On the other hand, some studies showed that saliva contains many antimicrobial substances. B-defensins which are cationic peptides with broad-spectrum antimicrobial activity are produced by human salivary glands and oral mucosal surfaces and most abundant in tissues of associated inflammations. Human B-defensins play an important role in the innate defenses against oral microorganisms (Mathews et al., 1999). Murakami et al. (2002) detected cathelicidin antimicrobial peptides in human saliva, contributing to broad-spectrum defense of the oral cavity. Also, cathelicidin are essential for the protection of skin against invasive bacterial infection. In addition, salivary histatins are potent in vitro antifungal agents and have great promise as therapeutic agent in humans with oral candidiasis caused by Candida albicans. Histatins caused loss of fungal cell integrity followed by its death ( Edgerton et al., 1998). Further more, Liu et al. (2008) purified and cloned a noval antimicrobial peptide from salivary glands of hard tick named ixoxin-B