Available online www.jocpr.com Journal of Chemical and Pharmaceutical Research, 2016, 8(12):173-179 Research Article ISSN : 0975-7384 CODEN(USA) : JCPRC5 173 Antibacterial Effects of Different Extracts of Crocus Sativus Linn Stigma on Several Oral Microorganisms Farnaz Hajifattahi 1 , Maryam Taheri 2 , Mina Taheri 3 , Arash Mahboubi 4 , and Mohammad Kamlinejad 5 1 Department of Oral and Maxillofacial Medicine, Islamic Azad University Dental branch of Tehran, Tehran, Iran 2 Private practice as Specialist in Oral and Maxillofacial Medicine, Tehran, Iran 3 Department of Periodontology, Tehran University of Medical Sciences School of Dentistry, Tehran, Iran 4 Department of Pharmaceutics, Shahid Beheshti University of Medical Sciences School of Pharmacy, Tehran, Iran 5 Department of Pharmacognosy, Shahid Beheshti University of Medical Sciences School of Pharmacy, Tehran, Iran __________________________________________________________________________________________ ABSTRACT Background: Antimicrobial therapy against oral pathogens is a common way to prevent or treat mouth diseases. Because of increasing resistance to synthetic medicine, herbal drugs are being used more and more. Material and Methods: Hydroalcoholic extract of powdered stigma from saffron flower was provided and used to prepare fractions in petroleum-ether, chloroform, and ethanol solvents respectively. Growth inhibition zone, MIC and MBC of the mentioned fractions were determined against Strep. mutans, Strep. sanguinis, Strep. salivarius, Strep. sobrinus, and E. faecalis and compared to those of chlorhexidine and ampicillin. Results: The hydroalcoholic extract, and ethanolic and chloroformic fractions of crocus sativus linn had antimicrobial effects, despite its petroleum etheric fraction and distillate. The best effect of hydroalcoholic extract was on Strep. sanguinis with the MIC and MBC of 31.25 mg/ml both. Maximum inhibitory effect of ethanol fraction was on Strep. sanguinis with MIC and MBC of 7.81 and 15.62 mg/ml respectively. Chloroform fraction presented most effect on Strep. sanguinis presenting MIC and MBC of 7.8 mg/ml. Conclusion: Crocus sativus linn contains agents with antimicrobial properties against some oral pathogens, particularly streptococcus sanguinis. It may be used to prepare antimicrobial drugs and mouthwashes in the future. Keywords: Saffron; Antimicrobial activity; Oral pathogens; Hydroalcoholic extract; Soluble fractions __________________________________________________________________________________________ INTRODUCTION Dental caries, periodontal disease, and opportunistic infections, common diseases in oral cavity, are caused by the accumulation of pathogenic microorganisms, inappropriate nutrition, and poor oral hygiene [1-4]. Oral streptococci are the first isolated species participating in the formation of dental plaque and development of caries [5-7]. Measures taken to clinically inhibit plaque accumulation, including tooth brushing, dental flossing, and use of mouthwashes (as an adjunct), are highly effective, prevent gingivitis and decrease the number of microorganisms [8, 9]. Chlorhexidine is one of the most widely used antimicrobial agents. However, it has side effects such as altered sense of taste and staining of the teeth and restorations [10-13]. Herbal medicine has a long history. Many people in developing countries strongly believe in the benefit of herbal medications for primary care [14, 15]. While synthetic drugs have side effects and there is an increasing number of resistant microorganisms to them, researchers are becoming more and more interested in finding alternative herbal medications and their active components [16-23].