Hindawi Publishing Corporation Evidence-Based Complementary and Alternative Medicine Volume 2012, Article ID 681207, 6 pages doi:10.1155/2012/681207 Research Article Study Bioprospecting of Medicinal Plant Extracts of the Semiarid Northeast: Contribution to the Control of Oral Microorganisms Maria Sueˆnia P. Silva,1, 2 Deysiane O. Branda˜o,1 Thiago P. Chaves,1 Amaro L. N. Formiga Filho,1, 2 Edja Maria M. de B. Costa,1, 2 Vanda L. Santos,1 and Ana Cl a´udia D. Medeiros1, 2 1 Laborato´rio de Desenvolvimento e Ensaio de Medicamentos, Universidade Estadual da Para´ıba, 58.429-500 Campina Grande, PB, Brazil 2 Programa de Po´s-gradua¸ca˜o em Odontologia, Universidade Estadual da Para´ıba, 58.429-500 Campina Grande, PB, Brazil Correspondence should be addressed to Ana Cla´udia D. Medeiros, anaclaudia@uepb.edu.br Received 2 February 2012; Revised 10 April 2012; Accepted 12 April 2012 Academic Editor: Vincenzo De Feo Copyright © 2012 Maria Sueˆnia P. Silva et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Dental pathologies can be caused by plaque-forming bacteria and yeast, which reside in the oral cavity. The bacteria growing in dental plaque, a naturally occurring bioﬁlm, display increased resistance to antimicrobial agents. The objective was the evaluation of a preclinical assay of medicinal plants of the semiarid region from the northeast against oral pathogenic microorganism, aiming at bioprospecting a new product. The selection of plant material for this study was based on the ethnobotanical data on the traditional use of plants from the semiarid region. The thirty extracts were subjected to the determination of antibioﬁlm activity against gram-positive, gram-negative bacteria and yeast. The hydroalcoholic extract which showed positive antibioﬁlm activity against most of the microorganisms tested in agar diﬀusion assay was further tested for the determination of minimum inhibitory concentration (MIC) and Bioassay with Artemia salina. Plant samples tested in this study exhibited good antibioﬁlm activity for the treatment of oral problems. The Schinopsis brasiliensis showed greater activity for Pseudomonas aeruginosa and Staphylococcus aureus, but toxicity against Artemia salina. 1. Introduction Dental caries, periodontal disease, and candidiasis are im- portant dental pathologies aﬀecting humankind. These conditions are caused by plaque-forming bacteria and yeast, which reside in the oral cavity. Periodontal diseases have mainly been associated with Actinomyces, Actinobacillus, Streptococcus, and Candida species [1]. It is generally rec- ognized that the bacterial growth in bioﬁlms imparts a substantial decrease in susceptibility to antimicrobial agents compared with cultures grown in suspension. It is therefore not surprising that bacteria growing in dental plaque, a naturally occurring bioﬁlm, display increased resistance to antimicrobial agents [2]. The resistance development by pathogens to the existing pharmaceutical has led to the intensiﬁcation of the search for novel drugs, against fungal, parasitic, bacterial, and viral infections. Plant-derived antimicrobials have a long history of providing the much needed novel therapeutics. A number of traditionally used medicinal plants have to date been screened for various biological activities in both in vivo and in vitro models. The chemical investigation from medicinal plants purported to have medicinal properties has yielded numerous puriﬁed compounds which have proven to be indispensable in the practice of modern medicine [3]. Brazil has a great potential for biodiversity and wealth of traditional knowledge accumulated by local people who have direct access to nature and the products of biodiversity. In this sense, the Caatinga, main semiarid’s biome, represents the fourth largest area covered by a single vegetation form in Brazil, accounting for about 60% of the northeast territory. There has been increasing interest in acquiring knowledge