaf, stem, flower, bark, fruit, peel, rhizome, essential oil, latex, bud, etc. The medicinal values of plants lie in phytochemicals present in them that produce a definite physiological action on the human body. Plants synthesize and accu- mulate in their cells a great variety of phytochemicals like tannins, flavonoids, phenolic compounds, glycosides, steroids, saponins, etc. Most of these are potent bioactive compounds that can be used for the synthesis of useful drugs. Phytochemicals regulate, protect and control many of the diseases in human beings, though the active principles differ from plant to plant because of their diverse biochemi- cal nature 3 . The development and spread of resistance to currently available an- tibiotics is a global concern. The crucial fact about the treatment of bacterial infections is the ability of bacteria to develop resistance to antimicrobial agents 4 . Indiscriminate use of antibiotics appears to pro- mote development of pathogens showing resistance to multiple drugs. The multiple drug resistance not only increases morbidity and mortal-